Pregnancy outcomes after antepartum diagnosis of oligohydramnios at or beyond 34 weeks' gestation

Prolonged oligohydramnios and the adverse composite outcome of death or severe neurodevelopmental impairment at 3 years of age in infants born at 22-29 gestational weeks

OBJECTIVE

To investigate the association between prolonged oligohydramnios and a composite outcome of death or severe neurodevelopmental impairment (NDI) at 3 years of age.

METHODS

This single-center retrospective cohort study enrolled infants born at 22-29 weeks of gestational age without major congenital anomalies. The patients were classified into three groups depending on the existence and duration of oligohydramnios: no/non-prolonged oligohydramnios (no or 0-7 days of oligohydramnios), prolonged oligohydramnios (8-14 days), and very prolonged oligohydramnios (> 14 days). The primary outcome was a composite of death or severe NDI, which was defined as severe cerebral palsy, developmental delay, severe visual impairment, or deafness at age 3.

RESULTS

Out of the 843 patients, 784 (93 %), 30 (3.6 %), and 29 (3.4 %) were classified into the no/non-prolonged, prolonged, and very prolonged oligohydramnios groups, respectively. After excluding patients lost to follow-up, the adverse composite outcome at 3 years of age was observed in 194/662 (29 %), 7/26 (27 %), and 8/23 (35 %) in the corresponding groups. The composite outcome showed no significant trend with the duration of oligohydramnios (P = 0.70). In a logistic regression model controlling the known predictors of gestational age, birth weight, small-for-gestational-age, male sex, multiple pregnancy, hypertensive disorders of pregnancy, antenatal corticosteroids, and the number of family-social risk factors, the duration of oligohydramnios was not independently associated with the composite outcome; odds ratio 1.3 (95 % confidence interval, 0.78-2.0).

CONCLUSION

Prolonged oligohydramnios was not associated with the composite outcome of death or severe NDI at 3 years of age.

Etiology of stillbirth in a tertiary care center: a retrospective cohort study assessing ultrasound, laboratory, and pathology investigations

BACKGROUND

Canadian stillbirth data are limited, and a significant proportion of pregnancies resulting in stillbirth have no attributable cause. The objective of this study was to characterize stillbirth case investigations and management at a tertiary care hospital in Ontario, Canada.

METHODS

This was a retrospective chart review study of all cases of singleton stillbirth at The Ottawa Hospital between 1 January 2012 and 31 December 2017. Terminations and multiples stillbirths were excluded. Chart reviews were conducted to extract maternal sociodemographic, obstetrical, and fetal characteristics, including results from antenatal ultrasounds, autopsy, placenta pathology, and laboratory investigations.

RESULTS

A total of 155 eligible cases of stillbirth were identified, resulting in a 6-year stillbirth rate of 4.2 per 1000 total births. The median maternal age was 31.0 years (IQR: 29.0, 35.0) and the median gestational age at delivery was 28 weeks (IQR: 24, 35). A total of 9 (5.8%) pregnant individuals had a history of previous stillbirth. Of the 155 stillbirths, 35% underwent the full suite of post-loss laboratory, placental, and fetal autopsy investigations. 63.2% of cases had post-loss laboratory investigations completed. 76% and 71% of cases had fetal autopsy and placenta pathology evaluations completed, respectively. Antenatal characteristics associated with stillbirth included fetal anomalies/genetic markers (27.1%), umbilical cord and placental anomalies (24.5%), fetal growth abnormalities (27.7%), cervical/uterine abnormalities (11.6%), and amniotic fluid abnormalities (25.1%). The most common autopsy findings included evidence of infection (22.7%), fetal anomalies (12.6%), and fetal hypoxia (10%). The most common placental pathology findings included features of placental insufficiency (21.8%), retroplacental abnormalities (16.3%), and umbilical cord accident/infarct (15.4%).

CONCLUSIONS

Our findings demonstrate that as many as two-thirds of singleton stillbirth cases at our center did not receive the post-perinatal loss investigations recommended by clinical practice guidelines. More thorough collection of post-stillbirth data at all levels (institutional, provincial, national) is warranted to improve our understanding of stillbirth epidemiology, etiology, and management in Canada.

Magnitude and associated factors of adverse perinatal outcomes among women with oligohydramnios at 3rd trimester at University of Gondar comprehensive specialized hospital, North West Ethiopia

Background

Oligohydramnios is a pregnancy condition characterized by low volume of amniotic fluid. Based on ultrasound measurement, it is defined as a single maximum vertical pocket of liquor less than 2 cm or summation of four quadrants vertical pockets of liquor measurement less than 5 cm. It is associated with multiple adverse perinatal outcomes (APO) and complicates 0.5%-5% of pregnancies.

Objective

To assess magnitude and associated factors of adverse perinatal outcome among women with oligohydramnios at 3rd trimester at University of Gondar Comprehensive Specialized Hospital, North West Ethiopia.

Methods

Institution based cross-sectional study was employed from April 1 to September 30, 2021 in which 264 participants were involved. All women with oligohydramnios at 3rd trimester who meet the inclusion criteria were included. Semi- structured questionnaire was used for data collection after Pre-tested. Collected data was checked for completeness; clarity then coded and entered using Epi data version 4.6.0.2 then exported to STATA version 14.1 for analysis.

Result

The magnitude of APO was 46.6% (95%CI: 40.5-52.7%). Null parity [AOR =  2.2, 95%CI (1.2-4.2)], presence of hypertensive disorders of pregnancy (HDP) [AOR = 4.9, 95%CI (2.0-12.1)] and presence of intrauterine growth restriction (IUGR) [AOR = 8.4, 95%CI (3.5-20.2)] were found to be predictors of APO.

Conclusion

Third trimester oligohydramnios is associated with APO. The presence of HDP, IUGR and being nulliparous were predictors of APO.

Comparison of Perinatal and Maternal Outcomes in Borderline Versus Normal Amniotic Fluid Index in a Tertiary Care Center in Odisha: An Observational Prospective Study

Background

Amniotic fluid is a protective fluid in the amniotic sac of a gravid uterus that serves many crucial functions by becoming part of an indicator of a functioning fetoplacental unit during the intrauterine life of a fetus. The most commonly used method for measuring amniotic fluid is the amniotic fluid index (AFI). In this study, we aimed to investigate the perinatal and maternal outcomes in borderline AFI versus normal AFI.

Methodology

This observational prospective study included 200 pregnant women who were admitted to Pradyumna Bal Memorial Hospital, Bhubaneswar from September 2019 to February 2021. Women with singleton pregnancy in their third trimester were enrolled in this study after applying inclusion and exclusion criteria. Of the included women, 100 were cases with borderline AFI, and 100 were control with normal AFI. Fetal and maternal outcomes were compared between the two groups. Data analysis was done using SPSS version 23 (IBM Corp., Armonk, NY, USA).

Results

Maternal outcomes such as preterm delivery, meconium-stained liquor, and lower segment cesarean section in women with borderline AFI were significantly higher (p ≤ 0.001). The borderline AFI group had a higher rate of perinatal complications such as Apgar score of <7 (p = 0.001), respiratory distress syndrome (p = 0.001), neonatal intensive care unit admission (p <0.001), intrauterine growth restriction (p < 0.001), and low birth weight (p < 0.001).

