Idiopathic polyhydramnios: persistence across gestation and impact on pregnancy outcomes

Induction of labor versus expectant management in patients with idiopathic polyhydramnios

OBJECTIVE

To evaluate whether induction of labor is associated with lower risk of cesarean section compared to expectant management in patients with isolated polyhydramnios.

STUDY DESIGN

This is a single-center, retrospective cohort study of patients with pregnancies complicated by idiopathic polyhydramnios, documented between 34 and 38 weeks gestation, who were delivered between July 2012 and February 2020. The primary outcome was cesarean delivery. Secondary outcomes included chorioamnionitis, endometritis, postpartum hemorrhage, preeclampsia/gestational hypertension, and composite neonatal morbidity.

RESULTS

There were 194 patients included with idiopathic polyhydramnios - 115 underwent induction and 79 patients were expectantly managed. Planned induction was associated with a lower rate of CD compared with expectant management but did not meet statistical significance (19.1 % vs 30.4 %, aOR 0.51, 95 % CI 0.24, 1.05). A similar effect was seen when stratifying for parity: both nulliparous (9.1 % vs 16.3 %, aOR 0.59, 95 % CI 0.17, 1.98) and multiparous (32.7 % vs 47.2 %, aOR 0.45, 95 % CI 0.18, 1.15) patients had a lower CD rate when there was a planned induction, though neither group met statistical significance. No differences in maternal or fetal secondary outcomes were identified (chorioamnionitis, endometritis, postpartum hemorrhage, preeclampsia/gestational hypertension, composite neonatal morbidity).

CONCLUSION

Lower rates of cesarean section were associated with labor induction for patients with isolated polyhydramnios, but confidence intervals did not reach statistical significance.

Amnioreduction vs expectant management in pregnancies with moderate to severe polyhydramnios

BACKGROUND

The rate of polyhydramnios is higher in pregnancies complicated by congenital anomalies. These pregnancies have higher rates of peripartum complications. Amnioreduction is offered to relieve maternal symptoms such as dyspnea, abdominal and respiratory discomfort, and other issues like satiety.

OBJECTIVE

This study aimed to report the rates of amnioreduction and its associated complications in pregnancies with moderate to severe polyhydramnios secondary to fetal anomalies. We also sought to determine if amnioreduction provided additional benefits, including prolongation of pregnancy and a decrease in the rates of peripartum morbidities associated with moderate to severe polyhydramnios.

STUDY DESIGN

This was a retrospective review of anomalous singleton pregnancies with moderate to severe polyhydramnios that were evaluated and delivered at a single center between 2013 and 2021. Peripartum outcomes were compared between pregnancies that underwent amnioreduction and those that were expectantly managed. Mann-Whitney U tests were used to compare continuous variables and Fisher's exact tests were used for categorical variables. A multiple regression model was created to understand the effects of amnioreduction on gestational age at delivery.

RESULTS

A total of 218 singleton pregnancies met the inclusion criteria of moderate to severe polyhydramnios in the study period. Of those, 110 patients (50.5%) underwent amnioreduction and 108 patients (49.5%) opted for expectant management. A total of 147 procedures were performed at a median gestational age of 32.5 weeks and a median of 1900 mL of amniotic fluid was removed per procedure. Complications occurred in 10.9% (n=16) of procedures, including preterm delivery within 48 hours in 5.4% cases (n=8). The median amniotic fluid index was higher in the amnioreduction group than in the expectant group (38.9 cm vs 35.5 cm; P<.0001). Patients who underwent amnioreduction had an earlier median gestational age at delivery (36.3 weeks vs 37.0 weeks; P=.048), however, the rates of spontaneous preterm delivery were similar. A higher percentage of women in the amnioreduction group had vaginal delivery (49.4% vs 30.5%; P=.01) and lower rates of uterine atony (2.4% vs 13.7%; P=.006). In the multiple linear regression analysis, the gestational age at delivery positively correlated with gestational age at amnioreduction after controlling for amniotic fluid volume (P<.0001; 95% confidence interval, 0.34-0.71). In addition, the patients in the amnioreduction group were twice as likely to have a vaginal delivery (P=.02).

