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

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.

Should we restrict food intake during labor? A randomized controlled trial

PURPOSE

To evaluate whether consuming food during labor influences its outcomes.

METHODS

This randomized controlled study included healthy, laboring patients at 37-41 weeks of gestation. After epidural anesthesia, patients were randomized into groups of eating at will versus drinking clear fluids only. The primary composite outcome included unplanned cesarean delivery, the need for general anesthesia, asphyxia, postpartum fever, and prolonged postpartum admission (more than 5 days). Secondary outcomes included the need for oxytocin, length of the second stage of labor, postpartum analgesia requirements, and early maternal and neonatal outcomes. Sample size analysis indicated that 126 patients needed to be randomized to detect a statistically significance difference between the groups.

RESULTS

A total of 129 patients were randomized: 58 to the fluids-only group and 71 to the food group. The groups had similar basic characteristics. The composite outcome of complications attributed to eating during labor and delivery was comparable between groups. Labor progression and the need for oxytocin augmentation were similar in both groups. The groups had comparable fetal heart rate tracings, modes of delivery, maternal and neonatal outcomes, and complications. None of the patients in the study experienced aspiration or an indication for general anesthesia.

CONCLUSION

While our data suggest that eating during labor does not adversely affect labor progression or outcomes, we recommend a cautious approach, allowing patients autonomy while considering individual risk factors.

TRIAL REGISTRATION

The study has been registered in the primary clinical trial registry on 02/12/2023. ISRCTN trial number ISRCTN11794106, registration number 44513. https://www.isrctn.com/ISRCTN11794106 .

Effect of type III female genital mutilation on obstetric outcomes: A systematic review and meta-analysis

Background

Controversial evidence suggests a potential association between female genital mutilation (FGM/C) and adverse obstetric outcomes, with type III FGM/C (infibulation) carrying the greatest risk. The aim of this systematic review and meta-analysis was to assess current rate of adverse obstetric outcomes in women with type III female genital mutilation and cutting (FGM/C; infibulation) delivering across different settings worldwide.

Methods

We searched PubMed, Scopus, Embase, and ClinicalTrials.gov databases from inception to Jan 1, 2023. Studies were selected if they included the main outcome of postpartum haemorrhage (PPH) or secondary outcomes, which included major conditions affecting maternal-neonatal health during labour and delivery. DerSimonian-Laird random effects meta-analysis including pooled effect estimates with corresponding 95 % confidence intervals was performed. Heterogeneity was assessed using the I2 statistic. Meta regression for relevant covariates was performed when data on relevant confounders were available. The Newcastle-Ottawa scale (NOS) was used to assess quality of observational studies. The level of evidence was assessed with the GRADE method.

Results

14 observational studies including 15,320 type III FGM/C women and 59,347 controls were eligible. The risk for postpartum haemorrhage was significantly increased in type III FGM/C, in the main analysis (OR 1.83, 95 % CI 1.03 to 3.24, I2 = 93 %), in pooling of data adjusted for confounders (aOR 1.76, CI 1.42 to 2.17, I2 = 0 %), and in sensitivity analysis of higher quality studies with NOS≥7 (OR 2.76, CI 1.38 to 5.51, I2 = 95 %). Meta-regression showed that nulliparity was significantly and positively associated with postpartum haemorrhage. Similarly, analysis of data adjusted for confounders showed an increased risk of episiotomy in type III FGM/C (aOR 1.56, CI 1.03 to 2.35, I2 = 52 %). Sensitivity analysis of studies with NOS≥7 revealed a significant increase for episiotomy (OR 7.53, CI 1.19 to 47.54, I2 = 96 %), perineal tears (OR 4.24, CI 1.09 to 16.46, I2 = 66 %), prolonged second stage of labour (OR 5.19, 95 % CI 1.00 to 26.85, I2 = 66 %), and Apgar score less than 7 (OR 4.19, CI 1.64 to 10.70, I2 = 0 %). No difference was found regarding obstetric anal sphincter injuries and mode of delivery in these women. Deinfibulation achieved similar obstetric and neonatal outcomes to women who never had type III FGM. The overall quality of the studies was adequate (median NOS score: 7; IQR: 6-8), the level of evidence, according to the GRADE assessment, was low.

