Maternal blood and amnionic oxytocin receptor gene expression and serum oxytocin levels in preterm birth: a case-control study

Abstract

Maternal blood and amnionic oxytocin receptor gene expression and serum oxytocin levels in preterm birth: a case-control study Kumari Anukriti1, *, Kiran Guleria2 , Vipin Tyagi3 , Amita Suneja2 , B D Banerjee3 1Department of Obstetrics and Gynaecology, AIIMS, 110029 Delhi, India 2Department of Obstetrics and Gynaecology, University College of Medical Sciences & G.T.B. Hospital (University of Delhi), Dilshad Garden, 110095 Delhi, India 3 Environmental Biochemistry and Molecular Biology Laboratory, Department of Biochemistry, University College of Medical Sciences & G.T.B. Hospital (University of Delhi), Dilshad Garden, 110095 Delhi, India *Correspondence: anukritieyes@gmail.com (Kumari Anukriti) DOI:10.31083/j.ceog.2021.02.2267 This is an open access article under the CC BY 4.0 license (https://creativecommons.org/licenses/by/4.0/). Submitted: 22 August 2020 Revised: 26 December 2020 Accepted: 11 January 2021 Published: 15 April 2021 Purpose of investigation: The oxytocin (OXT)-oxytocin receptor (OXTR) system provides a promising candidate gene for studies of genetic contributions to prematurity. The author studies the quantification and comparison of oxytocin receptor (OXTR) gene expression and serum OXT levels in the blood and amnion of women delivering preterm and evaluation of the correlation between OXTR gene expression in blood and amnion with serum OXT levels in them. Material and methods: Seventy pregnant women in spontaneous labor delivering vaginally preterm i.e., < 37 weeks and an equal number of matched controls delivering spontaneously at term (37--42 weeks) were recruited. Maternal serum OXT levels were quantified by ELISA collected in the active stage of labor i.e., 4 cm cervical dilatation. Gene expression studies in the maternal blood and amnion were done by using real-time quantitative polymerase chain reaction (RT-qPCR). Results: The mean serum OXT level in preterm labor (PTL) was 48.56 ± 6.97 pg/mL; significantly higher than in controls (43.00 ± 3.96 pg/mL), P < 0.001. OXTR gene expression in maternal blood (2.5 times) as well as in amnion (3.5 times) was significantly higher in PTL. A significant positive correlation was observed between serum OXT levels and OXTR gene expression in amnion (r = -0.190, P = 0.025). Conclusions: The serum OXT levels and OXTR gene expression in amnion surge significantly in the active phase of PTL. Thus, amnion probably links OXT-PTGs (prostaglandins) autocrine paracrine circuit to facilitate PTL. Future studies are needed to devise better OXTR receptor antagonists preferably acting on amnionic OXTRs to prevent inȠlammatory pathways leading to PTL. Keywords Preterm birth; Preterm labor; Oxytocin; Oxytocin receptor; Placenta; Amnion