Pregnancy outcomes of women exposed to laninamivir during pregnancy

The purpose of this study is to assess pregnancy outcomes of women treated with a novel neuraminidase inhibitor, laninamivir, during pregnancy.

A retrospective review of pregnancy outcomes of 112 pregnant women who were given laninamivir for treatment of influenza was performed. Possible adverse events, including miscarriages, preterm birth, foetal malformation and any neonatal morbidity requiring treatment, were assessed.

Seventeen, 39, 46 and 10 women were administered a single inhaled dose of 20 or 40 mg of laninamivir at gestational week (GW) 3-11, 12-21, 22-36 and 37 or more, respectively. One (1.8%) of 56 women with laninamivir at GW <22 experienced miscarriage at GW <12. The remaining 111 women gave birth to 111 viable infants but at preterm (GW <37) in nine (8.8%) of 102 women with laninamivir at GW <37. Three (2.7%) of the 111 newborns had malformations: forefoot varus deformity, foot polydactyly and cleft lip in one each born to a mother taking laninamivir at GW 6, 17 and 21, respectively. Five neonates (4.5%) were small for gestational age. Eleven (9.9%), five (4.5%) and no neonates required phototherapy for jaundice, transient respiratory supports for respiratory distress syndrome (n = 2) or transient tachypnoea of the newborn (n = 3), and glucose administration for hypoglycaemia, respectively.

Although this study included a small number of study women and no control women, the results suggested that maternal exposure to laninamivir did not increase the rate of adverse pregnancy and foetal outcomes.