Maternal smoking during pregnancy and offspring utilisation of health care services: A population-based cohort study

Maternal smoking during pregnancy (MSDP) has been associated with a wide range of adverse effects on offspring health, such as low birthweight, behavioural disorders, and asthma. The number of women that smoke during pregnancy in Denmark is still high, making it relevant to study the long-term health outcomes in offspring exposed to maternal smoking in utero.

We investigated whether exposure to MSDP is associated with more frequent use of health care services during the first 10 years of life.

This population-based cohort study included participants enrolled in the Danish National Birth Cohort between 1996 and 2003. Data on MSDP were obtained from two telephone interviews during pregnancy and one interview after pregnancy. The primary outcome was contacts to the health care system. From Danish national registries, we obtained information on number and type of contacts to the general practitioner (GP), and information on the specific types of services provided. Further, we obtained information on hospital admissions, and redemption of prescribed medicine. We fitted negative binomial regression models and Cox proportional hazards regression models to estimate associations. All analyses were adjusted for socio-economic status, birth year, and various maternal factors.

We studied 83,905 liveborn singletons and found that offspring exposed to maternal smoking in utero had more contacts to the GP in the first 10 years of life with an incidence rate ratio of 1.05, 95% confidence interval [CI] 1.04, 1.06. A higher rate of admission to hospital in 9 out of 20 categories was found, as was a higher rate of being prescribed psychoanaleptics (hazard ratio [HR] 1.41, 95% CI 1.25, 1.60), drugs for obstructive pulmonary disease (HR 1.14, 95% CI 1.14, 1.20), and antibiotics (HR 1.03, 95% CI 1.01, 1.05).

We found that offspring exposed to MSDP had a higher use of health care services than unexposed offspring.