Conclusions

The borderline AFI group was associated with adverse perinatal and maternal outcomes which were significantly higher in this group compared to the control group. Therefore, patients with borderline AFI should be monitored carefully during the antepartum and intrapartum period.

Ramadan Fasting during Pregnancy and Health Outcomes in Offspring: A Systematic Review

Ramadan is one of the five pillars of Islam, during which fasting is obligatory for all healthy individuals. Although pregnant women are exempt from this Islamic law, the majority nevertheless choose to fast. This review aims to identify the effects of Ramadan fasting on the offspring of Muslim mothers, particularly on fetal growth, birth indices, cognitive effects and long-term effects. A systematic literature search was conducted until March 2020 in Web of Science, Pubmed, Cochrane Library, Embase and Google Scholar. Studies were evaluated based on a pre-defined quality score ranging from 0 (low quality) to 10 (high quality), and 43 articles were included. The study quality ranged from 2 to 9 with a mean quality score of 5.4. Only 3 studies had a high quality score (>7), of which one found a lower birth weight among fasting women. Few medium quality studies found a significant negative effect on fetal growth or birth indices. The quality of articles that investigated cognitive and long-term effects was poor. The association between Ramadan fasting and health outcomes of offspring is not supported by strong evidence. To further elucidate the effects of Ramadan fasting, larger prospective and retrospective studies with novel designs are needed.

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.

Hourly fetal urine production rate in isolated oligohydramnios at term

OBJECTIVE

The aim of this study was to evaluate the hourly fetal urine production rate (HFUPR) via three-dimensional ultrasonography in women with isolated oligohydramnios and compare with normal pregnant women at term.

MATERIALS AND METHODS

This was a prospective observational cohort study of 112 women from 34 to 40 6/7 weeks' gestation. They were classified into three groups according to the amniotic fluid index (AFI) and ultrasonographic estimated fetal weight (EFW) as isolated oligohydramnios (defined as AFI below 5% and appropriate EFW corresponding to gestational age) (n = 34) and IUGR (defined as EFW below 5% corresponding to gestational age irrespective amniotic fluid) (n = 17), and normal pregnancy (n = 61). HFUPR was measured using three-dimensional virtual organ computer-aided analysis. Adverse perinatal outcomes in all participants were examined.

RESULTS

There was no significant difference in HFUPR between patients with isolated oligohydramnios and women with normal pregnancies (median, 40.0 mL/h [interquartile range [IQR] 31.0-66.5] vs. 48.6 [31.5-81.2], p = 0.224). HFUPR was significantly decreased in the IUGR group (13.8 mL/h [IQR 10.1-24.8]), compared to the normal pregnancy group (p<0.001) and the isolated oligohydramnios group (p<0.001). HFUPR was significantly decreased in neonates with adverse perinatal outcomes compared to the control (24.7 mL/h [IQR 13.4-47.4] vs. 43.6 [29.8-79.0], p = 0.016).

CONCLUSION

HFUPR was not decreased in patients with isolated oligohydramnios but was decreased in patients with IUGR when compared to normal controls at term.

Isolated oligohydramnios - should induction be offered after 36 weeks?

OBJECTIVE

Isolated oligohydramnios (IO) - oligohydramnios in the absence of maternal or gestational comorbidity is debated as an indication for induction of labor. Previous meta-analyses regarding perinatal outcomes of IO at term have yielded conflicting results. We aimed to investigate the neonatal outcomes among gestations with IO delivered at 36°^/7-39^6/7.

METHODS

The study cohort included all women undergoing a trial of labor between during 2011 and 2019 of a singleton gestation with cephalic presentation between 36°^/7 and 40°^/7. We allocated the study groups into women with IO and those with normal amniotic fluid volume. Neonatal outcomes were compared between the groups and in relation to gestational age and induction of labor.

RESULTS

Overall, there were 529/17,709 (3.0%) IO cases. IO was associated with maternal age <25 years (OR [95% CI] 1.62 (1.20-2.20), p = .001). Induction of labor was more common with IO (OR [95% CI] 1.33 (1.05-1.69) p = .01. IO was associated with preterm delivery (OR [95% CI] 1.81 (1.36-2.40), p < .001). The rate of neonatal adverse outcome did not differ between study groups. Overall composite adverse neonatal outcome occurred among 1,399/17,709 (7.9%) deliveries. Adverse neonatal outcome was associated with induction of labor (OR [95% CI] 1.61 (1.40-1.86), p < .001) and low birth weight (OR [95% CI] 7.41 (6.27-8.75), p < .001). When Stratified by gestational age, neonatal adverse outcome did not differ between IO and no IO groups. When examining cases of induction of labor per gestational age, induction of labor at 36 weeks among IO gestations, was associated with adverse neonatal outcome as compared to no IO group (OR [95% CI] 5.7 (1.23-26.3), p = .04).

CONCLUSIONS

Induction of labor in gestations complicated by IO at 36 weeks gestational age is associated with an increased risk for adverse neonatal outcome. Our study results adds to the current literature regarding outcomes of IO and time of delivery.

SYNOPSIS

Induction of labor in gestations complicated by IO at 36 weeks gestational age is associated with an increased risk for adverse neonatal outcome.

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

Amniotic fluid (AF) abnormalities are often associated with short-term adverse pregnancy outcomes, including cardiovascular-related. We sought to assess whether in utero exposure to AF abnormalities increases the risk for long-term cardiovascular morbidity of the offspring. We examined the incidence of cardiovascular disorders in singletons exposed and non-exposed to isolated oligohydramnios or polyhydramnios. Cardiovascular morbidity was assessed up to the age of 18 years according to a predefined set of ICD-9 codes. A Kaplan-Meier survival curves were used to compare cumulative morbidity incidence. A Cox proportional hazards model was constructed to control for confounders. During the study period, 195,943 newborns met the inclusion criteria, of which 2.0% (n = 4063) were in pregnancies diagnosed with isolated oligohydramnios and 2.9% (n = 5684) in pregnancies with isolated polyhydramnios. Children exposed to isolated AF disorders had significantly higher rates of long-term cardiovascular morbidity (p=.042). Children exposed to isolated oligohydramnios had higher cumulative incidence of cardiovascular morbidity (log-rank test p=.026) compared to unexposed children, opposing to what was demonstrate when comparing polyhydramnios vs. normal AFV (log-rank test p=.749). In the Cox regression model, while controlling for confounders, isolated oligohydramnios were found to be independently associated with long-term cardiovascular morbidity of the offspring.

LncRNA and transcriptomic analysis of fetal membrane reveal potential targets involved in oligohydramnios

Background

The multiple causes of oligohydramnios make it challenging to study. Long noncoding RNAs (lncRNAs) are sets of RNAs that have been proven to function in multiple biological processes. The purpose of this study is to study expression level and possible role of lncRNAs in oligohydramnios.

