BACKGROUND: In various countries, metoclopramide is the antiemetic drug of choice in pregnant women, but insufficient information exists regarding its safety in pregnancy. METHODS: We investigated the safety of metoclopramide use during the first trimester of pregnancy by linking a computerized database of medications dispensed between January 1, 1998, and March 31, 2007, to all women registered in the Clalit Health Services, southern district of Israel, with computerized databases containing maternal and infant hospital records from the district hospital during the same period. We assessed associations between the use of metoclopramide in pregnancy and adverse outcomes for the fetus, adjusting for parity, maternal age, ethnic group, presence or absence of maternal diabetes, smoking status, and presence or absence of peripartum fever. RESULTS: There were 113,612 singleton births during the study period. A total of 81,703 of the infants (71.9%) were born to women registered in Clalit Health Services; 3458 of them (4.2%) were exposed to metoclopramide during the first trimester of pregnancy. Exposure to metoclopramide, as compared with no exposure to the drug, was not associated with significantly increased risks of major congenital malformations (5.3% and 4.9%, respectively; odds ratio, 1.04; 95% confidence interval [CI], 0.89 to 1.21), low birth weight (8.5% and 8.3%; odds ratio, 1.01; 95% CI, 0.89 to 1.14), preterm delivery (6.3% and 5.9%; odds ratio, 1.15; 95% CI, 0.99 to 1.34), or perinatal death (1.5% and 2.2%; odds ratio, 0.87; 95% CI, 0.55 to 1.38). The results were materially unchanged when therapeutic abortions of exposed and unexposed fetuses were included in the analysis. CONCLUSIONS: In this large cohort of infants, exposure to metoclopramide in the first trimester was not associated with significantly increased risks of any of several adverse outcomes. These findings provide reassurance regarding the safety of metoclopramide for the fetus when the drug is given to women to relieve nausea and vomiting during pregnancy.