Borderline amniotic fluid index and its relation to fetal intolerance of labor: a 2-center retrospective cohort study

Comparison of the effectiveness and pregnancy outcomes of labor induction with dinoprostone or single-balloon catheter in term nulliparous women with borderline oligohydramnios

BACKGROUNDS

At present, there is no consensus on the induction methods in term pregnancy with borderline oligohydramnios. This study aimed to compare the effectiveness and pregnancy outcomes of labor induction with dinoprostone or single-balloon catheter (SBC) in term nulliparous women with borderline oligohydramnios.

METHODS

We conducted a retrospective cohort study from January 2016 to November 2018. During the study period, a total of 244 cases were enrolled. Of these, 103 cases were selected for induction using dinoprostone and 141 cases were selected for induction with SBC. The pregnancy outcomes between the two groups were compared. Primary outcomes were successful vaginal delivery rates. Secondary outcomes were maternal and neonatal adverse events. Multivariate logistic regression was used to assess the risk factors for vaginal delivery failure in the two groups.

RESULTS

The successful vaginal delivery rates were similar between the dinoprostone group and the SBC group (64.1% [66/103] vs. 59.6%, [84/141] P = 0.475), even after adjustment for potential confounding factors (adjusted odds ratio [aOR]: 1.07, 95% confidence interval [CI]: 0.57-2.00, P = 0.835). The incidence of intra-amniotic infection was lower in the dinoprostone group than in the SBC group (1.9% [2/103] vs. 7.8%, [11/141] P < 0.001), but the presence of non-reassuring fetal heart rate was higher in the dinoprostone group than in the SBC group (12.6% [13/103] vs. 0.7%, [1/141] P < 0.001). Multivariate logistic regression showed that nuchal cord was a risk factor for vaginal delivery failure after induction with dinoprostone (aOR: 6.71, 95% CI: 1.96-22.95). There were three factors related to vaginal delivery failure after induction with SBC, namely gestational age (aOR: 1.51, 95% CI: 1.07-2.14), body mass index (BMI) >30 kg/m2 (aOR: 2.98, 95% CI: 1.10-8.02), and fetal weight >3500 g (aOR: 2.49, 95% CI: 1.12-5.50).

CONCLUSIONS

Term nulliparous women with borderline oligohydramnios have similar successful vaginal delivery rates after induction with dinoprostone or SBC, with their advantages and disadvantages. In women with nuchal cord, the risk of vaginal delivery failure is increased if dinoprostone is used in the induction of labor. BMI >30 kg/m2, large gestational age, and estimated fetal weight >3500 g are risk factors for vaginal delivery failure after induction with SBC.

Does the Summer Season Affect the Amniotic Fluid Volume during Pregnancy?

Amniotic fluid is crucial for the well-being of the fetus. Recent studies suggest that dehydration in a pregnant woman leads to oligohydramnios. We assessed the variation in the amniotic fluid index (AFI) during the summer and non-summer seasons and evaluated neonatal outcomes. We retrospectively reviewed electrical medical records of pregnant women who visited the Konkuk University Medical Center for antenatal care, between July 2005 and July 2019. A total of 19,724 cases from 6438 singleton pregnant women were included after excluding unsuitable cases. All AFI values were classified as 2nd and 3rd trimester values. Additionally, borderline oligohydramnios (AFI, 5–8) and normal AFI (AFI, 8–24) were assessed according to the seasons. The average AFI between the summer and non-summer season was statistically different only in the 3rd trimester; but the results were not clinically significant. In the 3rd trimester, the summer season influenced the increased incidence of borderline oligohydramnios. The borderline oligohydramnios group showed an increased small-for-gestational-age (SGA) rate and NICU admission rate. In the summer season, the incidence of borderline oligohydramnios was seen to increase. This result would be significant for both physicians and pregnant women.

Amnioinfusion in severe oligohydramnios with intact membrane: an observational study

OBJECTIVE

The objective of this article was to evaluate the outcome of transabdominal amnioinfusion in pregnant patients with oligohydramnios.

METHOD

This is a prospective observational study involving 80 cases of oligohydramnios treated with transabdominal amnioinfusion guided by ultrasound, in the period between 2011 and 2016. The patients were treated in two centers; however, all the procedures were performed by the same operator.