Methods

In this study, total RNA was isolated from fetal membranes resected from oligohydramnios pregnant women (OP) and normal amount of amniotic fluid pregnant women (Normal). LncRNA microarray was used to analyze the differentially expressed lncRNAs and mRNAs. Kyoto Encyclopedia of Genes and Genomes (KEGG) was used to analyze the main enrichment pathways of differentially expressed mRNAs. Real-time quantitative PCR (qPCR) was used to validate the lncRNA expression level.

Results

LncRNA microarray analysis revealed that a total of 801 lncRNAs and 367 mRNAs were differentially expressed in OP; in these results, 638 lncRNAs and 189 mRNAs were upregulated, and 163 lncRNAs and 178 mRNAs were downregulated. Of the lncRNAs, 566 were intergenic lncRNAs, 351 were intronic antisense lncRNAs, and 300 were natural antisense lncRNAs. The differentially expressed lncRNAs were primarily located in chromosomes 2, 1, and 11. KEGG enrichment pathways revealed that the differentially expressed mRNAs were enriched in focal adhesion as well as in the signaling pathways of Ras, tumor necrosis factor (TNF), estrogen, and chemokine. The qPCR results confirmed that LINC00515 and RP11-388P9.2 were upregulated in OP. Furthermore, the constructed lncRNA–miRNA–mRNA regulatory network revealed tenascin R (TNR), cystic fibrosis transmembrane conductance regulator (CFTR), ATP-binding cassette sub-family A member 12 (ABCA12), and collagen 9A2 (COL9A2) as the candidate targets of LINC00515 and RP11-388P9.2.

Conclusions

In summary, we revealed the profiles of lncRNA and mRNA in OP. These results might offer potential targets for biological prevention for pregnant women with oligohydramnios detected before delivery and provided a reliable basis for clinical biological treatment in OP.

Delivery mode and perinatal outcomes after diagnosis of oligohydramnios at term in China

Objective: The purpose of this study is to assess the incidence of oligohydramnios at term and evaluate whether the mode of delivery in patients with oligohydramnios influences perinatal outcomes in China.Methods: A cross-sectional survey of all deliveries in 39 hospitals in China from 1 January 2011-31 December 2011 was evaluated for the mode of delivery and perinatal outcomes in women with oligohydramnios compared to those without known oligohydramnios after excluding preterm births, polyhydramnios, and oligohydramnios secondary to premature rupture of membranes.Results: Oligohydramnios complicated 3954 (4.4%) of the 89,050 pregnancies, analyzed. Pregnancy cases with oligohydramnios compared those without known oligohydramnios had a significantly higher incidence of preexisting or gestational diabetes mellitus, fetal growth restriction, nonreassuring fetal heart tracings, obesity and malpresentation (p<.001). The cesarean delivery (CD) rate was significantly higher in pregnancies with identified oligohydramnios compared to those without (84.4 versus 54.7%; p<.001). Furthermore, in 2/3 of these CD in pregnancies with oligohydramnios, the identification of oligohydramnios was the only indication for the CD. In pregnancies with oligohydramnios, vaginal delivery did not significantly increase the risks of adverse outcomes compared to vaginal delivery without oligohydramnios, except postpartum complication.Conclusion: CD is not indicated in term pregnancies with isolated oligohydramnios. Vaginal delivery of oligohydramnios is not associated with increased perinatal mortality.

Updating the amniotic fluid index nomograms according to perinatal outcome

Background: The two most commonly used nomograms for amniotic fluid index (AFI) were developed by Moore and Cayle and Magann et al. However, there are several inconsistencies between the two methods.Objective: The aim of the study was to determine whether these differences carry clinical significance.Methods: A retrospective cohort of women with singleton pregnancies evaluated for AFI during pregnancy at a tertiary medical center in 2007-2014 were divided into five groups: group A, definite oligohydramnios-AFI below the fifth percentile according to the nomograms of both Moore and Cayle and Magann et al.; group B, intermediate oligohydramnios-AFI below the fifth percentile according to only one nomogram (Moore and Cayle); group C, euhydramnios-normal AFI according to both nomograms; group D, intermediate polyhydramnios-AFI above the 95th percentile according to one nomogram (Magann et al.); group E, definite polyhydramnios-above the 95th percentile according to both nomograms. The association of group by maternal and perinatal outcomes was analyzed.Results: A total of 6987 women were included: group A, 996 (14%); group B, 1344 (19%); group C, 2561 (37%); group D, 1051 (15%); group E, 1034 (15%). Group B (intermediate oligohydramnios) was characterized by significantly lower rates of adverse perinatal outcomes than group A (definite oligohydramnios): small for gestational age neonate (12.3 versus 15.2%, p = .05), neonatal intensive care unit admission (11.1 versus 21.5%; p < .001), composite respiratory outcome (4.8 versus 9.8%; p < .001), and neonatal sepsis (6.4 versus 10.8%; p < .001). No such differences were found between groups B and C. Group D (intermediate polyhydramnios) differed from group E (definite polyhydramnios) by lower rates of 5 minutes Apgar score <7 (1.3 versus 3.2%; p = .003), neonatal intensive care unit admission (10.9 versus 14.4%; p = .02), and major congenital anomalies (1.7 versus 5.6%; p = .02). There was no difference in these parameters between groups D and C.Conclusion: This study suggests that intermediate oligohydramnios and intermediate polyhydramnios are not associated with adverse perinatal outcomes. Outcome in these pregnancies is similar to pregnancies with euhydramnios. Commonly used AFI nomograms should be updated.

Is pregnancy associated plasma protein-A (PAPP-A) a marker for adverse perinatal outcomes in preterm isolated oligohydramnios cases?

OBJECTIVE

Isolated oligohydramnios is defined as an amniotic fluid index below five centimeter with no other coexisting condition. There are still controversies about the management and pregnancy outcomes. A marker predicting these is crucial. Low pregnancy associated plasma protein-A levels were reported to be related with adverse pregnancy outcomes. We aimed to determine the role of first trimester pregnancy associated plasma protein-A for poor outcomes in preterm isolated oligohydramnios cases.

MATERIAL AND METHODS

Fifty-one patients with singleton pregnancies diagnosed as isolated oligohydramnios at 28/0-36/6 weeks of gestation and 110 gestational age matched healthy controls between January and December 2015 were included. Maternal age, gestational age at delivery, mode of delivery, indication for cesarean section, Apgar scores at first and fifth minutes, birth weight, neonatal intensive care unit admission and mortality were recorded. Pregnancy associated plasma protein-A levels were compared between groups and its role in adverse perinatal outcomes was evaluated.

RESULTS

Pregnancy associated plasma protein-A levels and pregnancy outcomes were similar in two groups (p > 0.050) except birth weight, gestational age at delivery and presence of fetal distress. Pregnancy associated plasma protein-A levels did not differ in terms of delivery mode, presence of fetal distress, first and fifth minutes Apgar scores and neonatal intensive care unit admission (p = 0.323,0.650,0.990,0.112,0.853). Also, it was not determined as a risk factor for cesarean section, presence of fetal distress, low Apgar scores and neonatal intensive care unit admission.

