Maternal fecundity and asthma among offspring-is the risk programmed preconceptionally? Retrospective observational study.

OBJECTIVE

To evaluate the association between maternal fecundity factors and time to pregnancy and risk of asthma in offspring.

DESIGN

Retrospective observational hospital-based birth cohort study.

SETTING

A university-based obstetrics and gynecology department.

PATIENT(S): A total of 40,914 women, who delivered between 1989 and 2007, were linked with the register for asthma reimbursement (n = 2,577) for their offspring. Fecundity factors were recorded during pregnancy. Logistic regression analyses were used.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Asthma among offspring.

RESULT(S): The risk of asthma was significantly increased if the mother had any infertility problems (adjusted odds ratio [adjusted OR] 1.39, 95% confidence interval [CI] 1.19-1.63), medical infertility treatment (aOR 1.43, 95% CI 1.13-1.80), or any infertility treatment (aOR 1.50, 95% CI 1.26-1.79). The risk of asthma among offspring was also higher among mothers who had more than two miscarriages (aOR 1.25, 95% CI 1.04-1.51) and time to pregnancy over 3 months (aOR 1.25, 95% CI 1.07-1.45).

CONCLUSION(S): These findings suggest that maternal subfertility exposes offspring to an increased risk of asthma.

CLINICAL TRIAL REGISTRATION NUMBER: The study is registered in Kuopio University Hospital register (TUTKI): ID 5302448.