Prediction Of Small For Gestational Age Infant By Maternal Serum Pigf And Papp-a In First Trimester

Objectives To explore relationship between maternal peripheral blood placenta growth factor and pregnancy associated plasma protein A during the first trimester of pregnancy and small for gestational age infant. And to examine the ability of predicting fetuses being small-for-gestational-age (SGA) at delivery with the maternal serum placenta growth factor and pregnancy associated plasma protein A by receiver-operating characteristic curve.Methods Pregnant women attending antenatal visits at maternal and child health centres in Hefei and Maanshan from October 2008 to September 2009 were recruited for inclusion in the cohort. After providing written informed consent, women who were recruited into the cohort were given the questionnaire during antenatal visits to investigate the data on social demographic characteristics, occupational experience, drug exposure and pregnancy complications including information on newborn gender,gestational weeks and birth weight at birth were collected by questionnaire from the first trimester of pregnancy. Eligible women also had their serum samples, 5ml, collected at their first prenatal visit, which were frozen at -80°C for future analysis. A case-control study was conducted using the cohort of women using the maternal serum markers PAPP-A and PIGF. We select 60 cases of SGA from the mothers whose serum samples were collected at gestational age of 10+0 weeks to 13+6 weeks . And 60 cases of AGA were chosed to match with SGA cases. Stored blood samples were analyzed for placenta growth factor and pregnancy associated plasma protein A using enzyme-linked immunosor-bent assay. The general state of health and socio-demographic information were analyzed by using Chi square test and t test. The correlation among PAPP-A, PIGF and birth weight were compared by Pearson correlation analysis. The distributions of PlGF and PAPP-A expressed in multiples of the median (MoM), in the control and SGA groups were compared. The performance of screening was determined by receiver-operating characteristic (ROC) curves.Results A total of 83 SGA cases were detected and the incidence was 3.5%. And cases of AGA and LGA were 1 722 and 582, respectively, with the incidence of 72.1% and 24.4%, respectively. Premature rupture of memberane is one of the most common complications of pregnancy, with the incidence of 14.3% (337cases).The median PlGF MoM (0.855 MoM) and PAPP-A MoM (0.725 MoM) were lower and in the SGA group than in the controls(PIGF:1.041 MoM; PAPP-A 1.103 MoM). In the SGA group there was a significant association between Log PlGF MoM and Log PAPP-A MoM (r=0.267,P<0.05). In the SGA group there was a significant association between log PlGF MoM (r=0.262, P<0.05) and log PAPP-A MoM (r=0.347, P<0.05) and birth weight. Similarly, in the control group there was a significant association between log PlGF MoM (r=0.256, P<0.05) and log PAPP-A MoM (r= 0.264, P<0.05) and birth weight. The areas under the ROC curves in screening by PlGF, PAPP-A, and by their combinations are 0.624(0.523～0.724), 0.664(0.567～0.761) and 0.683(0.588～0.779). Significant contributions for the prediction of SGA were provided by PlGF, PAPP-A and with combined screening the detection rate were 30.8%, 35.0% and 38.3% at a false-positive rate of 10%.Conclusions Birth weight is predetermined by placental development during the first trimester of pregnancy. Early prediction of fetuses being SGA is feasible by PlGF and PAPP-A in the first trimester.