CONCLUSION

Pregnancy associated plasma protein-A, a well-known prognostic factor for some of high risk pregnancy conditions, may not be used as a marker in preterm isolated oligohydramnios cases.

Oligohydramnios in complicated and uncomplicated pregnancy: a systematic review and meta-analysis

OBJECTIVE

To evaluate adverse pregnancy outcomes in singleton pregnancies diagnosed with oligohydramnios through a systematic review and meta-analysis of controlled trials.

METHODS

We searched electronic databases via OVID, EBSCO, Web of Science, Google Scholar and others from 1980 to 2015. Prospective and retrospective studies with a control group were included. Two authors independently reviewed the abstracts from the literature search. Inclusion criteria were: studies in English, singleton pregnancy, normal fetal anatomy, intact membranes and oligohydramnios determined by the amniotic fluid index (AFI) technique. We stratified the meta-analysis into two groups according to risk: high risk including studies of oligohydramnios with comorbid conditions (e.g. hypertension) and low risk including studies of isolated oligohydramnios.

RESULTS

Fifteen trials met the inclusion criteria. Nine were high-risk and six were low-risk studies, including 8067 and 27 526 women, respectively. Compared with women with normal AFI, those with isolated oligohydramnios had significantly higher rates of an infant with meconium aspiration syndrome (relative risk (RR), 2.83; 95% CI, 1.38-5.77), Cesarean delivery for fetal distress (RR, 2.16; 95% CI, 1.64-2.85) and admission to the neonatal intensive care unit (NICU) (RR, 1.71; 95% CI, 1.20-2.42). Patients with oligohydramnios and comorbidities were more likely to have an infant with low birth weight (RR, 2.35; 95% CI, 1.27-4.34). However, rates of 5-min Apgar score < 7 (RR, 1.85; 95% CI, 0.69-4.96), NICU admission (RR, 2.09; 95% CI, 0.80-5.45), meconium-stained amniotic fluid (RR, 1.32; 95% CI, 0.62-2.81) and Cesarean delivery for fetal distress (RR, 1.65; 95% CI, 0.81-3.36) were similar to those for women with normal AFI. Stillbirth rates were too low to analyze in the meta-analysis.

CONCLUSIONS

This review helps to delineate which adverse outcomes are increased with oligohydramnios in low-risk pregnancy (NICU admission, Cesarean delivery for fetal distress and meconium aspiration syndrome), but does not provide enough data to determine the optimal timing of delivery in such cases. Oligohydramnios in complicated pregnancy is associated with an increased risk of delivery of an infant with low birth weight, but this may be confounded by the comorbid condition. Therefore, in high-risk pregnancy, management should be dictated by the comorbid condition and not the presence of oligohydramnios. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Induction of Labor in Women with Oligohydramnios: Misoprostol Compared with Prostaglandin E2

Objective To compare perinatal outcomes in women with oligohydramnios and an unfavorable cervix undergoing labor induction with misoprostol to prostaglandin E2. Study Design We conducted a secondary analysis of women with oligohydramnios undergoing labor induction in the Consortium on Safe Labor study (2002-2008). Oligohydramnios was recorded in the medical chart. We evaluated perinatal outcomes. We limited the analysis to women with an unfavorable cervix defined by simplified Bishop score ≤ 4. Misoprostol was compared with prostaglandin E2. Women could have received oxytocin, underwent mechanical dilation, or had artificial rupture of membranes, but women who underwent induction with both misoprostol and prostaglandin E2 were excluded. We calculated adjusted odds ratios with 95% confidence intervals, controlling for maternal age, maternal body mass index (kg/m²), parity, and mechanical dilation. Results Among women with oligohydramnios and an unfavorable cervix who underwent induction of labor, 141 (39.4%) received misoprostol and 217 (60.6%) received prostaglandin E2. There were no significant differences in cesarean delivery, chorioamnionitis, postpartum hemorrhage, transfusion, neonatal intensive care unit (NICU) admission, NICU stay > 72 hours, mechanical ventilation, and neonatal sepsis. Conclusion In women with oligohydramnios and an unfavorable cervix, induction of labor with misoprostol was comparable to prostaglandin E2.

Perinatal outcomes with isolated oligohydramnios at term pregnancy

AIMS

To compare the outcomes of term gestations with oligohydramnios in the absence of other underlying disorders and term gestations with normal amniotic fluid.

METHODS

A retrospective analysis of obstetric outcomes in 27,708 term pregnancies. We compared three groups: labor induced because of oligohydramnios, spontaneous onset of labor with normal amniotic fluid, and labor induced because of late term pregnancy with normal amniotic fluid. We excluded pregnancies with maternal or fetal diseases or disorders potentially related with amniotic fluid alterations. The main outcome measures were mode of delivery, neonatal birth weight, umbilical artery blood pH, Apgar scores and neonatal discharge status.

RESULTS

Compared to spontaneous labor, induction of labor because of oligohydramnios was associated with a higher risk of cesarean delivery and small size of the fetus for gestational age (SGA). Compared to induction because of late term pregnancy there were no significant differences in neonatal, although neonates had a higher risk of being SGA.

CONCLUSION

The only perinatal outcome for which the risk was higher in term pregnancies with isolated oligohydramnios was SGA. The systematic induction of labor in these pregnancies should be questioned.

Antenatal fetal surveillance "Assessment of the AFV"

The evaluation of amniotic fluid volume (AFV) is an established part of the antenatal surveillance of pregnancies at risk for an adverse pregnancy outcome. The two most commonly used ultrasound techniques to estimate AFV are the amniotic fluid index (AFI) and the single deepest pocket (SDP). Four studies have defined normal AFVs, and although their normal volumes have similarities, there are also differences primarily due to the statistical methodology used in each study. Dye-determined AFV correlates with ultrasound estimates for normal fluid volumes but correlates poorly for oligohydramnios and polyhydramnios. The addition of color Doppler in estimating AFV leads to the overdiagnosis of oligohydramnios. Neither the AFI nor the SDP is superior in identifying oligohydramnios, but the SDP is a better measurement choice as the use of AFI increases the diagnosis rate of oligohydramnios and labor inductions without an improvement in pregnancy outcomes.

Explaining the 2001–2002 Infant Mortality Increase in the United States: Data from the Linked Birth/Infant Death Data Set

The U.S. infant mortality rate (IMR) increased from 6.8 infant deaths per 1,000 live births in 2001 to 7.0 in 2002, the first increase in more than 40 years. From 2001 to 2002, IMR increased for very low birthweight infants as well as for preterm and very preterm infants. Although IMR for very low birthweight infants increased, most of the increase in IMR from 2001 to 2002 was due to a change in the distribution of births by birthweight and, more specifically, to an increase in infants born weighing less than 750 grams. The majority of infants born at less than 750 grams die within the first year of life; thus, these births contribute disproportionately to overall IMR. Increases in births at less than 750 grams occurred for non-Hispanic white, non-Hispanic black, and Hispanic women. Most of the increase occurred among mothers 20 to 34 years of age. Although multiple births contributed disproportionately, most of the increase in births at less than 750 grams occurred among singletons. Three hypotheses were evaluated to assess their possible impact on the increase in less than 750-gram births: possible changes in (1) the reporting of births or fetal deaths, (2) the risk profile of births, and (3) medical management of pregnancy. Although each of these factors may have contributed to the increase, the relative effects of these and other factors remain unclear. More detailed studies are needed to further explain the 2001–2002 infant mortality increase.

