Labor induction at 41+0 gestational weeks or expectant management for the nulliparous woman: The Finnish randomized controlled multicenter trial

INTRODUCTION

Neonatal and maternal risks increase in term pregnancy as gestational age advances and become increasingly evident post-term. Management practices of late- and post-term pregnancies vary, and the optimal time point for intervention by labor induction is yet to be determined.

MATERIAL AND METHODS

This randomized controlled trial of 381 nulliparous women with unripe cervices compared labor induction at 41+0 gestational weeks (early induction) with expectant management and labor induction at 41+5 to 42+1 gestational weeks (expectant management). This multicenter study included all five university hospitals and the largest central hospital in Finland. The study period was 2018-2022. Participants were randomized to either early induction (48.8%, n = 186) or expectant management (51.2%, n = 195) with equal randomization ratios of 1:1. This was a superiority trial, and the primary outcomes were rates of cesarean section (CS) and composite of adverse neonatal outcomes. The trial was registered at the ISRCTN registry (ISRCTN83219789, https://doi.org/10.1186/ISRCTN83219789).

RESULTS

The rates of CS (16.7% [n = 31] vs. 24.1% [n = 47], RR 0.7 [95% CI: 0.5-1.0], p = 0.07) and a composite of adverse neonatal outcomes (9.7% [n = 18] vs. 14.4% [n = 28], RR 0.7 [95% CI: 0.4-1.2] p = 0.16) did not significantly differ between the groups, but the operative delivery rate was lower in the early induction group than in the expectant management group (30.6% [n = 57] vs. 45.6% [n = 89], p = 0.003). The rates of hemorrhage ≥1000 mL and neonatal weight ≥4000 g were also lower in the early induction group, as was the vacuum extraction rate in women with vaginal delivery. Of the women with expectant management, 45.6% (n = 89) had spontaneous onset of labor. No perinatal deaths occurred, but one case of eclampsia appeared in the expectant management group.

CONCLUSIONS

Offering labor induction to nulliparous women at 41+0 gestational weeks may decrease the probability of operative delivery, postpartum hemorrhage, and neonatal weight ≥4000 g. However, this study was underpowered to affirm the trends of rising rates of CS and adverse neonatal outcomes in the expectant management group. Thus, expectant management could remain an option for some, as one in two women with expectant management had a spontaneous onset of labor.

Quantitative cervicovaginal fetal fibronectin as a predictor of cervical ripening and induced labour duration in late-term pregnancy

We evaluated quantitative cervicovaginal foetal-fibronectin as a predictor of cervical ripening and labour duration in late-term pregnant women with an unfavourable cervix. This was an analytical cross-sectional study wherein 152 women, with late-term pregnancy and unfavourable cervix, at 41weeks3days gestational age, had pre-induction quantitative cervicovaginal foetal-fibronectin determined using ELISA. Data were compared in nulliparas and multiparas at a significance level < 0.05. The mean age of late-term pregnant women was 30.4 ± 4.3 years. Median cervicovaginal foetal-fibronectin levels in nulliparous and multiparous women were 45.35 ng/ml and 46.93 ng/ml respectively(p = 0.289). The correlation between foetal-fibronectin levels and cervical ripening duration was poor in nulliparous(r = 0.014) and multiparous(r = 0.024) women. The Youden's foetal-fibronectin cut-off level had a sensitivity of 53.5% and specificity of 71.6% in predicting cervical ripening duration of > 12 hours in late-term pregnancy with an area under the ROC curve of 0.634. Quantitative cervicovaginal foetal-fibronectin is a poor correlate and predictor of cervical ripening and induced labour duration in late-term pregnancy.IMPACT STATEMENTWhat is already known on this subject? Cervicovaginal foetal fibronectin is useful in the prediction of preterm delivery but its role in prolonged pregnancy is unclear.What the results of this study add? Cervicovaginal foetal fibronectin is a poor correlate and predictor of cervical ripening and induced labour duration in late-term pregnancyWhat the implications are of these findings for clinical practice and/or further research? Cervicovaginal fibronectin should not be used to predict ease and success of cervical ripening and induction of labour in women with late-term pregnancy.

A Retrospective Comparative Study of the Effect of Controlled-Release Dinoprostone Vaginal Delivery System (Propess®) and Mechanical Methods for Cervical Ripening in Nulliparous Women in Late-Term Pregnancy

OBJECTIVE

The effects of the controlled-release dinoprostone vaginal delivery system (Propess®) and mechanical methods for cervical ripening in nulliparous women in late-term pregnancy were compared retrospectively.

METHODS

This retrospective comparative study included 46 nulliparous pregnant women (24 in the Propess® group and 22 in the mechanical methods groups) with a low Bishop score (≤1) who needed labor induction at 41 weeks of gestation. The primary outcome was the success rate of cervical ripening (= Bishop score >6 or vaginal delivery) by the next day following the insertion of Propess® only or mechanical cervical dilation only. In the cases in which cervical ripening was unsuccessful, other methods were performed, and the success rate of cervical ripening the day after was compared as the secondary outcome.

