This longitudinal study examined the profile and pregnancy-related behaviours of women who reported smoking in two successive pregnancies when they presented for prenatal care in a large maternity hospital.

Over the 5 years, 6647 women delivered twice. Overall 5754 (86.6%) were persistent non-smokers in both pregnancies, 609 (9.2%) were persistent smokers in both pregnancies and between pregnancies 202 (3.0%) quit and 82 (1.2%) started smoking. Compared with persistent non-smokers, persistent smokers had higher rates of reported illicit drug use, alcohol consumption and psychological problems and lower rates of planned pregnancy, folic acid supplementation and breastfeeding in both pregnancies (all P < 0.001). In persistent smokers, folic acid supplementation practices deteriorated and illicit drug use increased in the subsequent pregnancy.