Isolated Oligohydramnios at Term as an Indication for Labor Induction: A Systematic Review and Meta-Analysis

OBJECTIVE

To investigate whether isolated oligohydramnios at term is associated with increased rates of perinatal morbidity and mortality and whether induction of labor in term pregnancies with isolated oligohydramnios is superior to conservative management in reducing perinatal morbidity and mortality.

STUDY DESIGN

We searched databases from inception to May 2015. We included studies that evaluated isolated oligohydramnios at term and perinatal outcome. Each outcome was analyzed separately, performing a comparative analysis between the study and control groups.

RESULTS

Twelve studies were included with 35,999 women: 2,414 (6.7%) with isolated oligohydramnios and 33,585 (93.29%) with normal amniotic fluid index. Patients with isolated oligohydramnios had significantly higher rates of labor induction [odds ratio (OR) 7.56, confidence interval (CI) 4.58-12.48] and Cesarean sections (OR 2.07, CI 1.77-2.41). There were higher rates of an Apgar score <7 at 1 and 5 min (OR 1.53, CI 1.03-2.26, and OR 2.01, CI 1.3-3.09, respectively) and admission to the neonatal intensive care unit (OR 1.47, CI 1.17-1.84). There were no significant differences in cord pH <7.1 and meconium-stained amniotic fluid. In the single randomized trial comparing induction of labor with expectant management, no differences were found in any significant maternal or neonatal outcomes.

CONCLUSION

Isolated oligohydramnios at term is associated with significantly higher rates of labor induction, Cesarean sections, and short-term neonatal morbidity.

Comparison of the Effect of Maternal Rest in Alternative Lateral Decubitus Positions on the Amniotic Fluid Index: A Randomized Controlled Trial

OBJECTIVES

To analyze the effect of maternal rest in the left and right lateral decubitus positions and resting alone on the amniotic fluid index (AFI).

METHOD

Sixty-nine women with singleton pregnancies and an AFI of 6 to 24 cm at 36 to 40 weeks' gestation were included in this randomized controlled trial. The women were randomized into 2 intervention groups. After initial AFI measurements, group 1 (n = 35) rested in the left lateral position for 15 minutes and then rested in the right lateral position for another 15 minutes. Group 2 (n = 34) rested in the right lateral position for 15 minutes and then rested in the left lateral position for another 15 minutes. To compare differences between groups, AFIs were measured at the end of each 15-minute period while the participants were kept on their backs in a semirecumbent position.

RESULTS

The demographic data, gestational ages, and initial AFI values did not differ between groups (P > .05). In group 1, the initial mean AFI ± SD of 12.25 ± 3.81 increased significantly during the first 15 minutes to 15.17 ± 4.27 and decreased significantly during the second 15 minutes to 13.30 ± 4.29 (P< .001); however, the 30-minute AFI was still significantly higher than the initial value (P = .008). In group 2, the initial AFI change during the first 15 minutes, from 12.83 ± 3.99 to 12.72 ± 3.87, was not significant (P> .05); however, it increased significantly to 15.63 ± 4.14 during the second 15 minutes (P< .001). The 30-minute AFI was still significantly higher than the initial value (P< .001).

CONCLUSIONS

Maternal rest in the right lateral decubitus position does not seem to either increase or decrease the AFI, and resting alone does not increase the AFI in the short term.

An Algorithm for Predicting Neonatal Mortality in Threatened Very Preterm Birth

OBJECTIVE

To develop a prediction model for neonatal mortality using information readily available in the antenatal period.

METHODS

A multiple logistic regression model of a complete population-based geographically defined cohort of very preterm infants of 23+0 to 30+6 weeks' gestation was used to identify antenatal factors which were predictive of mortality in this population. Infants lt; 23 weeks and those with major anomalies were excluded.

RESULTS

Between 1996 and 2012, 1240 live born infants lt; 31 weeks' gestation were born to women residing in Nova Scotia. Decreasing gestational age strongly predicted an increased mortality rate. Other factors significantly contributing to increased mortality included classification as small for gestational age, oligohydramnios, maternal psychiatric disorders, antenatal antibiotic therapy, and monochorionic twins. Reduced neonatal mortality was associated with antenatal use of antihypertensive agents and use of corticosteroids of any duration of therapy given at least 24 hours before delivery. An algorithm was developed to estimate the risk of mortality without the need for a calculator.

CONCLUSION

Prediction of the probability of neonatal mortality is influenced by maternal and fetal factors. An algorithm to estimate the risk of mortality facilitates counselling and informs shared decision making regarding obstetric management.

An Update on Maternal Hydration Strategies for Amniotic Fluid Improvement in Isolated Oligohydramnios and Normohydramnios: Evidence from a Systematic Review of Literature and Meta-Analysis

OBJECTIVE

Several trials aimed at evaluating the efficacy of maternal hydration (MH) in increasing amniotic-fluid-volume (AFV) in pregnancies with isolated oligohydramnios or normohydramnos have been conducted. Unfortunately, no evidences support this intervention in routine-clinical-practice. The aim of this systematic-literature-review and meta-analysis was to collect all data regarding proposed strategies and their efficacy in relation to each clinical condition for which MH-therapy was performed with the aim of increasing amniotic-fluid (AF) and improving perinatal outcomes.

MATERIALS AND METHODS

A systematic literature search was conducted in electronic-database MEDLINE, EMBASE, ScienceDirect and the Cochrane-Library in the time interval between 1991 and 2014. Following the identification of eligible trials, we estimated the methodological quality of each study (using QADAS-2) and clustered patients according to the following outcome measures: route of administration (oral versus intravenous versus combined), total daily dose of fluids administered (<2000 versus >2000), duration of hydration therapy: (1 day, >1 day but <1 week, >1 week), type of fluid administered (isotonic versus hypotonic versus combination).

RESULTS

In isolated-oligohydramnios (IO), maternal oral hydration is more effective than intravenous hydration and hypotonic solutions superior to isotonic solutions. The improvement in AFV appears to be time-dependent rather than daily-dose dependent. Regarding normohydramnios pregnancies, all strategies seem equivalent though the administration of hypotonic-fluid appears to have a slightly greater effect than isotonic-fluid. Regarding perinatal outcomes, data is fragmentary and heterogeneous and does not allow us to define the real clinical utility of MH.

CONCLUSIONS

Available data suggests that MH may be a safe, well-tolerated and useful strategy to improve AFV especially in cases of IO. In view of the numerous obstetric situations in which a reduced AFV may pose a threat, particularly to the fetus, the possibility of increasing AFV with a simple and inexpensive practice like MH-therapy may have potential clinical applications. Considering the various strategies of maternal hydration implemented in the treatment of IO, better results were observed when treatment was based on a combination of intravenous (for a period of 1 day) and oral (for a period of at least 14 days) hypotonic fluids (≥2000ml).

