In some countries, including Sweden, no risk is considered to exist with the use of
meclozine for
nausea and
vomiting in pregnancy (NVP), but in other countries warnings against use during pregnancy are given. Rat tests indicate a teratogenic risk and published epidemiological studies are of restricted size. Delivery outcome was studied in 16,536 women who reported the use of
meclozine in early pregnancy and was compared with all 540,660 women who gave birth. Information on
drug usage was obtained prospectively in early pregnancy. Risk factors for using
meclozine were young maternal age, to have had a previous child, not to
smoke, to have a low body mass index. The use of some other drugs (
antihypertensives,
thyroxine,
anticonvulsants) decreased the use of
meclozine. Maternal diagnoses of
preeclampsia or diabetes were less frequent when the woman had used
meclozine. The twinning rate was increased and the sex distribution of the infants low (female excess).
Preterm birth, low birth weight, short body length, and small head circumference occurred at a reduced rate after
meclozine use, notably for boys. Also the rate of congenital malformations was reduced. If anything, delivery outcome is better than expected when the mother used
meclozine. These beneficial effects are probably secondary to NVP.
Meclozine can apparently be used without risk at this condition.