Association between the expression difference of cortisol in umbilical cord blood and discordant growth in dichorionic twins: a cross-sectional survey.

Background: This study aimed to assess whether the expression difference of cortisol in umbilical cord blood is associated with dichorionic twin inconsistent growth.

Methods: This research included 108 patients with dichorionic twin pregnancy delivered at Jiaxing Maternity and Child Health Care Hospital between January 2021 and December 2024. Depending on whether or not they had twin inconsistent growth, participants were classified into the discordant twins (DT) group (47 pairs of discordant twins) as the experimental group and the concordant twins (CT) group (61 pairs of concordant twins) as the control group. According to the medical record, the maternal and neonatal information of the two groups were collected, and the differences in the basic conditions between the two groups of maternal and twin fetuses were analyzed. The fetal birth weight of the two groups was weighed, and the cortisol content of the umbilical cord blood was measured by chemiluminescence.

Results: There were no significant differences in maternal age, gestational age (GA), parity, body and mass index (BMI), mode of conception, delivery time, and fetal gender between the two groups of maternal characteristics. There were also no significant differences in the amniotic fluid depth, umbilical artery standard deviation (SD) value, umbilical cord entanglement, placental shape, and twin gender differences between the two groups of neonates. However, the smaller neonates in the DT group had a higher cortisol level in the umbilical cord blood, with a significant difference, while there was no significant difference in cortisol levels in the umbilical cord blood of the CT group of twin fetuses.

Conclusions: The difference in cortisol levels in the umbilical cord blood of twin fetuses may be related to the occurrence of inconsistent growth of dichorionic twins.