Silvano Angela, Ammar Oumaima, Parenti Astrid, Strambi Noemi, Seravalli Viola, Bani Daniele, Di Tommaso Mariarosaria
Department of Health Sciences, Division of Obstetrics and Gynecology, Careggi Hospital, University of Florence, Florence, Italy.
Department of Health Sciences, Clinical Pharmacology and Oncology Section, University of Florence, Florence, Italy.
J Obstet Gynaecol Res. 2025 Jan;51(1):e16190. doi: 10.1111/jog.16190.
Relaxin is a peptide hormone commonly associated with pregnancy when it is thought to play a role in modulating various physiological processes to optimize maternal-fetal adaptation. In twin pregnancies these adaptive requirements are higher than in singleton pregnancies, therefore it is important to understand how circulating relaxin behaves in such conditions. This prospective cohort study aims to determine the serum relaxin-2 levels throughout gestation in twin pregnancies and to investigate its association with the mode of conception.
Blood samples were collected during each trimester of gestation from 26 women with twin pregnancies obtained through spontaneous conception (SC, n = 18) or assisted reproductive technologies, specifically through intracytoplasmic sperm injection (ART, n = 8). Serum relaxin-2 levels were measured by a highly sensitive ELISA method.
The results indicated that serum relaxin-2 level peaks in the first trimester (491.05 ± 207.41 pg/mL), then decreases in the second trimester (446.27 ± 180.4 pg/mL; p < 0.057) and in the third trimester (422.19 ± 194.30 pg/mL; p < 0.025). Interestingly, the serum relaxin-2 level was higher in the spontaneous conception group with respect to the assisted reproductive technologies group (p < 0.001), when measured at each trimester of gestation. In addition, the multivariate regression analysis showed that only the assisted reproductive technologies had a significant impact on serum levels of relaxin-2 (p < 0.001), and no significant association was found with other women's clinical and demographic characteristics.
These findings extend the current knowledge about the pattern of circulating relaxin-2 throughout gestation in twin pregnancies, providing a sensitive measurement of serum relaxin-2 levels and a description of its putative physiological roles in humans.
松弛素是一种肽类激素，通常与妊娠有关，被认为在调节各种生理过程以优化母胎适应方面发挥作用。在双胎妊娠中，这些适应性需求高于单胎妊娠，因此了解循环松弛素在这种情况下的表现很重要。这项前瞻性队列研究旨在确定双胎妊娠整个孕期的血清松弛素-2水平，并研究其与受孕方式的关系。
从26例通过自然受孕（SC，n = 18）或辅助生殖技术，具体为卵胞浆内单精子注射（ART，n = 8）获得双胎妊娠的妇女在妊娠各期采集血样。采用高度敏感的ELISA方法测定血清松弛素-2水平。
结果表明，血清松弛素-2水平在孕早期达到峰值（491.05±207.41 pg/mL），然后在孕中期下降（446.27±180.4 pg/mL；p < 0.057），在孕晚期进一步下降（422.19±194.30 pg/mL；p < 0.025）。有趣的是，在妊娠各期测量时，自然受孕组的血清松弛素-2水平高于辅助生殖技术组（p < 0.001）。此外，多因素回归分析显示，只有辅助生殖技术对血清松弛素-2水平有显著影响（p < 0.001），未发现与其他女性临床和人口统计学特征有显著关联。
这些发现扩展了目前关于双胎妊娠整个孕期循环松弛素-2模式的知识，提供了血清松弛素-2水平的敏感测量方法，并描述了其在人类中的假定生理作用。
