Relationship between the natural cessation time of umbilical cord pulsation in full-term newborns delivered vaginally and maternal-neonatal outcomes: a prospective cohort study.

ABSTRACT

BACKGROUND: To analyze the impact of the time of natural cessation of the umbilical cord on maternal and infant outcomes in order to explore the time of clamping that would be beneficial to maternal and infant outcomes. METHODS: The study was a cohort study and pregnant women who met the inclusion and exclusion criteria at the Obstetrics and Gynecology Department of Qilu Hospital of Shandong University from September 2020 to September 2021. Analysis using Kruskal-Wallis rank sum test, Pearson's Chi-squared test, generalized linear mixed model (GLMM) and repeated measures ANOVA. If the difference between groups was statistically significant, the Bonferroni test was then performed. A two-sided test of P < 0.05 was considered statistically significant. RESULTS: A total of 345 pregnants were included in this study. The subjects were divided into the ≤60 seconds group (n = 134), the 61-89 seconds group (n = 106) and the ≥90 seconds group (n = 105) according to the time of natural arrest of the umbilical cord. There was no statistically significant difference in the amount of postpartum hemorrhage and the need for iron, medication, or supplements in the postpartum period between the different cord spontaneous arrest time groups for mothers (P > 0.05). The weight of the newborns in the three groups was (3316.27 ± 356.70) g, (3387.26 ± 379.20) g, and (3455.52 ± 363.78) g, respectively, and the number of days of cord detachment was 12.00 (8.00, 15.75) days, 10.00 (7.00, 15.00) days and 9.00 (7.00, 13.00) days, respectively, as the time of natural cessation of the cord increased. The neonatal lymphocyte ratio, erythrocyte pressure, and hemoglobin reached a maximum in the 61-89 s group at (7.41 ± 2.16) %, (61.77 ± 8.17) % and (194.52 ± 25.84) g/L, respectively. Lower incidence of neonatal hyperbilirubinemia in the 61-89 s group compared to the ≥90s group 0 vs 4.8 (P < 0.05). CONCLUSIONS: In full-term singleton vaginal births, maternal and infant outcomes are better when waiting for 61-89 s after birth for the cord to stop pulsating naturally, suggesting that we can wait up to 90s for the cord to stop pulsating naturally, and if the cord does not stop pulsating after 90s, artificial weaning may be more beneficial to maternal and infant outcomes.