Oligohydramnios and associated fetal complications

Comparison of Prenatal Ultrasound and Autopsy Findings of Fetuses Terminated in Second Trimester: A Five-Year Experience of a Tertiary Center

Objective: The aim of this study is to compare the prenatal ultrasonography (US) and the autopsy findings of the fetuses of 12-24th gestational weeks. Methods: This retrospective study comprises 84 fetuses autopsied. The correlation between US and autopsy findings was classified into four categories: (A) Compatible, (B) Minor findings added, (C) Major findings added, and (D) Incompatible. Results: Malformations were the most common medical termination indication. The most frequent findings at autopsy were multiple system findings followed by central nervous system. Prenatal US and autopsy findings were completely compatible in 48 fetuses (57.1%), while additional minor and major autopsy findings were found in 26 (31.0%) and 4 (4.8%), respectively. Autopsy and US findings were incompatible in 6 fetuses (7.1%). Conclusion: Prenatal ultrasound and fetal autopsy are complementary tools to obtain detailed and complete diagnosis of fetal anomalies and fetal autopsy is still a valuable tool to obtain further diagnostic information.

A randomized clinical trial of the intrapartum assessment of amniotic fluid volume: amniotic fluid index versus the single deepest pocket technique

OBJECTIVE

The purpose of this study was to determine whether an intrapartum assessment of amniotic fluid identifies a pregnancy that is at risk for an adverse outcome.

STUDY DESIGN

Parturients who were admitted for delivery were assigned randomly to have the amniotic fluid assessed either by amniotic fluid index or by the presence of a 2 x 1 pocket.

RESULTS

The amniotic fluid index was obtained in 499 pregnancies, and the 2 x 1 technique was performed in 501. Oligohydramnios was diagnosed in 25% of amniotic fluid index pregnancies versus 8% with the use of the 2 x 1 pocket technique (P <.001). Both techniques failed to identify patients who underwent an amnioinfusion for fetal distress (P=.864) or who experienced variable (P=.208) or late decelerations (P=.210) that influenced delivery, fetal distress in labor (P=.220), caesarean delivery for fetal distress (P=.133), and admission to neonatal intensive care unit (P=.686).

CONCLUSION

Neither the amniotic fluid index nor the 2 x 1 pocket technique that was undertaken as a fetal admission test identifies a pregnancy that is at risk for an adverse outcome.

Accuracy of prenatal diagnosis of renal agenesis with color flow imaging in severe second-trimester oligohydramnios

OBJECTIVE

Our purpose was to examine the potential of color flow imaging to assess the presence of renal arteries in second-trimester pregnancies complicated by severe oligohydramnios.

STUDY DESIGN

Thirty-three consecutive second-trimester pregnancies referred with severe oligohydramnios were prospectively studied with high-resolution color Doppler ultrasonography to establish the presence or absence of renal arteries. Prenatal findings were correlated with the presence or absence of fetal kidneys at postmortem or postnatal examination.

RESULTS

Neither renal artery was visualized in eight fetuses; postmortem examination confirmed bilateral renal agenesis in seven and unilateral renal agenesis with a contralateral atrophic multicystic kidney in the other. Only one renal artery was seen in three; postmortem examination demonstrated unilateral renal agenesis in two fetuses and bilateral multicystic dysplastic kidneys in the other. Postmortem or postnatal evaluation confirmed the presence of both kidneys in all 22 fetuses in which both renal arteries were identified prenatally.

CONCLUSIONS

Color Doppler ultrasonography is useful in the prenatal evaluation of fetuses with severe second-trimester oligohydramnios to demonstrate the presence or absence of renal arteries. This technique should be added to the armamentarium of prenatal tests to evaluate second-trimester fetuses with severe oligohydramnios.

Acute maternal hydration in third-trimester oligohydramnios: effects on amniotic fluid volume, uteroplacental perfusion, and fetal blood flow and urine output

OBJECTIVE

Our purpose was to determine whether acute maternal hydration in pregnancies with third-trimester oligohydramnios (1) increases amniotic fluid index and hourly fetal urine production rate and (2) alters uteroplacental perfusion and fetal blood flow.

STUDY DESIGN

Ten women with third-trimester oligohydramnios (amniotic fluid index < or = 5 cm) and 10 controls with normal amniotic fluid volume (amniotic fluid index > 7 cm) were prospectively recruited for this study. Maternal plasma and urine osmolality, amniotic fluid index, hourly fetal urine production rate, and Doppler flow velocimetry of maternal uterine artery and fetal umbilical, descending aorta, middle cerebral, and renal arteries were determined before and after oral hydration by having the patient drink 2 L of water over 2 hours.

RESULTS

There was a significant reduction in maternal plasma (p < 0.05) and urine osmolality (p < 0.0001) in both groups after short-term oral hydration. Hydration increased amniotic fluid volume in women with oligohydramnios (mean change in amniotic fluid index 3.2 cm, 95% confidence intervals 1.1 to 5.3; p < 0.02) but not in those with normal amniotic fluid volume (mean change in amniotic fluid index -2.0, 95% confidence intervals -4.1 to +0.2). The hourly fetal urine production rate, however, did not increase in either group (mean change in hourly fetal urine production rate 3.5 ml/hr, 95% confidence intervals -11.7 to +18.7 and -6.8 ml/hr, 95% confidence intervals -2.9 to -10.7, respectively). Hydration was associated with an increase in uterine artery mean velocity in the oligohydramnios group (mean change in mean velocity 16.7 cm/sec, 95% confidence intervals 8.0 to 25.3; p < 0.006) but not in controls (mean change in mean velocity 1.2 cm/sec, 95% confidence intervals -19.7 to +22.1). There was no change in pulsatility index or in velocity in any of the fetal vessels studied in either group.

CONCLUSIONS

Short-term maternal oral hydration increases the amniotic fluid index in women with third-trimester oligohydramnios. Although the mechanism for this effect remains unclear, it could not be accounted for by fetal urination in this study but instead was associated with improved uteroplacental perfusion.