CONCLUSION

Amnioreduction in the setting of moderate-severe polyhydramnios has a reasonably low rate of complications but does not provide any benefits in terms of prolonging the pregnancy. The procedure may increase the likelihood of vaginal delivery and lower the rates of uterine atony.

Idiopathic Polyhydramnios and Neonatal Morbidity at Term

OBJECTIVE

Idiopathic polyhydramnios is among the most common etiologies of polyhydramnios. However, conflicting evidence exists regarding the relationship between polyhydramnios and neonatal morbidity. We investigated the association between pregnancies with and without idiopathic polyhydramnios and neonatal morbidity at term.

STUDY DESIGN

This is a retrospective cohort study of singleton, term (i.e., ≥370/7 weeks) pregnancies from 2014 to 2018. Pregnancies complicated by fetal anomalies, pregestational diabetes, and multifetal gestation were excluded. Pregnancies complicated by idiopathic polyhydramnios were defined by the deepest vertical pocket (DVP) ≥8 cm or amniotic fluid index (AFI) ≥24 cm after 20 weeks' gestation and were compared with women without polyhydramnios at time of delivery. These groups were matched 1:2 by gestational age within 7 days at delivery and maternal race. The primary outcome was a composite neonatal morbidity (neonatal death, respiratory morbidity, hypoxic-ischemic encephalopathy, therapeutic hypothermia, seizures, and umbilical artery pH < 7.10). Outcomes were compared between pregnancies with and without idiopathic polyhydramnios. Unadjusted and adjusted risk ratios were estimated using multivariable logistic regression.

RESULTS

Idiopathic polyhydramnios was diagnosed in 192 pregnancies and were matched to 384 pregnancies without polyhydramnios. After adjustment for obesity, women with pregnancies complicated by idiopathic polyhydramnios had an increased risk of composite neonatal morbidity 21.4 versus 5.5% (adjusted risk ratio [aRR] = 4.0, 95% confidence interval [CI]: 2.3-6.7). Term neonatal respiratory morbidity was the primary driver 20.3 versus 4.2%, (aRR = 4.8, 95% CI: 2.7-8.7) and included higher use of continuous positive airway pressure 19.8 versus 3.4%, p <0.01 and the need for supplemental oxygen at >12 hours of newborn life 6.8 versus 1.8%, p <0.01.

CONCLUSION

Idiopathic polyhydramnios is associated with term neonatal respiratory morbidity at delivery and during the subsequent hours of newborn life, compared with pregnancies without idiopathic polyhydramnios. Further studies are needed to minimize neonatal morbidity at term.

KEY POINTS

· Idiopathic polyhydramnios is associated with increased risk of neonatal morbidity at term.. · Increasing idiopathic polyhydramnios severity was associated with a trend toward worsening morbidity at term.. · Idiopathic polyhydramnios at term requires respiratory support at delivery and during neonatal care..

Amniotic fluid volume and pregnancy outcomes in twin pregnancies: A systematic review and meta-analysis

Objective

To analyse amniotic fluid volume (AFV), specifically oligohydramnios or polyhydramnios, and associated pregnancy and neonatal outcomes in twin gestations through systematic review and meta-analysis.

Methods

We utilised systematic review methodology to identify items within published and grey literature resources. Prospective and retrospective studies with a control group were included. Inclusion criteria were as follows: studies in English, twin pregnancy in which AFVs and associated pregnancy and/or neonatal outcomes were evaluated. Exclusion criteria included the presence of an anomalous fetus, chromosome abnormality, monochorionic diamniotic twin pregnancy complicated by twin-twin transfusion syndrome or twin-reversed arterial perfusion, twin gestations undergoing therapeutic interventions (i.e. fetoscopic laser photocoagulation and serial amniocentesis) and monochorionic monoamniotic twin pregnancy.

