Abnormal fetal heart rate tracing patterns in patients with thick meconium staining of the amniotic fluid: association with perinatal outcomes

Correlation of Meconium-Stained Amniotic Fluid and Adverse Pregnancy Outcomes between 37 to 39 and 40 to 42 Weeks of Gestational Age

OBJECTIVE

We aimed at assessing the association between meconium-stained amniotic fluid (MSAF) and adverse maternal and neonatal outcomes in early-term versus late-term pregnancies.

STUDY DESIGN

Early-term pregnancies (37-39 weeks of gestation) presented with MSAF were compared with late-term (40-42 weeks of gestation) pregnancies with MSAF. The groups were compared with respect to background characteristics, maternal outcomes, and neonatal outcomes. The composite neonatal outcome was the primary outcome of the study, and secondary outcomes included maternal and neonatal outcomes.

RESULTS

The early-term group comprised 239 women, compared with 362 women in the late-term group. The primary outcome did not differ between groups. We found a higher prevalence of gestational diabetes (8.37 vs. 3%, p < 0.05), a shorter second stage of labor (45.61 ± 54.67 vs. 65.82 ± 62.99 minutes, p < 0.05), and a longer hospital stay (2.84 ± 2.21 vs. 2.53 ± 1.26 days, p < 0.05) in the early-term group. Other maternal and neonatal characteristics and outcomes were not significantly different between the two groups.

CONCLUSION

In term pregnancies complicated by MSAF, adverse neonatal and maternal delivery outcomes are equivalent, regardless of gestational age, and therefore, any term pregnancy complicated by MSAF should be considered high risk and managed appropriately.

KEY POINTS

· In term pregnancies complicated by MSAF, adverse neonatal and maternal delivery outcomes are equivalent, regardless of gestational age.. · Any term pregnancy complicated by MSAF should be considered high risk and managed appropriately.. · Deliveries presented with MSAF are typically considered to be high risk and require close fetal surveillance by a certified team with resuscitation skills.. · Our study may help to reduce the need for a close fetal surveillance and delivery interventions if MSAF is not identified as a risk factor for adverse outcomes in late-term pregnancies..

Risk factors for a serious adverse outcome in neonates: a retrospective cohort study of vaginal births

OBJECTIVE

To investigate the hypothesis that risk factors in addition to an abnormal fetal heart rate pattern (aFHRp) are independently associated with adverse neonatal outcomes of labour.

DESIGN

Observational prospective cohort study.

SETTING

17 UK maternity units.

SAMPLE

585 291 pregnancies between 1988 and 2000 inclusive.

METHODS

Adjusted odds ratios (OR) with 95% confidence intervals (95% CI) were estimated from multivariable logistic regression.

MAIN OUTCOME MEASURES

Adverse neonatal outcome at term (5-minute Apgar score <7, and a composite measure comprising 5-minute Apgar score <7, resuscitation by intubation and/or perinatal death).

RESULTS

Analysis was based on 302 137 vaginal births at 37-42 weeks inclusive. We found a higher odds of Apgar score at 5 minutes <7 with suspected fetal growth restriction (OR 1.34, 95% CI 1.16-1.53), induction of labour (OR 1.41, 95% CI 1.25-1.58), nulliparity (OR 1.48, 95% CI 1.34-1.63), booking body mass index ≥30 (OR 1.18, 95% CI 1.02-1.37), maternal age <25 (OR 1.23, 95% CI 1.10-1.39), black ethnicity (OR 1.21, 95% CI 1.03-1.43), early-term birth at 37-38 weeks (OR 1.13, 95% CI 1.02-1.25), late-term birth at 41-42 weeks (OR 1.14, 95% CI 1.01-1.28), use of oxytocin (OR 1.27, 95% CI 1.14-1.41), maternal pyrexia (OR 1.87, 95% CI 1.46-2.40), aFHRp and presence of meconium (aFHRp without meconium: OR 2.40, 95% CI 2.15-2.69; meconium without aFHRp: OR 2.20, 195% CI.94-2.49; both aFHRp and meconium: OR 4.26, 95% CI 3.74-4.87). The results were similar when the composite adverse outcome was considered.

CONCLUSIONS

A range of risk factors, including suspicion of fetal growth restriction, maternal pyrexia and presence of meconium, are implicated in poor birth outcomes in addition to aFHRp. Interpretation of the fetal heart rate pattern alone is insufficient as a basis for decisions about escalation and intervention.

