Effects on pregnancy outcome of changing partner between first two births: prospective population study.
OBJECTIVE
To compare the effects on pregnancy outcomes of changing partner between the first two births with having the same partner for both births.


METHODS
Prospective population study.


METHODS
Norway.


METHODS
31 683 women who changed partner between their first two births and 456 458 women with the same partner for both births.


RESULTS
After adjustment for maternal age and education, interval between births, and decade of birth, the risk of adverse pregnancy outcomes for the second birth was higher for women who changed partner between the first two births compared with those who had the same partner for both births: preterm birth (< 37 weeks; relative risk 2.0, 95% confidence interval 1.9 to 2.1), low birth weight (< 2500 g; 2.5, 2.3 to 2.6), and infant mortality (1.8, 1.6 to 2.1). For the first birth, the risk of these adverse pregnancy outcomes was only slightly higher for mothers who subsequently had a second birth with another partner.


CONCLUSIONS
Women who change partner between their first two births are at an increased risk of delivering a preterm, low birthweight baby with an increased risk of infant mortality compared with women who have the same partner for both births.
Vatten
Lars J
LJ
Department of Public Health and General Practice, Norwegian University of Science and Technology, NO-7489 Trondheim, Norway. lars.vatten@medisin.ntnu.no
Skjaerven
Rolv
R
D001722:Birth Order; D004522:Educational Status; D005260:Female; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008423:Maternal Age; D009664:Norway / Q000453:epidemiology; D007752:Obstetric Labor, Premature / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D011446:Prospective Studies; D012307:Risk Factors; D012747:Sexual Partners