Results

The literature search identified 1068 abstracts, only four met criteria for inclusion and analysis. The pooled data (two studies per outcome) revealed no significant difference in rate of pre-term delivery (OR: 2.94; CI: 0.20-43.81), pre-term delivery less than 32 weeks (OR: 1.97; CI: 0.43-9.12), umbilical cord pH < 7 (OR: 2.66; CI: 0.22-32.51), rate of stillbirth (OR: 4.13; CI: 0.40-42.70), neonatal death (OR: 1.48; CI: 0.05-43.94), rate of NICU admission (OR: 1.38; CI: 0.61-3.11) or rate of small-for-gestational-age (SGA) infants (OR: 1.39; CI: 0.33-5.94).

Conclusion

Based on the pooled data (two studies per outcome), there was no difference in the fate of pre-term delivery, umbilical cord pH < 7, stillbirth, neonatal death or SGA infants. What is disturbing is the lack of studies (1946-2020) that analysed the association between AFV and pregnancy outcomes in twin pregnancies.

Amniotic Fluid Disorders: From Prenatal Management to Neonatal Outcomes

Amniotic fluid volume assessment has become standard in the surveillance of fetal well-being, especially in high-risk pregnancies. Amniotic fluid disorders are a frequent and important topic in fetal and perinatal medicine. However, although important advances have been achieved, many important and challenging questions remain unanswered to date. An abnormally low amniotic fluid volume, referred to as oligohydramnios, has been traditionally considered a possible indicator of placental insufficiency or fetal compromise and is associated with an increased rate of obstetric interventions. An excess of amniotic fluid, referred to as polyhydramnios, may be secondary to fetal or maternal conditions and has been associated with a variety of adverse pregnancy outcomes, especially when it is severe. The ultrasonographic detection of an amniotic fluid disorder should prompt a proper workup to identify the underlying etiology. Data on the association of isolated oligohydramnios or idiopathic polyhydramnios with adverse obstetric and perinatal outcomes are conflicting. While the management of secondary oligohydramnios is usually guided by the underlying condition, the management of isolated oligohydramnios is poorly defined. Similarly, the management of idiopathic and secondary polyhydramnios is not yet standardized. There is an urgent need for randomized clinical trials to provide stronger recommendations on the management of these two common conditions.

Title: Is Mild Idiopathic Polyhydramnios Associated with an Increased Risk for an Intrauterine Fetal Demise? A Retrospective Cohort Study

Objective

Antenatal fetal surveillance has been recommended for moderate/severe idiopathic polyhydramnios but not for mild idiopathic polyhydramnios. The purpose of this study is to determine if pregnancies with mild idiopathic polyhydramnios have an increased risk for an intrauterine fetal demise (IUFD).

Methods

Medical records and amniotic fluid volume ultrasound data from 2016 to 2021 at a university medical center were examined. Pregnancies with fetal anomalies, fetal infection, isoimmunization, multiple gestation, maternal diabetes and oligohydramnios were excluded. Normal amniotic fluid volume was defined as an amniotic fluid index (AFI) <24 cm which was compared to mild idiopathic polyhydramnios, AFI of ≥24.0 cm-29.9 cm, and moderate/severe polyhydramnios which is an AFI ≥30 cm.

