The physiology of intrapartum fetal compromise at term

Construction of a risk prediction model for adverse pregnancy outcomes in primipara with gestational diabetes mellitus combined with pregnancy-induced hypertension syndrome

OBJECTIVE

This study aims to identify risk factors for adverse pregnancy outcomes in primipara with gestational diabetes mellitus (GDM) combined with pregnancy-induced hypertension syndrome (PIH) and to develop a predictive model for such outcomes.

METHODS

A total of 120 primipara with GDM and PIH, admitted from January 2019 to May 2023, were divided into two groups: the adverse group (n = 57) and the good group (n = 63), based on pregnancy outcomes. Multivariate logistic regression analysis was used to identify independent risk factors for adverse outcomes. A nomogram was constructed based on these factors, and its efficacy was validated through internal evaluation.

RESULTS

The adverse group had higher proportions of elderly parturients, higher pre-pregnancy BMI, and more weight gain during pregnancy. Additionally, the adverse group showed a higher incidence of family history of diabetes, and more severe types of PIH. Biochemical markers such as HbA1c and total cholesterol (TC) were higher in the adverse group, while high-density lipoprotein cholesterol (HDL-C) was lower (p < .01, p < .05). Multivariate logistic regression revealed that advanced maternal age, pre-pregnancy BMI, family history of diabetes, preeclampsia/chronic hypertension complicated by preeclampsia, and elevated HbA1c were independent risk factors for adverse pregnancy outcomes (p < .01). A nomogram prediction model was developed, with an AUC of 0.821. Bootstrap internal validation confirmed the model's robust discriminative ability.

CONCLUSION

Advanced maternal age, pre-pregnancy BMI, family history of diabetes, preeclampsia, and elevated HbA1c are significant risk factors for adverse pregnancy outcomes in GDM combined with PIH. The nomogram model provides an effective tool for predicting such outcomes.

Intrauterine fetal resuscitation: from maternal repositioning to the latest pharmacological strategies

Intrauterine resuscitation includes different interventions which aim to improve fetal oxygenation when intrapartum fetal hypoxic stress leading to abnormal CTG features is suspected. Based on the etiology of the hypoxic stress, prompt institution of specific conservative measures, aiming to restore fetal oxygenation and normalize the features of the CTG trace, may reduce the incidence of unnecessary operative deliveries. However, there is paucity of evidence supporting the effectiveness of intrauterine resuscitation measures: based on available data, routine administration of fluid boluses is not recommended and should be limited only to volume-depleted patients, in which intravenous hydration has been associated with potential benefits. Similarly, amnioinfusion and maternal oxygen administration cannot be recommended as previous studies on their efficacy reported conflicting results, and some have suggested that these measures may be potentially harmful. On the other hand, changing maternal position seems to be a potentially useful maneuver with no side effects in cases of supine hypotension syndrome or in cases of suspected sustained umbilical cord compression. Administration of tocolytics for ongoing excessive uterine activity is associated with fetal heart rate improvement; within the most used tocolytic drugs, terbutaline (a beta-agonist) is often recommended as the first-choice agent to be administered for intrapartum acute tocolysis due to its efficacy, ease of administration and side effect profile.

Advancements in Fetal Heart Rate Monitoring: A Report on Opportunities and Strategic Initiatives for Better Intrapartum Care

Cardiotocography (CTG), introduced in the 1960s, was initially expected to prevent hypoxia-related deaths and neurological injuries. However, more than five decades later, evidence supporting the evidence of intrapartum CTG in preventing neonatal and long-term childhood morbidity and mortality remains inconclusive. At the same time, shortcomings in CTG interpretation have been recognised as important contributory factors to rising caesarean section rates and missed opportunities for timely interventions. An important limitation is its high false-positive rate and poor specificity, which undermines reliably identifying foetuses at risk of hypoxia-related injuries. These shortcomings are compounded by the technology's significant intra- and interobserver variability, as well as the subjective and complex nature of fetal heart rate interpretation. However, human factors and other environmental factors are equally significant. Advancements in fetal heart rate monitoring are crucial to support clinicians in improving health outcomes for newborns and their mothers, while at the same time avoiding unnecessary operative deliveries. These limitations highlight the clinical need to enhance neonatal outcomes while minimising unnecessary interventions, such as instrumental deliveries or caesarean sections. We believe that achieving this requires a paradigm shift from subjective interpretation of complex and nonspecific fetal heart rate patterns to evidence-based, quantifiable solutions that integrate hardware, engineering and clinical perspectives. Such transformation necessitates an international, multidisciplinary effort encompassing the entire continuum of pregnancy care and the broader healthcare ecosystem, with emphasis on well-defined, actionable health outcomes. Achieving this will depend on collaborations between researchers, clinicians, medical device manufacturers and other relevant stakeholders. This expert review paper outlines the most relevant and promising directions for research and strategic initiatives to address current challenges in fetal heart rate monitoring. Key themes include advancements in computerised fetal heart rate monitoring, the application of big data and artificial intelligence, innovations in home and remote monitoring and consideration of human factors.

Peripartum fetal Doppler sonography and perinatal outcome: a systematic review and meta-analysis

OBJECTIVE

Systematically review and critically appraise the literature on the association between peripartum fetal Doppler sonography findings, i.e., acquired upon admission for spontaneous or induced labor, and perinatal outcome in term (37-42w) pregnancies.

METHODS

Medline, Embase, Web of Science, Cochrane Library, and clinicaltrials.gov databases were systematically searched from inception to 05/2024. Studies conducted in unselected populations of term (37-42w) pregnancies, admitted for spontaneous or induced labor, reporting the association between fetal Doppler findings and perinatal outcome, were eligible for inclusion. Study eligibility was assessed independently by two reviewers. Methodological quality was assessed using the Quality In Prognosis Studies (QUIPS)-tool. Effect estimates were pooled using random-effects meta-analyses. Summary Odds Ratios (ORs) and Mean Differences (MDs) are reported with 95% confidence intervals.

RESULTS

Thirty-seven studies, reporting on 11.505 women and neonates, were included. Fourteen studies reported on findings from the umbilical artery (UA), four on the middle cerebral artery (MCA), five on the umbilical vein (UV), and nine on the cerebroplacental ratio (CPR). An abnormal UA Doppler and CPR increased the odds of fetal distress (FD) during labor (UA: OR 3.67 [1.14, 11.78], I2 = 72% - CPR: OR 3.19 [2.68, 3.80], I2 = 0%) and subsequent operative delivery (ODFD) (UA: OR 3.65 [1.66, 8.04], I2 = 81% - CPR: OR 2.48 [1.66, 3.70], I2 = 57%). Likewise, the presence of UV pulsations was strongly associated with both outcomes (FD: OR 28.78 [11.21, 73.87], I2 = 0% - ODFD: OR 303.36 [11.11, 8279.82], I2 = 0%). Regarding neonatal outcome, an Apgar-score < 7 at 5 min and NICU admission occurred more frequently if Doppler findings were abnormal in the UA (Apgar: OR 3.65 [1.82, 7.34], I2 = 0% - NICU: OR 3.92 [2.36, 6.51], I2 = 0%), or in case of an abnormal CPR (Apgar: OR 3.64 [2.03, 6.54], I2 = 0% - NICU: OR 2.71 [1.15, 6.38], I2 = 0%). Neonatal birthweight was also lower in the presence of an abnormal UA or CPR result, with a MD of -630.61g ([-1234.29, -26.93], I2 = 80%) and -146.52g ([-285.03, -8.01], I2 = 0%) respectively. Most studies (70.3%) were at high risk of bias on one or more domains; only 11 studies had an overall low risk of bias score.

CONCLUSION

Doppler sonography in the peripartum period allows for the identification of fetuses at risk of adverse birth outcomes. Further research on optimal thresholds to define at-risk cases and subsequent management strategies is needed.

PROSPERO REGISTRATION NUMBER

CRD42023413264.

Intrapartum monitoring of the fetal heart rate using transabdominal electrocardiography: A reliability and accuracy study

INTRODUCTION

In this study, we evaluated the performance of an intrapartum monitoring system (the TOCONAUTE) for fetal heart rate estimation using transabdominal electrocardiography.

METHOD

This prospective study was conducted in Lille University Hospital's maternity ward between August 2022 and November 2023 to assess the performance of the TOCONAUTE compared to a cardiotocograph (CTG). Pregnant women in labor at 36 weeks or more of gestation with a singleton in cephalic presentation were eligible for enrollment in the study. In addition to the cardiotocograph, the participants received an abdominal electrode patch after providing their written informed consent. The positive percent agreement with the cardiotocograph indicated reliability, and the Bland-Altman analysis determined accuracy.

RESULTS

Of the 60 patient recruited, 35 patients were included in the recording analysis. The recordings had a mean duration of 519 ± 210 min. The TOCONAUTE's fetal heart rate (FHR) overall positive percent of agreement (PPA) was 84.2 ± 10.4 %. The PPA was greater than 80 % for all labor phases, except for expulsion (44.7 %). The overall mean bias was 1.7 ± 2.4. For the FHR, the mean bias was lower than 2 bpm for all labor phases, except for expulsion (14.13 ± 15.04 bpm).

CONCLUSION

Compared with traditional CTG, this study demonstrated the TOCONAUTE's reliability and accuracy for FHR estimation in all labor phases except expulsion.

Value of cerebroplacental ratio in predicting adverse perinatal outcome in uncomplicated twin pregnancies: a retrospective study

To evaluate the performance of the cerebroplacental ratio (CPR) in predicting operative delivery for intrapartum fetal compromise (OD for IFC) and adverse perinatal outcomes in uncomplicated twin pregnancies with attempted vaginal delivery.This was a retrospective cohort study of 72 twin pregnancies in a single tertiary referral center between January 2018 and August 2024. All MCDA and DCDA twin pregnancies with an attempted vaginal delivery after 34+0 weeks were screened for eligibility and those without further risk factors were included in the study. Outcome parameters were OD for IFC and a composite of adverse perinatal outcomes (CAPO) including OD for IFC, 5-minute Apgar score <7, umbilical artery pH <7.10, or admission to the neonatal intensive care unit (NICU). The predictive performance of CPR was evaluated using ROC analyses and multivariable logistic regression.16 MCDA and 56 DCDA pregnancies met the inclusion criteria. CAPO of at least one of the twins occurred in 27 (37.5%) of the cases. ROC analyses showed that low CPR MoM of neither the presenting twin nor the second twin predicted CAPO. Similarly, the prediction of the need for OD for IFC of twin 2 was not possible using low CPR MoM as the predicting variable. However, logistic regression analyses showed that nulliparity and twin-to-twin delivery time interval were independently associated with CAPO.Low CPR MoM was not predictive for CAPO or OD for IFC in uncomplicated twin pregnancies after 34 weeks of gestation. However, nulliparity and twin-to-twin delivery time interval were independently associated with CAPO.