Meconium-stained amniotic fluid

Green-stained amniotic fluid, often referred to as meconium-stained amniotic fluid, is present in 5% to 20% of patients in labor and is considered an obstetric hazard. The condition has been attributed to the passage of fetal colonic content (meconium), intraamniotic bleeding with the presence of heme catabolic products, or both. The frequency of green-stained amniotic fluid increases as a function of gestational age, reaching approximately 27% in post-term gestation. Green-stained amniotic fluid during labor has been associated with fetal acidemia (umbilical artery pH <7.00), neonatal respiratory distress, and seizures as well as cerebral palsy. Hypoxia is widely considered a mechanism responsible for fetal defecation and meconium-stained amniotic fluid; however, most fetuses with meconium-stained amniotic fluid do not have fetal acidemia. Intraamniotic infection/inflammation has emerged as an important factor in meconium-stained amniotic fluid in term and preterm gestations, as patients with these conditions have a higher rate of clinical chorioamnionitis and neonatal sepsis. The precise mechanisms linking intraamniotic inflammation to green-stained amniotic fluid have not been determined, but the effects of oxidative stress in heme catabolism have been implicated. Two randomized clinical trials suggest that antibiotic administration decreases the rate of clinical chorioamnionitis in patients with meconium-stained amniotic fluid. A serious complication of meconium-stained amniotic fluid is meconium aspiration syndrome. This condition develops in 5% of cases presenting with meconium-stained amniotic fluid and is a severe complication typical of term newborns. Meconium aspiration syndrome is attributed to the mechanical and chemical effects of aspirated meconium coupled with local and systemic fetal inflammation. Routine naso/oropharyngeal suctioning and tracheal intubation in cases of meconium-stained amniotic fluid have not been shown to be beneficial and are no longer recommended in obstetrical practice. A systematic review of randomized controlled trials suggested that amnioinfusion may decrease the rate of meconium aspiration syndrome. Histologic examination of the fetal membranes for meconium has been invoked in medical legal litigation to time the occurrence of fetal injury. However, inferences have been largely based on the results of in vitro experiments, and extrapolation of such findings to the clinical setting warrants caution. Fetal defecation throughout gestation appears to be a physiologic phenomenon based on ultrasound as well as in observations in animals.

Evaluación integrada del bienestar en un feto apropiado para la edad gestacional (AGA) e insuficiencia placentaria aguda debido a corioamnionitis histológica: Reporte de caso

Introducción. La insuficiencia vascular útero placentaria aguda es una causa de desenlace fetal adverso en fetos con crecimiento adecuado para la edad gestacional. Caso clínico. Paciente de 24 años, con 37 semanas de edad gestacional acude al Instituto Nacional Materno Perinatal de Lima, Perú, por referir escaso sangrado vía vaginal. En la evaluación clínica, se encontró una PA 90/60 mmHg, altura uterina 32 cm, latidos cardiacos fetales en 152. A la evaluación ecográfica, a 1 hora de la admisión se reportó feto de 2902 gramos (percentil 34 Hadlock), un Perfil Biofísico Fetal 6/8 por movimientos corporales disminuidos, Índice de líquido amniótico 11cm, placenta fúndica posterior grado III, IP Doppler de Arteria Cerebral Media 1.18, IP Doppler de la arteria umbilical 0.56, IP ductus venoso 0.26 e Istmo Aórtico con diástole ausente. La prueba estresante a las 3 horas de la admisión fue reportada en 5 puntos con movimientos fetales disminuidos, variabilidad disminuida y aceleraciones ausentes. Se indicó cesárea de emergencia obteniéndose recién nacido masculino de 2846 gr, talla 47.5 cm, Apgar 8 – 9. Se encontró líquido meconial de aspecto sanguinolento oscuro. Al corte de la placenta, se observó parénquima con infartos vellosos: recientes 10% y antiguos 5%. Vellosidades coriales hipoplásicas con espacios intervellosos amplios e infiltrado inflamatorio agudo en corion y amnios, correspondientes a Corioamnionitis aguda y funisitis aguda en el cordón umbilical. Conclusiones. La vigilancia integrada de fetos AEG permiten detectar a fetos en riesgo de desenlace adverso por una insuficiencia placentaria aguda secundaria a corioamnionitis histológica o subclínica.

The Incidence and Outcomes of Late-Term Pregnancy

BACKGROUND

Little is known about the outcomes of late-term pregnancy. In this study, we aim to assess the incidence and adverse prenatal outcomes associated with late-term pregnancy.

METHODS

We retrospectively assessed all singleton pregnant mothers who gave birth at Khalij-e-Fars Hospital in Bandar Abbas, Iran, between January 2020 and 2022. All preterm and post-term deliveries were excluded. Mothers were divided into two groups: late-term mothers (41 0/7-41 6/7 weeks of gestation) and term mothers (37 0/7-40 6/7 weeks of gestation). Demographic factors, obstetric factors, maternal comorbidities, and prenatal outcomes were extracted from the electronic data of each mother. The incidence of late-term births was calculated. The chi-squared test was used to compare differences between the groups. Logistic regression models were used to assess the association of prenatal outcome with late-term pregnancy.

RESULTS

There were 8,888 singleton deliveries during the study period, and 1,269 preterm and post-term pregnancies were ruled out. Of the 7,619 deliveries, 309 (4.1%) were late-term, while 7,310 (95.9%) were term. There were no sociodemographic differences between term and late-term mothers. The late-term group had a higher prevalence of primiparous mothers, and the term group had a higher prevalence of diabetes. Late-term mothers had a higher risk of macrosomia (adjusted odds ratio (aOR): 2.24 (95% confidence interval (CI): 1.34-3.01)), meconium amniotic fluid (aOR: 2.32 (95% CI: 1.59-3.14)), and fetal distress (aOR: 2.38 (95% CI: 1.54-2.79)). When compared to term pregnancy, the risk of low birth weight (LBW) was lower in late-term pregnancy (aOR: 0.69 (95% CI: 0.36-0.81)).

