Hydramnios and small for gestational age: prevalence and clinical significance

Abstract

Objective: To investigate the clinical significance of combined obstetrical pathology of small for gestational age and hydramnios as a predictor of peripartum complications, intrapartum morbidity and poor neonatal outcome.

Methods: The study population consisted of 152 small for gestational age neonates with hydramnios out of 67,806 singleton deliveries during the study period (0.22%). We compared the 152 small for gestational age neonates with hydramnios (hydramnios/small for gestational age) to a sample of 1% of the appropriate for gestational age neonates with normal amniotic fluid (normal amniotic fluid/appropriate for gestational age) (582 cases). Analyses were conducted for the entire cohort as well as for the cohort in which all cases with congenital malformations were excluded.

Results: There was a significantly higher rate of congenital anomalies in the hydramnios/small for gestational age group compared with the normal amniotic fluid/appropriate for gestational age group (25% vs. 2.4%, p<0.001). There were significantly more previous perinatal deaths, infertility treatments and diabetes type B-R among the hydramnios/small for gestational age group. These findings remained significant after exclusion of the neonates with congenital malformations. The rates of labor dystocia, placental abruptio, abnormal presentations, prolapse of cord and cesarean sections were significantly higher in the hydramnios/ small for gestational age group compared with normal amniotic fluid/appropriate for gestational age group (5.9/2.4%, p<0.05; 5.9/0.7%, p<0.001; 14.5/3.2%, p<0.001; 2/0.2%, p<0.01; 24.3/8.2%,p<0.001; respectively). Rates of ante partum death and post partum death as well as low 1 and 5 minute Apgar scores were significantly higher in the hydramnios/small for gestational age group (9.9/0.3%; 14.5/0.3%; 12.8/2.1%; 11.7/0.6%, p<0.001, respectively).

Conclusions: The combination of small for gestational age and hydramnios is a risk factor for peripartum complications and perinatal mortality even in the absence of congenital malformations.