Paternity change and the recurrence risk in familial hypertensive disorder in pregnancy

To investigate if there is an increased risk for recurrence of hypertensive disorder in pregnancy with a new partner and whether this is affected by maternal age and the interbirth interval through use of familial material.

Data on 614 multiparous women, with confirmed de novo hypertensive disorder in a first pregnancy, were used to assess the effect of paternity and interbirth interval on recurrence of hypertensive disorders.

There were 121 women (19.7%) who had changed partner. Recurrent hypertension occurred in 318 women (64.5%) with the same partner and in 75 women (62%) with a new partner. The odds ratio (OR) for recurrence with the same partner was 1.115 (95% CI 0.739-1.680) and with a new partner 0.897 (95% CI 0.595-1.353). The mean interbirth interval was longer for women with recurrent hypertension (4.9 vs. 4.0 years, p = 0.0002). The OR for developing recurrent hypertensive disorder was 1.154 (95% CI 1.049-1.269) for every interval year with the same partner and 1.145 (95% CI 0.958-1.368) with a new partner after correction for maternal age.

In women with a positive family history and previous hypertension in pregnancy, change of paternity does not influence the risk of recurrence. Increasing interbirth interval may account for a 15% recurrence risk for each year, independent of maternal age. There was no indication that a change of partner conferred any influence on the recurrence risk that is not explained with birth interval or age.