Pruritic urticarial papules and plaques of pregnancy and its relationship to maternal-fetal weight gain and twin pregnancy.

Thirty women who were seen at our institution between 1984 and 1988 for pruritic urticarial papules and plaques of pregnancy (PUPPP) were retrospectively evaluated and interviewed. We found a significantly increased maternal weight gain and newborn birth weight in patients with PUPPP, compared with age and parity-matched controls. The average weight gain during pregnancy was 18.1 +/- 0.9 (SEM) kg for the patients with PUPPP (excluding twin gestations) and 14.6 +/- 1.0 kg for the controls. The mean newborn birth weight was 3.6 +/- 0.09 kg for the PUPPP group and 3.3 +/- 0.08 kg for the control group. There were three twin pregnancies (10%), compared with the twin gestation rate at our institution of 1.6%. Therefore, based on our findings of an increased maternal weight gain and neonatal birth weight, an increased twin rate, and an abdominal eruption that occurs in primigravidas in their third trimester of pregnancy, we suggest that abdominal distention or a reaction to it may play a role in the development of PUPPP.