Beyond proximity: an observational study of stillbirth rates and emergency obstetric and newborn care accessibility in The Gambia

INTRODUCTION

Stillbirths are disproportionately concentrated in sub-Saharan Africa, where geographical accessibility to basic/comprehensive emergency obstetric and newborn care (BEmONC and CEmONC) significantly influences maternal and perinatal outcomes. This study describes stillbirth rates within healthcare facilities in The Gambia and examines their distribution in relation to the geographical accessibility of these facilities.

METHODS

We analysed 97 276 births recorded between 1 January 2013 and 31 December 2018, from 10 major public healthcare facilities in The Gambia. To standardise definitions, stillbirths were defined as fetal deaths with a birth weight of ≥500 g. Fresh stillbirths were reclassified as intrapartum, and macerated stillbirths were reclassified as antepartum. Linear regression with cubic splines was used to model trends, and AccessMod software estimated travel times to facilities.

RESULTS

Among recorded births, 5.1% (4873) were stillbirths, with an overall stillbirth rate of 51.3 per 1000 births (95% CI: 27.5 to 93.6). Intrapartum stillbirths accounted for 53.8% (27.6 per 1000 births; 95% CI: 14.4 to 49.8). Fully functional CEmONC facilities reported the highest stillbirth rates, including the National Teaching Hospital (101.7 per 1000 births, 95% CI: 96.8 to 106.8). Approximately 42.8%, 58.9% and 68.3% of women aged 15-49 lived within a 10, 20 and 30 min travel time, respectively, to fully functional CEmONC facilities, where high stillbirth rates were concentrated.

CONCLUSIONS

In The Gambia, intrapartum stillbirth rates remain alarmingly high, even in geographically accessible CEmONC facilities. Inadequate documentation of fetal heart rate on admission hampers accurate classification, complicating targeted interventions. Ensuring that EmONC-designated facilities-particularly those providing BEmONC services-are fully functional with essential equipment, trained staff and robust referral systems, while enhancing the timeliness and quality of obstetric care, is crucial to reducing stillbirth rates.

Soluble fms-like tyrosine kinase-1/placental growth factor ratio at 36 weeks' gestation: association with spontaneous onset of labor and intrapartum fetal compromise in low-risk pregnancies

BACKGROUND

Previous evidence showed that placental dysfunction triggers spontaneous preterm or term births and intrapartum fetal compromise and often requires urgent delivery, thereby exposing both the fetus and the mother to significant risks. Predicting spontaneous labor onset and intrapartum fetal compromise could improve obstetrical management and outcomes, but this is currently difficult, particularly in low-risk populations.

OBJECTIVE

The objective of this study was to examine whether placental dysfunction, as assessed at 36 weeks' gestation by the soluble fms-like tyrosine kinase-1 to placental growth factor ratio, is associated with the interval to spontaneous onset of labor and intrapartum fetal compromise that requires cesarean delivery in a routinely examined population.

STUDY DESIGN

This was a retrospective analysis of prospectively collected data of women with singleton pregnancies who underwent routine assessment at 35+0 to 36+6 weeks' gestation at the King's College Hospital (London, England). Using a general linear model, the study examined the outcomes related to the soluble fms-like tyrosine kinase-1/placental growth factor ratio, including the time interval from testing to spontaneous onset of labor and the subsequent rate of fetal compromise that required a cesarean delivery. Patients who underwent induction of labor or prelabor cesarean deliveries were excluded from the study. Competing risks regression and Cox regression models were used to estimate the cumulative incidence and the risk of the outcomes of interest.

RESULTS

In the screened population of 45,375 patients, 23,831 (52.5%) had spontaneous onset of labor and were included in the analysis. Cases with an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 delivered about 1 week earlier than those with a ratio of ≤50 (39.2 vs 40.0 weeks' gestation; P<.001). The general linear model showed that a larger soluble fms-like tyrosine kinase-1/placental growth factor ratio was associated with earlier spontaneous onset of labor (P<.001), particularly among multiparous women. The soluble fms-like tyrosine kinase-1/placental growth factor ratio was significantly associated, as expected, with cases of preeclampsia and advanced maternal age. The cumulative incidence of spontaneous onset of labor was significantly higher in cases with an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 than in those with a ratio 50 (P<.001). Cox regression showed that the risk for spontaneous onset of labor increased with an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 (hazard ratio, 1.424; 95% confidence interval, 1.253-1.618; P<.001) and, as expected, the risk was mitigated over time from when the soluble fms-like tyrosine kinase-1/placental growth factor ratio was measured to spontaneous labor onset (P<.001). Cases with intrapartum fetal compromise had a higher mean soluble fms-like tyrosine kinase-1/placental growth factor ratio than those without intrapartum fetal compromise (21.79 vs 17.67; P<.001). Qualitative addition of fetal compromise to the general linear model showed a higher soluble fms-like tyrosine kinase-1/placental growth factor ratio in cases with fetal compromise than in those without fetal compromise (P=.014). Competing risks regression showed a positive dose-response effect for fetal compromise with increasing soluble fms-like tyrosine kinase-1/placental growth factor ratios (P<.001). Above and below the optimal cutoff of 50, the quoted cumulative incidences were 6.7% and 4.7%, respectively (P<.001). The effect of the soluble fms-like tyrosine kinase-1/placental growth factor ratio remained significant even after adjusting for preeclampsia, which is a well-known major risk factor for fetal compromise. Finally, the proportion of cases with intrapartum fetal compromise who had an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 decreased from 35% to 0% with advancing gestation.

CONCLUSION

This study showed that an increased soluble fms-like tyrosine kinase-1/placental growth factor ratio at 36 weeks' gestation is associated with an earlier gestational age at spontaneous onset of labor and higher rates of intrapartum fetal compromise. There are 2 major implications, namely an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 indicates imminent labor onset with about a 40% mean risk increase and immediate clinical translation for term pregnancy monitoring. In addition, an increased soluble fms-like tyrosine kinase-1/placental growth factor ratio increases the risk for intrapartum fetal compromise, although outcome variability indicates reassessment within multimarker models.

Changes During Reopening in Premature Constriction or Closure of the Ductus Arteriosus: A Report of Two Cases

Although premature constriction or closure of the ductus arteriosus (PCDA) is associated with poor prognosis and early delivery is considered before deterioration occurs, some cases may improve and have a good prognosis, but the changes in fetal Doppler during the reopening of the ductus arteriosus are unclear, as are the factors related to its reopening. We encountered two cases of PCDA. In the first case, right cardiac function and ductus venosus flow normalized in a few days and the ductus arteriosus reopened spontaneously, and became vaginal delivery at 37 weeks of gestation. In the second case, labor induction was performed due to confirmed fetal cardiac stress associated with the closure of the ductus arteriosus at 38 weeks of gestation, and cesarean section was performed due to non-reassuring fetal status. The improvement in the right ventricular myocardial performance index, ductus venosus pulsatility index, the tendency for ductus arteriosus diastolic velocity to decrease, and confirmation of prograde flow into the pulmonary artery within a few days could serve as predictive indicators for the reopening of the ductus arteriosus.

Heme oxygenase/carbon monoxide system and development of the heart

Progressive differentiation controlled by intercellular signaling between pharyngeal mesoderm, foregut endoderm, and neural crest-derived mesenchyme is required for normal embryonic and fetal development. Gasotransmitters (criteria: 1) a small gas molecule; 2) freely permeable across membranes; 3) endogenously and enzymatically produced and its production regulated; 4) well-defined and specific functions at physiologically relevant concentrations; 5) functions can be mimicked by exogenously applied counterpart; and 6) cellular effects may or may not be second messenger-mediated, but should have specific cellular and molecular targets) are integral to gametogenesis and subsequent embryogenesis, fetal development, and normal heart maturation. Important for in utero development, the heme oxygenase/carbon monoxide system is expressed during gametogenesis, by the placenta, during embryonic development, and by the fetus. Complex sequences of biochemical pathways result in the progressive maturation of the human heart in utero . The resulting myocardial architecture, consisting of working myocardium, coronary arteries and veins, epicardium, valves and cardiac skeleton, endocardial lining, and cardiac conduction system, determines function. Oxygen metabolism in normal and maldeveloping hearts, which develop under reduced and fluctuating oxygen concentrations, is poorly understood. "Normal" hypoxia is critical for heart formation, but "abnormal" hypoxia in utero affects cardiogenesis. The heme oxygenase/carbon monoxide system is important for in utero cardiac development, and other factors also result in alterations of the heme oxygenase/carbon monoxide system during in utero cardiac development. This review will address the role of the heme oxygenase/carbon monoxide system during cardiac development in embryo and fetal development.

Vertebroplacental ratio for prediction of perinatal outcome and operative delivery for suspected fetal compromise: prospective observational cohort study

OBJECTIVE

To investigate differences in fetal vertebroplacental ratio (VPR) depending on the occurrence of operative delivery for suspected fetal compromise (ODFC) and composite perinatal outcome (CPO) at delivery.

METHODS

This was a prospective observational cohort study conducted in the Department of Obstetrics and Gynecology at the University Hospitals of Leuven, Leuven, Belgium, between December 2022 and April 2024. Women with a term (37-42 gestational weeks) singleton pregnancy with an appropriate-for-gestational-age (AGA) fetus were recruited, before cervical dilatation reached 5 cm, for sonographic fetal weight estimation (EFW) and Doppler sonography of the umbilical artery (UA), umbilical vein (UV), middle cerebral artery (MCA) and vertebral artery (VA). The primary outcomes were differences in VPR multiples of the median (MoM) depending on the occurrence of ODFC and CPO at delivery (based on UA cord blood pH and base excess, 1-min and 5-min Apgar score, and neonatal intensive care unit admission). We explored the technical feasibility of fetal Doppler sonography in this setting and differences in Doppler findings from individual fetal vessels (UA, UV blood flow (UVF), MCA, VA) and related parameters (UVF/EFW and cerebroplacental ratio (CPR)). We also investigated whether adding individual sonographic variables to baseline clinical prediction models could improve discriminatory power (using the area under the receiver-operating-characteristics curve (AUC)) and predictive accuracy (using the Brier score) for both outcomes.

RESULTS

A total of 161 women were recruited. The mean ± SD maternal age was 32.2 ± 3.8 years and approximately half (53.4%) of the women were nulliparous. Most (88.2%) women had labor induced. The mean ± SD gestational age at delivery was 39.3 ± 1.0 weeks and the mean ± SD ultrasound-to-delivery interval was 10.4 ± 2.75 h. An adverse CPO occurred in 13.3% of cases and ODFC occurred in 17.4%. No difference in mean VPR MoM was observed between cases with normal vs adverse CPO (1.04 ± 0.26 vs 1.17 ± 0.25; P = 0.09), or between cases which underwent ODFC vs those which did not (1.06 ± 0.29 vs 1.06 ± 0.26; P = 0.97). Likewise, no differences in other Doppler variables (UA pulsatility index (PI) MoM, MCA-PI MoM, VA-PI MoM, CPR MoM) were observed for both outcomes, except for significantly higher UVF rates in the adverse CPO group (both absolute (P = 0.02) and corrected for EFW (P = 0.048)). For both outcomes, adding VPR MoM or any other sonographic variable to baseline prediction models, which consisted solely of clinical variables, did not improve predictive accuracy or discriminatory power. The baseline model AUC and Brier score values were 0.68 (95% CI, 0.57-0.79) and 0.14 for adverse CPO, and 0.72 (95% CI, 0.61-0.83) and 0.13 for ODFC, respectively.