RESULTS

The mean gestational age at the first treatment was 24 weeks. Some patients received more than one amnioinfusion. The mean interval between the first infusion and delivery was 31 d. Perinatal and neonatal mortalities were 45% and 35%, respectively. There were five cases of chorioamnioitis and in majority of the cases; the final diagnosis was made after amnioinfusion.

CONCLUSION

The procedure has been proven to be very safe. The result showed a high perinatal mortality which was not surprising, as these pregnancies were complicated by a major fetal malformation. Significantly, this study showed that the diagnosis accuracy of the concomitant congenital fetal malformation was significantly improved. The diagnosis accuracy had a major impact on the management of patients, especially the mode of delivery.

Investigating gene methylation signatures for fetal intolerance prediction

Pregnancy is a complicated and long procedure during one or more offspring development inside a woman. A short period of oxygen shortage after birth is quite normal for most babies and does not threaten their health. However, if babies have to suffer from a long period of oxygen shortage, then this condition is an indication of pathological fetal intolerance, which probably causes their death. The identification of the pathological fetal intolerance from the physical oxygen shortage is one of the important clinical problems in obstetrics for a long time. The clinical syndromes typically manifest five symptoms that indicate that the baby may suffer from fetal intolerance. At present, liquid biopsy combined with high-throughput sequencing or mass spectrum techniques provides a quick approach to detect real-time alteration in the peripheral blood at multiple levels with the rapid development of molecule sequencing technologies. Gene methylation is functionally correlated with gene expression; thus, the combination of gene methylation and expression information would help in screening out the key regulators for the pathogenesis of fetal intolerance. We combined gene methylation and expression features together and screened out the optimal features, including gene expression or methylation signatures, for fetal intolerance prediction for the first time. In addition, we applied various computational methods to construct a comprehensive computational pipeline to identify the potential biomarkers for fetal intolerance dependent on the liquid biopsy samples. We set up qualitative and quantitative computational models for the prediction for fetal intolerance during pregnancy. Moreover, we provided a new prospective for the detailed pathological mechanism of fetal intolerance. This work can provide a solid foundation for further experimental research and contribute to the application of liquid biopsy in antenatal care.

Universal late pregnancy ultrasound screening to predict adverse outcomes in nulliparous women: a systematic review and cost-effectiveness analysis

BACKGROUND

Currently, pregnant women are screened using ultrasound to perform gestational aging, typically at around 12 weeks' gestation, and around the middle of pregnancy. Ultrasound scans thereafter are performed for clinical indications only.

OBJECTIVES

We sought to assess the case for offering universal late pregnancy ultrasound to all nulliparous women in the UK. The main questions addressed were the diagnostic effectiveness of universal late pregnancy ultrasound to predict adverse outcomes and the cost-effectiveness of either implementing universal ultrasound or conducting further research in this area.

DESIGN

We performed diagnostic test accuracy reviews of five ultrasonic measurements in late pregnancy. We conducted cost-effectiveness and value-of-information analyses of screening for fetal presentation, screening for small for gestational age fetuses and screening for large for gestational age fetuses. Finally, we conducted a survey and a focus group to determine the willingness of women to participate in a future randomised controlled trial.

DATA SOURCES

We searched MEDLINE, EMBASE and the Cochrane Library from inception to June 2019.

REVIEW METHODS

The protocol for the review was designed a priori and registered. Eligible studies were identified using keywords, with no restrictions for language or location. The risk of bias in studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Health economic modelling employed a decision tree analysed via Monte Carlo simulation. Health outcomes were from the fetal perspective and presented as quality-adjusted life-years. Costs were from the perspective of the public sector, defined as NHS England, and the costs of special educational needs. All costs and quality-adjusted life-years were discounted by 3.5% per annum and the reference case time horizon was 20 years.

RESULTS

Umbilical artery Doppler flow velocimetry, cerebroplacental ratio, severe oligohydramnios and borderline oligohydramnios were all either non-predictive or weakly predictive of the risk of neonatal morbidity (summary positive likelihood ratios between 1 and 2) and were all weakly predictive of the risk of delivering a small for gestational age infant (summary positive likelihood ratios between 2 and 4). Suspicion of fetal macrosomia is strongly predictive of the risk of delivering a large infant, but it is only weakly, albeit statistically significantly, predictive of the risk of shoulder dystocia. Very few studies blinded the result of the ultrasound scan and most studies were rated as being at a high risk of bias as a result of treatment paradox, ascertainment bias or iatrogenic harm. Health economic analysis indicated that universal ultrasound for fetal presentation only may be both clinically and economically justified on the basis of existing evidence. Universal ultrasound including fetal biometry was of borderline cost-effectiveness and was sensitive to assumptions. Value-of-information analysis indicated that the parameter that had the largest impact on decision uncertainty was the net difference in cost between an induced delivery and expectant management.

