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

Objective: This study was undertaken to determine whether women with high-risk pregnancies and an amniotic fluid index of ≤5 cm require labor induction to prevent adverse perinatal outcomes. Study Design: All women at high risk at ≥34 weeks’ gestation with an amniotic fluid index of ≤5 cm were admitted to the hospital for labor induction. Each woman was compared with the next patient at high risk seen with an amniotic fluid index of >5 cm and the same pregnancy complication. Case patients were also matched with control subjects for maternal race, age, parity, and gestational age. Results: Prospectively, 79 women at high risk with an amniotic fluid index of ≤5 cm were compared with 79 control subjects. There were no statistically significant differences between the 2 groups in the risks of thick meconium (P = .29), variable decelerations (moderate P = .27, severe P = .37), amnioinfusion (P = .37), cesarean delivery for fetal distress (P = .4), and umbilical artery pH <7.10 (P = .29). Conclusion: High-risk pregnancies with an amniotic fluid index of ≤5 cm appear to carry intrapartum complication rates similar to those of similar high-risk pregnancies with an amniotic fluid index of >5. (Am J Obstet Gynecol 1999;180:1354-9.)     

Amino acids in amniotic fluid in the 15th–16th weeks of gestation and preterm labor

Objective. To investigate amino acids in amniotic fluid collected at the time of genetic amniocentesis.

Methods. We analyzed 128 fluids from the 15^th week of gestation and 53 from the 16^th week of gestation from normal pregnancies, and eight in the 15^th week and seven in the 16^th week from pregnancies that lead to preterm deliveries. We calculated the mean values for each week and the ratios between each pair of amino acids. The data for both groups (normal and preterm delivery) were compared.

Results. The most abundant amino acid in both groups was alanine. The comparisons of the groups showed significant differences for isoleucine in the 15^th gestational week (p < 0.05). Some amino acids had different evolutions between both gestational ages on comparing the normal group and preterm group. Eighteen ratios in the 15^th week showed significant differences (mainly in the ratios of arginine and taurine), and three in the 16^th week.

Conclusions. The amino acid profiles in amniotic fluid, particularly in the 15^th week of gestation, showed differences in the pregnancies that lead to preterm delivery.     

High placental index and poor pregnancy outcomes: a retrospective study of 18 386 pregnancies

Abstract

Introduction: Our aim was to state the correlation between placental index and pregnancy outcomes or in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) pregnancies.

Materials and methods: We included in this retrospective study all singleton births in a third level clinic during the period 2001–2011 (n?=?18?386). We divided placental index into quartiles and analyzed the differences between the groups in term of pregnancy outcomes. Then, we estimated crude and adjusted odds ratios (ORs) for placental index over the third centile of the distribution to correlate with pregnancy outcomes. We also analyzed the correlation between IVF/ICSI conceived pregnancies and placental index.

Results: Poor pregnancy outcomes were overrepresented in the highest quartile of placental index distribution. Thus, placental index was higher in pregnancies characterized by pregnancy-related hypertensive disorders (PRHDs), small for gestational age infants, newborn needing cardiopulmonary resuscitation or hospitalization in neonatal intensive care unit. These findings were independent of maternal age, length of gestation at delivery, IVF/ICSI conception and ethnicity. For IVF/ICSI pregnancies, the OR for being over the third quartile of placental index distribution was 2.01 (CI.95 1.40–2.90) after adjustment for maternal age, length of gestation, ethnicity, birth weight, parity, fetal sex, alteration of glucose metabolism in pregnancy and PRHDs.

Conclusions: We found a high placental index among pregnancies characterized by poor outcomes and conceived by IVF/ICSI.     

Meconium-stained amniotic fluid – risk factors and immediate perinatal outcomes among SGA infants

Objective: To detect factors that are associated with meconium-stained amniotic fluid (MSAF) among deliveries of small for gestational age (SGA) neonates and to identify perinatal outcomes of deliveries of SGA infants complicated with MSAF.

Methods: A population-based study comparing deliveries of SGA neonates with and without MSAF was conducted. Deliveries occurred during the years 1988–2007 at the Soroka University Medical Center. Risk factors for MSAF among SGA infants were evaluated. Incidence of adverse pregnancy outcomes were compared between deliveries of SGA neonates with and without MSAF.

