Biophysical and biochemical markers in the third trimester of gestation in prediction of adverse perinatal outcome

Resumo

Objectives: The purpose of this thesis was to investigate the potential value of biophysical and biochemical markers at the third trimester of pregnancy in the prediction of adverse perinatal outcome. Methods: We performed a prospective screening for adverse perinatal outcomes in singleton pregnancies assessed at 30-34 weeks' gestation or at 35-37 weeks' gestation as part of a routine prenatal visit. We screened more than 30 .000 women at 30-34 weeks' gestation and more than 3.900 at 35-37 weeks' gestation. Ethical approval was obtained for these studies. Multivariate regression analysis was used to define the contribution of each maternal characteristic and biomarker in predicting each adverse outcome, including preeclampsia (PE), birth of small for gestational age (SGA) neonate, stillbirth, fetal distress before or during labor leading to cesarean section, low cord blood pH, low Apgar score or neonatal unit admission. Results: The combined predictive models could correctly identify the vast majority of pregnancies complicated with PE and SGA and the prediction was better if these occurred befo re 37 weeks' gestation. Prediction of cesarean section for fetal distress before labor was also possible with these models. Prediction for stillbirth, fetal distress during labor, low cord blood pH, low Apgar score or neonatal unit admission was poor for cases other than those with PE and/or SGA. Conclusion: Third trimester assessment by biophysical and biochemical markers of impaired placentation provides good prediction for PE, SGA and fetal distress before labor, but poor or no prediction for stillbirth and adverse events in labor or after birth.