Serial amniotic fluid index in severe preeclampsia: a poor predictor of adverse outcome

Comparing maternal outcomes in spontaneous singleton pregnancies versus in vitro fertilization conception: Single-center 10-year cohort study

OBJECTIVE

A successful assisted reproductive technique (ART) cycle is not flawless, and several studies have reported high incidences of maternal complications, but the association is inconclusive. In addition, the racial and ethnic effects of the Asian population undergoing ART on maternal outcomes is not well studied. This study attempts to compare various maternal outcome parameters ART and spontaneously conceived singleton pregnancies from a single high volume tertiary care centre.

METHODS

A retrospective cohort study from a single tertiary infertility center was conducted from January 2011 to September 2020. The study included 1125 IVF conceived singletons (AP group) and 7193 spontaneous conceived singletons (SP group). The groups were compared using the Pearson Chi-square test and the adjusted odds ratio calculated using multivariate analysis.

RESULTS

Maternal outcomes like gestational hypertension, pre-eclampsia, gestational diabetes (GDM), oligohydramnios, chorioamnionitis, operative, and instrumental delivery were significantly different in the two groups (p<0.05). The AP group had a significantly increased risk of GDM (aOR 1.093; 95% CI 1.076-1.110) and pregnancy-induced hypertension (PIH) (aOR 1.577; 95% CI 1.288-1.930) as compared to the SP group. IVF significantly increases the risk of abruption by 2 times (p=0.028), and independently increases the risk of caesarean section by 3.1-fold (p<0.001). But overall the IVF is the protective factor for oligohydramnios (p=0.024).

CONCLUSIONS

ART increases the likelihood of pregnancy-related maternal complications, such as PIH, GDM, abruption, chorioamnionitis, and an increased rate of caesarean delivery. Thus, all patients undergoing ART procedures should receive pre-conceptional counselling regarding the associated obstetric risks and consider ART pregnancy as a high-risk pregnancy.

Correlation of amniotic fluid index and placental aquaporin 1 levels in terms of preeclampsia

INTRODUCTION

Aquaporin 1 (AQP1) plays an important role in regulation of maternal-fetal fluid exchange and amniotic fluid volume. This present study aimed to determine the relationship between amniotic fluid index and placental AQP1 levels in terms of preeclampsia, and to reveal possible pathophysiological changes of AQP1 expression under preeclamptic conditions.

METHODS

Placental tissues and medical records information were obtained from 389 preeclamptic and 447 uncomplicated pregnancies. Placental AQP1 levels were analyzed by molecular biological methods, DNA methylation within gene promotor was determined by targeted bisulfite sequencing assay.

RESULTS

Here, we found that preeclamptic pregnancy had a greater frequency of oligohydramnios, and higher placental AQP1 levels. There was a significantly inverse correlation between amniotic fluid index and placental AQP1 levels in preeclampsia cases. Additionally, the increased AQP1 was correlated with a decreased DNA methylation within its gene promoter.

DISCUSSION

Overall, this was the first description that a greater frequency of oligohydramnios in preeclampsia was strongly associated with reprogrammed AQP1 expression via a DNA methylation-mediated epigenetic mechanism. This study suggested AQP1 might play an important role in regulating maternal-fetal fluid balance under preeclamptic conditions, providing new information for further understanding the pathophysiological mechanism of oligohydramnios in preeclampsia.

Risk Factors for Adverse Fetal Outcome in Hemodialysis Pregnant Women

Introduction

Pregnancy in women on dialysis is associated with a higher risk of adverse events, and the best care for this population remains to be established.

Methods

In this series, we aimed to identify factors associated with the risk of adverse fetal outcomes among 93 pregnancies in women on hemodialysis. Dialysis dose was initially assigned according to the presence of residual diuresis, body weight, and years on dialysis. Subsequent adjustments on dialysis dose were performed according to several parameters.

Results

The overall successful delivery rate was 89.2%, with a dialysis regimen of 2.6 ± 0.7 h/d, 15.4 ± 4.0 h/wk, and mean weekly standard urea Kt/V of 3.3 ± 0.6. In the logistic models, preeclampsia, lupus, primigravida, and average midweek blood urea nitrogen (BUN) level were positively related to the risk of a composite outcome of perinatal death or extreme prematurity, whereas polyhydramnios was inversely related to it. In multivariable linear regression, preeclampsia, polyhydramnios, primigravida, average midweek BUN, and residual diuresis remained significantly and independently related to fetal weight, which is a surrogate marker of fetal outcome. An average midweek BUN of 35 mg/dl was the best value for discriminating the composite outcome, and BUN ≥35 mg/dl was associated with a significant difference in a Kaplan-Meier curve (P = 0.01).