Results

Of 12,725 patients meeting inclusion study criteria, there were 249 with idiopathic polyhydramnios (n = 249) which was associated with an increased odds of IUFD (aOR) of 3.27 (CI 1.50-7.15), NICU admission (aOR 1.28, CI 0.96-1.70), 5-minute APGAR score less than 7 (aOR 2.16, CI 1.52-3.07), and large for gestational age infant (LGA) (aOR 4.04, CI 2.83-5.78) compared to normal amniotic fluid volume (AFV). In the mild polyhydramnios group (n = 204, out of the 249 women with polyhydramnios) compared to the 12,476 pregnancies with normal AFV group, IUFD (aOR 3.38, CI 1.46-7.82), NICU admission (aOR 1.19, CI 0.87-1.64), 5-minute APGAR score less than 7 (aOR 1.68, CI 1.10-2.55) and LGA (aOR 3.87, CI 2.59-5.78). In moderate/severe polyhydramnios group (n = 45) compared to the normal AFV group, there was no increased odds of IUFD (aOR 2.78, CI 0.38-20.29) or NICU admission (aOR 1.74, CI 0.93-3.26) but an increased odds for a 5-minute APGAR score less than 7 (aOR 4.94, CI 2.57-9.53) and LGA fetus (aOR 4.80, CI 2.26-10.22).

Conclusion

There is an increased odds of IUFD in pregnancies complicated by mild idiopathic polyhydramnios. Patients should be counseled on an increased odds of adverse pregnancy outcomes associated with idiopathic polyhydramnios, and in those pregnancies with mild idiopathic polyhydramnios, antenatal fetal surveillance should be considered.

Term Idiopathic Polyhydramnios, and Labor Complications

Background and Aim: Polyhydramnios is associated with an increased risk of various adverse pregnancy outcomes, yet complications during labor have not been sufficiently studied. We assessed the labor and perinatal outcomes of idiopathic polyhydramnios during term labor. Methods: Retrospective cohort study at a tertiary medical center between 2010 and 2014. Women with idiopathic polyhydramnios defined as an amniotic fluid index (AFI) greater than 24 cm or a deep vertical pocket (DVP) > 8 cm (cases) were compared with women with a normal AFI (5-24 cm) (controls). Statistics: Descriptive, means ± SDs, medians + IQR. Comparisons: chi-square, Fisher's exact test, Mann-Whitney Test, multivariate logistic models. Results: During the study period 11,065 women had ultrasound evaluation completed by a sonographer within two weeks of delivery. After excluding pregnancies complicated by diabetes (pre-gestational or gestational), fetal anomalies, IUFD, multifetal pregnancies, elective cesarean deliveries (CD) or missing data, we included 750 cases and 7000 controls. The degree of polyhydramnios was mild in 559 (75.0%) cases (AFI 24-30 cm or DVP 8-12 cm), moderate in 137 (18.0%) cases (30-35 cm or DVP 12-15 cm) and severe in 54 (7.0%) cases (AFI >35 cm or DVP > 15 cm). Idiopathic polyhydramnios was associated with a higher rate of CD 9.3% vs. 6.2%, p = 0.004; a higher rate of macrosomia 22.8% vs. 7.0%, p < 0.0001; and a higher rate of neonatal respiratory complications 2.0% vs. 0.8%, p = 0.0001. A multivariate regression analysis demonstrated an independent relation between polyhydramnios and higher rates of CD, aOR 1.62 (CI 1.20-2.19 p = 0.002) and composite adverse neonatal outcome aOR 1.28 (CI 1.01-1.63 p = 0.043). Severity of polyhydramnios was significantly associated with higher rates of macrosomia and CD (p for trend <0.01 in both). Conclusions: The term idiopathic polyhydramnios is independently associated with macrosomia, CD and neonatal complications. The severity of polyhydramnios is also associated with macrosomia and CD.

Transient Idiopathic Polyhydramnios: Maternal and Perinatal Outcomes: Maternal and Perinatal Outcomes

OBJECTIVES

To compare maternal and perinatal outcomes in pregnancies with transient and persistent idiopathic polyhydramnios to those with normal amniotic fluid volume.

METHODS

This retrospective cohort study included subjects delivering a singleton pregnancy between January 1, 2015, and June 30, 2020, with sonography ≥26 weeks' gestation demonstrating transient or persistent idiopathic polyhydramnios (amniotic fluid index [AFI] ≥24.0 cm) or normal AFI (referent group). The primary maternal outcome was a composite of spontaneous preterm delivery <37 weeks, cesarean delivery for malpresentation, abnormal labor progress, or nonreassuring fetal status, operative vaginal delivery, hemorrhage requiring transfusion, and umbilical cord prolapse. The primary perinatal outcome was a composite of birthweight >4500 g, fetal or neonatal death, 5-minute Apgar score <7, and neonatal intensive care unit admission for >24 hours.