CONCLUSIONS

Late-term pregnancy was found to be more likely to be associated with macrosomia, meconium amniotic fluid, and fetal distress, but serious maternal and neonatal adverse events were comparable to term pregnancy.

Fetal Heart Tracing Patterns and the Outcomes of Newborns With Meconium-Stained Amniotic Fluid

Objective

To determine if the presence of meconium-stained amniotic fluid (MSAF) by itself or in combination with abnormal fetal heart tracing (FHT) (category II and III) is associated with poor neonatal outcomes in full-term newborns.

Design/methods

This is a retrospective cohort study. Cases included singleton and full-term neonates with MSAF. Cases were compared to matched controls (clear amniotic fluids) for the outcomes. SPSS (IBM SPSS Statistics for Windows, Version 22.0, Armonk, NY, USA) and SAS 9.4 (SAS Institute Inc., Cary, NC, USA) were used for data analysis.

Results

From 5512 deliveries, 210 cases (MSAF group) and 210 matched controls were identified. Cases and controls were similar in most maternal characteristics. Abnormal FHT was present in 43.2% of cases compared to 17.6% of controls (p<0.001). Low Apgar scores (<7) at one and five minutes were more common in the MSAF group (p=0.03 and 0.007, respectively). The neonatal intensive care unit (NICU) admission rate was also higher in the MSAF group (p=0.002). However, the mean hospital stay was similar in both groups (p=0.44). Twenty-two (10.5%) cases required resuscitation at birth compared to six (2.9%) controls (p=0.003). After applying the logistic regression model to adjust for the FHT pattern and Apgar scores at one minute, the association of MSAF with resuscitation lost significance. The factors associated with resuscitation requirement at birth were Apgar score at one minute (adjusted odds ratios (aOR) 4.1; 95% CI 2.8-5.1, p<0.001) and abnormal FHTs (aOR, 0.03; 95% CI 0.004-0.257, p=0.001).

Conclusions

Neonates born with MSAF were more likely to have abnormal FHT and require resuscitation at birth. However, after adjusting for confounding factors, abnormal FHT and one-minute Apgar scores were the only variables predictive of resuscitation needs at birth.

Can we improve our ability to interpret category II fetal heart rate tracings using additional clinical parameters?

OBJECTIVES

This study examined predictive factors, in addition to Category II Fetal Herat Rate (FHR) monitoring that might imply fetal acidosis and risk of asphyxia.

METHODS

This retrospective cohort study compared three groups of patients with Category II FHR monitoring indicating need for imminent delivery. Groups were divided based on fetal cord blood pH: pH≤7.0, 7.0<pH<7.2 and pH≥7.2. Demographics, medical history, delivery data and early neonatal outcomes were reviewed.

RESULTS

The cohort included 417 women. Nine (2.2%) had cord pH≤7.0, 105 (25.2%) pH 7.0 to 7.2 and 303 (72.6%) ad pH≥7.2. Background characteristics, pregnancy follow-up and intrauterine fetal evaluation prior to delivery were similar in all groups. As expected, more patients in the low pH group had cesarean section (55.6%), than vaginal delivery or vacuum extraction (p=0.02). Five-minute Apgar scores were similar in all groups.

CONCLUSIONS

This retrospective study did not detect a specific parameter that could help predict the prognosis of fetal acidosis and risk of asphyxia. As we only included patients with a Category II tracing that was worrisome enough to lead to imminent delivery, it is reasonable to believe that this is due to patient selection, meaning that when the Category II FHR results in decision for prompt delivery, there is no added value in additional clinical characteristics. The evaluation should be expanded to all patients with Category II tracing for better interpretation tools for Category II FHR monitors, as well as a larger study population.

Approach to the Connection between Meconium Consistency and Adverse Neonatal Outcomes: A Retrospective Clinical Review and Prospective In Vitro Study

Whether meconium-stained amniotic fluid (MSAF) serves as an indicator of fetal distress is under debate; however, the presence of MSAF concerns both obstetricians and pediatricians because meconium aspiration is a major contributor to neonatal morbidity and mortality, even with appropriate treatment. The present study suggested that thick meconium in infants might be associated with poor outcomes compared with thin meconium based on chart reviews. In addition, cell survival assays following the incubation of various meconium concentrations with monolayers of human epithelial and embryonic lung fibroblast cell lines were consistent with the results obtained from chart reviews. Exposure to meconium resulted in the significant release of nitrite from A549 and HEL299 cells. Medicinal agents, including dexamethasone, L-Nω-nitro-arginine methylester (L-NAME), and NS-398 significantly reduced the meconium-induced release of nitrite. These results support the hypothesis that thick meconium is a risk factor for neonates who require resuscitation, and inflammation appears to serve as the primary mechanism for meconium-associated lung injury. A better understanding of the relationship between nitrite and inflammation could result in the development of promising treatments for meconium aspiration syndrome (MAS).

