A longitudinal, observational study of women who persisted in smoking in successive pregnancies

Background: 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.

Methods: Using the hospital electronic medical records, women who delivered two successive singleton pregnancies during the years 2011-15 were analyzed. Standardized data were computerized by a midwife at the first prenatal visit, following delivery and before discharge.

Results: 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.

Conclusions: We found that approximately one in 10 women smoked in two consecutive pregnancies. Furthermore, compared with non-smokers, persistent smokers were more likely to report other health behaviours associated with adverse pregnancy outcomes and may require additional multidisciplinary support.