Sensitivity analyses
The prevalence of gestational hypertension was 7.7% with a median
gestational age at diagnosis of 37+0 weeks
(interquartile range 34+2 to 38+6weeks). A high dose of calcium-based antacids (≥1 g/day) in gestational
weeks 0-19 was associated with an increased risk of gestational
hypertension (adjusted RR 1.6 [95% CI 1.2-2.1], Table S4). Use of
calcium-based antacids after gestational week 19 and use of PPIs in
early and late pregnancy was not associated with the risk of gestational
hypertension (Tables S4 and S5).
Within the PRIDE Study, 38.4% of women (N = 2,078) was at high risk of
developing preeclampsia. Among these women, excess risks for exposure in
early and mid-pregnancy were more evident compared to the total
population with an adjusted RR of 2.3 (95% CI 1.2-4.4) for low-dose
calcium-based antacids in gestational weeks 0-16 and 2.2 (95% CI
1.2-4.3) for any PPI use in gestational weeks 0-33 (Table S6). The
latter was attributable to PPI use in gestational weeks 17-33, as no
increased risk was observed for PPI use in gestational weeks 0-16
(adjusted RR 1.4 [95% CI 0.5-4.3]). We did not observe associations
between late-onset preeclampsia and any calcium-based antacid use
(adjusted HR 0.7 [95% CI 0.3-1.3]) or PPI use (adjusted HR 2.1
[95% CI 0.8-5.2]) after gestational week 33 among women at high
risk of developing preeclampsia (Table S7). Restricting the analyses to
women who did not use calcium-containing supplements during pregnancy
(N=1,482) did not materially change the results, although these analyses
were hampered by small numbers (Tables S8 and S9).