RESULTS

Patients with transient polyhydramnios (n = 259) exhibited maternal outcomes similar to those of the referent group (n = 435) but had significantly increased odds for the primary perinatal outcome (odds ratio [OR] 1.70, 95% confidence interval [CI] 1.15-2.53; P = .008) and for birthweight ≥4500 g (OR 8.70, 95% CI 1.89-40.0; P = .005). Persistent polyhydramnios (n = 176) was significantly associated with both the primary maternal (OR 1.93, 95% CI 1.27-2.95, P = .002) and primary perinatal outcome (OR 2.15, 95% CI 1.40-3.30; P < .001), and individually with cesarean delivery for abnormal labor (OR 3.22, 95% CI 1.55-6.68; P = .002) and birthweight ≥4500 g (OR 8.97, 95% CI 1.84-43.6; P = .007).

CONCLUSIONS

Transient idiopathic polyhydramnios does not impact maternal outcomes but is associated with increased odds of newborn birthweight >4500 g. Persistent polyhydramnios is associated with both adverse maternal and perinatal outcomes.

Moderate-to-Severe Polyhydramnios: Cutoffs for Deepest Vertical Pocket Corresponding to Amniotic Fluid Index

OBJECTIVE

Society for Maternal-fetal medicine Consult Series (#46) states "antenatal fetal surveillance is not required for mild idiopathic" polyhydramnios defined as amniotic fluid index (AFI) of 24 cm or a deepest vertical pocket (DVP) between 8 and 11 cm. The objective of this study was to determine the cutoff for DVP which correlates with AFI ≥ 30 cm.

METHODS

This retrospective study of singleton third trimester ultrasounds included a study group randomly divided into test and validation. In the test group, DVP cutoffs correlating with AFI ≥ 30 cm which was used to define moderate-severe polyhydramnios were calculated in two ways, rounded to the nearest whole number: 1) a receiver operating curve and Youden's J statistic (DVP-Youden) and 2) calculation of the DVP percentile that corresponded with AFI of 30 cm (DVP-Percentile). Using the validation group, diagnostic characteristics were DVP-Youden and DVP-Percentile for diagnosis of AFI ≥ 30 cm and were compared against SMFM cutoffs (DVP-SMFM).

RESULTS

Seventy one thousand eight hundred and ninety three ultrasound exams in the 3rd trimester had assessment of AFI and DVP. Moderate-severe polyhydramnios occurred in 286 (1.2%) in test group and 571 (1.2%) in validation group. AFI of 30 cm corresponded to the 98.9th percentile, which in turn correlated to a DVP of 10 cm (DVP-Percentile). The calculated cutoff for moderate-severe polyhydramnios was 8 cm for DVP-Youden.

CONCLUSION

Using 8.0 cm rather than 12.0 cm increased the detection of moderate-severe polyhydramnios to 100% with a false positive rate under 5%. For those utilizing DVP for amniotic fluid evaluation, identification of a DVP ≥ 8.0 cm should prompt further evaluation with complete AFI.

