Recurrence of prolonged and post-term gestational age across generations: maternal and paternal contribution
Article first published online: 10 OCT 2011
© 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2011 RCOG
BJOG: An International Journal of Obstetrics & Gynaecology
Volume 118, Issue 13, pages 1630–1635, December 2011
How to Cite
Morken, N.-H., Melve, K. and Skjaerven, R. (2011), Recurrence of prolonged and post-term gestational age across generations: maternal and paternal contribution. BJOG: An International Journal of Obstetrics & Gynaecology, 118: 1630–1635. doi: 10.1111/j.1471-0528.2011.03154.x
- Issue published online: 11 NOV 2011
- Article first published online: 10 OCT 2011
- Accepted 16 August 2011. Published Online 10 October 2011.
- post-term pregnancy;
- prolonged pregnancy
Please cite this paper as: Morken N-H, Melve K, Skjaerven R. Recurrence of prolonged and post-term gestational age across generations: maternal and paternal contribution. BJOG 2011;118:1630–1635.
Objective To estimate intergenerational recurrence risk of prolonged and post-term gestational age.
Design Population-based cohort study.
Setting Norway, 1967–2006.
Population Intergenerational data from the Medical Birth Registry of Norway of singleton mothers and fathers giving birth to singleton children: 478 627 mother–child units and 353 164 father–child units. A combined mother–father–child file including 295 455 trios was also used.
Methods Relative risks were obtained from contingency tables and relative risk modelling.
Main outcome measures Gestational age ≥41 weeks (≥287 days), ≥42 weeks (≥294 days) and ≥43 weeks (≥301 days) of gestation in the second generation.
Results A post-term mother (≥42 weeks) had a 49% increased risk of giving birth to a child at ≥42 weeks (relative risk [RR] 1.49, 95% CI 1.47–1.51) and a post-term father had a 23% increased risk of fathering a child at ≥42 weeks (RR 1.23, 95%CI 1.20–1.25). The RRs for delivery at ≥41 weeks were 1.29 (1.28–1.30) and 1.14 (1.13–1.16) for mother and father, respectively, and for ≥43 weeks 1.55 (1.50–1.59) and 1.22 (1.17–1.27). The RR of a pregnancy at ≥42 weeks in the second generation was 1.76 (1.68–1.84) if both mother and father were born post-term. Adjustment for maternal age in both generations, fetal sex in the second generation, parity, and maternal and paternal birthweight did not influence the risk estimates.
Conclusions There is a familial factor related to recurrence of prolonged pregnancy across generations and both mother and father seem to contribute.