Adriëtte Oostvogels

2 51 pBMI, lipids and BP during pregnancy Discussion This study shows that both prepregnancy weight status and early pregnancy lipid profile have an independent effect on BP course during pregnancy. Apart from a higher BP from the start, the BP course does not differ according to maternal weight status. Women with higher lipid levels in early pregnancy also have higher SBP and DBP from the start; however, if these women are also overweight, their DBP is increased even more. We found no evidence for our hypothesis that women with overweight with a more atherogenic lipid profile have the most detrimental BP course. Other studies investigating the association between prepregnancy weight status and BP course during pregnancy found (as confirmed by our study) that women with overweight had both a higher SBP (range: 4.0-8.7 mmHg) and DBP (range: 1.6-5.6 mmHg) from the start of pregnancy onwards. 2,5-7 Moreover, in our study and in a similar cohort these differences remained stable over time. 2 Two other studies reported that these differences decreased slightly over time, as women with normal weight had a more rapid increase in BP at the end of pregnancy compared to women with overweight or obesity. 6,7 To our knowledge, no other studies have examined the independent effect of maternal lipids, or the combined effect of maternal pBMI and lipids, on BP course during pregnancy. Other studies found a positive association between maternal lipids and the risk of hypertensive disorders in pregnancy, which suggests an influence of the lipid level on the BP course. 13-17 Our results add to this knowledge by showing that this increased risk might be caused by a higher BP at the very start of the pregnancy. Moreover, our DBP results suggest a smaller decrease in BP in early pregnancy and a stronger increase at the end of pregnancy in those women in the highest TG tertile. This pattern is associated with an increased risk for hypertensive disorders. 13-17 Strengths and Limitations The present investigation was based on a large prospective cohort study with (on average) 10 serial measurements of BP recordings throughout each individual pregnancy. The model we used took into account: i) the correlation of all BP measurements within each individual woman, as well as ii) the gestational age at birth, since women with hypertensive disorders of pregnancy give birth earlier than women with normotensive pregnancies. To examine the effect of pBMI and maternal lipids on BP course, we excluded women with both pre-existent and gestational diabetes, pre-existent hypertension and women using lipid-lowering medication.