CONCLUSIONS

Although technically feasible to measure in most women with an AGA fetus admitted for spontaneous or induced labor at term, no difference in VPR MoM was observed depending on the occurrence of ODFC or CPO at delivery. Moreover, adding VPR MoM or any other sonographic variable to a baseline clinical prediction model did not improve predictive accuracy or discriminatory power for either outcome. Hence, peripartum ultrasound for the assessment of fetal weight and placental function has limited added value for predicting adverse labor outcomes in a low-risk obstetric population. © 2025 International Society of Ultrasound in Obstetrics and Gynecology.

Enduring effects of acute prenatal ischemia in rat soleus muscle, and protective role of erythropoietin

Motor disorders are considered to originate mainly from brain lesions. Placental dysfunction or maternal exposure to a persistently hypoxic environment is a major cause of further motor disorders such as cerebral palsy. Our main goal was to determine the long-term effects of mild intrauterine acute ischemic stress on rat soleus myofibres and whether erythropoietin treatment could prevent these changes. Rat embryos were subjected to ischemic stress at embryonic day E17. They then received an intraperitoneal erythropoietin injection at postnatal days 1-5. Soleus muscles were collected at postnatal day 28. Prenatal ischemic stress durably affected muscle structure, as indicated by the greater fiber cross-sectional area (+ 18%) and the greater number of mature vessels (i.e. vessels with mature endothelial cells) per myofibres (+ 43%), and muscle biochemistry, as shown by changes in signaling pathways involved in protein synthesis/degradation balance (-81% for 4EBP1; -58% for AKT) and Hif1α expression levels (+ 95%). Erythropoietin injection in ischemic pups had a weak protective effect: it increased muscle mass (+ 25% with respect to ischemic pups) and partially prevented the increase in muscle degradation pathways and mature vascularization, whereas it exacerbated the decrease in synthesis pathways. Hence, erythropoietin treatment after acute ischemic stress contributes to muscle adaptation to ischemic conditions.

The 36-week preeclampsia risk by the Fetal Medicine Foundation algorithm is associated with fetal compromise following induction of labor

BACKGROUND

Previous studies demonstrated that placental dysfunction leads to intrapartum fetal distress, particularly when an abnormal pattern of angiogenic markers is demonstrated at 36 weeks of gestation. The prediction of intrapartum fetal compromise is particularly important in patients undergoing induction of labor because of different indications for delivery, as this can be a useful in optimizing the method and timing of induction of labor.

OBJECTIVE

This study aimed to examine whether the risk of preeclampsia assessed using the Fetal Medicine Foundation algorithm (derived from a combination of maternal risk factors, mean arterial pressure, placental growth factor, and soluble fms-like tyrosine kinase-1) is associated with the risk of intrapartum fetal compromise requiring cesarean delivery in a population of patients with singleton pregnancies undergoing induction of labor for various indications.

STUDY DESIGN

This was a retrospective analysis on prospectively collected data from women with singleton pregnancies who underwent routine assessments at 35 0/7 to 36 6/7 weeks of gestation at King's College Hospital (London, United Kingdom). The study outcome was the rate of fetal compromise requiring cesarean delivery, examined in relation to the risk of preeclampsia assessed at 36 weeks of gestation using the Fetal Medicine Foundation risk model. Patients who underwent spontaneous labor and prelabor cesarean deliveries were excluded. In addition, 5 risk categories for preeclampsia were created on the basis of the Fetal Medicine Foundation 36-week risk model: A (≥1/2), B (<1/2- ≥1/5), C (<1/5- ≥1/20), D (<1/20-≥1/50), and E (<1/50). Based on the reason for induction of labor, we created 5 categories: premature rupture of membranes, postterm pregnancy (˃41 weeks of gestation), preeclampsia, fetal growth restriction (estimated fetal weight of ˂5th percentile), and preeclampsia and fetal growth restriction. A multinomial logistic regression was used to assess the risk of fetal compromise across the Fetal Medicine Foundation risk categories, accounting for all delivery outcomes (spontaneous or operative vaginal delivery and urgent cesarean delivery for fetal compromise, failure to progress, or other reasons) and allowing accurate and generalizable risk assessment of fetal compromise.

RESULTS

Of 45,375 pregnant women, 26,597 (58.6%) had spontaneous onset of labor, 6529 (14.0%) underwent elective prelabor cesarean delivery, which were excluded from the analysis. A total of 12,249 pregnant women were included, of which 182 had birth at ≤37 weeks of gestation and 1444 had fetal compromise (crude risk of 11.8%). The rate of vaginal delivery in the study population was 69.4%. The rates of fetal compromise in the 5 induction categories were 9.7% for premature rupture of membranes, 13.5% for postterm pregnancy, 14.8% for preeclampsia, 17.2% for fetal growth restriction, and 23.4% for preeclampsia and fetal growth restriction. Cases with intrapartum fetal compromise had a higher mean preeclampsia risk than cases without intrapartum fetal compromise (1/45 vs 1/81, respectively; P<.001). The risk of cesarean delivery for fetal compromise increased with (1) advancing gestational age (each week increase at 35-40 weeks: +1%; at 41-42 weeks: +5%), (2) nulliparity (+7%-10%) vs multiparity, (3) higher Fetal Medicine Foundation risk of preeclampsia (from the low-risk category of <1/50 to the high-risk category of ≥1/2: +18%; with greater effect for higher preeclampsia risk). In this study population, the rates of fetal compromise were lower with diagnoses of preeclampsia and rupture of membranes and higher with fetal growth restriction (alone or in combination with preeclampsia) and postterm pregnancy.

CONCLUSION

Our study highlights the clinical use of the Fetal Medicine Foundation 36-week PE risk model in determining the risk of fetal compromise requiring cesarean delivery after induction of labor. The same model can be combined with standard obstetric indications to induction of labour to establish the risk of fetal compromise requiring cesarean delivery. Therefore, the Fetal Medicine Foundation 36-week PE risk model can be used to optimize induction of labor.

Analysis of CTG patterns in cases with metabolic acidosis at birth with and without neonatal neurological alterations

OBJECTIVE

To determine cardiotocographic patterns in newborns with metabolic acidosis, based on clinical signs of neurological alteration (NA) and the need for hypothermic treatment.

METHODS

All term newborns with metabolic acidosis in a single center from 2016 to 2020 were included in the study. Three segments of intrapartum CTG (cardiotocography) were considered (first 30 min of active labor, 90 to 30 min before birth, and last 30 min before delivery) and a longitudinal analysis of CTG pattern was performed according to the 2015 FIGO classification.

RESULTS

Three hundred and twenty-four neonates with metabolic acidosis diagnosed at birth were divided into three groups: the first group included all neonates with any clinical sign of neurological alteration, requiring hypothermia according to the recommendation of the Italian Society of Neonatology (group TNA-Treated neurological Alteration, n = 17), the second encompassed neonates with any clinical sign of neurological alteration not requiring hypothermia (group NTNA-Not Treated neurological Alteration, n = 83), and the third enclosed all neonates without any sign of clinical neurological involvement (group NoNA-No neurological Alteration, n = 224). The most frequent alterations of CTG in TNA group were late decelerations, reduced variability, bradycardia, and tachysystole. Unexpectedly, from the longitudinal analysis of the CTG, 49% of all cases with metabolic acidosis never showed a pathological CTG with normal trace at the beginning of labor followed by normal or suspicious trace in the final part of labor, the same as in TNA and NTNA groups (10 and 39%, respectively).

CONCLUSIONS

CTG has limited specificity in identifying cases of acidosis at birth, even in babies who will develop NA.

The peripheral chemoreflex and fetal defenses against intrapartum hypoxic-ischemic brain injury at term gestation

Fetal hypoxemia is ubiquitous during labor and, when severe, is associated with perinatal death and long-term neurodevelopmental disability. Adverse outcomes are highly associated with barriers to care, such that developing countries have a disproportionate burden of perinatal injury. The prevalence of hypoxemia and its link to injury can be obscure, simply because the healthy fetus has robust coordinated defense mechanisms, spearheaded by the peripheral chemoreflex, such that hypoxemia only becomes apparent in the minority of cases associated with stillbirth, severe metabolic acidemia or adverse neurodevelopmental outcomes. This represents only the extreme end of the spectrum, when defense mechanisms have failed due to severe/prolonged hypoxemia, or the fetal defenses are compromised by additional risk factors. Understanding the fetal defenses to hypoxemia and when the fetus begins to decompensate is crucial to understanding perinatal health and disease, by linking antenatal health, intrapartum events, the neonatal trajectory and ultimately life-long neurodevelopmental health.

Value of Cerebroplacental Ratio in Predicting Adverse Perinatal Outcome in Term Pregnancies Complicated by Obesity

Objectives

To evaluate the performance of cerebroplacental ratio (CPR) in predicting composite adverse perinatal outcome (CAPO) in women with obesity compared to non-obese women at term.

Methods

This is a retrospective cohort study in a single tertiary referral centre over a 3-year period. All singleton pregnancies with CPR measurements ≥ 37 + 0 weeks and estimated fetal weight ≥ 10 th centile and attempted vaginal delivery were included and divided into two groups defined by pre-pregnancy body mass index (BMI)

Results

The study cohort included 1207 pregnancies, of which 112 were women with a BMI ≥ 30 kg/m 2 . In obese women, CAPO occurred in 21 cases (18.8%) compared to 247 (22.6%) cases in women with BMI < 30 kg/m 2 (p = 0.404). In the entire study cohort, CPR MoM was significantly lower in the CAPO and OD for IFC group. ROC analyses revealed a significant predictive value of low CPR MoM for CAPO in obese women (AUC = 0.64, p = 0.024). Furthermore, CPR was predictive for OD for IFC not only in obese (AUC = 0.72, p = 0.023) but also in non-obese (AUC = 0.61, p = 0.003) women.

Conclusions

Low CPR MoM was predictive for CAPO and OD for IFC in obese women without additional risk factors. However, the overall predictive performance of CPR for CAPO in obese women was poor.