Conclusions

These results consistently show an increased risk of adverse obstetric outcomes in women with FGM/C type III. Infibulation substantially increases the risk for PPH, particularly in nulliparae. Systematic Review registration: PROSPERO CRD42023421993.

Clinical analysis of incomplete rupture of the uterus secondary to previous cesarean section

Uterine rupture is a rupture of the body or lower part of the uterus during pregnancy or delivery. Total of 98 cases with incomplete uterine rupture were classified as the incomplete uterine rupture group, 100 cases with a history of cesarean delivery without uterine rupture were classified as the non-ruptured uterus group, and controls were selected using a systematic sampling method. The maternal age ≥35 years were associated with 2.18 times higher odds of having an incomplete uterine rupture. The odd of having an incomplete uterine rupture was 3.744 times higher for a woman with delivery interval ≤36 months. Having pregnancy complication was associated with 3.961 times higher odds of having an incomplete uterine rupture. The neonatal weight was lighter in the incomplete uterine rupture group (P = 0.007). The number of preterm birth and transfer to the NICU were higher in the incomplete uterine rupture group (P ＜ 0.01). The operation time and the length of time in hospital were longer in the group with incomplete uterine rupture (P ＜ 0.01). Age ≥35 years, delivery interval ≤36 month, and pregnancy with complication were independent risk factors of incomplete rupture of the uterus secondary to previous cesarean section.

Does maternal oxygen administration during non-reassuring fetal status affect the umbilical artery gas measures and neonatal outcomes?

PURPOSE

To clarify whether maternal oxygen administration during vaginal delivery improves umbilical artery (UA) gas measurements and neonatal outcomes.

METHODS

Singleton pregnancies requiring operative vaginal delivery or emergency cesarean section (CS) due to non-reassuring fetal status (NRFS) during vaginal delivery at our hospital from 2018 to 2021 were retrospectively investigated. Intrapartum fetal wellbeing was evaluated based on the 5-tier fetal heart rate (FHR) pattern which is a delivery management method widely used in Japan. Operative vaginal deliveries or emergency CS was performed under integrated judgment in NRFS. Patients were divided into the oxygen group to whom oxygen (10 L/min) was supplied by a facemask and the room air group. The UA gas measurements and neonatal outcomes were compared. The oxygen administration was classified by conditions before and after the coronavirus disease 2019 pandemic. As a secondary evaluation, stratification of FHR pattern levels and factors associated with UA pH < 7.15 were examined.

RESULTS

A total of 250 patients required obstetric surgical delivery due to NRFS, including 140 (56%) and 110 (44%) in the oxygen and room air groups, respectively. No differences in maternal background factors were found between both groups, except for maternal age. UA gas measurements and neonatal outcomes also showed no significant differences. No significant factors were extracted in the multivariate analysis for UA pH < 7.15.

CONCLUSIONS

Trans-maternal oxygen administration for intrapartum NRFS did not affect neonatal cord blood gasses or neonatal outcomes. Thus, routine oxygen administration for intrapartum NRFS may not always be necessary.

Does intrapartum epidural analgesia influence rate of emergency delivery for fetal compromise?

Linked articles: This Editorial comments on Damhuis et al. and Tabernée Heijtmeijer et al.

Diagnostic accuracy of pre-induction cervical elastography, volume, length, and uterocervical angle for the prediction of successful induction of labor with dinoprostone

PURPOSE

The study's aim is to define among a group of ultrasonographic cervical measurements a candidate parameter predictive of successful of induction of labor in term pregnancies with unfavorable cervix.

METHODS

This prospective observational study included 141 pregnant women at term with an unfavorable cervix (Bishop score ≤ 6). All patients underwent clinical and ultrasonographic cervical evaluation before dinoprostone induction. Pre-induction cervical assessments included the Bishop score, cervical length, cervical volume, uterocervical angle, and cervical elastographic parameters. Vaginal delivery (VD) was accepted as successful dinoprostone induction. Multivariate logistic regression was conducted to identify the potential risk factors significantly associated with CS while controlling for possible confounding variables.