Survival outcomes of very low birth weight infants with trisomy 18

Trisomy 18 (T18) is one of the most commonly diagnosed aneuploidies leading to poor survival outcome. However, little is known about the dual risk of T18 and very low birth weight (VLBW, weighing <1500 g at birth). We aimed to investigate the survival and clinical features of VLBW infants with T18. In this observational cohort study, infants with T18 admitted to the neonatal intensive care unit in Kyushu University Hospital from 2000 to 2019 were eligible. Among 30 infants with T18 who were enrolled as study participants, 11 (37%) were born with VLBW. VLBW infants had lower gestational age (34.4 vs. 39.4 weeks, p < 0.01) and a higher incidence of esophageal atresia (64% vs. 11%, p < 0.01) than non-VLBW infants. The proportions of patients who underwent any surgery (55% vs. 5%, p < 0.01) and positive pressure ventilation (82% vs. 32%, p = 0.02) were higher in VLBW than non-VLBW infants. One-year overall survival rate (45% vs. 26%, p = 0.32 by log-rank test) did not differ between the two groups. In conclusion, being born at VLBW may not be fatal for infants with T18 undergoing active interventions.

Prenatal exposure to isolated amniotic fluid disorders and the risk for long-term endocrine morbidity of the offspring

BACKGROUND

Amniotic fluid abnormalities may be associated with adverse perinatal outcomes, some of which are endocrine related.

OBJECTIVE

To evaluate whether in utero exposure to amniotic fluid abnormalities is associated with long-term endocrine morbidity in the offspring.

STUDY DESIGN

In this cohort study, the incidence of long-term endocrine disorders was compared between singletons exposed and non-exposed to oligohydramnios or polyhydramnios.

RESULTS

During the study period, 195 943 newborns were included in the study, of them 2.0% (n = 4072) and 2.9% (n = 5684) were exposed to oligohydramnios and polyhydramnios, respectively. Long-term endocrine morbidity was higher among children exposed to isolated amniotic fluid disorders, as was also noted in the Kaplan-Meier survival curve (log-rank test p < 0.001). Abnormal amniotic fluid volume was found to be independently associated with long-term endocrine morbidity of the offspring according to a Cox regression model controlled for clinically related confounders.

CONCLUSION

In utero exposure to isolated amniotic fluid abnormalities is independently associated with long-term endocrine morbidity in the offspring.

Adverse perinatal outcomes in 665,244 term and post-term deliveries-a Norwegian population-based study

OBJECTIVE

To assess the prevalence and risk of adverse perinatal outcomes in early-term (37⁺⁰-38⁺⁶ weeks), full-term (39⁺⁰-40⁺⁶ weeks), late-term (41⁺⁰-41⁺⁶ weeks), and post-term (>42⁺⁰ weeks) deliveries with spontaneous labor onset.

STUDY DESIGN

A population-based cohort with data from the Medical Birth Registry Norway (MBRN) and Statistics Norway (SSB) was conducted. The study population consisted of 665,244 women with cephalic singleton live births at term or post-term with spontaneous labor onset during the period of 1999-2014 in Norway. Maternal, obstetric, and fetal characteristics were obtained from the MBRN. Maternal education data were obtained from the SSB. The prevalence rates of adverse perinatal outcomes for each gestational age (GA) group were estimated. Inter-group differences were detected with Chi square tests. Multivariable regression analysis adjusted for maternal age, educational level, smoking, parity, maternal diabetes, and preeclampsia was used to assess adverse outcome prevalence for early- late-, and post-term births compared to full-term births.

RESULTS

Deliveries at early-term were associated with an increased prevalence of neonatal jaundice, polyhydramnios, small for gestational age (SGA) status, respiratory support, and neonatal intensive care unit (NICU) admission compared with deliveries at GAs of 39-43 weeks (p < 0.001). Low 5-min Apgar scores and newborn antibiotic treatment occurred at an increased prevalence in both early-term and post-term infants, relative to the full-term group (p < 0.001). The prevalence of oligohydramnios, meconium-stained amniotic fluid, and newborn birth injuries increased with increasing GA.

CONCLUSIONS

More perinatal morbidity was observed among early-term infants compared to infants with later term deliveries, underscoring the need for cautious management of low-risk early-term deliveries.

