Risks of repeated miscarriage
Article first published online: 7 FEB 2006
Paediatric and Perinatal Epidemiology
Volume 20, Issue 2, pages 119–126, March 2006
How to Cite
George, L., Granath, F., Johansson, A. L. V., Olander, B. and Cnattingius, S. (2006), Risks of repeated miscarriage. Paediatric and Perinatal Epidemiology, 20: 119–126. doi: 10.1111/j.1365-3016.2006.00703.x
- Issue published online: 7 FEB 2006
- Article first published online: 7 FEB 2006
- recurrent miscarriage;
- maternal smoking;
- maternal age
There is a lack of well-designed epidemiological studies of possible risk factors for repeated miscarriage. In this Swedish population-based case–control study, we investigated the association between sociodemographic and anthropometric factors, obstetric history and life-style factors, with respect to the risks of first-trimester repeated miscarriage. Information on maternal characteristics was collected through in-person interviews. Plasma blood samples were analysed for cotinine and folate concentrations. Adjusted odds ratios (OR) with 95% confidence interval [CI] were used to estimate the relative risk of repeated miscarriage.
The risks of repeated miscarriage were increased for women aged ≥35 years (adjusted OR 2.9 [95% CI 1.4, 5.8]), as well as for women aged ≤24 years (OR 2.8 [95% CI 1.1, 6.8]). Women with a history of at least one preceding miscarriage prior to the two index pregnancies, women reporting prolonged time to conceive, and women with a history of myoma, faced a more than fourfold increased risk of repeated miscarriage. Smokers were at an increased risk of repeated miscarriage (OR 2.1 [95% CI 1.1, 4.1]). Among non-smoking women with high caffeine intake, there was an increased risk of repeated miscarriage, whereas there was no such association among smokers. Low plasma folate levels were not associated with increased risks.