LIMITATIONS

The primary literature on the diagnostic effectiveness of ultrasound in late pregnancy is weak. Value-of-information analysis may have underestimated the uncertainty in the literature as it was focused on the internal validity of parameters, which is quantified, whereas the greatest uncertainty may be in the external validity to the research question, which is unquantified.

CONCLUSIONS

Universal screening for presentation at term may be justified on the basis of current knowledge. The current literature does not support universal ultrasonic screening for fetal growth disorders.

FUTURE WORK

We describe proof-of-principle randomised controlled trials that could better inform the case for screening using ultrasound in late pregnancy.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017064093.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 15. See the NIHR Journals Library website for further project information.

Perinatal outcomes following labor induction with dinoprostone in pregnancies with borderline amniotic fluid index at term: A clinical observation study

AIM

To compare perinatal outcomes of dinoprostone for induced labor in pregnancies with a borderline versus normal amniotic fluid index (AFI) at term, and to investigate the related factors affecting outcomes of cesarean section.

METHODS

The retrospective study was carried out in Hubei Maternal and Child Health Hospital with singleton pregnancies of 37-42 weeks' gestation from January to August 2016. A total of 992 subjects were divided into two groups: borderline AFI group (n =125) with 5 < AFI ≤ 8 and normal AFI group (n = 867) with 8 < AFI ≤ 24.

RESULTS

Time to delivery (P =0.004) and use of oxytocin augmentation (P = 0.011) were significantly lower in pregnancies with borderline AFI. There were no significant differences between the two groups in terms of delivery mode, time to onset of labor, fetal distress, Apgar scores, meconium-stained amniotic fluid, birth weight, or incidences of admission to neonatal intensive care unit (NICU). Gestational hypertension and birth weight were the major factors affecting outcomes of cesarean section in the borderline group (odds ratio [OR] = 13.61, 95% confidence interval [CI] 1.96-94.49, P =0.008 and OR = 1.003, 95% CI 1.001-1.005, P =0.001, respectively). Maternal age (OR = 1.12, 95% CI 1.06-1.19, P < 0.001), parity (OR = 7.57, 95% CI 3.05-18.76, P < 0.001), biparietal diameter (OR = 0.55, 95% CI 0.33-0.91, P = 0.021), and meconium-stained amniotic fluid (OR = 1.56, 95% CI 1.12-2.17, P = 0.009) were related factors in the normal group.

CONCLUSION

The perinatal outcomes of dinoprostone for induced labor are comparable between the two groups. Gestational hypertension and birth weight are factors related to outcomes of cesarean section in the borderline group.

Evaluation of Maternal and Perinatal Outcomes of Induction in Borderline Oligohydramnios at Term

Introduction

Oligohydramnios is described as decreased amniotic fluid volume relative to gestational age. Semiquantitatively it is described using the Amniotic Fluid Index (AFI) which is calculated by adding the depth in centimetres of the largest vertical pocket in each of four equal uterine quadrants. AFI less than or equal to 5 cm is defined as oligohydramnios. A Borderline Oligohydramnios (BO) is defined as AFI 5.1-8 cm.

Aim

To assess the maternal and perinatal outcome of induction in borderline oligohydramnios cases at term.

Materials and Methods

This is a retrospective observational study done from December 2015 to November 2016 in Mahatma Gandhi Medical College and Research Institute, Puducherry, India. Fifty cases of BO with AFI 5.1 cm - 8 cm taken as case and another 50 cases of Normal Liquor (NL) with AFI 8.1 cm - 18 cm taken as control. Data was collected and analysed by SPSS software version 20.0 For qualitative data, the χ²-test or Fisher's-exact test were used and for continuous variables, the t-test was used.

Results

Cases and controls were matched in baseline parameters. More number of cases were found with meconium stained liquor during labour which is statistically significant (p<0.05). Otherwise there were no statistical significant difference between cases and controls in maternal and perinatal outcome.

Conclusion

Induction of labour in cases with BO cases compared to those with NL at term did not show very statistically significant difference in terms of induction to delivery interval and neonatal outcome.