Ultrasonographic Identification of Polyhydramnios

Abstract

Polyhydramnios is a condition where there is more amniotic fluid than is normal for gestational age, and it is associated with various maternal and fetal abnormalities. Ultrasonography is the primary means of assessing the amount of amniotic fluid. To date, an association between polyhydramnios and aneuploidy has not been firmly established. Therefore, a retrospective analysis was conducted of 766 patients who were referred to a high-risk referral center between January 1, 1986 and January 1, 1990 for ultrasound examination and genetic amniocentesis, to investigate the relationship between polyhydramnios and aneuploidy. During the course of the complete ultrasound examination, the amniotic fluid was quantified using standard methods and patients were categorically placed into one of two groups. Group 1 included all patients with normal or decreased amounts of amniotic fluid, and group 2 included all patients with polyhydramnios. The results of the fetal cytogenetic analysis were obtained for each fetus. A total of 726 patients met the criteria to be included in the study. The rate of aneuploidy was 3% (19 cases in 690 patients) in group 1 and 17% (6 cases in 36 patients) in group 2. A statistically significant difference between the two groups in the incidence of aneuploidy was observed (P = 0.0001). This study also showed that only 28% (10 out of 36) of nondiabetic and nonsensitized patients had an uncomplicated pregnancy outcome. It is therefore concluded that within a high-risk population pregnancies complicated by polyhydramnios are at significant risk for aneuploidy; prenatal cytogenetic analysis may be offered to patients with polyhydramnios, regardless of concomitant ultrasonographic findings; and pregnancies complicated by polyhydramnios are at risk for peripartum complications and poor pregnancy outcome.