Determination of reference values for third trimester amniotic fluid index: a retrospective analysis of a large cohort of pregnancies with comparison to previous nomograms

Purpose: To establish a new set of reference values for third-trimester amniotic fluid index (AFI) and compare them to other previously published normograms.Methods: A retrospective cross-sectional cohort analysis of all singleton sonographic evaluations >22 gestational weeks in one university affiliated medical center between 2013 and 2017. Pregnancies complicated by rupture of membranes, major anomalies/chromosomal abnormalities were excluded. One evaluation per patient per pregnancy was randomly selected. Reference values were constructed using a best-fit regression model for estimation of mean and standard deviation at each gestational age after normalization of variables and compared with previously published norms.Results: A total of 7037 ultrasound evaluations entered the analysis. Correlation between AFI and gestational age was best represented by a first-degree polynomial equation. AFI decreased gradually from 16.4 at 22 weeks to 13.3 at 40 weeks (cm, median). The standard deviation increased with gestational age with AFI ranging from 12.9-20.2 at 22 weeks and 4.7-26.2 at 40 weeks (cm, 2.5-97.5 percentile). Compared to other curves, our reference values demonstrated a higher median AFI throughout all gestation.Conclusions: Reference values for the third trimester AFI were established. Curves should be correlated with perinatal outcome prior to wide clinical implementation.

Comparative proteome analysis of amniotic fluids and placentas from patients with idiopathic polyhydramnios

INTRODUCTION

Idiopathic polyhydramnios (IPH) is an abnormal increase in amniotic fluid volume (AFV). This condition has unknown etiologies and is associated with various adverse pregnancy outcomes including maternal and fetal complication. This study aims to establish a comparative proteome profile for the human amniotic fluid (AF) of IPH and normal pregnancies and identify the responsible mediators and pathways that regulate AFV.

METHODS

We first employed coupled isobaric tags for relative and absolute quantitation (iTRAQ) proteomics and bioinformatics analysis to examine the differentially expression proteins (DEPs) in the AF of IPH and normal pregnancies. Second, CUL5, HIP1, FSTL3, and LAMP2 proteins were selected for verification in amnion, chorion, and placental tissues by Western blot analysis.

RESULTS

We identified 357 DEPs with 282 upregulated and 75 downregulated. Bioinformatics analysis revealed that cell, cellular process, and binding were the most enriched Gene Ontology terms. Amoebiasis, hematopoietic cell lineage, and NF-kappa B signaling pathway were the top significant pathways. In the verification procedure, FSTL3 protein had a highly significant expression in the amnion, chorion, and placentas of IPH and normal AFV groups (p < 0.05).

DISCUSSION

Our results provide new insights into idiopathic polyhydramnios and offer fundamental points for future studies on AFV.

The frequency and clinical significance of intra-amniotic inflammation in twin pregnancies with preterm labor and intact membranes

OBJECTIVE

The objective of this study is to evaluate the frequency and clinical significance of intra-amniotic inflammation in twin pregnancies with preterm labor and intact membranes.

STUDY DESIGN

Amniotic fluid (AF) was retrieved from both sacs in 90 twin gestations with preterm labor and intact membranes (gestational age between 20 and 34 6/7 weeks). Preterm labor was defined as the presence of painful regular uterine contractions, with a frequency of at least 2 every 10 min, requiring hospitalization. Fluid was cultured and assayed for matrix metalloproteinase-8. Intra-amniotic inflammation was defined as an AF matrix metalloproteinase-8 concentration >23 ng/mL.

RESULTS

The prevalence of intra-amniotic inflammation for at least 1 amniotic sac was 39% (35/90), while that of proven intra-amniotic infection for at least one amniotic sac was 10% (9/90). Intra-amniotic inflammation without proven microbial invasion of the amniotic cavity was found in 29% (26/90) of the cases. Intra-amniotic inflammation was present in both amniotic sacs for 22 cases, in the presenting amniotic sac for 12 cases, and in the non-presenting amniotic sac for one case. Women with intra-amniotic inflammation observed in at least one amniotic sac and a negative AF culture for microorganisms had a significantly higher rate of adverse pregnancy outcome than those with a negative AF culture and without intra-amniotic inflammation (lower gestational age at birth, shorter amniocentesis-to-delivery interval, and significant neonatal morbidity). Importantly, there was no significant difference in pregnancy outcome between women with intra-amniotic inflammation and a negative AF culture and those with a positive AF culture.