What does fetal autopsy unmask in oligohydramnios?

OBJECTIVE

We aimed to determine the value of autopsy in fetuses with antenatally diagnosed oligohydramnios.

PATIENTS AND METHODS

We evaluated all fetal losses over a period of 6.5 years. Those with oligohydramnios on antenatal scan were critically analyzed. Oligohydramnios was defined as amniotic fluid index of less than five objectively or as an obvious lack of liquor at subjective assessment. A detailed postmortem examination was carried out in all the fetuses after obtaining an informed consent.

RESULTS

Fetal autopsy was conducted in 255 cases. Fifty-five (21.5%) fetuses were diagnosed to have oligohydramnios on antenatal ultrasonography. On analysis of antenatal causes of oligohydramnios, maternal/placental factors were noted in 18%, ultrasound findings known to affect amniotic fluid in 27% while cause remained unidentified in 54.5% of cases. On autopsy, fetal malformations were noted in 61.8% cases, intrauterine growth retardation in 21.8% fetuses and no obvious malformations in 16.3% fetuses. Renal anomalies were noted in 40% cases and non-renal malformations in 21.8% cases.

CONCLUSION

The postmortem examination helped us to identify the cause of fetal loss in 46 (83.6%) fetuses with antenatal oligohydramnios. A working diagnosis could not have been established without autopsy in 19 (34.5%) cases.

Intra-vaginal prostaglandin E2 versus double-balloon catheter for labor induction in term oligohydramnios

OBJECTIVE

Compare mechanical and pharmacological ripening for patients with oligohydramnios at term.

STUDY DESIGN

Fifty-two patients with oligohydramnios ⩽ 5 cm and Bishop score ⩽ 6 were randomized for labor induction with a vaginal insert containing 10 mg timed-release dinoprostone (PGE2) or double-balloon catheter. The primary outcome was time from induction to active labor. Time to labor, neonatal outcomes and maternal satisfaction were also compared.

RESULT

Baseline characteristics were similar. Time from induction to active labor (13 with PGE2 vs 19.5 h with double-balloon catheter; P = 0.243) was comparable, with no differences in cesarean rates (15.4 vs 7.7%; P = 0.668) or neonatal outcomes. The PGE2 group had higher incidence of early device removal (76.9 vs 26.9%; P = 0.0001), mostly because of active labor or non-reassuring fetal heart rate. Fewer PGE2 patients required oxytocin augmentation for labor induction (53.8 vs 84.6% P = 0.034). Time to delivery was significantly shorter with PGE2 (16 vs 20.5 h; P = 0. 045).

CONCLUSION

Intravaginal PGE2 and double-balloon catheter are comparable methods for cervical ripening in term pregnancies with oligohydramnios.

Perinatal outcome after diagnosis of oligohydramnious at term

Background:

Oligohydramnious is threatening condition to fetal health for which some treatment are available and some are under evaluation. Oligohydramnious, is associated with increased pregnancy complication, congenital anomalies and perinatal mortality. There is an inverse relationship between the amniotic fluid index (AFI) and the adverse perinatal outcome. Oligo hydramnlious is clinical condition characteries by amniotic fluid index (AFI) of 5cm or less. Its incidence is 3-5 % of all the pregnancies an accurate and reproducible method of determining abnormality in amniotic fluid volume (AFI) is sonographic asessment of amniotic fluid index (AFI). It often increase the risk of small for gestational age (SGA) and also the incidence of cesarean section, meconium stained, low apgar score and Neonatal intensive care (NICU) admission.

Objectives:

The aim of study was to analyze the fetal out come in low risk pregnant women with oligohydramnious at term. This is a prospective, descriptive study.

Materials and Methods:

The study was conducted at Amiralmomenin hospital in Zabol for a period of 8 months from 2012/Mar/27 to 2012/Nov/5.It included 100 pregnant women diagnosed with the AFI of or less than 5cm at term. Control group included 300 pregnant women with AFI more than 8cm. Comparison was done between the study group and the control group. Regarding the fetal and pregnancy outcome using chi square and p value, detail were recorded in terms of fetal weight, apgar score at 1 and 5 minutes.

Results:

Mode of delivery, NICU admission neonatal death and induction of labour. Oligohydramnious is associated with a high rate of pregnancy complication and increased preinatal morbidity and mortality. Women with oligohydramnious usually have low birth babies.

Conclusions:

However, it can expect a safe and good outcome for which proper fetal surveillance and regular antenatal care visits are required.

Oligohydramnios increases the risk of respiratory hospitalization in childhood: a population-based study

BACKGROUND

Pulmonary hypoplasia is associated with reduced lung function in infancy. The aim of this study was to evaluate the hypothesis that children exposed to oligohydramnios display an increased risk of hospitalization for respiratory illness by using a population-based matched-cohort design.

METHODS

We used three nationwide population-based data sets to identify 5,228 women who gave birth during 2004 to 2007 and were diagnosed with oligohydramnios during the third trimester of pregnancy. A cohort of 20,912 unaffected pregnant women was matched with these cases, according to neonatal sex and gestational age, maternal age and education, and level of prenatal care. Respiratory hospitalization and respiratory failure were defined using discharge diagnostic codes.

RESULTS

Oligohydramnios-exposed children had an 8% higher incidence rate of respiratory hospitalization and an 80% higher incidence rate of respiratory failure, compared with children without oligohydramnios exposure. This risk remained after adjusting for all potential risk factors. Cox regression analyses indicated that the adjusted hazard ratios of respiratory hospitalization and respiratory failure were 1.07 (95% confidence interval (CI): 1.01-1.15; P = 0.030) and 2.20 (95% CI: 1.26-3.84; P = 0.005), respectively.

CONCLUSION

Children exposed to oligohydramnios during the third trimester of pregnancy display an increased risk of hospitalization for respiratory illness.

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

OBJECTIVES

To determine whether a borderline amniotic fluid index (AFI) in the third trimester is associated with an increased rate of cesarean delivery for fetal intolerance of labor, meconium-stained amniotic fluid, and intrauterine growth restriction, among other adverse perinatal outcomes.

METHODS

Patients with a diagnosis of a borderline AFI between January 2008 and August 2012 were identified. Antepartum, delivery, and neonatal data were collected and compared to a cohort with a normal AFI.

RESULTS

We enrolled 739 patients, including 177 with a borderline AFI (>5 and <10 cm) and 562 with a normal AFI (≥ 10-24 cm); 360 patients delivered at University of Arizona Medical Center, and 379 delivered at St Joseph's Hospital. Combined and individual analyses of each center revealed no significant difference in fetal intolerance of labor (P = .19) or cesarean delivery for fetal intolerance (P = .074) between cohorts. In both settings, patients with a borderline AFI were more likely than those with a normal AFI to undergo antepartum testing (P < .001). A statistically significant increase in intrauterine growth restriction in the borderline AFI group was noted, with a calculated risk ratio of 13.76 (P < .001). There was no difference between groups for meconium-stained amniotic fluid (P = .23), neonatal intensive care unit admission (P = .054), preterm delivery (P = .31), or operative vaginal delivery (P = .45).

