American Journal of Epidemiology Advance Access published online on October 23, 2009
American Journal of Epidemiology, doi:10.1093/aje/kwp324
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Original Contribution |
Maternal Contributions to Preterm Delivery
* Correspondence to Dr. Heather A. Boyd, Department of Epidemiology Research, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen, Denmark (e-mail: hoy{at}ssi.dk).
Received for publication February 6, 2009. Accepted for publication June 15, 2009.
Preterm delivery (PTD) is a complex trait with a significant familial component. However, no specific inheritance patterns have been established. The authors examined the contribution of PTDs in both the woman's family and her partner's family to her risk of PTD. The authors linked birth information from Danish national registers with pedigree information from the Danish Family Relations Database for 1,107,124 live singleton deliveries occurring from 1978 to 2004. Risk ratios were estimated comparing women with and without various PTD histories. Women with previous PTDs were at greatly increased risk of recurrent PTD (risk ratio = 5.6, 95% confidence interval: 5.5, 5.8); however, their PTD risk was unaffected by a partner's history of preterm children with other women. PTDs to a woman's mother, full sisters, or maternal half-sisters also increased her PTD risk (risk ratio = 1.6, 95% confidence interval: 1.5, 1.6), whereas PTDs in her paternal half-sisters, the female partners of her male relatives, or members of her partner's family did not affect her PTD risk. Inheritance patterns were similar for all gestational ages from very early through late PTD. The substantial portion of PTD risk explained by effects passed through the female line suggests a role for either imprinting or mitochondrial inheritance.
cohort studies; family; genetics; inheritance patterns; premature birth
Abbreviations: CI, confidence interval; PTD, preterm delivery; RR, risk ratio
Editor's note: Related articles appear on pages 000 and 000, an invited commentary on the 3 articles is published on page 000, and a response by the authors of the second article to the commentary is on page 000. In accordance with Journal policy, the authors of the first and third articles were asked whether they wanted to respond to the commentary but chose not to do so.