July 17, 2015 — The FDA has received 475 reports of birth defects and other fetal adverse outcomes linked to Zofran since it was approved in 1991, according to a Freedom of Information Act (FOIA) investigation by Monheit Law.
Several studies have already linked Zofran and heart defects. One study (PDF) involving 900,000 pregnancies in Denmark found the following risks:
- Atrial septal defect was 2.1-times more common
- Ventricular septal defect was 2.3-times more common
- Atrioventricular septal defect was 4.8-times more common
The FDA also received more than 50 reports of craniofacial birth defects linked to Zofran, including cleft lip, cleft palate, microcephaly (abnormally small head), and a disorder known as Robin’s Syndrome that includes cleft palate and other facial defects. In 2011, Birth Defects Research published a study in which Zofran was linked to a 2.4-fold increased risk of cleft palate. Conclusions were based on data from the National Birth Defects Prevention Study.
Another common birth defect in the FDA database was intrauterine growth restriction, with 63 reports. This condition involves fetal growth below the 10th percentile for gestational age. In June 2014, investigators with the Toronto Star highlighted six reports from Canadian women who took Zofran:
“Four of the Canadian babies featured in the FDA side-effect reports reviewed by the Star were born weighing as little as four-and-a-half pounds. In six cases, a suspected side-effect of ondansetron was listed as “fetal growth restriction.”
Other adverse fetal outcomes included 86 reports of lung defects, including pulmonary hypoplasia (under-development of the lungs) and neonatal respiratory distress syndrome. Another 73 reports linked Zofran and premature delivery, and 55 referenced fetal death, stillbirth, or spontaneous abortion.