Interpretation of Fetal Heart Rate Monitoring in the Clinical Context

Use of intrapartum fetal heart rate (FHR) monitoring has had limited success in preventing hypoxic injury to neonates. One of the most common limitations of FHR interpretation is the failure to consider chronic and acute clinical factors that may increase the risk of evolving acidemia. This manuscript reviews common clinical factors that may affect the FHR and should be considered when determining the need for early intervention based on changes in the FHR.

Perinatal characteristics and delivery room management of infants born through MSAF

The immediate delivery room (DR) management of non-vigorous (NV) infants with meconium stained amniotic fluid (MSAF) is controversial. A recent ILCOR suggestion is not to perform routine direct laryngoscopy (DL) with or without tracheal suctioning in NV infants. Our practice is to perform DL and endotracheal (ET) suctioning in targeted NV infants. The study objective was to describe the perinatal characteristics and DR Management of infants born through MSAF and admitted to the neonatal intensive care unit (NICU).

METHODS

Retrospective study evaluating the DR management of infants >35 weeks delivered through MSAF. Data retrieved included fetal heart rate abnormalities (FTHR), presence of thick/thin MSAF, DR management and postnatal course.

RESULTS

118 infants were resuscitated and directly admitted to the NICU, including 58 intubated for meconium, 29 receiving immediate PPV (n = 25) or CPAP (n = 4) and 31 (17%) initially stable developed delayed respiratory symptoms and administered CPAP. Sixty-four (35.2%) infants initially stable in the DR were subsequently admitted to NICU. ET suctioning was performed in 58/182 infants with meconium obtained in 41/58; meconium aspiration syndrome (MAS) was diagnosed in 21 infants. ET suctioning was positive in 10/21 cases. FHRT abnormalities (n = 50) were noted with thick meconium and associated with a 2.8-fold increased risk for meconium below the cords, and 3.1-fold increased risk of MAS.

CONCLUSION

NV infants delivered through thick versus thin meconium were more likely to be intubated with a high yield of recovery. Serious pulmonary morbidity was uncommon. Most respiratory symptomatology were not related to MAS.

Proportion and Associated Factors of Nonreassuring Fetal Heart Rate Patterns in Finote Selam Primary Hospital, North West Ethiopia

Introduction

Nonreassuring fetal heart rate patterns (NRFHRP) suggest fetal conciliation or a deteriorating ability to handle the stress of labor. Nearly half of stillbirths occurring worldwide are due to hypoxia which is primarily manifested by NRFHRP. Hence, this study assessed the proportion and associated factors of NRFHRP in the Finote Selam primary hospital, North West Ethiopia.

Methods

An institution-based retrospective cross-sectional study was conducted from March 1 to April 1, 2019, on 364 charts of mothers who gave birth from January 2017 to January 2018 at the Finote Selam primary hospital. A computer-based simple random sampling technique was used to select charts. A secondary data was collected using a structured questionnaire adapted from different literatures. The data was entered and analyzed using Epi Info version 7 and Statistical Package for the Social Sciences (SPSS) version 23.0. Binary logistic regression was executed, and all explanatory variables with p value < 0.2 were entered into multivariable logistic regressions. Multivariable logistic regression was used to control the effect of confounding variables and to identify factors affecting NRFHRP. Odds ratios with 95% confidence intervals were computed, and statistical significance was declared if p < 0.05.

Result

Out of 364 total deliveries, NRFHRP was detected on 55 (15.1%) fetuses, and the commonest NRFHRP detected was bradycardia 44 (80%). Most NRFHRP (38.18%) occurred on the deceleration phase of labor. There was no identified possible cause for NRFHRP on 34.5% of cases. Referral from nearby health institutions [AOR = 2.832 (95% CI 1.457, 5.503)], primigravida [AOR = 2.722 (95% CI 1.377, 5.381)], augmentation of labor [AOR = 3.664 (95% CI 1.782, 7.534)], and meconium-stained amniotic fluid [AOR = 6.491 (95% CI 3.198, 13.173)] were significantly associated with NRFHRP.

Conclusion

The proportion of NRFHRP is high. Referral from nearby health institutions, primigravida mothers, augmentation of labor, and meconium-stained amniotic fluid were significantly associated with NRFHRP. Implementing a better referral link and close monitoring during follow-up could minimize NHFHRP.

The risk of meconium aspiration syndrome (MAS) increases with gestational age at term

Objective: To examine the risk of meconium aspiration syndrome (MAS) by the week of gestational age in pregnancies with meconium-stained amniotic fluid (MSAF).Methods: This is a retrospective cohort study derived from term pregnancies at a single tertiary institution over an 18-year period. Outcomes analyzed included MAS, acidemia, and Apgar scores. Univariate analysis was performed using chi-square and multivariable logistic regression was used to adjust for potential confounders.Results: A total of 34,303 deliveries ≥37 weeks were included; 23.7% were complicated by MSAF. Of the total study cohort, 272 (0.7%) neonates were diagnosed with MAS; this represented 3% of all deliveries complicated by MSAF. In the presence of MSAF, the risk of MAS increased with gestational age, from 1.3% at 38 weeks to 4.8% at 42 weeks (p < .001). Similarly, the risk of acidemia increased from 3.0% at 38 weeks to 7.0% at 42 weeks (p < .001). These findings were also demonstrated in patients with MAS in the absence of MSAF. The risk for both MAS and acidemia in the presence of MSAF persisted after controlling for potential confounders (aOR 1.31 [95% CI 1.18-1.46] and 1.20 [95% CI 1.05-1.37], respectively).Conclusion: In women with MSAF, as gestational age increases, the risk of meconium aspiration syndrome also increases. Other factors with late-term and post-term pregnancy besides the presence of meconium may contribute to the evolution of MAS.