CONCLUSION

Intra-amniotic inflammation is present in 39% of twin pregnancies with preterm labor and intact membranes and is a risk factor for impending preterm delivery and adverse outcome, regardless of the presence or absence of bacteria detected using cultivation techniques.

SMFM Consult Series #46: Evaluation and management of polyhydramnios

Polyhydramnios, or hydramnios, is an abnormal increase in the volume of amniotic fluid. Identification of polyhydramnios should prompt a search for an underlying etiology. Although most cases of mild polyhydramnios are idiopathic, the 2 most common pathologic causes are maternal diabetes mellitus and fetal anomalies, some of which are associated with genetic syndromes. Other causes of polyhydramnios include congenital infection and alloimmunization. The purpose of this document is to provide guidance on the evaluation and management of polyhydramnios. The following are Society for Maternal-Fetal Medicine recommendations: (1) we suggest that polyhydramnios in singleton pregnancies be defined as either a deepest vertical pocket of ≥8 cm or an amniotic fluid index of ≥24 cm (GRADE 2C); (2) we recommend that amnioreduction be considered only for the indication of severe maternal discomfort, dyspnea, or both in the setting of severe polyhydramnios (GRADE 1C); (3) we recommend that indomethacin should not be used for the sole purpose of decreasing amniotic fluid in the setting of polyhydramnios (GRADE 1B); (4) we suggest that antenatal fetal surveillance is not required for the sole indication of mild idiopathic polyhydramnios (GRADE 2C); (5) we recommend that labor should be allowed to occur spontaneously at term for women with mild idiopathic polyhydramnios; that induction, if planned, should not occur at <39 weeks of gestation in the absence of other indications; and that mode of delivery should be determined based on usual obstetric indications (GRADE 1C); and (6) we recommend that women with severe polyhydramnios deliver at a tertiary center due to the significant possibility that fetal anomalies may be present (GRADE 1C).

Outcome of pregnancy in women diagnosed with idiopathic polyhydramnios

INTRODUCTION

Polyhydramnios is present in approximately 2% of pregnancies and it has been associated with a variety of adverse pregnancy outcomes.

OBJECTIVES

The aim of our study was to evaluate the association between polyhydramnios and adverse pregnancy outcomes.

METHODS

This was a retrospective case control study of 288 singleton pregnancies delivered in the Rotunda Hospital, Dublin, between 2013 and 2014. Polyhydramnios was defined as: (i) amniotic fluid index (AFI) ≥ 25 cm; (ii) maximal vertical pocket (MVP) of ≥8 cm; and (iii) a gestational age-specific threshold for AFI. Demographic information, obstetric and neonatal outcomes were obtained by review of hospital databases. Exclusion criteria included gestational or pre-existing diabetes, multiple pregnancy, carrying a fetus with structural or chromosomal abnormalities, Rhesus factor isoimmunisation, and TORCH screen positive. Outcomes were compared with outcomes of those without polyhydramnios.

RESULTS

A total of 8798 deliveries occurred during the study period. The frequency of polyhydramnios was 1.6%. One hundred and forty-four women were selected in each group. There was no significant difference in preterm deliveries, low birth weight, low Apgar score at one minute and five minutes and perinatal mortality. However, increase in caesarean delivery rate (43.1% vs 21.5%), number of fetal distresses (17.4% vs 6.9%) and number of neonatal intensive care unit (NICU) admissions (17.4% vs 4.9%) were observed in our study.

CONCLUSION

In conclusion, idiopathic polyhydramnios is associated with specific adverse outcomes, such as higher rate of caesarean delivery, fetal distress and NICU admissions. Therefore, close surveillance of these pregnancies is required, especially near term.