Autopsy Findings in Fetuses with Oligohydramnios

Lee, Sang Don; Yoon, Jong Byung

Abstract

PURPOSE: After 16 weeks of gestational age, amniotic fluid is mainly consisted fetal urine. There is a close correlation between oligohydramnios associated with urinary tract anomaly and pulmonary development. Therefore, fetuses with oligohydramnios starting in the second trimester are considered to have uniformly fatal outcomes. We try to survey clinical characteristics of fetuses with oligohydramnios on autopsy and to find the need of perinatal management in fetuses with urinary tract anomaly and oligohydramnios which is occurred since second trimester.
MATERIALS AND METHODS
We retrospectively analysed gestational age at presentation, maternal age, causes of oligohydramnios, external physical examination, prenatal sonographic findings, underlying urologic anomalies, associated anomalies of other organs and ultimate outcomes in eighteen fetuses with oligohydramnios among 301 autopsy fetuses from 1986 to 1991.
RESULTS
It occurred predominantly in male as a ratio of 2.6:1 Gestational age of fetuses at presentation ranged from 21 to 47 weeks(average: 32.6) and maternal age from 20 to 33 years(average: 28.3). Causes of oligohydramnios in 18 fetuses ware fetal renal anomalies with intrauterine growth retardation(IUGR)(6), fetal renal anomalies(3), fetal death in uterine(3), urinary tract obstruction with IUGR(2) et al Inaccuracy rate between prenatal sonographic findings and autopsy findings was 53.8%, 0% in fetuses with urologic anomalies and with non-urologic anomalies, respectively. Underlying urinary tract anomalies consisted of bilateral renal dysplasia(4), posterior urethral valves(2), bilateral renal agenesis(1), bilateral renal hypoplasia(1), unilateral renal dysplasia and contralateral renal hypoplasia(1), infantile polycyctic kidney(1) et al. The most frequent anomaly of other organ was respiratory system anomalies, especially pulmonary hypoplasia. The prognosis in our cases with oligohydramnios was dismal as much as all fetuses except one, still birth, died of respiratory failure at perinatal periods.
CONCLUSIONS
Based on these experiences we have the policy to induce delivery and early perinatal management in cases with second or third trimester onset of severe oligohydramnics with urinary tract abnormalites.