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Key Words

• BMI
• adverse perinatal outcome
• cerebroplacental ratio
• obesity

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Affiliation(s)

Gabriel Eisenkolb Department of Gynecology and Obstetrics, TUM School of Medicine and Health, Technical University Munich (TUM), TUM University Hospital, Munich, Germany
Anne Karge Department of Gynecology and Obstetrics, TUM School of Medicine and Health, Technical University Munich (TUM), TUM University Hospital, Munich, Germany
Javier U. Ortiz Department of Gynecology and Obstetrics, TUM School of Medicine and Health, Technical University Munich (TUM), TUM University Hospital, Munich, Germany
Eva Ostermayer Department of Gynecology and Obstetrics, TUM School of Medicine and Health, Technical University Munich (TUM), TUM University Hospital, Munich, Germany
Silvia M. Lobmaier Department of Gynecology and Obstetrics, TUM School of Medicine and Health, Technical University Munich (TUM), TUM University Hospital, Munich, Germany
Bettina Kuschel Department of Gynecology and Obstetrics, TUM School of Medicine and Health, Technical University Munich (TUM), TUM University Hospital, Munich, Germany
Oliver Graupner Department of Gynecology and Obstetrics, TUM School of Medicine and Health, Technical University Munich (TUM), TUM University Hospital, Munich, Germany

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The iSEARCH randomised controlled trial protocol: a pragmatic Australian phase III clinical trial of intrapartum sildenafil citrate to improve outcomes potentially related to intrapartum hypoxia

INTRODUCTION

We showed in a phase II randomised controlled trial (RCT) that oral sildenafil citrate in term labour halved operative birth for fetal distress. We outline the protocol for a phase III RCT (can intrapartum SildEnafil safely Avert the Risks of Contraction-induced Hypoxia? (iSEARCH)) of 3200 women in Australia to assess if sildenafil citrate reduces adverse perinatal outcomes related to intrapartum hypoxia.

METHODS AND ANALYSIS

iSEARCH will enrol 3200 Australian women in term labour to determine whether up to three 50 mg oral doses of sildenafil citrate versus placebo reduce the relative risk of a primary composite end point of 10 perinatal outcomes potentially related to intrapartum hypoxia by 35% (from 7% to 4.55%). Secondary aims are to evaluate reductions in the relative risk of emergency caesarean section or instrumental vaginal birth for fetal distress by 25% (from 20% to 15%) and in healthcare costs. To detect a 35% reduction in the primary outcome for an alpha of 0.05 and power of 80% with 10% dropout in each arm requires 3200 women (1600 in each arm). This sample size will also yield >90% power to detect a 25% reduction for the secondary outcome of any operative birth (caesarean section or instrumental vaginal birth) for fetal distress.

ETHICS AND DISSEMINATION

Ethical approval for the iSEARCH RCT was granted by the Hunter New England Human Research Ethics Committee (ref no: 2020/ETH02791). Results will be disseminated through websites, peer-reviewed publications, scientific meetings and social media, news outlets, television and radio.

TRIAL REGISTRATION NUMBER

ACTRN12621000231842.

RidStress 2 randomised controlled trial protocol: an Australian phase III clinical trial of intrapartum sildenafil citrate or placebo to reduce emergency caesarean birth for fetal distress in women with small or suboptimally grown infants at term (≥37 weeks)

INTRODUCTION

Small for gestational age (SGA) infants are at increased risk of fetal distress in labour requiring emergency operative birth (by caesarean section (CS), vacuum or forceps). We have previously shown that maternal oral sildenafil citrate (SC) in labour halves the need for operative birth for suspected fetal distress in women with appropriately grown term infants.

METHODS AND ANALYSIS

RidStress 2 is a phase III randomised, double-blinded, placebo-controlled trial of 660 women with an SGA or suboptimally grown fetus (estimated fetal weight or abdominal circumference<10th centile for gestational age) planning a vaginal birth at term. The trial will determine whether oral intrapartum SC (50 mg eight hourly) reduces the relative risk of emergency CS for fetal distress compared with placebo. The primary outcome is CS for fetal distress, and the secondary outcomes are any operative birth for fetal distress, cost-effectiveness of SC treatment and 2-year childhood neurodevelopmental outcomes. To detect a 33% reduction in the primary outcome from 30% to 20% for an alpha of 0.05 and power of 80% with 10% dropout, requires approximately 660 women (330 in each arm). This sample size will also yield >90% power to detect a similar reduction for the secondary outcome of any operative birth (CS or instrumental vaginal birth) for fetal distress.

ETHICS AND DISSEMINATION

Ethics approval was granted by the Mater Misericordiae Limited Human Research Ethics Committee (EC00332) on 11 September 2020. We plan to disseminate the results of this randomised controlled trial through presentations at scientific meetings and peer-reviewed journals, adhering to all relevant reporting guidelines.

TRIAL REGISTRATION NUMBER

RidStress 2 is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12621000354886, 29/03/2021) and the Therapeutic Goods Association of Australia (date registered: 16 March 2021).

[Fetal monitoring: Current limitations and new approaches based on analysis of the fetal autonomic nervous system]

OBJECTIVE

Currently, fetal monitoring during labor is based on visual analysis of the fetal heart rate (FHR). This test is imperfect, with high intra- and inter-observer variability and a moderate to poor prediction of the occurrence of neonatal acidosis or anoxic-ischaemic encephalopathy. In situations where there is an intermediate risk of acidosis, it is possible to use second-line tests such as blood scalp sampling (with pH or lactate measurement) or ST segment analysis of the fetal ECG. However, these invasive tests have many limitations and their place is debated. Some authors suggest a more physiological approach to FHR assessment. The main actor in maintaining fetal homeostasis is the autonomic nervous system (ANS). Its activity can be assessed by analysing heart rate variability (HRV). The aim is to assess whether HRV can be used to identify situations at risk of acidosis.

MATERIALS AND METHODS

Our team has developed an index, the Fetal Stress Index, to measure HRV. To test it in a situation of acidosis, we used a pregnant ewe model. We also developed in parallel a human fetal ECG recording system.

RESULTS

In our experimental model, we have shown that this index reflects variations in the parasympathetic system and correlates with the onset of acidosis. As its use in clinical practice requires the acquisition of a beat-to-beat FHR signal, we have also developed an abdominal patch that allows highly accurate analysis of the fetal ECG.

CONCLUSION

The future is therefore to validate the FSI as a marker of acidosis in a prospective cohort using the signal obtained from our patch. This could be a new tool for fetal monitoring during labor.

"…We never considered it important…": a qualitative study on perceived barriers on use of non-pharmacological methods in management of labour pain by nurse-midwives in eastern Tanzania

BACKGROUND

A significant number of women experience labour without effective pain management and thus suffer from unbearable labour pain to the extent they term labour as the most agonizing event in their lives. Unresolved labour pain can lead to stress, fear, and confusion, which may compromise placental perfusion and lead to birth asphyxia. Although various pharmacological and non-pharmacological labour pain management methods exist, the use of non-pharmacological methods (NPMs) to manage labour pain has remained low in low-resource settings. This paper explored the barriers for using NPMs to manage labour pain by nurse-midwives in eastern Tanzania.

METHODS

We conducted an exploratory qualitative study with 18 nurse-midwives purposefully recruited from the labour wards of two selected district hospitals in eastern Tanzania. Qualitative content analysis guided the data analysis.

RESULTS

Two categories illustrating barriers to using NPMs were generated: individual-level and institutional-level barriers. Individual-level barriers include (i) limited competencies of nurse-midwives on the use of NPMs for managing labour pain, (ii) inadequate exposure to labour pain management practices, (iii) misconceptions about labour pain relief, and (iv) a lack of opportunities for knowledge acquisition. The institutional barriers include (i) a critical staff shortage amidst many clients and (ii) an unfavourable healthcare facility environment.

CONCLUSION

The implementation of NPMs for labour pain management by nurse-midwives in eastern Tanzania faces several institutional and individual barriers. We recommend addressing both supply- and demand-side barriers. Strengthening nurse midwives' competencies in NPMs adoption and use and improving the facility environment to ensure privacy during labour can be a starting point for addressing supply-side issues. We recommend dispelling myths and misconceptions through health promotion education to address demand-side barriers.

Biliary atresia

Biliary atresia (BA) is a progressive inflammatory fibrosclerosing disease of the biliary system and a major cause of neonatal cholestasis. It affects 1:5,000-20,000 live births, with the highest incidence in Asia. The pathogenesis is still unknown, but emerging research suggests a role for ciliary dysfunction, redox stress and hypoxia. The study of the underlying mechanisms can be conceptualized along the likely prenatal timing of an initial insult and the distinction between the injury and prenatal and postnatal responses to injury. Although still speculative, these emerging concepts, new diagnostic tools and early diagnosis might enable neoadjuvant therapy (possibly aimed at oxidative stress) before a Kasai portoenterostomy (KPE). This is particularly important, as timely KPE restores bile flow in only 50-75% of patients of whom many subsequently develop cholangitis, portal hypertension and progressive fibrosis; 60-75% of patients require liver transplantation by the age of 18 years. Early diagnosis, multidisciplinary management, centralization of surgery and optimized interventions for complications after KPE lead to better survival. Postoperative corticosteroid use has shown benefits, whereas the role of other adjuvant therapies remains to be evaluated. Continued research to better understand disease mechanisms is necessary to develop innovative treatments, including adjuvant therapies targeting the immune response, regenerative medicine approaches and new clinical tests to improve patient outcomes.

In Utero Extrahepatic Bile Duct Damage and Repair: Implications for Biliary Atresia

Biliary atresia (BA) is a cholangiopathy affecting the extrahepatic bile duct (EHBD) of newborns. The etiology and pathophysiology of BA are not fully understood; however, multiple causes of damage and obstruction of the neonatal EHBD have been identified. Initial damage to the EHBD likely occurs before birth. We discuss how different developmental stages in utero and birth itself could influence the susceptibility of the fetal EHBD to damage and a damaging wound-healing response. We propose that a damage-repair response of the fetal and neonatal EHBD involving redox stress and a program of fetal wound healing could-regardless of the cause of the initial damage-lead to either obstruction and BA or repair of the duct and recovery. This overarching concept should guide future research targeted toward identification of factors that contribute to recovery as opposed to progression of injury and fibrosis. Viewing BA through the lens of an in utero damage-repair response could open up new avenues for research and suggests exciting new therapeutic targets.

Uterine contractile activity and neonatal outcome - A blind analysis of a randomized controlled trial cohort

INTRODUCTION

Sufficient contractions are necessary for a successful delivery but each contraction temporarily constricts the oxygenated blood flow to the fetus. Individual fetal or placental characteristics determine how the fetus can withstand this temporary low oxygen saturation. However, only a few studies have examined the impact of uterine activity on neonatal outcome and even less attention has been paid to parturients' individual characteristics. Our objective was therefore to find out whether fetuses compromised by maternal or intrapartum risk factors are more vulnerable to excessive uterine activity.

