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Recurrence of hyperemesis gravidarum across generations: population based cohort study

BMJ 2010; 340 doi: (Published 29 April 2010) Cite this as: BMJ 2010;340:c2050
  1. Åse Vikanes, PhD student1,
  2. Rolv Skjærven, professor12,
  3. Andrej M Grjibovski, professor345,
  4. Nina Gunnes, research fellow1,
  5. Siri Vangen, senior scientist and consultant16,
  6. Per Magnus, professor17
  1. 1Division of Epidemiology, Norwegian Institute of Public Health, PO Box 4404, Nydalen, N-0403 Oslo, Norway
  2. 2Department of Public Health and Primary Health Care, University of Bergen, Norway
  3. 3Department of Infectious Diseases Epidemiology, Norwegian Institute of Public Health, Norway
  4. 4Institute of Community Medicine, University of Tromsø, Norway
  5. 5International School of Public Health, Northern State Medical University, Arkhangelsk, Russia
  6. 6National Resource Centre for Women’s Health, Department of Obstetrics and Gynaecology, Oslo University Hospital, Norway
  7. 7Institute of General Practice and Community Medicine, University of Oslo, Norway
  1. Correspondence to: Å Vikanes ase.vigdis.vikanes{at}
  • Accepted 18 March 2010


Objective To estimate the risk of hyperemesis gravidarum (hyperemesis) according to whether the daughters and sons under study were born after pregnancies complicated by hyperemesis.

Design Population based cohort study.

Setting Registry data from Norway.

Participants Linked generational data from the medical birth registry of Norway (1967-2006): 544 087 units of mother and childbearing daughter and 399 777 units of mother and child producing son.

Main outcome measure Hyperemesis in daughters in mother and childbearing daughter units and hyperemesis in female partners of sons in mother and child producing son units.

Results Daughters who were born after a pregnancy complicated by hyperemesis had a 3% risk of having hyperemesis in their own pregnancy, while women who were born after an unaffected pregnancy had a risk of 1.1% (unadjusted odds ratio 2.9, 95% confidence interval 2.4 to 3.6). Female partners of sons who were born after pregnancies complicated by hyperemesis had a risk of 1.2% (1.0, 0.7 to 1.6). Daughters born after a pregnancy not complicated by hyperemesis had an increased risk of the condition if the mother had hyperemesis in a previous or subsequent pregnancy (3.2 (1.6 to 6.4) if hyperemesis had occurred in one of the mother’s previous pregnancies and 3.7 (1.5 to 9.1) if it had occurred in a later pregnancy). Adjustment for maternal age at childbirth, period of birth, and parity did not change the estimates. Restrictions to firstborns did not influence the results.

Conclusions Hyperemesis gravidarum is more strongly influenced by the maternal genotype than the fetal genotype, though environmental influences along the maternal line cannot be excluded as contributing factors.


  • Contributors: All authors planned the project. ÅV, NG, and RS analysed the data. ÅV drafted the paper. All authors contributed to interpreting the data and revising the content and gave their approval of the final version of the paper. RS is guarantor.

  • Funding: The study was funded by the Norwegian Research Council (grant No 166145/V50).

  • Competing interests: All authors have completed the Unified Competing Interest form at (available on request from the corresponding author). I hereby declare that (1) ÅV has support from The Research Council of Norway for the submitted work; (2) RS, AMG, NG, SV and PM have no relationships that might have an interest in the submitted work in the previous 3 years; nor have their spouses, partners, or children financial relationships that may be relevant to the submitted work.

  • Ethical approval: Not required.

  • Data sharing: No additional data available.

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