CONCLUSIONS

The findings of this study suggest that there is no difference in the rate of fetal intolerance of labor in pregnancies with a borderline AFI and those with a normal AFI. Pregnancies complicated by a borderline AFI are more likely to undergo antepartum testing, yet the benefit is unclear. Significantly more patients with a borderline AFI had underlying growth restriction, which may provide a useful tool for risk stratification in the management of a borderline AFI.

Which is the safer method of labor induction for oligohydramnios women? Transcervical double balloon catheter or dinoprostone vaginal insert

OBJECTIVE

To compare the effectiveness and safety of two cervical ripening methods in term primiparous women with unfavorable cervices and oligohydramnios.

METHODS

Women (126 cases) with oligohydramnios [amniotic fluid index (AFI) ≤5 cm] and a low Bishop Score (≤6) were assigned randomly to use double balloon catheter (mechanical method group, 67 cases) or dinoprostone 10 mg controlled-release vaginal insert (pharmacological method group, 59 cases) for induction of labor. The study's primary outcome was caesarean section rate (CSR). The secondary outcome measures included maternal and neonatal morbidity, an incremental changes in Bishop Score, and intrapartum interventions.

RESULTS

There was no significant difference between the mechanical method group and the pharmacological method group in CSR and change in Bishop Score. Tacysystole, non-reassuring fetal heart patterns, and cases of newborn umbilical-cord arterial blood pH<7.1 were significantly lower with the mechanical method compared with the pharmacological method (p < 0.05). More patients needed additional intervention in the mechanical method group.

CONCLUSIONS

Both methods resulted in a similar CSR. Double balloon catheter resulted in fewer labor complications, but more frequent use of oxytocin and amniotomy. Compared with dinoprostone vaginal insert, double balloon catheter use may be less problematic in women with oligohydramnios.

Amniotic fluid as a vital sign for fetal wellbeing

Introduction: Amniotic fluid, once thought to merely provide protection and room for necessary movement and growth for the fetus, is now understood to be a highly complex and dynamic system that is studied as a data point to interpret fetal wellbeing. Methods: Assessment of amniotic fluid volume is now routine when performing a sonographic evaluation of fetal status and is an important consideration in the assessment and management of perinatal morbidity and mortality.1,2 In this review, we will cover the dynamics that affect amniotic fluid volume, review methods for measurement and quantification of volume, review definitions for normative data as related to neonatal outcomes, and provide evidence based guidance on the workup and management options for oligoydramnios and polyhydramnios in singleton and twin pregnancies. Conclusions: When abnormalities of fluid exist, appropriate workup to uncover the underlying etiology should be initiated as adverse fetal outcomes are sometimes associated with these variations from normalcy.

The Effects of Intravenous Hydration on Amniotic Fluid Index in Pregnant Women with Preterm premature Rupture of Membranes: A Randomized Clinical Trial

INTRODUCTION

Preterm premature rupture of membranes (PPROM) can result in fetal complications such as oligohydramnios. This study aimed to determine the effects of intravenous (IV) fluid bolus on amniotic fluid index (AFI) in pregnant women with PPROM.

METHODS

24 women with PPROM during singleton live pregnancy of 28 to 34 weeks whose baseline AFI was ≤ 5cm were randomized into two groups. The study group received one liter intravenous fluid bolus of isotonic Ringer serum during 30-minute period. Reevaluations of amniotic fluid index in both groups were made 90 minutes and 48 hours after baseline measurement. Independent t-test and paired t-test were used to compare the two groups and mean amniotic fluid index before and after treatment, respectively.

RESULTS

The results of this study demonstrate that AFI decreased statistically significant in both the control and study groups. AFI decreased in both groups at 48 hours later. This decrease was not statistically significant in any group. The mean change in AFI (90 minutes and baseline) and (48 hours and baseline) between the two groups were not significant. The time between mean baseline measurements and delivery were 196.41 and 140.58 hours in the study and control groups, respectively. This difference was not statistically significant.

CONCLUSION

This study did not find significant impact of hydration On AFI as a prophylactic method on oligohydramnios in pregnant women with PPROM.

The effects of intravenous hydration on amniotic fluid volume and pregnancy outcomes in women with term pregnancy and oligohydramnios: a randomized clinical trial

INTRODUCTION

Amniotic fluid is an important factor in the prediction of fetal survival. The aim of this research was to evaluate the effects of intravenous hydration of mothers on amniotic fluid volume and in turn on pregnancy outcomes.

METHODS

The current single blind controlled clinical trial was conducted on 20 pregnant mothers with amniotic fluid index of lower or equal to 5 cm and gestational age of 37-41 weeks. The subjects were divided into two groups of case and control through simple random sampling. Amniotic fluid index was measured in all participants. The case group received one liter of isotonic saline during 30 minutes by the bolus method. Reevaluations of amniotic fluid index in both groups were made 90 minutes after baseline measurement. Independent t-test and paired t-test were used to compare the two groups and mean amniotic fluid index before and after treatment, respectively.

RESULTS

Hydration of mothers significantly increased the amniotic fluid index in the case group (mean change: 1.5 cm; 95%CI: 0.46 - 2.64; P = 0.01). The mean change of amniotic fluid index in the control group did not significantly increase (P = 0.06). The elevation of amniotic fluid index in the hydration group (32%) was significantly higher than the control group (1%) (P = 0.03).

CONCLUSION

In this study intravenous hydration increased amniotic fluid index of mothers with term pregnancy and oligohydramnios. Since it caused no complications for the mother and the fetus, it can be used as an effective method in management of oligohydramnios.

Short-term outcome among term singleton infants with intrapartum oligohydramnios

AIM

To evaluate rates of early short-term neonatal complications among term singleton newborn infants with oligohydramnios.

METHODS

Retrospective data were collected on 456 term infants with prenatal diagnosis of oligohydramnios and on matched controls, including information on maternal condition and on infant perinatal complications.

RESULTS

Infants in the study group were born with lower birthweight and were SGA compared with those in the control group. Rates of renal malformations were significantly higher in the study group compared with the controls (15-3.3% and 3-0.7%, respectively; p = 0.007). Among the severe oligohydramnios subgroup (Amniotic Fluid Index <2), renal anomalies were even more prevalent compared to other infants with oligohydramnios and to the controls (6-9.8%, 9-2.3% and 3-0.7%, respectively; p < 0.001). The incidence of skeletal deformities (developmental dislocation of hip and torticollis) was higher among the study group.

CONCLUSION

Term infants with oligohydramnios that was detected near birth are associated with a greater prevalence of renal malformations (mostly mild hydronephrosis) as well as congenital torticollis and developmental dislocated hips compared with controls. Postnatal renal evaluation should be considered in infants with severe oligohydramnios.