MATERIAL AND METHODS

Uterine contractile activity was assessed by intrauterine pressure catheters. Women (n = 625) with term singleton pregnancies and fetus in cephalic presentation were included in this secondary, blind analysis of a randomized controlled trial cohort. Intrauterine pressure as Montevideo units (MVU), contraction frequency/10 min and uterine baseline tone were calculated for 4 h prior to birth or the decision to perform cesarean section. Uterine activity in relation to umbilical artery pH linearly or ≤7.10 was used as the primary outcome. Need for operative delivery (either cesarean section or vacuum-assisted delivery) due to fetal distress was analyzed as a secondary outcome. In addition, belonging to vulnerable subgroups with, for example, chorioamnionitis, hypertensive or diabetic disorders, maternal smoking or neonatal birthweight <10th percentile were investigated as additional risk factors.

RESULTS

A linear decline in umbilical artery pH was seen with increasing intrauterine pressure in all deliveries (p < 0.001). Among parturients with suspected chorioamnionitis, every increasing 10 MVUs increased the likelihood of umbilical artery pH ≤7.10 (odds ratio [OR] 1.17, 95% confidence interval [CI] 1.02-1.34, p = 0.023). The need for operative delivery due to fetal distress was increased among all laboring women by every increasing 10 MVUs (OR 1.05, 95% CI 1.01-1.09, p = 0.015). This association with operative deliveries was further increased among parturients with hypertensive disorders (OR 1.23, 95% CI 1.05-1.43, p = 0.009) and among those with diabetic disorders (OR 1.13, 95% CI 1.04-1.28, p = 0.003).

CONCLUSIONS

Increasing intrauterine pressure impairs umbilical artery pH especially among parturients with suspected chorioamnionitis. Fetuses in pregnancies affected by chorioamnionitis, hypertensive or diabetic disorders are more vulnerable to high intrauterine pressure.

Three-Dimensional Fractional Moving Blood Volume: A Robust Bedside Tool for Evaluation of Fetal Multiorgan Perfusion

INTRODUCTION

Three-dimensional fractional moving blood volume (3D-FMBV) may provide superior noninvasive measurement of feto-placental perfusion compared to current methods. This study investigated the feasibility and repeatability of producing 3D-FMBV measurements of the placenta, fetal liver, kidney, and brain in a single ultrasound consultation.

METHODS

The placenta, fetal liver, kidney, and brain were scanned in triplicate using 3D power Doppler ultrasound (3D-PDU) in 48 women ≥22 weeks of gestation with healthy fetuses. 3D-FMBV was calculated by two analyzers. Feasibility was assessed as the percentage of cases where 3D-FMBV could be evaluated; repeatability (intraobserver and interobserver) using two-way mixed measure intraclass correlation coefficients (ICCs).

RESULTS

3D-FMBV was calculated for 100% of scanned organs. Intraobserver ICCs (95% CI) were good to excellent; 0.93 (0.88-0.96) and 0.87 (0.78-0.92) for placenta, 0.95 (0.92-0.97) and 0.98 (0.96-0.99) for fetal liver, 0.96 (0.94-0.98) and 0.91 (0.85-0.95) for fetal kidney, and 0.98 (0.97-0.99) and 0.97 (0.95-0.98) for fetal brain. Interobserver ICCs (95% CI) were 0.50 (0.08-0.73), 0.92 (0.85-0.96), 0.89 (0.78-0.94), and 0.71 (0.46-0.85) for placenta, fetal liver, kidney, and brain.

CONCLUSION

Feto-placental perfusion assessment with 3D-FMBV is highly reliable in healthy pregnancies ≥22 weeks of gestation and can be feasibly calculated in four feto-placental vascular beds in a single ultrasound consultation.

Prediction of Cesarean Section for Intrapartum Fetal Compromise: A Multivariable Model from a Prospective Observational Approach

OBJECTIVE

A cesarean section for intrapartum fetal compromise (IFC) is performed to avoid potential damage to the newborn. It is, therefore, crucial to develop an accurate prediction model that can anticipate, prior to labor, which fetus may be at risk of presenting this condition.

MATERIAL AND METHODS

To calculate a prediction model for IFC, the clinical, epidemiological, and ultrasonographic variables of 538 patients admitted to the maternity of La Fe Hospital were studied and evaluated using univariable and multivariable logistic regression analysis, using the area under the curve (AUC) and the Akaike Information Criteria (AIC).

RESULTS

In the univariable analysis, CPR MoM was the best single parameter for the prediction of CS for IFC (OR 0.043, p < 0.0001; AUC 0.72, p < 0.0001). Concerning the multivariable analysis, for the general population, the best prediction model (lower AIC) included the CPR multiples of the median (MoM), the maternal age, height, and parity, the smoking habits, and the type of labor onset (spontaneous or induction) (AUC 0.80, p < 0.0001). In contrast, for the pregnancies undergoing labor induction, the best prediction model included the CPR MoM, the maternal height and parity, and the smoking habits (AUC 0.80, p < 0.0001). None of the models included estimated fetal weight (EFW).

CONCLUSIONS

CS for IFC can be moderately predicted prior to labor using maternal characteristics and CPR MoM. A validation study is pending to apply these models in daily clinical practice.

Acute-on-chronic: using magnetic resonance imaging to disentangle the haemodynamic responses to acute and chronic fetal hypoxaemia

Introduction

The fetal haemodynamic response to acute episodes of hypoxaemia are well characterised. However, how these responses change when the hypoxaemia becomes more chronic in nature such as that associated with fetal growth restriction (FGR), is less well understood. Herein, we utilised a combination of clinically relevant MRI techniques to comprehensively characterize and differentiate the haemodynamic responses occurring during acute and chronic periods of fetal hypoxaemia.

Methods

Prior to conception, carunclectomy surgery was performed on non-pregnant ewes to induce FGR. At 108-110 days (d) gestational age (GA), pregnant ewes bearing control (n = 12) and FGR (n = 9) fetuses underwent fetal catheterisation surgery. At 117-119 days GA, ewes underwent MRI sessions where phase-contrast (PC) and T2 oximetry were used to measure blood flow and oxygenation, respectively, throughout the fetal circulation during a normoxia and then an acute hypoxia state.

Results

Fetal oxygen delivery (DO2) was lower in FGR fetuses than controls during the normoxia state but cerebral DO2 remained similar between fetal groups. Acute hypoxia reduced both overall fetal and cerebral DO2. FGR increased ductus venosus (DV) and foramen ovale (FO) blood flow during both the normoxia and acute hypoxia states. Pulmonary blood flow (PBF) was lower in FGR fetuses during the normoxia state but similar to controls during the acute hypoxia state when PBF in controls was decreased.

Conclusion

Despite a prevailing level of chronic hypoxaemia, the FGR fetus upregulates the preferential streaming of oxygen-rich blood via the DV-FO pathway to maintain cerebral DO2. However, this upregulation is unable to maintain cerebral DO2 during further exposure to an acute episode of hypoxaemia. The haemodynamic alterations required at the level of the liver and lung to allow the DV-FO pathway to maintain cerebral DO2, may have lasting consequences on hepatic function and pulmonary vascular regulation after birth.

Perinatal compromise affects development, form, and function of the hippocampus part one; clinical studies

The hippocampus is a neuron-rich specialised brain structure that plays a central role in the regulation of emotions, learning and memory, cognition, spatial navigation, and motivational processes. In human fetal development, hippocampal neurogenesis is principally complete by mid-gestation, with subsequent maturation comprising dendritogenesis and synaptogenesis in the third trimester of pregnancy and infancy. Dendritogenesis and synaptogenesis underpin connectivity. Hippocampal development is exquisitely sensitive to perturbations during pregnancy and at birth. Clinical investigations demonstrate that preterm birth, fetal growth restriction (FGR), and acute hypoxic-ischaemic encephalopathy (HIE) are common perinatal complications that alter hippocampal development. In turn, deficits in hippocampal development and structure mediate a range of neurodevelopmental disorders, including cognitive and learning problems, autism, and Attention-Deficit/Hyperactivity Disorder (ADHD). In this review, we summarise the developmental profile of the hippocampus during fetal and neonatal life and examine the hippocampal deficits observed following common human pregnancy complications. IMPACT: The review provides a comprehensive summary of the developmental profile of the hippocampus in normal fetal and neonatal life. We address a significant knowledge gap in paediatric research by providing a comprehensive summary of the relationship between pregnancy complications and subsequent hippocampal damage, shedding new light on this critical aspect of early neurodevelopment.

The influence of birthweight on mortality and severe neonatal morbidity in late preterm and term infants: an Australian cohort study

Background

The aim of this study was to detail incidence rates and relative risks for severe adverse perinatal outcomes by birthweight centile categories in a large Australian cohort of late preterm and term infants.

Methods

This was a retrospective cohort study of singleton infants (≥34+0 weeks gestation) between 2000 and 2018 in Queensland, Australia. Study outcomes were perinatal mortality, severe neurological morbidity, and other severe morbidity. Categorical outcomes were compared using Chi-squared tests. Continuous outcomes were compared using t-tests. Multinomial logistic regression investigated the effect of birthweight centile on study outcomes.

Findings

The final cohort comprised 991,042 infants. Perinatal mortality occurred in 1944 infants (0.19%). The incidence and risk of perinatal mortality increased as birthweight decreased, peaking for infants <1st centile (perinatal mortality rate 13.2/1000 births, adjusted Relative Risk Ratio (aRRR) of 12.96 (95% CI 10.14, 16.57) for stillbirth and aRRR 7.55 (95% CI 3.78, 15.08) for neonatal death). Severe neurological morbidity occurred in 7311 infants (0.74%), with the highest rate (19.6/1000 live births) in <1st centile cohort. There were 75,243 cases of severe morbidity (7.59% livebirths), with the peak incidence occurring in the <1st centile category (12.3% livebirths). The majority of adverse outcomes occurred in infants with birthweights between 10 and 90th centile. Almost 2 in 3 stillbirths, and approximately 3 in 4 cases of neonatal death, severe neurological morbidity or other severe morbidity occurred within this birthweight range.

Interpretation

Although the incidence and risk of perinatal mortality, severe neurological morbidity and severe morbidity increased at the extremes of birthweight centiles, the majority of these outcomes occurred in infants that were apparently "appropriately grown" (i.e., birthweight 10th-90th centile).

Funding

National Health and Medical Research Council, Mater Foundation, Royal Australian College of Obstetricians and Gynaecologists Women's Health Foundation - Norman Beischer Clinical Research Scholarship, Cerebral Palsy Alliance, University of Queensland Research Scholarship.

Assessment of the cerebroplacental ratio and uterine arteries in low-risk pregnancies in early labour for the prediction of obstetric and neonatal outcomes

BACKGROUND

The evidence-based management of human labor includes the antepartum identification of patients at risk for intrapartum hypoxia. However, available evidence has shown that most of the hypoxic-related complications occur among pregnancies classified at low-risk for intrapartum hypoxia, thus suggesting that the current strategy to identify the pregnancies at risk for intrapartum fetal hypoxia has limited accuracy.

