A study was conducted on 613 pregnant women who were given meclozine during the first trimester to control dizziness and vomiting, and no increase in the probability of fetal malformations was observed. Another study of 317 pregnant women prescribed meclozine during the first trimester resulted in: 9 malformed infants including: 2 central nervous system defects 2 cardiovascular system defects 4 gastrointestinal system defects 1 musculoskeletal system defect 1 cancerous tumor These rates did not differ from rates in people suffering from dizziness and vomiting who were not prescribed meclozine. A third study monitored 50 mothers with 282 children who were exposed to meclozine during 16 weeks of pregnancy, showing that pregnancy risk rates and malformations did not change with meclozine use.