Spontaneous preterm birth and small for gestational age infants in women who stop smoking early in pregnancy: prospective cohort study

As women were recruited at 15 weeks, miscarriage was not an endpoint in this study. The primary outcomes were SGA infants and spontaneous preterm birth. For the question re smoking sub-groups < 10 versus >=10 cigarettes daily we refer to our recent response to Dr Salam “Quitting smoking in early pregnancy and adverse birth outcomes: questions unanswered”. Our logistic regression models for both spontaneous preterm birth and SGA included alcohol use at 15 weeks gestation (yes/no) and this did not have a significant effect on either outcome in this study. We have collected more detailed data about alcohol and drug exposure and these factors will be included in our analyses to investigate the prediction of spontaneous preterm birth and SGA infants. We do not have data about the number of women taking antidepressant medications nor do we have late pregnancy measures of depression.

Competing interests: None declared