The outcomes of pregnancy in women exposed to newly marketed drugs in general practice in England

Abstract

Objective: To determine the proportion and nature of congenital anomalies in babies born to women exposed to newly marketed drugs during the first trimester.

Design: Non-interventional observational cohort studies.

Methods: The women were identified in confidence by the Prescription Pricing Authority. The doctor was sent a questionnaire to determine clinical events, including pregnancy, occurring after the drug was dispensed. A supplementary questionnaire determined the outcome of each reported pregnancy.

Setting: General medical practice in England.

Population: Women exposed to newly marketed drugs in whom pregnancy was recorded.

Main outcome measures: Outcomes of pregnancies, the proportion and nature of congenital anomalies in the babies born.

Results: 2511 pregnancies were reported. In 831 of these pregnancies a newly marketed drug had been taken during the first trimester and in 74 during the second/third trimester. The outcome was ascertained for 780 (94%) of these 831 pregnancies: 547 (66%) births; 10 (1%) ectopic pregnancies; 94 (11%) spontaneous miscarriages; 5 (< 1%) missed abortions; 120 (14%) legal abortions; and 4 (< 1%) intrauterine deaths. 557 infants were born, of whom 14 (2.5%) had congenital anomalies.

Conclusions: The proportion of live infants with a congenital abnormality born to mothers exposed to newly marketed drugs in the first trimester was similar to the percentage of congenital anomalies estimated by the Office for National Statistics. These data add valuable information to the safety database of these drugs.