Investigating maternal risk factors as potential targets of intervention to reduce socioeconomic inequality in small for gestational age: a population-based study

BACKGROUND

The major aim of this study was to investigate whether maternal risk factors associated with socioeconomic status and small for gestational age (SGA) might be viable targets of interventions to reduce differential risk of SGA by socioeconomic status (socioeconomic SGA inequality) in the metropolitan area of Vancouver, Canada.

METHODS

This study included 59,039 live, singleton births in the Vancouver Census Metropolitan Area (Vancouver) from January 1, 2006 to September 17, 2009. To identify an indicator of socioeconomic SGA inequality, we used hierarchical logistic regression to model SGA by area-level variables from the Canadian census. We then modelled SGA by area-level average income plus established maternal risk factors for SGA and calculated population attributable SGA risk percentages (PAR%) for each variable. Associations of maternal risk factors for SGA with average income were investigated to identify those that might contribute to SGA inequality. Finally, we estimated crude reductions in the percentage and absolute differences in SGA risks between highest and lowest average income quintiles that would result if interventions on maternal risk factors successfully equalized them across income levels or eliminated them altogether.

RESULTS

Average income produced the most linear and statistically significant indicator of socioeconomic SGA inequality with 8.9% prevalence of SGA in the lowest income quintile compared to 5.6% in the highest. The adjusted PAR% of SGA for variables were: bottom four quintiles of height (51%), first birth (32%), bottom four quintiles of average income (14%), oligohydramnios (7%), underweight or hypertension, (6% each), smoking (3%) and placental disorder (1%). Shorter height, underweight and smoking during pregnancy had higher prevalence in lower income groups. Crude models assuming equalization of risk factors across income levels or elimination altogether indicated little potential change in relative socioeconomic SGA inequality and reduction in absolute SGA inequality for shorter height only.

CONCLUSIONS

Our findings regarding maternal height may indicate trans-generational aetiology for socioeconomic SGA inequalities and/or that adult height influences social mobility. Conditions affecting foetal and childhood growth might be viable targets to reduce absolute socioeconomic SGA inequality in future generations, but more research is needed to determine whether such an approach is appropriate.

Risk factors for pulmonary artery hypertension in preterm infants with moderate or severe bronchopulmonary dysplasia

BACKGROUND

Despite the potential importance of pulmonary artery hypertension (PAH) in preterm infants with bronchopulmonary dysplasia (BPD), little is known about the risk factors for PAH.

OBJECTIVES

To investigate the risk factors for PAH in preterm infants with BPD.

METHODS

Infants diagnosed with BPD were assigned to the PAH group or non-PAH group except for infants with mild BPD who had no PAH. PAH was diagnosed on the basis of echocardiograms demonstrating elevated right ventricle pressure beyond the postnatal age of 2 months. Logistic regression analysis was done for the multivariate assessment of the risk factors for PAH in preterm infants with moderate or severe BPD.

RESULTS

A total of 98 infants among 145 infants with BPD were divided into a PAH group (n = 25) or non-PAH group (n = 73), while the remaining 47 infants had mild BPD with no PAH. Among the study patients, survival rate of the PAH group was significantly lower than that of the non-PAH group. Infants with PAH had more severe cases of BPD and underwent longer durations of oxygen therapy, conventional or high-frequency ventilation, and hospitalization compared to those without PAH. Low 5-min Apgar scores (≤6; relative risk (RR) 6.2; 95% confidence interval (CI) 1.4-28.0; p = 0.017) and oligohydramnios (RR 7.7; 95% CI 2.0-29.6; p = 0.030) were found to be significant risk factors for PAH according to multivariate analysis.

CONCLUSIONS

The present study shows that oligohydramnios is a specific risk factor for PAH in preterm infants with moderate or severe BPD.

Long-term health effects on the next generation of Ramadan fasting during pregnancy

Each year, many pregnant Muslim women fast during Ramadan. Using Indonesian cross-sectional data and building upon work of Almond and Mazumder (2011), I show that people who were prenatally exposed to Ramadan fasting have a poorer general health than others. As predicted by medical theory, this effect is especially pronounced among older people, who also more often report symptoms indicative of coronary heart problems and type 2 diabetes. Among exposed Muslims the share of males is lower, which is most likely caused by death before birth. I show that these effects are unlikely the result of common health shocks correlated to the occurrence of Ramadan, or of fasting mainly occurring among women who would have had unhealthier children anyway.

Amniotic fluid and the clinical relevance of the sonographically estimated amniotic fluid volume: oligohydramnios

The amniotic fluid volume (AFV) is regulated by several systems, including the in-tramembranous pathway, fetal production (fetal urine and lung fluid) and uptake (fetal swallowing), and the balance of fluid movement via osmotic gradients. The normal AFV across gestation has not been clearly defined; consequently, abnormal volumes are also poorly defined. Actual AFVs can be measured by dye dilution techniques and directly measured at cesarean delivery; however, these techniques are time-consuming, are invasive, and require laboratory support, and direct measurement can only be done at cesarean delivery. As a result of these limitations, the AFV is estimated by the amniotic fluid index (AFI), the single deepest pocket, and subjective assessment of the AFV. Unfortunately, sonographic estimates of the AFV correlate poorly with dye-determined or directly measured amniotic fluid. The recent use of color Doppler sonography has not improved the diagnostic accuracy of sonographic estimates of the AFV but instead has led to overdiagnosis of oligohydramnios. The relationship between the fixed cutoffs of an AFI of 5 cm or less and a single deepest pocket of 2 cm or less for identifying adverse pregnancy outcomes is uncertain. The use of the single deepest pocket compared to the AFI to identify oligohydramnios in at-risk pregnancies seems to be a better choice because the use of the AFI leads to an increase in the diagnosis of oligohydramnios, resulting in more labor inductions and cesarean deliveries without any improvement in peripartum outcomes.

Oligohydramnios, small for gestational age and pregnancy outcomes: an analysis using precise measures

BACKGROUND/AIM

Marginal or decreased amniotic fluid volume by ultrasound estimate and fetal growth restriction have been shown to be significantly associated with perinatal mortality. The association of fetal growth restriction and precisely measured amniotic fluid volume is unknown. The purpose of this study was to determine if adverse pregnancy outcomes are more likely in pregnancies complicated by small-for-gestational-age (SGA) neonates and dye-determined oligohydramnios.

METHODS

Admissions to neonatal intensive care unit (NICU) and other pregnancy outcomes were analyzed in parturients with known amniotic fluid volume, calculated by the dye-dilution technique. The pregnancy outcomes of those with oligohydramnios and SGA were compared with pregnancies complicated by just one of these two conditions and pregnancies with normal fluid and birth weight.

RESULTS

Of 202 patients, oligohydramnios was present in 26% (53), SGA in 15% (30) and both conditions in (5%) (11). Logistic regression, controlling for gestational age, demonstrated that the combination of oligohydramnios and SGA, compared to normal growth and fluid strongly predicted NICU admission (OR 11.1; 95% CI 2.1-59.2) but not other complications. (OR 4.8; 95% CI 0.3-62.9).

CONCLUSIONS

SGA with oligohydramnios significantly increases the likelihood of a NICU admission, but not other morbidity.