Risk factors for nonreassuring fetal heart rate tracings after artificial rupture of membranes in spontaneous labor

BACKGROUND

We aimed to characterize factors associated with nonreassuring fetal heart (FHR) tracings after artificial rupture of membranes (AROM), during the active phase of labor.

METHODS

Delivery charts of patients who presented in spontaneous labor, at term, between 2015 and 2016 were reviewed. We identified cases in which AROM was performed during the active stage of labor. We compared deliveries with a normal FHR and those who developed nonreassuring FHR. Nonreassuring FHR was defined as fetal tracing that necessitated intrauterine resuscitation, which included: oxytocin withheld, amnioinfusion, or immediate instrumental or cesarean birth.

RESULTS

Of 664 deliveries, nonreassuring FHR occurred in 141 (21.2%) and normal FHR in 523 (78.7%). Both groups were notable for similar maternal characteristics and a similar gestational age. Epidural block was significantly more common in the nonreassuring FHR group (P < .001), as was meconium during delivery (P = .01). Deliveries in the nonreassuring FHR group were characterized by significantly lower Bishop scores at AROM. Mean birthweight was significantly lower in the nonreassuring FHR group (3201 ± 418 vs 3342 ± 376 g, P < .001), yet, neonatal outcome did not differ between the groups. In a multivariate logistic regression model, nulliparity, AROM at a station lower than -2, and increased birthweight were all significantly associated with a decreased rate of nonreassuring FHR, while prolonged duration from AROM to delivery and oxytocin augmentation significantly increased the risk for nonreassuring FHR.

DISCUSSION

Nonreassuring FHR after AROM during delivery is associated with parity, fetal station at AROM, birthweight, and oxytocin augmentation.

Update on Fetal Monitoring: Overview of Approaches and Management of Category II Tracings

Electronic fetal monitoring (EFM) is widely used to assess fetal status in labor. Use of intrapartum continuous EFM is associated with a lower risk of neonatal seizures but a higher risk of cesarean or operative delivery. Category II fetal heart tracings (FHTs) are indeterminate in their ability to predict fetal acidemia. Certain patterns of decelerations and variability within this category may be predictive of neonatal morbidity. Adjunct tests of fetal well-being can be used during labor to further triage patients. Intrauterine resuscitation techniques should target the suspected etiology of intrapartum fetal hypoxia. Clinical factors play a role in the interpretation of EFM.

Intermittent fetal heart rate monitoring using a fetoscope or hand held Doppler in rural Tanzania: a randomized controlled trial

BACKGROUND

Neonatal mortality is a global challenge, with an estimated 1.3 million intrapartum stillbirths in 2015. The majority of these were found in low resource settings with limited options to intrapartum fetal heart monitoring devices. This trial compared frequency of abnormal fetal heart rate (FHR) detection and adverse perinatal outcomes (i.e. fresh stillbirths, 24-h neonatal deaths, admission to neonatal care unit) among women intermittently assessed by Doppler or fetoscope in a rural low-resource setting.

METHODS

This was an open-label randomized controlled trial conducted at Haydom Lutheran Hospital from March 2013 through August 2015. Inclusion criteria were; women in labor, singleton, cephalic presentation, normal FHR on admission (120-160 beats/minute), and cervical dilatation ≤7 cm. Verbal consent was obtained.

RESULTS

A total of 2684 women were recruited, 1309 in the Doppler and 1375 in the fetoscope arms, respectively. Abnormal FHR was detected in 55 (4.2%) vs 42 (3.1%). (RR = 1.38; 95%CI: 0.93, 2.04) in the Doppler and fetoscope arms, respectively. Bag mask ventilation was performed in 80 (6.1%) vs 82 (6.0%). (RR = 1.03; 95%CI: 0.76, 1.38) of neonates, and adverse perinatal outcome was comparable 32(2.4%) vs 35(2.5%). (RR = 0.9; 95%CI: 0.59, 1.54), in the Doppler and fetoscope arms, respectively.

CONCLUSION

This trial failed to demonstrate a statistically significant difference in the detection of abnormal FHR between intermittently used Doppler and fetoscope and adverse perinatal outcomes. However, FHR measurements were not performed as often as recommended by international guidelines. Conducting a randomized controlled study in rural settings with limited resources is associated with major challenges.

TRIAL REGISTRATION

This clinical trial was registered on April 2013 with registration number NCT01869582 .