Results: During the study period 9583 deliveries were of SGA neonates. Of these, 16.6% (n?=?1597) were complicated with MSAF. Among SGA neonates, older maternal age, multiparty, lack of prenatal care and weight were significantly associated with MSAF. Having delivered an SGA infant with MSAF was associated with decreased rates of induction of labor and increased rates of labor dystocia, delivery by cesarean section and fetal distress. Using multivariable regression models, having delivered an SGA infant with MSAF was independently associated with fetal distress.

Conclusion: Among SGA neonates, deliveries complicated with MSAF are associated with additional adverse pregnancy outcomes.     

Impact of amniotic fluid “sludge” on the risk of preterm delivery

Objective: To evaluate the impact of amniotic fluid “sludge” (AFS) on the risk of preterm delivery and to describe the effect of antibiotic treatment in that situation.

Methods: Case–control study including singleton pregnancies with or without AFS, between 15–32 weeks of gestation. Factors associated with preterm delivery before 32 weeks, 34 weeks and 37 weeks were evaluated with univariate and multivariate logistic regression. Since all women with AFS in this study were treated with antibiotics, a historical comparison was performed with similar patients with AFS found before 2007 and not treated with antibiotics.

Results: AFS was observed in 90/1220 patients (7.4%). AFS was associated with shorter cervical length, greater body mass index, cervical cerclage and preterm birth before 28 weeks. However, after adjustment, AFS did not remain associated with preterm delivery before 32 or 34 weeks. The historical comparison suggested that azithromycin could significantly reduce the risk of preterm delivery before 34 weeks (odds ratio: 0.2; 95% CI: 0.04–0.92).

Conclusions: AFS, treated with azithromycin, was associated with a higher risk of prematurity, but not independently after adjustment for cervical length and second trimester vaginal bleeding. Further studies need to evaluate the effect of antibiotics in pregnancies with AFS.     

Is amniotic fluid volume status predictive of fetal acidosis at delivery?

OBJECTIVE: To ascertain if dye-determined amniotic fluid volume just prior to delivery correlates with fetal acidosis at delivery. DESIGN: The present was a prospective observational study. SETTING: The study took place at the University of Mississippi Medical Center, Jackson MS, USA. POPULATION: The population included 100 unlaboured women undergoing an amniocentesis for the assessment of fetal lung maturity before an elective Caesarean delivery between January 1997 and December 2000. MAIN OUTCOMES MEASURED: The amniotic fluid volume was estimated by ultrasound measurement and quantified by dye-determined methodology immediately prior to Caesarean delivery. Umbilical cord artery pH was collected at the time of Caesarean delivery. RESULTS: The predictive accuracy of an amniotic fluid index < or = versus > 5 to identify an umbilical artery pH of < 7.20 had a sensitivity of 0%, a specificity of 84%, and a likelihood ratio of zero. None of the dye-determined low amniotic fluid volumes were identified using the single deepest pocket technique. Dye-determined low, normal, and high amniotic fluid volume groups contained a similar number of fetuses with umbilical cord arterial pH < 7.20 (P = 0.371), < 7.10 (P = 0.460), and < 7.00 (P = 0.614). Receiver-operating characteristic curves could not identify any amniotic fluid index from 0 to 18, single deepest pocket from 0 to 12, or dye-determined amniotic fluid volume 100-1900 mL to differentiate between the two newborns with an umbilical cord artery pH < 7 from 98 babies with cord pH > or = 7.0. CONCLUSIONS: Neither ultrasound estimates nor dye-determined amniotic fluid volumes are predictive of a low umbilical artery pH at delivery.     

Cytokine levels in amniotic fluid: a marker of preterm labor?

The aim of this study was to determine levels of Interleukin 6 (IL-6) in amniotic fluid at the beginning of the second trimester and to establish whether IL-6 can be used as a marker for premature birth as it would appear to be an important prenatal marker of chorionic inflammation. Thirty-three patients, between 16 and 19 weeks of gestation, who were undergoing amniocentesis to establish the presence or not of fetal genetic pathologies were enrolled into the study. Amniotic fluid (3 ml) was taken from each patient and used to perform enzyme-linked immunosorbent assays (ELISAs). The results were analyzed using the Mann-Whitney test and Pearson and Spearman coefficient. The patients were divided into three groups on the basis of the levels of IL-6 found: a) up to 450 pg/ml; b) between 450 and 900 pg/ml; c) over 900 pg/ml; These data were then evaluated alongside the date of parturition and the presence of any maternal or fetal pathologies. The results of our analyses, however, were inconclusive: levels of IL-6 were normal in patients presenting pathologies while obstetric pathologies were absent in patients with high levels of IL-6. In conclusion, this data would indicate that a different method or approach is required for the identification of a marker for premature birth.     

