Pemphigoid gestationis: Early onset and blister formation are associated with adverse pregnancy outcomes

Background It is unclear whether clinical features of pemphigoid gestationis (PG), such as timing of onset and severity, may affect pregnancy outcomes or whether the adverse outcomes in pregnancies complicated by PG are related to or worsened by systemic corticosteroid treatment. Objectives To evaluate the associations of adverse pregnancy outcomes with clinical features, autoantibody titre of PG, and systemic corticosteroid treatment. Methods We conducted a retrospective cohort study recruiting 61 pregnancies complicated by PG from the St John's Institute of Dermatology database which enrolled cases from dermatologists across the U.K., and two tertiary hospitals in the U.K. and Taiwan. Outcome measures included gestational age at delivery, preterm birth, birthweight, low birthweight (LBW, i.e. birthweight < 2500 g), small-for-gestational-age (i.e. birthweight below the 10th percentile for gestational age), fetal loss, congenital malformation, and mode of delivery. Results After controlling for maternal age and comorbidity, decreased gestational age at delivery was significantly associated with presence of blisters (P = 0·017) and disease onset in the second trimester (P = 0·001). Reduced birthweight was significantly associated with disease onset in the first and second trimesters (P = 0·030 and 0·018, respectively) as was also LBW [adjusted odds ratio (95% confidence interval) 13·71 (1·22-154·59) and 10·76 (1·05- 110·65), respectively]. No significant associations of adverse pregnancy outcomes with autoantibody titre or systemic corticosteroid treatment were found. Conclusions Onset of PG in the first or second trimester and presence of blisters may lead to adverse pregnancy outcomes including decreased gestational age at delivery, preterm birth, and LBW children. Such pregnancies should be considered high risk and appropriate obstetric care should be provided. Systemic corticosteroid treatment, in contrast, does not substantially affect pregnancy outcomes, and its use for PG in pregnant women is justified.