Maternal serum screening marker levels in twin pregnancies affected by gestational diabetes.

To investigate the levels of maternal serum screening markers in the first and second trimester twin pregnancies, which subsequently developed gestational diabetes mellitus (GDM). 145 twin pregnancies were recruited in the first trimester. Stored blood samples were retrospectively tested for pregnancy-associated plasma protein (PAPP)-A, human chorionic gonadotrophin (hCG), placental growth factor (PlGF), placental protein (PP)13, α-fetoprotein (aFP) and inhibin A. Values were expressed in multiples of the gestation-specific median (MoMs) in singletons, adjusted for maternal weight and parity, as appropriate. Twenty samples of first and second trimester were available from 11 twins who subsequently developed GDM and 219 samples from unaffected twins. The median PAPP-A level in the affected twins was 3.61 MoM compared with 2.46 MoM in unaffected twins (P < 0.001, Wilcoxon rank sum test, two tailed); significant results were found in both trimesters. The median PP13 was also increased but to a lesser extent. It was only statistically significant overall (P < 0.05) and in second trimester samples (P < 0.02). No other marker differed significantly. Logistic regression found that combining PAPP-A and maternal weight had a 55% detection rate for a 10% false-positive rate. Early prenatal marker evaluation in twin pregnancies can be also useful for predicting the risk for developing GDM and should be further investigated.