OBJECTIVE

To evaluate the role of the combined assessment of the cerebroplacental ratio (CPR) and uterine arteries (UtA) Doppler in the prediction of obstetric intervention (OI) for suspected intrapartum fetal compromise (IFC) within a cohort of low-risk singleton term pregnancies in early labor.

METHODS

Prospective multicentre observational study conducted across four tertiary Maternity Units between January 2016 and September 2019. Low-risk term pregnancies with spontaneous onset of labor were included. A two-step multivariable model was developed to assess the risk of OI for suspected IFC. The baseline model included antenatal and intrapartum characteristics, while the combined model included antenatal and intrapartum characteristics plus Doppler anomalies such as CPR MoM < 10th percentile and mean UtA Doppler PI MoM ≥ 95th percentile. Predictive performance was determined by receiver-operating characteristics curve analysis.

RESULTS

804 women were included. At logistic regression analysis, CPR MoM < 10th percentile (aOR 1.269, 95 % CI 1.188-1.356, P < 0.001), mean UtA PI MoM ≥ 95th percentile (aOR 1.012, 95 % CI 1.001-1.022, P = 0.04) were independently associated with OI for suspected IFC. At ROC curve analysis, the combined model including antenatal characteristics plus abnormal CPR and mean UtA PI yielded an AUC of 0.78, 95 %CI(0.71-0.85), p < 0.001, which was significantly higher than the baseline model (AUC 0.61, 95 %CI(0.54-0.69), p = 0.007) (p < 0.001). The combined model was associated with a 0.78 (95 % CI 0.67-0.89) sensitivity, 0.68 (95 % CI 0.65-0.72) specificity, 0.15 (95 % CI 0.11-0.19) PPV, and 0.98 (0.96-0.99) NPV, 2.48 (95 % CI 2.07-2.97) LR + and 0.32 (95 % CI 0.19-0.53) LR- for OI due to suspected IFC.

CONCLUSIONS

A predictive model including antenatal and intrapartum characteristics combined with abnormal CPR and mean UtA PI has a good capacity to rule out and a moderate capacity to rule in OI due to IFC, albeit with poor predictive value.

Intrapartum use of sildenafil citrate to prevent fetal compromise and emergency operative birth in term pregnancies in the United Kingdom and Australia: A preliminary cost-effectiveness analysis

OBJECTIVE

To compare cost-effectiveness of oral sildenafil citrate, administered after onset of labor, with standard care to health system funders in the UK and Australia.

METHODS

We conducted a modeled cost-effectiveness analysis, measuring costs and quality adjusted life years (QALYs), using a decision-analytic model covering onset of labor to 1 month post-birth. The relative risk of emergency cesarean section and operative vaginal birth was taken from a Phase 2 placebo controlled double blinded randomized control trial.

RESULTS

Both options of care resulted in the same QALYs gained over the model time period (0.08). Sildenafil citrate was cost-saving compared with standard care, saving £92 per birth in the UK (AU$303 per birth in Australia). Sensitivity analyses did not identify any areas of uncertainty that stopped sildenafil citrate being cost saving compared with standard care. Threshold analysis revealed that sildenafil citrate would be cost saving up to a per birth drug or administration cost of £152.32 in the UK (AU$333.61 in Australia).

CONCLUSION

Oral sildenafil citrate may be cost saving compared with standard care; however, the effects on neonatal outcomes still need to be demonstrated in large randomized trials.

Clinical decisions in fetal-neonatal neurology II: Gene-environment expression over the first 1000 days presenting as "four great neurological syndromes"

Interdisciplinary fetal-neonatal neurology (FNN) training considers a woman's reproductive and pregnancy health histories when assessing the "four great neonatal neurological syndromes". This maternal-child dyad exemplifies the symptomatic neonatal minority, compared with the silent majority of healthy children who experience preclinical diseases with variable expressions over the first 1000 days. Healthy maternal reports with reassuring fetal surveillance testing preceded signs of fetal distress during parturition. An encephalopathic neonate with seizures later exhibited childhood autistic spectrum behaviors and intractable epilepsy correlated with identified genetic biomarkers. A systems biology approach to etiopathogenesis guides the diagnostic process to interpret phenotypic form and function. Evolving gene-environment interactions expressed by changing phenotypes reflect a dynamic neural exposome influenced by reproductive and pregnancy health. This strategy considers critical/sensitive periods of neuroplasticity beyond two years of life to encompass childhood and adolescence. Career-long FNN experiences reenforce earlier training to strengthen the cognitive process and minimize cognitive biases when assessing children or adults. Prioritizing social determinants of healthcare for persons with neurologic disorders will help mitigate the global burden of brain diseases for all women and children.

Fetal monitoring technologies for the detection of intrapartum hypoxia - challenges and opportunities

Intrapartum fetal hypoxia is related to long-term morbidity and mortality of the fetus and the mother. Fetal surveillance is extremely important to minimize the adverse outcomes arising from fetal hypoxia during labour. Several methods have been used in current clinical practice to monitor fetal well-being. For instance, biophysical technologies including cardiotocography, ST-analysis adjunct to cardiotocography, and Doppler ultrasound are used for intrapartum fetal monitoring. However, these technologies result in a high false-positive rate and increased obstetric interventions during labour. Alternatively, biochemical-based technologies including fetal scalp blood sampling and fetal pulse oximetry are used to identify metabolic acidosis and oxygen deprivation resulting from fetal hypoxia. These technologies neither improve clinical outcomes nor reduce unnecessary interventions during labour. Also, there is a need to link the physiological changes during fetal hypoxia to fetal monitoring technologies. The objective of this article is to assess the clinical background of fetal hypoxia and to review existing monitoring technologies for the detection and monitoring of fetal hypoxia. A comprehensive review has been made to predict fetal hypoxia using computational and machine-learning algorithms. The detection of more specific biomarkers or new sensing technologies is also reviewed which may help in the enhancement of the reliability of continuous fetal monitoring and may result in the accurate detection of intrapartum fetal hypoxia.

Interdisciplinary fetal-neonatal neurology training applies neural exposome perspectives to neurology principles and practice

An interdisciplinary fetal-neonatal neurology (FNN) program over the first 1,000 days teaches perspectives of the neural exposome that are applicable across the life span. This curriculum strengthens neonatal neurocritical care, pediatric, and adult neurology training objectives. Teaching at maternal-pediatric hospital centers optimally merges reproductive, pregnancy, and pediatric approaches to healthcare. Phenotype-genotype expressions of health or disease pathways represent a dynamic neural exposome over developmental time. The science of uncertainty applied to FNN training re-enforces the importance of shared clinical decisions that minimize bias and reduce cognitive errors. Trainees select mentoring committee participants that will maximize their learning experiences. Standardized questions and oral presentations monitor educational progress. Master or doctoral defense preparation and competitive research funding can be goals for specific individuals. FNN principles applied to practice offer an understanding of gene-environment interactions that recognizes the effects of reproductive health on the maternal-placental-fetal triad, neonate, child, and adult. Pre-conception and prenatal adversities potentially diminish life-course brain health. Endogenous and exogenous toxic stressor interplay (TSI) alters the neural exposome through maladaptive developmental neuroplasticity. Developmental disorders and epilepsy are primarily expressed during the first 1,000 days. Communicable and noncommunicable illnesses continue to interact with the neural exposome to express diverse neurologic disorders across the lifespan, particularly during the critical/sensitive time periods of adolescence and reproductive senescence. Anomalous or destructive fetal neuropathologic lesions change clinical expressions across this developmental-aging continuum. An integrated understanding of reproductive, pregnancy, placental, neonatal, childhood, and adult exposome effects offers a life-course perspective of the neural exposome. Exosome research promises improved disease monitoring and drug delivery starting during pregnancy. Developmental origins of health and disease principles applied to FNN practice anticipate neurologic diagnoses with interventions that can benefit successive generations. Addressing health care disparities in the Global South and high-income country medical deserts require constructive dialogue among stakeholders to achieve medical equity. Population health policies require a brain capital strategy that reduces the global burden of neurologic diseases by applying FNN principles and practice. This integrative neurologic care approach will prolong survival with an improved quality of life for persons across the lifespan confronted with neurological disorders.

The Placenta and Neonatal Encephalopathy with a Focus on Hypoxic-Ischemic Encephalopathy

Background: Placental examination is important for its diagnostic immediacy to correlate with maternal and/or fetal complications and parturitional difficulties. In a broader context, clinicopathologic studies of the placenta have addressed a range of pathogenetic questions that have led to conclusive and inconclusive results and interpretations. Methods: Recent standardized morphologic criteria and terminology of placental lesions have facilitated the ability to compare findings from studies that have focused on complications and outcomes of pregnancy. This review is an evaluation of recent studies on placental lesions associated with hypoxic-ischemic encephalopathy (HIE). Conclusion: No apparent consensus exists on whether it is fetal inflammation with the release of cytokines or chronic maternal and/or fetal vascular malperfusion is responsible for HIE with a lowering of the threshold for hypoxic ischemia. The counter argument is that HIE occurs solely as an intrapartum event. Additional investigation is necessary.

Mediation analysis quantifying the magnitude of stillbirth risk attributable to small for gestational age infants

BACKGROUND

Many risk factors for stillbirth are linked to placental dysfunction, which leads to suboptimal intrauterine growth and small for gestational age infants. Such infants also have an increased risk for stillbirth.

OBJECTIVE

This study aimed to investigate the effect of known causal risk factors for stillbirth, and to identify those that have a large proportion of their risk mediated through small for gestational age birth.

STUDY DESIGN

This retrospective cohort study used data from all births in the state of Queensland, Australia between 2000 and 2018. The total effects of exposures on the odds of stillbirth were determined using multivariable, clustered logistic regression models. Mediation analysis was performed using a counterfactual approach to determine the indirect effect and percentage of effect mediated through small for gestational age. For risk factors significantly mediated through small for gestational age, the relative risks of stillbirth were compared between small for gestational age and appropriate for gestational age infants. We also investigated the proportion of risk mediated via small for gestational age for late stillbirths (≥28 weeks).

RESULTS

The initial data set consisted of 1,105,612 births. After exclusions, the final study cohort constituted 925,053 births. Small for gestational age births occurred in 9.9% (91,859/925,053) of the study cohort. Stillbirths occurred in 0.5% of all births (4234/925,053) and 1.5% of small for gestational age births (1414/91,859). Births at ≥28 weeks occurred in 99.4% (919,650/925,053) of the study cohort and in 98.9% (90,804/91,859) of all small for gestational age births. Of the ≥28-week births, stillbirths occurred in 0.2% (2156/919,650) of all births and 0.8% (677/90,804) of the small for gestational age births. Overall, increased odds of stillbirth were significantly mediated through small for gestational age for age <20 years, low socioeconomic status, Indigenous ethnicity, birth in sub-Saharan and North Africa or the Middle East, smoking, nulliparity, multiple pregnancy, assisted conception, previous stillbirth, preeclampsia, and renal disease. Preeclampsia had the largest proportion mediated through small for gestational age (66.7%), followed by nulliparity (61.6%), smoking (29.4%), North-African or Middle Eastern ethnicity (27.6%), multiple pregnancy (26.3%), low socioeconomic status (25.8%), and Indigenous status (18.7%). Sensitivity analysis showed that for late stillbirths, the portions mediated through small for gestational age remained very similar for many of the risk factors.

