Substance misuse in early pregnancy and relationship to fetal outcome

To establish the frequency of substance misuse in early pregnancy in an urb an UK population, 807 consecutive positive pregnancy test urine samples wer e screened for a range of drugs, including cotinine as an indicator of mate rnal smoking habits. A positive test for cannabinoids was found in 117 (14. 5%) samples. Smaller numbers of samples were positive for other drugs:- opi ates (11), benzodiazepines (4), cocaine (3 and one each for amphetamines an d methadone. Polydrug use was detected in nine individuals. Only two sample s tested positive for ethanol. The proportion with a urine cotinine level i ndicative of active smoking was 34.3%. The outcome of the pregnancy was tra ced for 288 subjects. Cannabis use was associated with a lower gestational age at delivery (P < 0.005), an increased risk of prematurity (P < 0.02) an d reduction in birth weight (P < 0.002). Whilst maternal smoking was associ ated with a reduction in infant birth weight (P < 0.05), this was less pron ounced than the effect of other substance misuse. Conclusion This study suggests that one in six women in South London are us ing drugs in early pregnancy and that cannabinoid use is associated with a poorer pregnancy outcome.