Study of 224 cases of oligohydramnios and congenital malformations in a series of 225,669 consecutive births

Abstract

Objectives: To provide data on oligohydramnios associated with congenital anomalies in 225,669 consecutive pregnancies.

Material and methods: The malformations in this study came from births of known outcome recorded in our registry of congenital malformations. Routine ultrasonographic examination was performed. Diagnosis of oligohydramnios was made ultrasonographically. For each case, a control was chosen.

Results: The prevalence of this association was 0.99 per thousand (224 cases). A case-control study allowed the examination of genetic and environmental factors for the origin of oligohydramnios associated with congenital malformations. Diagnosis of oligohydramnios associated with congenital malformations was made prenatally in 32.6% of the cases; 12.0% of the infants were stillborn. Fifty-nine percent of the cases had more than one malformation, 13.8% had a chromosomal aberration, and 27.6% had multiple malformations that do not constitute a syndrome. The more frequent malformations associated with oligohydramnios were urinary, musculoskeletal, digestive and cardiac. There was increased parental consanguinity. The frequency of oligohydramnios and congenital anomalies among first-degree relatives was 4.5% and first-degree relatives had more malformations than controls (8.0 vs. 3.1%, p < 0.05). Threatened abortions and diabetes mellitus were significantly more frequent among mothers of the children with congenital malformations associated with oligohydramnios than among the controls.

Conclusions: Our study demonstrated that careful fetal examination has to be performed when oligohydramnios is diagnosed as congenital malformations are often associated with oligohydramnios. We recommend the use of fetal chromosome analysis and careful ultrasonographic examination in every pregnancy complicated by oligohydramnios.