CONCLUSION

Although small for gestational age is an important mediator between many pregnancy risk factors and stillbirth, mitigating the risk of small for gestational age is likely to be of value only when it is a major contributor in the pathway to fetal demise.

Effect of intrapartum epidural analgesia on rate of emergency delivery for presumed fetal compromise: nationwide registry-based cohort study

OBJECTIVES

To determine the rate of emergency delivery for presumed fetal compromise after epidural analgesia (EDA) compared with that after alternative analgesia or no analgesia, and to assess whether this rate is increased in pregnancies with reduced placental reserve.

METHODS

This was a nationwide registry-based cohort study of 629 951 singleton pregnancies delivered at 36 + 0 to 42 + 0 weeks of gestation that were recorded in the Dutch national birth registry between 2014 and 2018, including 120 426 cases that received EDA, 86 957 that received alternative analgesia and 422 568 that received no analgesia during labor. Pregnancies with congenital anomaly, chromosomal abnormality, fetal demise, planned Cesarean delivery, non-cephalic presentation at delivery and use of multiple forms of analgesia were excluded. The primary outcome was emergency delivery for presumed fetal compromise. Secondary outcomes included delivery characteristics and neonatal outcome. Negative binomial regression analysis was stratified by parity and results are presented according to birth-weight centile, after adjusting for confounding.

RESULTS

Among women who received EDA, 13.2% underwent emergency delivery for presumed fetal compromise, compared with 4.1% of women who had no analgesia (relative risk (RR), 3.23 (95% CI, 3.16-3.31)) and 7.0% of women who received alternative analgesia (RR, 1.72 (95% CI, 1.67-1.77)). Independent of birth weight, the RR of presumed fetal compromise after EDA vs no analgesia was higher in parous women (adjusted RR (aRR), 2.15 (95% CI, 2.04-2.27)) compared with nulliparous women (RR, 1.88 (95% CI, 1.84-1.94)). Stratified for parity, the effect of EDA was modified significantly by birth-weight centile (interaction P-value, < 0.001 for nulliparous and 0.004 for parous women). The emergency delivery rate following EDA was highest in those with a birth weight < 5th centile (25.2% of nulliparous and 16.6% of parous women), falling with each increasing birth-weight centile category up to the 91st -95th centile (11.8% of nulliparous and 7.2% of parous women).

CONCLUSIONS

Intrapartum EDA is associated with a higher risk of emergency delivery for presumed fetal compromise compared with no analgesia and alternative analgesia, after adjusting for relevant confounding. The highest rate of emergency delivery for presumed fetal compromise was observed at the lowest birth-weight centiles. RRs of emergency delivery for presumed fetal compromise after EDA were modestly but consistently modified by birth-weight centile, supporting the hypothesis that the adverse effects of EDA are exacerbated by reduced placental function. While EDA provides effective pain relief during labor, alternative strategies for pain management may be preferable in pregnancies with a high background risk of fetal compromise. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Three-tiered fetal heart rate interpretation system and adverse neonatal and maternal outcomes: a systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the rate of adverse neonatal or maternal outcomes in parturients with fetal heart rate tracings categorized as I, II or, III within the last 30 to 120 minutes of delivery.

DATA SOURCES

The MEDLINE Ovid, Scopus, Embase, CINAHL, and Clinicaltrials.gov databases were searched electronically up to May 2022, using combinations of the relevant medical subject heading terms, keywords, and word variants that were considered suitable for the topic.

STUDY ELIGIBILITY CRITERIA

Only observational studies of term infants reporting outcomes of interest with category I, II, or III fetal heart rate tracings were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

The coprimary outcome was the rate of either Apgar score <7 at 5 minutes or umbilical artery pH <7.00. Secondary outcomes were divided into neonatal and maternal adverse outcomes. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale. Random-effect meta-analyses of proportions were used to estimate the pooled rates of each categorical outcome in fetal heart rate tracing category I, II, and III patterns, and random-effect head-to-head meta-analyses were used to directly compare fetal heart rate tracings category I vs II and fetal heart rate tracing category II vs III, expressing the results as summary odds ratio or as mean differences with relative 95% confidence intervals.

RESULTS

Of the 671 articles reviewed, 3 publications met the inclusion criteria. Among them were 47,648 singletons at ≥37 weeks' gestation. Fetal heart rate tracings in the last 30 to 120 minutes before delivery were characterized in the following manner: 27.0% of deliveries had category I tracings, 72.9% had category II tracings, and 0.1% had category III tracings. A single study, which was rated to be of poor quality, contributed 82.1% of the data and it did not provide any data for category III fetal heart rate tracings. When compared with category I fetal heart rate tracings (0.74%), the incidence of an Apgar score <7 at 5 minutes were significantly higher among deliveries with category II fetal heart rate tracings (1.51%) (odds ratio, 1.56; 95% confidence interval, 1.23-1.99) and among those with category III tracings (14.63%) (odds ratio, 14.46; 95% confidence interval, 2.77-75.39). When compared with category II tracings, category III tracings also had a significantly higher likelihood of a low Apgar score at 5 minutes (odds ratio, 14.46; 95% confidence interval, 2.77-75.39). The incidence of an umbilical artery pH <7.00 were similar among those with category I and those with category II tracings (0.08% vs 0.24%; odds ratio, 2.85; 95% confidence interval, 0.41-19.55). When compared with category I tracings, the incidence of an umbilical artery pH <7.00 was significantly more common among those with category III tracings (31.04%; odds ratio, 161.56; 95% confidence interval, 25.18-1036.42); likewise, when compared with those with category II tracings, those with category III tracings had a significantly higher likelihood of having an umbilical artery pH <7.00 (odds ratio, 42.29; 95% confidence interval, 14.29-125.10). Hypoxic-ischemic encephalopathy occurred with similar frequency among those with categories I and those with category II tracings (0 vs 0.81%; odds ratio, 5.86; 95% confidence interval, 0.75-45.89) but was significantly more common among those with category III tracings (0 vs 18.97%; odds ratio, 61.43; 95% confidence interval, 7.49-503.50). Cesarean delivery occurred with similar frequency among those with category I (13.41%) and those with category II tracings (11.92%) (odds ratio, 0.87; 95% confidence interval, 0.72-1.05) but was significantly more common among those with with category III tracings (14.28%) (odds ratio, 3.97; 95% confidence interval, 1.62-9.75). When compared with those with category II tracings, cesarean delivery was more common among those with category III tracings (odds ratio, 4.55; 95% confidence interval, 1.88-11.01).

CONCLUSION

Although the incidence of an Apgar score <7 at 5 minutes and umbilical artery pH <7.00 increased significantly with increasing fetal heart rate tracing category, about 98% of newborns with category II tracings do not have these adverse outcomes. The 3-tiered fetal heart rate tracing interpretation system provides an approximate but imprecise measurement of neonatal prognosis.

Perinatal mortality rate and adverse perinatal outcomes presumably attributable to placental dysfunction in (near) term gestation: A nationwide 5-year cohort study

INTRODUCTION

Placental dysfunction can lead to perinatal hypoxic events including stillbirth. Unless there is overt severe fetal growth restriction, placental dysfunction is frequently not identified in (near) term pregnancy, particularly because fetal size is not necessarily small. This study aimed to evaluate, among (near) term births, the burden of hypoxia-related adverse perinatal outcomes reflected in an association with birth weight centiles as a proxy for placental function.

MATERIAL AND METHOD

A nationwide 5-year cohort of the Dutch national birth registry (PeriNed) including 684,938 singleton pregnancies between 36+0 and 41+6 weeks of gestation. Diabetes, congenital anomalies, chromosomal abnormalities and non-cephalic presentations at delivery were excluded. The main outcome was antenatal mortality rate according to birthweight centiles and gestational age. Secondary outcomes included perinatal hypoxia-related outcomes, including perinatal death and neonatal morbidity, analyzed according to birthweight centiles.

RESULTS

Between 2015 and 2019, 1,074 perinatal deaths (0.16%) occurred in the study population (n = 684,938), of which 727 (0.10%) antenatally. Of all antenatal- and perinatal deaths, 29.4% and 27.9% occurred in birthweights below the 10th centile. The incidence of perinatal hypoxia-related outcomes was highest in fetuses with lowest birthweight centiles (18.0%), falling gradually up to the 50th and 90th centile where the lowest rates of hypoxia-related outcomes (5.4%) were observed.

CONCLUSION

Perinatal hypoxia-related events have the highest incidence in the lowest birthweight centiles but are identifiable throughout the entire spectrum. In fact, the majority of the adverse outcome burden in absolute numbers occurs in the group with a birthweight above the 10th centile. We hypothesize that in most cases these events are attributable to reduced placental function. Additional diagnostic modalities that indicate placental dysfunction at (near) term gestation throughout all birth weight centiles are eagerly wanted.

Vitality in Newborn Farm Animals: Adverse Factors, Physiological Responses, Pharmacological Therapies, and Physical Methods to Increase Neonate Vigor

Vitality is the vigor newborn animals exhibit during the first hours of life. It can be assessed by a numerical score, in which variables, such as heart rate, respiratory rate, mucous membranes' coloration, time the offspring took to stand up, and meconium staining, are monitored. Vitality can be affected by several factors, and therapies are used to increase it. This manuscript aims to review and analyze pharmacological and physical therapies used to increase vitality in newborn farm animals, as well as to understand the factors affecting this vitality, such as hypoxia, depletion of glycogen, birth weight, dystocia, neurodevelopment, hypothermia, and finally, the physiological mechanism to achieve thermostability. It has been concluded that assessing vitality immediately after birth is essential to determine the newborn's health and identify those that need medical intervention to minimize the deleterious effect of intrapartum asphyxia. Vitality assessment should be conducted by trained personnel and adequate equipment. Evaluating vitality could reduce long-term neonatal morbidity and mortality in domestic animals, even if it is sometimes difficult with the current organization of some farms. This review highlights the importance of increasing the number of stock people during the expected days of parturitions to reduce long-term neonatal morbidity and mortality, and thus, improve the farm's performance.

Hazard and cumulative incidence of umbilical cord metabolic acidemia at birth in fetuses experiencing the second stage of labor and pathologic intrapartum fetal heart rate requiring expedited delivery

PURPOSE

The aim of the study was to determine the cause-specific hazard (CSH) and the cumulative incidence function (CIF) for umbilical cord metabolic acidemia at birth (MA; pH < 7.0 and/or BE [Formula: see text] - 12 mmol/L) at delivery in patients experiencing the 2nd stage of labor (2STG), stratified for both FIGO-2015 pathologic intrapartum cardiotocography requiring expedited delivery (CTG_RED) and duration of 2nd stage of labor.

