Human epididymis protein 4 and fetal lung maturity.

OBJECTIVES: To document the maternal and fetal cord blood levels of human epididymis protein 4 (HE-4) in term and preterm newborns in order to investigate the possible physiological role of HE-4 in fetal lung development. METHODS: This cross-sectional study was conducted in a university-affiliated hospital between April 2018 and September 2018. The study population consisted of cesarean section (C-section) deliveries after 24 weeks of pregnancy. Both maternal and umbilical cord HE-4 levels (mHE-4 and uHE-4, respectively) were measured using chemiluminescent microparticle immunoassay. Amniotic fluid was sampled from each case to determine the lamellar body count (LBC) as the gold standard test for lung maturation. All the parameters, including the uHE-4 levels, were compared between the term delivery (≥37 weeks) (n=52) and preterm delivery (24-37th weeks) (n=30) groups. The best cut-off value of uHE-4 was calculated for fetal lung maturity. RESULTS: There were no statistically significant differences between the groups regarding the demographic data. The mHE-4 levels did not statistically significantly differ between the groups (p>0.05) whereas the uHE-4 level of the preterm newborns was significantly higher than that of the term newborns (p<0.05). There was a significant negative association between the uHE-4 level and LBC (r=-0.389; p<0.001). The uHE-4 level was the only statistically significant fetal parameter indicating fetal lung maturity confirmed by LBC. At a cut-off value of 281 pmol/L, uHE-4 had 96.8% sensitivity, 45% specificity, 84.5% positive predictive value, and 81.8% negative predictive value for fetal lung maturity. CONCLUSIONS: Although the exact physiological role of HE-4 has not yet been elucidated, this preliminary study supports the idea that HE-4 plays a role in fetal lung maturation to some extent.