Meconium aspiration syndrome: a role for fetal systemic inflammation

BACKGROUND

Meconium aspiration syndrome (MAS) is a leading cause of morbidity and mortality in term infants. Meconium-stained amniotic fluid (MSAF) occurs in approximately 1 of every 7 pregnancies, but only 5% of neonates exposed to MSAF develop MAS. Why some infants exposed to meconium develop MAS while others do not is a fundamental question. Patients with MSAF have a higher frequency of intraamniotic inflammation/infection than those with clear fluid. We propose that fetal systemic inflammation is a risk factor for the development of MAS in patients with MSAF.

OBJECTIVE

We sought to investigate whether intraamniotic inflammation and funisitis, the histopathologic landmark of a fetal inflammatory response, predispose to MAS.

STUDY DESIGN

A prospective cohort study was conducted from 1995 through 2009. Amniotic fluid (AF) samples (n = 1281) were collected at the time of cesarean delivery from women who delivered singleton newborns at term (gestational age ≥38 weeks). Intraamniotic inflammation was diagnosed if the AF concentration of matrix metalloproteinase-8 was >23 ng/mL. Funisitis was diagnosed by histologic examination if inflammation was present in the umbilical cord.

RESULTS

The prevalence of MSAF was 9.2% (118/1281), and 10.2% (12/118) of neonates exposed to MSAF developed MAS. There were no significant differences in the median gestational age or umbilical cord arterial pH at birth between neonates who developed MAS and those who did not (each P > .1). Mothers whose newborns developed MAS had a higher median of AF matrix metalloproteinase-8 (456.8 vs 157.2 ng/mL, P < .05). Newborns exposed to intraamniotic inflammation had a higher rate of MAS than those who were not exposed to intraamniotic inflammation [13.0% (10/77) vs 0% (0/32), P = .03], as did those exposed to funisitis [31.3% (5/16) vs 7.3% (6/82); relative risk, 4.3; 95% confidence interval, 1.5-12.3]. Among the 89 newborns for whom both AF and placental histology were available, MAS was more common in patients with both intraamniotic inflammation and funisitis than in those without intraamniotic inflammation and funisitis [28.6% (4/14) vs 0% (0/28), P = .009], while the rate of MAS did not show a significant difference between patients with intraamniotic inflammation alone (without funisitis) and those without intraamniotic inflammation and funisitis [10.9% (5/46) vs 0% (0/28)].

CONCLUSION

The combination of intraamniotic inflammation with fetal systemic inflammation is an important antecedent of MAS. This concept has implications for the understanding of the mechanisms of disease responsible for MAS and for the development of prognostic models and therapeutic interventions for this disorder.

Should fetal scalp blood sampling be performed in the case of meconium-stained amniotic fluid?

OBJECTIVE

To investigate the effect of using fetal scalp blood sampling on the risk of neonatal respiratory distress syndrome (NRDS) with meconium-stained amniotic fluid (MSAF).

METHODS

Prospective data collection with regard to MSAF during labor for low-risk term cephalic singleton live birth from 2012 to 2014. Maternal, obstetric and neonatal data were compared according to the occurrence of respiratory distress syndrome (RDS group) or not (no RDS group).

RESULTS

Of 515 newborns born through MSAF, 46 experienced RDS and from them 10 experienced meconium aspiration syndrome. No difference was observed according to maternal characteristic, abnormal fetal heart rate tracing pattern irrespective of its category and cesarean rate. Apgar at one minute was lower in the group RDS (7.6 versus 8.5, p < 0.05). The mean umbilical artery pH values did not differ between the two groups. Significant difference between newborns with and without RDS in terms of fetal scalp lactate sampling during the labor (71.1% versus 55.1%, p < 0.05), and neonatal care unit (NCU) admissions (22.8% versus 10.8%, p < 0.05). Secondary rather than primary meconium was associated with RDS when performing fetal scalp blood assessment (p < 0.05). A significant correlation between RDS, fetal scalp blood assessment and MSAF diagnosed during the first stage of labor (after spontaneous rupture of membranes or at amniotomy) was found.

CONCLUSION

In case of MSAF, fetal scalp blood sampling did not reduce the risk of RDS.

Interpreting category II fetal heart rate tracings: does meconium matter?

OBJECTIVE

Category II fetal heart rate (FHR) tracings are considered indeterminate; thus, improved risk stratification of category II FHR tracings is needed. We estimated whether the presence of meconium increased the risk of adverse neonatal outcomes.

STUDY DESIGN

This study was conducted within a prospective cohort of 5000 women with singleton pregnancies who were admitted in labor at term. Pregnancies with category II FHR in the 60 minutes before delivery were included. FHR data were extracted by trained nurses who were blinded to clinical outcome. The exposure was the presence of meconium. The primary outcome was a composite neonatal morbidity defined as ≥1 of the following: neonatal death, neurologic morbidity, respiratory morbidity, hypotension that required treatment, and sepsis. Secondary outcomes were nursery admission, cord pH, 5-minute Apgar score, and components of the composite. Logistic regression was used to adjust for confounders.