How well do the amniotic fluid index and single deepest pocket indices (below the 3rd and 5th and above the 95th and 97th percentiles) predict oligohydramnios and hydramnios?

OBJECTIVE: This study was undertaken to determine whether the amniotic fluid index (AFI) and single deepest pocket percentiles can reliably identify a dye-determined amniotic fluid volume. STUDY DESIGN: Ultrasound measurements and dye-determined volumes were prospectively collected. Oligohydramnios predictors included AFI and single deepest pocket below the 3rd and 5th percentiles, and hydramnios predictors were based on AFI and single deepest pocket above the 95th and 97th percentiles. RESULTS: Two hundred ninety-one women with singleton pregnancies participated, including 75 pregnancies (26%) with oligohydramnios and 31 pregnancies (10%) with hydramnios. The predictive ability of the AFI and single deepest pocket indices (<3rd and 5th percentiles) to identify oligohydramnios was between 11% and 27% and to identify hydramnios (>95th and 97th percentiles) ranged between 33% and 46%. The best prediction was for normal fluid volume with an accuracy of 83% to 94%. CONCLUSION: Amniotic fluid indices perform best for the identifying normal AF volumes, whereas the identification of oligohydramnios or hydramnios is poor.     

Documentation of amniotic fluid embolism via lung histopathology. Fact or fiction?

OBJECTIVE: To evaluate pulmonary histopathology for confirming amniotic fluid embolism. STUDY DESIGN: The Capra hircus (goat) model with fresh, homologous amniotic fluid was used. Raw fluid (n = 8), fluid filtered through a 5-microns filter (n = 14) and meconium-stained fluid with 1-7% solid debris (n = 7) were injected. Three hours after embolization the animals were euthanized and specimens collected. Three to five areas of lung were sampled based on the most abnormal areas visually. Traditional and special stains were utilized. The study protocol was approved by the institutional review board and animal use and care committee. Statistical analysis was by chi 2 with Yates correction. Significance was defined as P < .05. RESULTS: Amniotic fluid debris (fetal squames, mucin or foreign pigments) was found in 10 of 29 animals (34.5%). Debris was found in 7/7 (100%) of the meconium group, 2/8 (25%) of the raw fluid group and 1/14 of the filtered group (7%). The likelihood of finding debris in amniotic fluid embolism with meconium-stained fluid was greater than with raw (P < .017) or filtered amniotic fluid (P < .001). CONCLUSION: In this animal model, histopathologic confirmation of amniotic fluid embolism was an unreliable marker of the event except in cases of amniotic fluid embolism involving meconium-stained fluid.     

Transabdominal collection of amniotic fluid “sludge” and identification of Candida albicans intra-amniotic infection

A G3P2 patient who conceived while using an intrauterine contraceptive device (IUD) presented at 20 weeks of gestation with mild irregular uterine contractions and vaginal bleeding. Sonographic examination at admission showed the presence of dense amniotic fluid “sludge” and a long sonographic uterine cervix (42 mm). To assess the microbiologic significance of amniotic fluid “sludge”, we performed a transabdominal amniocentesis. The procedure was performed under real-time ultrasound, and fluid resembling pus at gross examination was noted. Rapid amniotic fluid analysis showed the presence of a high white blood cell count and structures resembling hyphae. Amniotic fluid cultures were positive for Candida albicans. Treatment was begun with broad-spectrum antibiotics, including Fluconazole, upon the visualization of pus in the “sludge” material because of the presence of hyphae in the Gram stain. Despite treatment, the patient went into spontaneous preterm labor and delivered five days after admission. Placental examination revealed acute fungal histologic chorioamnionitis and funisitis. This represents the first report of transabdominal collection and analysis of amniotic fluid “sludge” and the microbiologic detection of Candida albicans in this material. This report provides evidence that transabdominal retrieval of “sludge” is possible and may be of significant value for patient management and selection of antimicrobial agents.     