RESULTS

The vaginal delivery rate was 74% (n = 93) and the cesarean section (CS) rate was 26% (n = 32). Sixteen patients who had a cesarean section due to fetal distress before the active phase of labor were excluded from the study. The mean induction-to-delivery interval was 1176.1 ± 352 (540-2150) for VD and 1359.4 ± 318.4 (780-2020) for CS (p = 0.01). Bishop score was lower in women with cesarean section (p = 0.002). When both groups were compared in terms of delivery type, no difference was found between cervical elastography values, cervical volume, cervical length, and uterocervical angle measurements. Multivariable logistic regression model failed to show significant differences between cervical elastography values, cervical volume, cervical length, and uterocervical angle measurements.

CONCLUSION

Cervical length, cervical elastography, cervical volume, and uterocervical angle measurements did not provide a clinically useful prediction of outcomes following labor induction in our study group with unfavorable cervix. Cervical length measurements significantly predicted the time interval from induction to delivery.

Accuracy of intrapartum cardiotocography in identifying fetal acidemia by umbilical cord blood analysis in low-risk pregnancies

OBJECTIVE

The aim of this study was to evaluate the accuracy of intrapartum cardiotocography in identifying fetal acidemia by umbilical cord blood analysis in low-risk pregnancies.

METHODS

This is a retrospective cohort study of low-risk singleton pregnancies in labor after performing intrapartum cardiotocography categories I, II, and III. The presence of fetal acidemia at birth was identified by analyzing the pH of umbilical cord arterial blood (pH<7.1).

RESULTS

No significant effect of the cardiotocography category on the arterial (p=0.543) and venous (p=0.770) pH of umbilical cord blood was observed. No significant association was observed between the cardiotocography category and the presence of fetal acidemia (p=0.706), 1-min Apgar score <7 (p=0.260), hospitalization in the neonatal intensive care unit (p=0.605), newborn death within the first 48 h, need for neonatal resuscitation (p=0.637), and adverse perinatal outcomes (p=0.373). Sensitivities of 62, 31, and 6.0%; positive predictive values of 11.0, 16.0, and 10.0%; and negative predictive values of 85, 89.0, and 87.0% were observed for cardiotocography categories I, II, and III, respectively.

CONCLUSION

The three categories of intrapartum cardiotocography presented low sensitivities and high negative predictive values to identify fetal acidemia at birth in low-risk pregnancies.

The incidence and risk factors of meconium amniotic fluid in singleton pregnancies: an experience of a tertiary hospital in Iran

BACKGROUND

Several common maternal or neonatal risk factors have been linked to meconium amniotic fluid (MAF) development; however, the results are contradictory, depending on the study. This study aimed to assess the prevalence and risk factors of MAF in singleton pregnancies.

METHODS

This study is a retrospective cohort that assessed singleton pregnant mothers who gave birth at a tertiary hospital in Bandar Abbas, Iran, between January 1st, 2020, and January 1st, 2022. Mothers were divided into two groups: 1) those diagnosed with meconium amniotic fluid (MAF) and 2) those diagnosed with clear amniotic fluid. Mothers with bloody amniotic fluid were excluded. Demographic factors, obstetrical factors, and maternal comorbidities were extracted from the electronic data of each mother. The Chi-square test was used to compare differences between the groups for categorical variables. Logistic regression models were used to assess meconium amniotic fluid risk factors.

RESULTS

Of 8888 singleton deliveries during the study period, 1085 (12.2%) were MAF. MAF was more common in adolescents, mothers with postterm pregnancy, and primiparous mothers, and it was less common in mothers with GDM and overt diabetes. The odds of having MAF in adolescents were three times higher than those in mothers 20-34 years old (aOR: 3.07, 95% CI: 1.87-4.98). Likewise, there were significantly increased odds of MAF in mothers with late-term pregnancy (aOR: 5.12, 95% CI: 2.76-8.94), and mothers with post-term pregnancy (aOR: 7.09, 95% CI: 3.92-9.80). Primiparous women were also more likely than multiparous mothers to have MAF (aOR: 3.41, 95% CI: 2.11-4.99).

CONCLUSIONS

Adolescents, primiparous mothers, and mothers with post-term pregnancies had a higher risk of MAF. Maternal comorbidities resulting in early termination of pregnancy can reduce the incidence of MAF.