Conclusion

Our results showed that a good fetal outcome could be reached and that preeclampsia, lupus, primigravida, residual diuresis, polyhydramnios, and hemodialysis dose were important variables associated with this outcome. In addition, we suggested that a midweek BUN <35 mg/dl might be used as a target for adjusting dialysis dose until hard data were generated.

Does the level of amniotic fluid have an effect on the accuracy of sonographic estimated fetal weight at term?

OBJECTIVE

Controversy exists concerning the impact of amniotic fluid index (AFI) on the accuracy of sonographic estimation of fetal weight (EFW). Thus, we aimed to evaluate whether differences in AFI has an influence on the accuracy of sonographic EFW.

METHODS

All term, singleton pregnancies which underwent a sonographic EFW and measurement of AFI within a week from delivery were included. Cases were stratified into three categories according to AFI: (1) Normal AFI (51-249 mm), (2) Oligohydramnios (AFI ≤ 50 mm) and (3) Polyhydramnios (AFI ≥ 250 mm). Inaccurate EFW was defined if there was more than 15% difference between sonographic EFW and actual birthweight.

RESULTS

Overall, 1746 pregnancies were identified (1096 with normal AFI, 455 with oligohydramnios and 195 with polyhydramnios). Mean AFI was 115.8 ± 60 mm, 28.1 ± 13 mm and 293 ± 35 mm, p < 0.001, and mean sonographic EFW was 3182.5 ± 573 g, 3118.8 ± 517 g and 3713.2 ± 461 g, p < 0.001, respectively. Demographic data and gestational age at delivery were similar. Mean birthweight was 3221.7 ± 535 g, 3132.5 ± 505 g and 3654.1 ± 480 g, p < 0.001, respectively. The rate of inaccurate EFW was similar between the groups (8.4%, 8.7% and 9.7%, p = 0.19, respectively). On multivariate analysis, AFI was not associated with EFW inaccuracy (OR 1.01, 95% C.I 0.67-1.54, p = 0.93).

CONCLUSION

AFI has limited impact on the percentage of errors in sonographic fetal weight estimation a week prior delivery.

Borderline or marginal amniotic fluid index and peripartum outcomes: a review of the literature

The predictive accuracy of a borderline amniotic fluid index (AFI) for an adverse pregnancy outcome is uncertain. Pregnancy outcomes of a borderline versus normal AFI suggest an increased risk of meconium-stained fluid, intrauterine growth restriction, cesarean delivery for a nonreassuring fetal heart rate, low Apgar scores, and neonatal intensive care unit admission with borderline fluid. These results are inconclusive because of study design variations, the absence of receiver-operating characteristic curves, our inability to calculate likelihood ratios, and a lack of randomized trials. There is currently insufficient evidence to recommend additional antenatal testing delivery based on a borderline AFI. Sonography could be considered for evaluating fetal growth until a definitive association or lack of an association between a borderline AFI and intrauterine growth restriction/small size for gestational age can be determined.

Induction of labor and perinatal outcome: the impact of the amniotic fluid index

OBJECTIVE

The purpose was to determine the impact of the amniotic fluid index on the perinatal outcome of patients admitted for induction of labor at term.

STUDY DESIGN

Patients (n=180) included in the study were those admitted for induction of labor at 37-42 weeks' gestation, with unfavorable cervix and intact membranes. The amniotic fluid index (AFI) was determined in all patients using the four-quadrant technique within 24 h of the induction of labor. Patients were divided into two groups based on their AFI: the oligohydramnios group with AFI < or = 5 cm (n = 66) and a normal group with AFI > 5 cm (n = 114). The perinatal outcomes of the two groups were compared.

RESULTS

The two groups were similar with regard to maternal age, gestational age, and birth weight. Meconium staining of the amniotic fluid was significantly higher in the group with AFI < or = 5 cm (p = 0.040). The number of cesarean deliveries due to fetal distress was significantly higher even after adjusting for other confounding factors in the group with AFI < or = 5 cm (adjusted OR 6.52 [95% CI 1.82, 23.2]; p < or = 0.0001). There was no significant difference between the two groups with regard to Apgar scores or neonatal admission.