Perinatal outcomes of unplanned out-of-hospital deliveries: a case–control study

Purpose

To compare the pregnancy and perinatal outcomes of unplanned home or car births vs. in-hospital deliveries.

Methods

A retrospective, case–control study of women who underwent unplanned out-of-hospital deliveries vs. in-hospital deliveries from 2004 through 2014. Matching was based on gestational age and parity in a ratio of 2:1.

Results

There were no significant differences between the groups regarding demographic criteria, prenatal care and delivery complications. Women who delivered out of hospital (n = 90) had significantly fewer cesarean deliveries (1.1 vs. 10.6%; p = 0.05) and operative deliveries (2.2 vs. 13.3%; p = 0.004) in their obstetrical history than did the control group (n = 180). Significantly more newborns delivered out of the hospital had polycythemia (25.6 vs. 1.7%; p < 0.0001) and hypothermia (3.3 vs. 0%; p = 0.036) compared to the control group.

Conclusion

Women with unplanned out-of-hospital deliveries tend to have fewer complications in their previous deliveries. Higher rates of polycythemia and hypothermia require attention for neonates born out of the hospital.

     

Does residual amniotic fluid after preterm premature rupture of membranes have an effect on perinatal outcomes? 12 years experience of a tertiary care center

Objective  

To review our experience with preterm premature rupture of membranes at a tertiary-care hospital in Turkey to determine whether the amount of residual amniotic fluid after rupture has prognostic value for adverse maternal and fetal outcomes.     

Is pregnancy loss after amniocentesis related to the volume of amniotic fluid obtained?

Objective  The objective was to determine whether pregnancy loss after amniocentesis is related to the amount of amniotic fluid obtained during the procedure. Study design  The study enrolled 2,400 women, all in their sixteenth to twentieth week of pregnancy. A 22G spinal needle was inserted for amniocentesis. The amount of amniotic fluid obtained from 1,200 patients in Group 1 was 4 ml and from 1,200 patients in Group 2 was 20 ml. In Group 1, the amniotic fluid was analyzed with a quantitative fluorescent polymerase chain reaction technique, whereas in Group 2, conventional cytogenetic analysis was used. SPSS 16.0 (chi-square and t tests) was used for statistical analyses. Results  In Group 1, postamniocentesis premature rupture of membranes (PROM) occurred in four patients (0.3%). There was one unintended fetal loss and postamniocentesis miscarriage rate was 0.08%. In Group 2, postamniocentesis PROM occurred in 12 patients (1%). Eight of these patients experienced fetal loss (0.67%). Fetal loss rates were higher in Group 2 compared with Group 1. These results did not show statistical differences between the groups according to chi-square test (P > 0.05). Conclusion  Although statistical analysis denies the positive effect of obtaining small amounts of amniotic fluid to reduce fetal loss rates in patients after amniocentesis, six to eight times lower fetal loss rates based on the amount of fluid obtained cannot be undervalued.     

Should fetal scalp blood sampling be performed in the case of meconium-stained amniotic fluid?

Objective: To investigate the effect of using fetal scalp blood sampling on the risk of neonatal respiratory distress syndrome (NRDS) with meconium-stained amniotic fluid (MSAF).

Methods: Prospective data collection with regard to MSAF during labor for low-risk term cephalic singleton live birth from 2012 to 2014. Maternal, obstetric and neonatal data were compared according to the occurrence of respiratory distress syndrome (RDS group) or not (no RDS group).

Results: Of 515 newborns born through MSAF, 46 experienced RDS and from them 10 experienced meconium aspiration syndrome. No difference was observed according to maternal characteristic, abnormal fetal heart rate tracing pattern irrespective of its category and cesarean rate. Apgar at one?minute was lower in the group RDS (7.6 versus 8.5, p?<?0.05). The mean umbilical artery pH values did not differ between the two groups. Significant difference between newborns with and without RDS in terms of fetal scalp lactate sampling during the labor (71.1% versus 55.1%, p?<?0.05), and neonatal care unit (NCU) admissions (22.8% versus 10.8%, p?<?0.05). Secondary rather than primary meconium was associated with RDS when performing fetal scalp blood assessment (p?<?0.05). A significant correlation between RDS, fetal scalp blood assessment and MSAF diagnosed during the first stage of labor (after spontaneous rupture of membranes or at amniotomy) was found.

Conclusion: In case of MSAF, fetal scalp blood sampling did not reduce the risk of RDS.