Analysis of pregnancy-associated major basic protein levels throughout gestation.

Previous studies have shown that MBP levels rise before labour and have suggested the use of pMBP levels as a predictor of labour. We hypothesize that pMBP levels show a common pattern in pregnant women including a late third trimester rise in pMBP which predicts the onset of labour. Serum pMBP levels were measured throughout gestation in 112 pregnant women. We then analysed the relationship of pMBP levels to the time of labour onset, and to other features of pregnancy. An exponential increase in pMBP levels was seen early in gestation from weeks 5 to 21 in all pregnant women. In total, 79 per cent of the women showed rises in pMBP of > or = 25 per cent above baseline during the third trimester. pMBP levels were shown to be associated with placental weight, multiple gestation, and parity. pMBP levels could not, however, be used to form a precise model for the prediction of labour. The role of pMBP in pregnancy remains unclear.