CONCLUSION

Induction of labor at term in patients with oligohydramnios is associated with an increased risk of cesarean delivery due to fetal distress.

Delivery of patients with early onset, severe pre-eclampsia

OBJECTIVES

To compare the effects of induction/labor to delivery before labor in early onset, severe pre-eclampsia.

METHODS

Five-year prospective case series. Delivery course and neonatal outcome were examined for 335 women with viable singletons.

RESULTS

Induction was successful in 45% of attempts. Women exposed to labor had longer (5.5 days, P<0.0001) admissions to delivery periods and were more often delivered for maternal indications (RR=2.87, 95% CI=1.98-4.16). Their babies were born 1.6 weeks older (P<0.0001) and 352 g heavier (P<0.0001) than those delivered before labor. Babies exposed to labor needed intensive care less often (RR=0.4, 95% CI=0.27-0.58), had lower rates of severe hyaline membrane disease (RR=0.26, 95% CI=0.11-0.59) and sepsis (RR=0.56, 95% CI=0.33-0.93), and were discharged earlier (P<0.0001).

CONCLUSIONS

Exposure to induction/labor in selected patients is not detrimental to neonatal outcome in early, severe pre-eclampsia.

Perinatal outcome and amniotic fluid index in the antepartum and intrapartum periods: A meta-analysis

OBJECTIVE

Our purpose was to perform a meta-analysis of studies on the risks of cesarean delivery for fetal distress, 5-minute Apgar score <7, and umbilical arterial pH <7.00 in patients with antepartum or intrapartum amniotic fluid index >5.0 or <5.0 cm.

STUDY DESIGN

Using a MEDLINE search, we reviewed all studies published between 1987 and 1997 that correlated antepartum or intrapartum amniotic fluid index with adverse peripartum outcomes. The inclusion criteria were studies in English that associated at least one of the selected adverse outcomes with an amniotic fluid index of </=5.0 cm versus >5.0 cm. Contingency tables were constructed for each study, and relative risks and standard errors of their logs were calculated. Fixed-effects pooled relative risks were calculated for groups of studies that were homogeneous, whereas random-effects pooled relative risks were calculated for significantly heterogeneous groups of studies.

RESULTS

Eighteen reports describing 10,551 patients met our inclusion criteria. An antepartum amniotic fluid index of </=5.0 cm, in comparison with >5.0 cm, is associated with an increased risk of cesarean delivery for fetal distress (pooled relative risk, 2.2; 95% confidence interval, 1.5-3.4) and an Apgar score of <7 at 5 minutes (pooled relative risk, 5.2; 95% confidence interval, 2.4-11.3). An intrapartum amniotic fluid index of </=5.0 cm is also associated with an increased risk of cesarean delivery for fetal distress (pooled relative risk, 1.7; 95% confidence interval, 1.1-2.6) and an Apgar score <7 at 5 minutes (pooled relative risk, 1.8; 95% confidence interval, 1.2-2.7). A poor correlation between the amniotic fluid index and neonatal acidosis was noted in the only study that examined this end point. More than 23,000 patients are necessary to demonstrate that the incidence of umbilical arterial pH <7.00 is 1.5 times higher among those with oligohydramnios in labor than among those with adequate amniotic fluid index (alpha = 0.05; beta = 0.2)

CONCLUSIONS

An antepartum or intrapartum amniotic fluid index of </=5.0 cm is associated with a significantly increased risk of cesarean delivery for fetal distress and a low Apgar score at 5 minutes. There are few reports linking amniotic fluid index and neonatal acidosis, the only objective assessment of fetal well-being. A multicenter study with sufficient power should be undertaken to demonstrate that a low amniotic fluid index is associated with an umbilical arterial pH <7.00.

Amniotic fluid volume assessment in singleton and twin pregnancies

The best method of ultrasonic mensuration to identify abnormal AFV reliably in singletons and the individual sacs of diamniotic twins remains elusive. With respect to twins, localization of the dividing membrane seems to be necessary for AFV assessments of each amniotic cavity. The relationship of ultrasonic estimates, actual AFV, and pregnancy outcome remains undetermined. In the authors' opinion, the subjective assessment in twin gestation may be as accurate as semiquantitative ultrasonic estimates of AFV, similar to the situation in singleton pregnancies. The authors propose that further prospective research address the following questions: (1) What is the appropriate threshold for intervention when AFI decreases to lower ranges? (2) What other factors (e.g., cervical examination, fetal heart rate patterns, underlying obstetric conditions, fetal growth pattern) are important when the AFI falls to low values in making clinical decisions?

