Variation of Papp-A Level in the First Trimester of Pregnancy and Its Clinical Outcome

Introduction

Abnormalities in maternal serum marker levels and fetal measurements obtained during the first trimester screening can be a marker not only for certain chromosomal disorders and anomalies in the fetus but also for specific pregnancy complications. In particular, low maternal serum pregnancy-associated plasma protein-A (PAPP-A), at 11–13 weeks of gestation, is associated with stillbirth, infant death, intrauterine growth restriction, preterm birth, and pre-eclampsia in chromosomally normal fetuses, while a raised nuchal translucency is associated with specific structural abnormalities and genetic syndromes. We have studied the serum Papp-A level in 560 pregnant patients (11–13 weeks gestation) registered at Bharati Hospital and Research Centre, Pune. All patients undergoing testing were followed till the delivery and their neonatal outcome was also taken into consideration.

Aims and Objectives

Our aim is to study the pregnancy outcome in relation to the variations of Papp-A level in the first trimester of pregnancy.

Materials and Methods

Every patient visiting the antenatal OPD was counseled for testing of First Trimester Screening to assess fetal well-being. Patients who were registered for delivery at our hospital were taken into the trial. Blood samples were taken at 11–13 weeks of pregnancy and sent to the PerkinElmer lab for analysis. Results were expressed in Multiple of Median and patients having MOM value less than 0.5 were carefully observed till the delivery, and a thorough neonatal examination was done by a pediatrician.

Observations

524 patients were included in the trial out of which 452 patients were found to have a normal Papp-A level of >0.5 MOM. All these patients were followed further during the antenatal period where 18 patients developed preterm labor and few patients developed pregnancy-induced hypertension. The obstetric outcome of patients with a normal Papp-A level was fairly uneventful as compared to others with a low Papp-A level.

Conclusions

Though Papp-A level in the first trimester of pregnancy (11–13 weeks) is an important predictor of future obstetric outcome, it has poor positive predictive value. Patients having a Papp-A level less than 0.5 MOM have a high risk for preterm delivery, fetal growth restriction, and stillbirths along with increased incidence of hypertensive disorders of pregnancy. A low Papp-A level is a useful indicator of risk of preterm delivery and future chance of development of pregnancy-induced hypertension.