Obstetrics & Gynecology Science

Original Article: Korean J Obstet Gynecol. 2001;44(9):1685-1690. Published online September 1, 2001.; Fetal Plasma Cortisol and Dehydroepiandrosterone Sulfate in Pregnancy and Term Parturition.; Soo Young Oh, Bo Hyun Yoon; ¹Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea.
²Laboratory of Fetal Medicine Research, Clinical Research Institute, Seoul National University Hospital, Seoul, Korea.

Abstract: OBJECTIVE
The role of steroid hormones in the control of human parturition has been a subject of debate. The objective of the study was to examine if changes in fetal plasma cortisol or dehydroepiandrosterone sulfate (DHEA-S) are associated with human term parturition. METHODS: Fetal plasma cortisol and DHEA-S were measured in 374 singleton pregnancies delivered at term. Umbilical cord blood was obtained from patients in the following 6 groups: 1) preterm gestations undergoing cordocentesis for clinical indications before 36 weeks of gestation (n=93), 2) women undergoing cordocentesis for clinical indications after 36 weeks of gestation (n=9), 3) elective cesarean section (C/S) at term without labor (n=140), 4) C/S at term with early labor (cervical dilatationp< or = 3 cm) (n=18), 5) C/S at term with active labor (cervical dilatation 4cm or greater) (n=26), 6) vaginal delivery at term (n=88). Corticosteroids were not administered before blood collection. RESULTS: 1) Fetal plasma cortisol remain unchanged until 36 weeks of gestation and increased thereafter to term; 2) Active labor was associated with a significant increase in fetal plasma cortisol; 3) Fetal plasma DHEA-S increased in term gestation (>36 weeks) but did not increase during active labor; 4) The cortisol/ DHEA-S ratio (stress index) increased with advancing gestation and with active labor at term. CONCLUSION: Human parturition at term is associated with an increase in fetal plasma cortisol and cortisol/DHEA-S ratio, but not DHEA-S.

Keywords :human parturition;term;cordocentesis;cortisol;DHEA-S;cortisol/DHEA-S ratio