RESULTS

Of the 3257 women with category II FHR tracings, 693 women (21.3%) had meconium, and 2564 women (78.7%) did not. Meconium was associated with higher risk of the composite morbidity (adjusted odds ratio, 2.49; 95% confidence interval, 1.78-3.48) and increased risks of the secondary outcomes. The associations remained significant when infants with meconium aspiration syndrome were excluded. Thick meconium was associated significantly with the composite morbidity.

CONCLUSION

The presence of meconium is associated with an increased risk of neonatal morbidity in women with category II FHR pattern. This clinical factor may assist clinicians in managing category II FHR patterns in labor.

Opinions of maternity care professionals about integration of care during labor for "moderate risk" indications: a Delphi study in the Netherlands

BACKGROUND

The percentage of referrals during labor from primary midwife-led care to obstetrician-led care has increased over the past years in The Netherlands. Most women are referred for indications with a moderate increase in risk and are looked after by clinical midwives. This study aims to provide insight into the opinions of maternity care professionals about integration of care and involvement of primary care midwives in the intrapartum care of women with "moderate risk" factors.

METHODS

A Delphi study consisting of three rounds was conducted. A purposively selected heterogenic panel of 50 professionals, including obstetricians, primary care midwives, clinical midwives, and obstetric nurses, answered questions anonymously.

RESULTS

Although primary care midwives would like to expand their responsibilities and tasks with respect to "moderate risk" indications, consensus among panel members was only reached concerning prolonged rupture of membranes for which the primary care midwife could remain the caregiver.

CONCLUSION

This study shows that most participants support more integration of care during labor. The lack of consensus among Dutch maternity care professionals with regard to the distribution of responsibilities and tasks for "moderate risk" indications is a challenge. Further studies should explore how to deal with differences in opinions among professionals when integrating maternity care systems.

Association between hypoxia and perinatal arterial ischemic stroke: a meta-analysis

BACKGROUND

Perinatal arterial ischemic stroke (AIS) occurs in an estimated 17 to 93 per 100000 live births, yet the etiology is poorly understood. Although investigators have implicated hypoxia as a potential cause of AIS, the role of hypoxia in AIS remains controversial. The aim of this study was to estimate the association between perinatal hypoxia factors and perinatal arterial ischemic stroke through a meta-analysis of published observational studies.

PATIENTS AND METHODS

A systematic search of electronically available studies published through July 2013 was conducted. Publication bias and heterogeneity across studies were evaluated and summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with fixed-effects or random-effects models.

RESULTS

A total of 8 studies describing the association between perinatal hypoxia factors and neonatal arterial ischemic stroke (AIS) met inclusion criteria, and 550 newborns with AIS were enrolled. The associations were found for AIS: preeclampsia (OR 2.14; 95% CI, 1.25 to 3.66), ventouse delivery (OR 2.23; 95% CI, 1.26 to 3.97), fetal heart rate abnormalities (OR 6.30; 95% CI, 3.84 to 10.34), reduced fetal movement (OR 5.35; 95% CI, 2.17 to 13.23), meconium-stained liquor (OR 3.05; 95% CI, 2.02 to 4.60), low Apgar score (OR 5.77; 95% CI, 1.66 to 20.04) and resuscitation at birth (OR 4.59; 95% CI, 3.23 to 6.52). Our data did not show any significant change of the mean risk estimate for oxytocin induction (OR 1.33; 95% CI, 0.84 to 2.11) and low arterial umbilical cord ph (OR 4.63; 95% CI 2.14 to 9.98).

CONCLUSIONS

There is a significant association between perinatal hypoxia factors and AIS. The result indicates that perinatal hypoxia maybe one of causes of AIS. Large scale prospective clinical studies are still warranted.

New onset of meconium during labor versus primary meconium-stained amniotic fluid - is there a difference in pregnancy outcome?

OBJECTIVE

To compare pregnancy outcome between deliveries complicated by new onset of meconium during labor following prior evidence of clear amniotic fluid and labors in which meconium was present to begin with.

METHODS

A retrospective cohort study of all singleton term (≥37 + 0 weeks) deliveries complicated by intrapartum meconium-stained amniotic fluid in a tertiary referral medical center during the year 2012. Outcome was compared between deliveries with new onset of meconium during labor following prior evidence of clear amniotic fluid (secondary meconium group) and those in which meconium was already evident at the time of membranes rupture (primary meconium group).

RESULTS

Of the 9167 deliveries during the study period, 694 were eligible for the study group. Of these, 537 were complicated by primary meconium and 157 by secondary meconium. Only secondary meconium, but not primary meconium, was independently associated with an increased risk of operative vaginal delivery (OVD) and adverse neonatal outcome. Pregnancies complicated by secondary meconium were independently associated with a higher rate of OVD (28.0% versus 11.4%, p < 0.001), POP position of the fetal head (6.4% versus 2.6%, p = 0.02), and adverse neonatal outcome (17.2% versus 8.9%, p = 0.003).

CONCLUSION

Secondary meconium is associated with a higher rate of adverse obstetrical and neonatal outcome compared with primary meconium.

