Ondansetron use during pregnancy: a case series.

This is a descriptive retrospective case series of 14 pregnant women treated with ondansetron for hyperemesis gravidarum (HG) at CHU Sainte-Justine, from January 2002 to October 2011. Two of the patients received ondansetron during two separate pregnancies. Both pregnancies were analyzed separately for the purposes of this study. Another woman had twins who were included in the analysis. Therefore, the outcomes of 16 pregnancies and 17 newborns are presented. The patients were on average 28.1 ± 4.6 years old and were admitted to the hospital 5.0 ± 4.0 times. All patients who received ondansetron had previously been treated using the standard HG protocol to which they had not optimally responded. Ondansetron was initiated on average at 11.8 ± 4.8 weeks' gestation. In seven cases, administration was carried out during organogenesis. We observed 16 live births, including a set of twins, and one minor birth defect (isolated atrial and ventricular septal defects) reported after a second trimester exposure. Mean gestational age at birth was 36.9 ± 3.4 weeks and mean birth weight was 2.85±0.86 kg. We also noted six other pregnancy or neonatal outcomes (intrauterine growth retardation [IUGR] for each twin and a in a single pregnancy, a transient tachypnea, a mild hydrocele, and an extrarenal pelvis). Furthermore, we noted two premature births, one at 24 weeks of gestation and her infant died in the first weeks of life due to complications of prematurity and a second birth at 36 2/7 weeks of gestation. Teratogenicity associated with the use of ondansetron has so far not been shown in humans. This case series adds information on ondansetron use during pregnancy. However, until we have more published data, ondansetron should be used as a second-line agent for the management of HG.