Expectant management of severe preeclampsia remote from term

Traditionally, preeclamptic women who meet accepted criteria for severe disease are delivered expeditiously, regardless of gestational age. Although delivery is always appropriate therapy for the mother, it may not be optimal for the fetus remote from term. Several recent randomized clinical trials support expectant management of severe preeclampsia remote from term in well-selected patients. We have described our rationale and guidelines for management, which we believe should be performed only at tertiary perinatal centers.

Antenatal testing among 1001 patients at high risk: the role of ultrasonographic estimate of amniotic fluid volume

OBJECTIVE

Our goal was to compare the accuracy of the amniotic fluid index and the 2-diameter pocket technique with respect to accuracy in predicting an adverse pregnancy outcome among patients at high risk undergoing antenatal testing.

STUDY DESIGN

All women with high-risk pregnancies and intact membranes who underwent antenatal testing during an 18-month period were prospectively enrolled. Ultrasonographic estimates of amniotic fluid volume were performed by means of the amniotic fluid index and the 2-diameter pocket technique. Relative risks with 95% confidence intervals and receiver operator characteristic curves were calculated for patients with an ultrasonographic estimate of oligohydramnios (amniotic fluid index of </=5 cm or 2-diameter pocket of </=15 cm2) versus normal fluid level (amniotic fluid index of >5 cm or 2-diameter pocket of >15 cm2). Outcome variables studied were intrapartum and neonatal complications.

RESULTS

Among 1001 patients the mean (+/-SD) amniotic fluid index was 10.5 +/- 5 cm and the mean (+/-SD) 2-diameter pocket was 18.7 +/- 13.6 cm2. Significantly more patients (46%) were considered to have oligohydramnios according to the 2-diameter pocket criteria than according to the amniotic fluid index (21%, P <.0001, relative risk 1.7, 95% confidence interval 1.5-1.8). No significant differences in the incidences of nonreactive nonstress test results, meconium-stained amniotic fluid, cesarean delivery for fetal distress, low Apgar scores, or infants with cord pH of <7.10 were observed between the oligohydramnios and normal amniotic fluid groups (P >.05) when assessed by relative risk with confidence interval and by receiver operator characteristic curves.

CONCLUSIONS

Current ultrasonographic measurements with the amniotic fluid index and the 2-diameter pocket technique are poor diagnostic tests to determine whether a patient is at high risk for an adverse perinatal outcome.

Does an amniotic fluid index of </=5 cm necessitate delivery in high-risk pregnancies? A case-control study

OBJECTIVE

This study was undertaken to determine whether women with high-risk pregnancies and an amniotic fluid index of </=5 cm require labor induction to prevent adverse perinatal outcomes.

STUDY DESIGN

All women at high risk at >/=34 weeks' gestation with an amniotic fluid index of </=5 cm were admitted to the hospital for labor induction. Each woman was compared with the next patient at high risk seen with an amniotic fluid index of >5 cm and the same pregnancy complication. Case patients were also matched with control subjects for maternal race, age, parity, and gestational age.

RESULTS

Prospectively, 79 women at high risk with an amniotic fluid index of </=5 cm were compared with 79 control subjects. There were no statistically significant differences between the 2 groups in the risks of thick meconium (P =.29), variable decelerations (moderate P =.27, severe P =.37), amnioinfusion (P =.37), cesarean delivery for fetal distress (P =.4), and umbilical artery pH <7.10 (P =.29).

CONCLUSION

High-risk pregnancies with an amniotic fluid index of </=5 cm appear to carry intrapartum complication rates similar to those of similar high-risk pregnancies with an amniotic fluid index of >5.

Management of complicated preeclampsia

The complicated preeclamptic patient represents a challenge for the clinician faced with her antepartum or postpartum care. The most serious sequelae of preeclampsia account for a significant portion of maternal morbidity and mortality. Severe preeclampsia also results in an appreciable portion of perinatal morbidity and mortality. In this review, developing trends in the treatment of severe preeclampsia are discussed. Expectant treatment of the patient remote from term, anesthesia choices, and delivery route are reviewed. Developing trends in the pharmacological approach to complicated preeclampsia are discussed. New concepts in the treatment of cerebrovascular preeclampsia and hepatic rupture are outlined and reviewed.