Electronic fetal monitoring in the United States: temporal trends and adverse perinatal outcomes

OBJECTIVE

To examine trends in electronic fetal monitoring (EFM) use and quantify the extent to which such trends are associated with changes in rates of primary cesarean delivery and neonatal morbidity and mortality.

METHODS

We carried out a retrospective study of more than 55 million nonanomalous singleton live births (24-44 weeks of gestation) delivered in the United States between 1990 and 2004. Changes in the risks of neonatal mortality, cesarean delivery, and operative vaginal delivery for fetal distress, 5-minute Apgar score lower than 4, and neonatal seizures (at 34 weeks of gestation or after) were examined in relation to changes in EFM use.

RESULTS

Electronic fetal monitoring use increased from 73.4% in 1990 to 85.7% in 2004, a relative increase of 17% (95% confidence interval 16-18%). This increase was associated with an additional 5% and 2% decline in early and late neonatal deaths, respectively, at 24-33 weeks of gestation as well as a 4-7% additional decline in the 5-minute Apgar score lower than 4 at 24-33, 34-36, and 37-44 weeks of gestation. Increasing EFM use was associated with a 2-4% incremental increased rate of both cesarean delivery and operative vaginal delivery for fetal distress at 24-33, 34-36, and 37-44 weeks of gestation. Increasing EFM was not associated with any temporal changes in the rate of neonatal seizures.

CONCLUSIONS

The temporal increase in EFM use in the United States appears to be modestly associated with the recent declines in neonatal mortality, especially at preterm gestations.

LEVEL OF EVIDENCE

II.

A Population-Based Study of Meconium Aspiration Syndrome in Neonates Born between 37 and 43 Weeks of Gestation

The epidemiology of meconium aspiration syndrome (MAS) in term neonates is described in a population-based retrospective study of data recorded for all births from 2000 to 2007 in a French region (Burgundy). Of the 132 884 eligible term newborns, the rate of meconium-stained amniotic fluid (MSAF) was 7.93%. The prevalence of severe MAS was 0.067% in the overall population. MAS rate was 0.11% at 37-38 weeks of gestation (WG), 0.20% at 39–41 WG, and 0.49% at 42-43 WG. Factors independently associated with severe MAS were identified by a case-control study, that is, thick meconium amniotic fluid, fetal tachycardia, Apgar score ≤3 at 1 minute, and birth in a level III facility. Our results confirm the high prevalence of MSAF after 37 WG but also show the low frequency of severe MAS in a period corresponding to the new international recommendations on the management of birth with MSAF.

Electronic fetal heart rate monitoring and its relationship to neonatal and infant mortality in the United States

OBJECTIVE

To examine the association between electronic fetal heart rate monitoring and neonatal and infant mortality, as well as neonatal morbidity.

STUDY DESIGN

We used the United States 2004 linked birth and infant death data. Multivariable log-binomial regression models were fitted to estimate risk ratio for association between electronic fetal heart rate monitoring and mortality, while adjusting for potential confounders.

RESULTS

In 2004, 89% of singleton pregnancies had electronic fetal heart rate monitoring. Electronic fetal heart rate monitoring was associated with significantly lower infant mortality (adjusted relative risk, 0.75); this was mainly driven by the lower risk of early neonatal mortality (adjusted relative risk, 0.50). In low-risk pregnancies, electronic fetal heart rate monitoring was associated with decreased risk for Apgar scores <4 at 5 minutes (relative risk, 0.54); in high-risk pregnancies, with decreased risk of neonatal seizures (relative risk, 0.65).

CONCLUSION

In the United States, the use of electronic fetal heart rate monitoring was associated with a substantial decrease in early neonatal mortality and morbidity that lowered infant mortality.

Refusal of emergency caesarean delivery in cases of non-reassuring fetal heart rate is an independent risk factor for perinatal mortality

OBJECTIVE

To assess pregnancy outcome in women who initially refused medically indicated caesarean delivery (CD) in cases of non-reassuring fetal heart rate (FHR) patterns.

STUDY DESIGN

A retrospective cohort study, comparing patients who refused and did not refuse caesarean delivery (CD) due to non-reassuring FHR tracings, was conducted. Deliveries occurred between the years 1988 and 2009 in a tertiary medical center. Multivariate analysis was performed to control for confounders.

RESULTS

Out of 10,944 women who were advised to undergo CD due to non-reassuring FHR patterns, 203 women initially refused CD. Women refusing medical intervention tended to be older (30.6 ± 6.9 vs. 28.29 ± 6.1, P<0.001) and of higher parity (46.8% vs. 19.9% had more than 5 deliveries; P<0.001) as compared to the comparison group. Refusal of CD was significantly associated with adverse perinatal outcome. Using a multiple logistic regression model controlling for confounders such as maternal age, refusal of treatment was found as an independent risk factor for perinatal mortality (adjusted OR=3.3, C.I. 95% 1.8-5.9, P<0.001). A non-significant trend towards higher rates of adverse perinatal outcome was found when refusal latency time was longer than 20 min (OR=2, 95% CI 0.36-11.95; P=0.29).

CONCLUSION

Refusal of CD in cases of non-reassuring FHR tracings is an independent risk factor for perinatal mortality.