Inter-pregnancy weight change and pregnancy hypertension

OBJECTIVES: To determine the relationship between interpregnancy weight change and the primary incidence or recurrence of gestational hypertension and preeclampsia in the second pregnancy; and whether it is influenced by the initial BMI.

METHODS: The study population was women who had their first and second consecutive births at Aberdeen from 1986 to 2007, who booked before 24 weeks gestation on both occasions and whose height and weight were measured. 12,740 women were included. Maternal weight was adjusted to take into account gestation at booking. The corrected weight was used to determine BMI for both pregnancies. Inter-pregnancy change in BMI was then calculated, and the association between inter-pregnancy BMI change and hypertensive disorders determined using logistic regression.

RESULTS: BMI increased from 24.5 at first pregnancy to 25.5 at the second over an average interval of 3.4 years. Women who were overweight at baseline and who had a modest or large gain in BMI between pregnancies had an increased risk of primary preeclampsia compared to those whose BMI was stable. [adjusted odds ratio (OR) and 95% confidence limits, 2.29 (1.06-4.95) and 3.03 (1.38-6.64), respectively]. This did not hold for those who were normal weight at baseline. Weight loss of >2BMI units was protective against recurrent preeclampsia whereas a gain of >2BMI units led to an increased risk of recurring gestational hypertension. The latter was true for all women irrespective of baseline BMI.

CONCLUSIONS: Inter pregnancy weight change variously impacts pregnancy hypertension, but what advice to give women should also consider the impact on other complications eg. IUGR or preterm delivery.

DISCLOSURES: D.M. Campbell: None. S. Bhattacharya: None. G. Horgan: None. J. Wallace: None.