Study: Metoclopramide May Not Raise Risks to Fetus


The use of metoclopramide to control nausea and vomiting in the first trimester does not increase the risk for congenital malformations, low birth weight, or perinatal death, according to a report in the New England Journal of Medicine.

These findings from a large retrospective cohort study “provide reassurance about the safety of metoclopramide,” which has not been convincingly established until now, wrote Ilan Matok of Ben-Gurion University of the Negev, Beer-Sheva, Israel, and associates.

“Despite its extensive use, only a few studies have assessed the safety to the fetus of maternal exposure to metoclopramide during the first trimester, and the relatively small sizes of these studies limited their power to detect adverse effects of the drug,” they noted.

The researchers assessed singleton deliveries between 1998 and 2007 at the largest HMO in Israel, where metoclopramide is the antiemetic drug of choice during pregnancy. Approximately half of the 81,703 infants in the study were born to Jewish parents and half to Bedouin Muslim parents.

A total of 3,458 (4%) of these infants were exposed to metoclopramide during the first trimester. The mean duration of exposure was 1 week.

The rate of major congenital malformations was 5.3% among exposed infants, compared with 4.9% among unexposed infants, a nonsignificant difference. This difference remained nonsignificant when data from pregnancies that were terminated were included in the analysis.

The rates of minor congenital malformations (3.8% vs. 3.5%) and of multiple malformations (2.5% vs. 2.3%) also were similar between exposed and nonexposed infants. There also were no significant associations between subclasses of congenital malformations and metoclopramide exposure, nor was there any clustering of anomalies among exposed infants.

When the data were analyzed according to subjects' ethnic backgrounds, the drug did not raise risks to infants of either Jewish or Bedouin Muslim parents (N. Engl. J. Med. 2009;360:2528–35).

Metoclopramide also was not associated with an increased risk of preterm birth, low Apgar scores, perinatal death, or low birth weight.

A subgroup of 758 mothers who took metoclopramide refilled their prescriptions at least once. No dose-response effect of exposure to the drug was found.

The researchers reported having no relevant conflicts of interest.

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