RESULTS

As the primary outcome, there was not a significant difference in the success rate of cervical ripening between the Propess® and mechanical methods groups (21 vs. 22%, p = 0.88). As for the secondary outcomes, there was not a significant difference in the total success rate of cervical ripening between the two groups (75 (5+13/24) vs. 73 (5+11/22)%, p = 0.86)). Of the unsuccessful cervical ripening cases as secondary outcomes, the Bishop score of all was ≤2 on the second day of hospitalization.

CONCLUSION

The combined use of Propess® and mechanical methods was effective for cervical ripening in nulliparous women with a low Bishop score in late-term pregnancy, regardless of order.

Predictive Value of Cervical Shear Wave Elastography in the Induction of Labor in Late-Term Pregnancy Nulliparous Women: Preliminary Results

The prediction of induction of labor continues to be a paradigm nowadays. Bishop Score is the traditional widely spread method but with a low reliability. Ultrasound cervical assessment has been proposed as an instrument of measurement. Shear wave elastography (SWE) should be a promising tool in the prediction of the success of labor induction in nulliparous late-term pregnancies. Ninety-two women with nulliparous late-term pregnancies who were going to be induced were included in the study. A shear wave measurement of the cervix divided into six regions (inner, middle and outer in both cervical lips), cervical length and fetal biometry was performed by blinded investigators prior to routine hand cervical assessment (Bishop Score (BS)) and induction of labor. The primary outcome was success of induction. Sixty-three women achieved labor. Nine women did not, and they underwent a cesarean section due to failure to induce labor. SWE was significantly higher in the inner part of the posterior cervix (p < 0.0001). SWE showed an area under the curve (AUC): 0.809 (0.677-0.941) in the inner posterior part. For CL, AUC was 0.816 (0.692-0.984). BS AUC was 0.467 (0.283-0.651). The ICC of inter-observer reproducibility was ≥0.83 in each region of interest (ROI). The cervix elastic gradient seems to be confirmed. The inner part of the posterior cervical lip is the most reliable region to predict induction of labor results in SWE terms. In addition, cervical length seems to be one of the most important procedures in the prediction of induction. Both methods combined could replace the Bishop Score.

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.

The effect of gestational diabetes mellitus on fetal right heart growth in late-term pregnancy: A prospective study

BACKGROUND

Gestational diabetes mellitus (GDM) is a complication of pregnancy strongly associated with an increased risk of structural fetal abnormalities. As the fetal heart grows quickly during the late-term pregnancy period, it is important to understand fetal heart growth before birth. This study explored how GDM affects fetal heart growth by evaluating basic echocardiography indicators during late pregnancy.

METHODS

This prospective, longitudinal study included 63 GDM patients (GDM group) and 67 healthy pregnant women (control group). All subjects underwent fetal echocardiography scans at gestational weeks 28-32, 32-36, and 36-40. Twelve echocardiographic indicators were assessed at each observation and analyzed by using a mixed model.

RESULTS

The left atrial diameter (LA) and left ventricular end-diastolic diameter (LV) similarly increased from the first to the third observation. The right ventricular end-diastolic diameter (RV) was significantly different between the groups, and a group × time interaction was detected. The tricuspid annular peak systolic velocity (s') increased more rapidly in the GDM than the control group during the first to second observations, and the group × time interaction was significant. The increase in the tricuspid annular plane systolic excursion (TAPSE) of the GDM group was "slow-fast", while that of the control group was "fast-slow", during three observations. After adjusting covariates, the group difference and interaction effect of TAPSE and RV remained significant.

CONCLUSIONS

The differences in fetal right heart indicators between the GDM and control groups suggest that GDM may affect the structure and functional growth of the fetal right heart during late-term pregnancy.

The value of measuring cervical length between 24 and 28 weeks of gestation for predicting the risk of late and post-term pregnancy

OBJECTIVE

The aim of this study was to investigate the value of measuring cervical length (CL) between 24 and 28 weeks of gestation for predicting the risk of late and post-term pregnancy.

METHODS

In this prospective longitudinal study, pregnant women whose CL was measured between 24 and 28 weeks were followed until delivery. The CL was adjusted for confounders and the results are presented using odds ratio and receiver operating characteristic curve (ROC).

RESULTS

A total of 874 women met the inclusion criteria. The median value of CL measured between 24 and 28 weeks was 34.0 mm (30.0-38.0 25%, 75% interquartile range). The risk of late and post-term pregnancy was 5.8 times higher in pregnant women with a CL above 35 mm between the 24 and 28 weeks of gestation (95% CI: 2.65-12.94 adjusted OR = 5.8, p < .001). For pregnancies exceeding the 38th week, it was observed that the duration of the gestation increases as CL values increase.

CONCLUSIONS

In this study, it has been demonstrated that measuring the CL between 24 and 28 weeks of gestation can predict late and post-term pregnancy. Prolonged pregnancy may cause neonatal and fetal complications and anxiety. CL measurement performed in these weeks can help prepare pregnant women for a possible prolonged pregnancy and cope with prolonged pregnancy anxiety.