METHODS

3459 pregnancies experiencing the 2nd stage of labor and delivering at the Division of Obstetrics and Prenatal Medicine, IRCCS Sant'Orsola-Malpighi Hospital, Bologna (Italy), were identified between 2018 and 2019. Survival analysis was used to assess CSH and CIF for MA, stratified for FIGO-2015 pathologic CTG and relevant covariates.

RESULTS

FIGO-2015 pathological CTG with expedited operative delivery or urgent cesarean section within 10 or 20 min from diagnosis, respectively occurred in 282/3459 (8.20%). The rate of MA at delivery was 3.32% (115/3459). The spline of CSH for MA showed a direct correlation with the duration of 2STG always presenting higher values and greater slope in the presence of pathologic CTG, with plateau between 60 and 120 min and rapid increase after 120 min. The CIF at 180 min in the 2STG was 2.67% for nonpathological and 10.63% for pathological CTG_RED. Nulliparity, pathological CTG, and meconium-stained amniotic fluid resulted significant predictors of MA in our multivariable model.

CONCLUSION

The risk for MA increases moderately across the 2STG with nonpathological CTG and quadruples with pathological CTG_RED. Adjustment for other predictors of MA including meconium-stained amniotic fluid and nulliparity reveals a significant hazard increase for MA associated with pathologic CTG_RED.

Foetal Intrapartum Compromise at Term: Could COVID-19 Infection Be Involved? A Case Report

The impact of the SARS-CoV-2 infection on pregnancy has been studied and many reports have been published, mainly focussing on complications and in utero transmission with neonatal consequences. Although the effects of other viruses on foetuses are well known, the impact of maternal COVID-19 during pregnancy is not completely understood. We report a case of acute foetal intrapartum hypoxia without other risk factors than maternal COVID-19 disease 2 weeks previous to birth at term. Placental histological changes suggested that the viral infection could have been the culprit for the unfavourable outcome during labour. The neonate was promptly delivered by Caesarean section. Neonatal intensive care was started, including therapeutic hypothermia. The procedure was successful, the evolution of the neonate was favourable, and she was discharged after 10 days. Follow-up at 2 months of life indicated a normal neurological development but a drop in head growth. The case raises the idea that pregnancies with even mild COVID-19 symptoms may represent the cause of neonate compromise in a low-risk pregnancy. An important follow-up in the neonatal period and infancy is required to identify and treat any subsequent conditions. Further long-term studies are necessary to identify a cause–effect relationship between COVID-19 pregnancies and the whole spectrum of neonatal and infant consequences.

Does a physiology-based interpretation of cardiotocography allow to dispense with second-line methods? A cross-sectional online survey

CONTEXT

Second line methods are used to help obstetricians to identify abnormalities that reflect fetal acidosis. Since the use of a new technique of cardiotocography (CTG) interpretation based on the pathophysiology of the fetal period, the use of second-line tests has been questioned.

OBJECTIVE

To evaluate the impact of specific training in CTG physiology-based interpretation on professional attitudes towards the use of second-line methods.

METHODS

This cross-sectional study included 57 French obstetricians divided into two groups: the trained group (obstetricians who had already participated in a training course in physiology-based interpretation of CTG) and the control group. Ten medical records of patients who had abnormal CTG tracings and underwent fetal blood sampling pH measurement during labour were presented to the participants. They were given three choices: use a second-line method, continue labour without using second-line method, or perform a caesarean section. The main outcome measures was the median number of decisions to use second-line method.

RESULTS

Forty participants were included in the trained group and 17 in the control group. The median number of recourses to second-line method was significantly inferior for the trained group (4/10 second-line methods) than for the control group (6/10, p=0.040). Regarding the 4 records for which a caesarean section was the real outcome, the median number of decisions of continuing labour was significantly superior in the trained group than in the control group (p=0.032).

CONCLUSIONS

Participation in a training course in physiology-based interpretation of CTG could be associated with a less frequent use of second-line method at the cost of more frequently continuing labour with the risk compromising fetal and maternal well-being. Additional studies are required to determine whether this change in attitude is safe for the fetal well-being.

Back to the Womb: A Perinatal Perspective on Mammalian Hibernation

AbstractThe idea of putting astronauts into a hibernation-like state during interplanetary spaceflights has sparked new interest in the evolutionary roots of hibernation and torpor. In this context, it should be noted that mammalian fetuses and neonates respond to the environmental challenges in the perinatal period with a number of physiological mechanisms that bear striking similarity to hibernation and torpor. These include three main points: first, prenatal deviation from the overall metabolic size relationship, which adapts the fetus to the low-oxygen conditions in the womb and corresponds to the metabolic reduction during hibernation and estivation; second, intranatal diving bradycardia in response to shortened O₂ supply during birth, comparable to the decrease in heart rate preceding the drop in body temperature upon entry into torpor; and third, postnatal onset of nonshivering thermogenesis in the brown adipose tissue, along with the increase in basal metabolic rate up to the level expected from body size, such as during arousal from hibernation. The appearance of hibernation-like adaptations in the perinatal period suggests that, conversely, hibernation and torpor may be composed of mechanisms shared by all mammals around birth. This hypothesis sheds new light on the origins of hibernation and supports its potential accessibility to nonhibernating species, including humans.

Perinatal brain damage - what the obstetrician needs to know

Perinatal brain damage is still one of the leading contributors to perinatal death and postnatal disability worldwide. However, the term perinatal brain damage encompasses very different aetiological entities that result in an insult to the developing brain and does not differentiate between the onset, cause and severity of this insult. Hypoxic-ischemic encephalopathy (HIE), intraventricular haemorrhage, periventricular leukomalacia and perinatal stroke are often listed as the major aetiologies of perinatal brain damage. They differ by type and timing of injury, neuropathological and imaging findings and their clinical picture. Along the timeline of neurodevelopment in utero, there appears to be a specific "window of vulnerability" for each type of injury, but clinical overlap does exist. In the past, peripartum acute hypoxia was believed to be the major, if not the only, cause of perinatal brain damage, but intrauterine inflammation, prematurity, chronic hypoxia/growth retardation and genetic abnormalities appear to be at least equally important contributors.

Prognostic Value of Cerebroplacental Ratio in Appropriate-for-Gestational-Age Fetuses Before Induction of Labor in Late-Term Pregnancies

PURPOSE

 To evaluate the relationship between cerebroplacental ratio (CPR) and the need for operative delivery due to intrapartum fetal compromise (IFC) and adverse perinatal outcome (APO) in appropriate-for-gestational-age (AGA) late-term pregnancies undergoing induction of labor. The predictive performance of CPR was also assessed.

MATERIALS AND METHODS

 Retrospective study including singleton AGA pregnancies that underwent elective induction of labor between 41 + 0 and 41 + 6 weeks and were delivered before 42 + 0 weeks. IFC was defined as persistent pathological CTG or pathological CTG and fetal scalp pH < 7.20. Operative delivery included instrumental vaginal delivery (IVD) and cesarean section (CS). APO was defined as a composite of umbilical artery pH < 7.20, Apgar score < 7 at 5 minutes, and admission to the neonatal intensive care unit for > 24 hours.

RESULTS

 The study included 314 women with 32 (10 %) IVDs and 49 (16 %) CSs due to IFC and 85 (27 %) APO cases. Fetuses with CPR < 10^th percentile showed a significantly higher rate of operative delivery for IFC (40 % (21/52) vs. 23 % (60/262); p = 0.008) yet not a significantly higher rate of APO (31 % (16/52) vs. 26 % (69/262); p = 0.511). The predictive values of CPR for operative delivery due to IFC and APO showed sensitivities of 26 % and 19 %, specificities of 87 % and 84 %, positive LRs of 2.0 and 1.2, and negative LRs of 0.85 and 0.96, respectively.

CONCLUSION

 Low CPR in AGA late-term pregnancies undergoing elective induction of labor was associated with a higher risk of operative delivery for IFC without increasing the APO rate. However, the predictive value of CPR was poor.

Uterine activity modifies the response of the fetal autonomic nervous system at preterm active labor

Background

The autonomic nervous system of preterm fetuses has a different level of maturity than term fetuses. Thus, their autonomic response to transient hypoxemia caused by uterine contractions in labor may differ. This study aims to compare the behavior of the fetal autonomic response to uterine contractions between preterm and term active labor using a novel time-frequency analysis of fetal heart rate variability (FHRV).

Methods

We performed a case-control study using fetal R-R and uterine activity time series obtained by abdominal electrical recordings from 18 women in active preterm labor (32-36 weeks of gestation) and 19 in active term labor (39-40 weeks of gestation). We analyzed 20 minutes of the fetal R-R time series by applying a Continuous Wavelet Transform (CWT) to obtain frequency (HF, 0.2-1 Hz; LF, 0.05-0.2 Hz) and time-frequency (Flux0, Flux90, and Flux45) domain features. Time domain FHRV features (SDNN, RMSSD, meanNN) were also calculated. In addition, ultra-short FHRV analysis was performed by segmenting the fetal R-R time series according to episodes of the uterine contraction and quiescent periods.

Results

No significant differences between preterm and term labor were found for FHRV features when calculated over 20 minutes. However, we found significant differences when segmenting between uterine contraction and quiescent periods. In the preterm group, the LF, Flux0, and Flux45 were higher during the average contraction episode compared with the average quiescent period (p<0.01), while in term fetuses, vagally mediated FHRV features (HF and RMSSD) were higher during the average contraction episode (p<0.05). The meanNN was lower during the strongest contraction in preterm fetuses compared to their consecutive quiescent period (p=0.008).

Conclusion

The average autonomic response to contractions in preterm fetuses shows sympathetic predominance, while term fetuses respond through parasympathetic activity. Comparison between groups during the strongest contraction showed a diminished fetal autonomic response in the preterm group. Thus, separating contraction and quiescent periods during labor allows for identifying differences in the autonomic nervous system cardiac regulation between preterm and term fetuses.

Placental pathology and neonatal encephalopathy

Neonatal encephalopathy (NE) is an important cause of neonatal morbidity and mortality worldwide; however, there remain gaps in our knowledge about its pathogenesis. The placenta has been implicated in the pathogenesis of this disease but conclusive evidence related to the placental factors that influence it is sparse. This review aims to outline the current knowledge on the role of the placenta with particular attention to its role in NE as a consequence of hypoxia-ischemia. A total of 26 original articles/review papers were used to compile this review. Three themes were identified from these publications: fetal vascular malperfusion including umbilical cord pathology, inflammatory changes in the placenta, and maternal vascular malperfusion including placental weight. These features were identified as being significant in the development of NE. Advancing our understanding of this relationship between placental pathology and NE may facilitate the development of additional antenatal screening to better identify at-risk fetuses. We highlight areas for further research through antenatal screening and placental histology.