Maternal Serum Neuropilin a Prognostic Marker in Fetal Growth Restriction: A Tertiary Center Experience

Fetal growth restriction (FGR) is defined as a pathological decrease in the rate of fetal growth. Neuropilin-1 (NRP1) is a transmembrane glycoprotein, involved in the regulation of angiogenesis, and has emerged as a potential biomarker for various pregnancy-related complications. A recent study showed that NRP1 is downregulated in the placenta of FGR pregnancies. This study aimed to evaluate the role of NRP1 as a prognostic marker in FGR.

This was a case-control study, carried out in the department of obstetrics and gynecology in collaboration with pathology over a period of 1 year. After informed consent and ethical clearance, a total of 200 pregnant women were enrolled. FGR was defined as per Delphi criteria 2016. 100 women who had FGR, were classified into two groups, 37 had severe FGR, 63 had mild FGR, and 100 women who had appropriate for gestational age fetuses were considered controls. 2 ml venous blood sample was withdrawn and maternal serum NRP1 (sNRP1) level was measured by ELISA technique using (Elabscience) ELISA kit as per producer protocol.

Severe FGR was found in 18.5% and mild FGR in 31%. On umbilical artery Doppler, mean pulsatility index (PI) and resistive index (RI) were increased in severe FGR fetuses as compared to mild FGR (PI 2.170 vs. 1.462 and RI 0.723 vs. 0.725). Mean sNRP1 level was high in severe FGR as compared to mild FGR, (1970.84 pg/ml vs. 1708.31 pg/ml) while a significant low level of sNRP1 (1080.75 pg/ml) was found in fetuses of appropriate for gestation age ( P ≤ 0.001). At the cutoff value of sNRP1 >1493 had a sensitivity of 100% and specificity of 96% for prediction of FGR ( P < 0.001).

Maternal serum sNRP1 has good diagnostic and prognostic value in FGR.