Poster session II Diabetes, labor, medical-surgical-disease, obstetric quality & safety, prematurity, ultrasound-imaging: Abstracts 237 – 386| Volume 206, ISSUE 1, SUPPLEMENT , S163-S164, January 01, 2012

347: Hydramnios in twin gestations


      To evaluate the effect of hydramnios on pregnancy outcomes in dichorionic (DC) and monochorionic (MC) twins.

      Study Design

      This is a retrospective cohort study of all twin pregnancies that received prenatal ultrasound evaluation between August 1997 and December 2010 and delivered live-born infants >24 weeks of gestation. Chorionicity was assessed sonographically. Sonography was routinely performed every 4 to 6 weeks. Hydramnios was defined as a single deepest pocket of amniotic fluid >8 cm, and further qualified as mild (8-9.9 cm), moderate (10-11.9 cm), and severe (>12 cm). The greatest degree of hydramnios identified during pregnancy was used for analysis. Monoamniotic pregnancies and pregnancies complicated by twin-twin transfusion syndrome were excluded. Infants with major structural anomalies were analyzed separately.


      There were 1919 twin pregnancies meeting inclusion criteria, of which 1301 (68%) were DC and 618 (32%) MC. Hydramnios was identified in 323 pregnancies (17%), with no differences in prevalence or severity according to chorionicity. Outcomes are presented in the table below. The prevalence of major structural anomalies increased significantly with the degree of hydramnios in both DC and MC pregnancies. The remainder of the analyses excluded anomalous infants. In DC pregnancies, there was a significant association between degree of hydramnios and infant birthweight; however, this relationship was not present in MC pregnancies. Hydramnios was not associated with preterm birth, birthweight discordance, or neonatal death.
      Tabled 1
      Table thumbnail grt56


      Hydramnios is common in twin gestations and is associated with an increased risk for fetal anomalies. In the absence of malformations, we did not identify an increased risk for adverse pregnancy outcomes.