Relationship between the duration of the second stage of labor and postpartum hemorrhage within 2 hours in primiparas undergoing epidural analgesia
10.3760/cma.j.cn113903-20230828-00160
- VernacularTitle:硬膜外分娩镇痛初产妇第二产程时长与产后2 h出血量的关系
- Author:
Ran MENG
1
;
Xiufeng SHI
1
;
Yuan GAO
1
;
Ling QIN
1
;
Jiaojiao LI
1
;
Shanshan CHEN
1
;
Wenwen YANG
1
;
Ran SI
1
;
Xia YIN
1
;
Fangxiang DONG
1
Author Information
1. 济宁医学院附属医院产科，济宁 272029
- Publication Type:Journal Article
- Keywords:
Labor stage, second;
Analgesia, epidural;
Postpartum hemorrhage;
Regression analysis
- From:
Chinese Journal of Perinatal Medicine
2024;27(12):1071-1075
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the relationship between the duration of the second stage of labor and the amount of postpartum hemorrhage within 2 hours in primiparas using epidural analgesia.Methods:A retrospective study was conducted on the clinical data of pregnant women who delivered vaginally in the obstetrics department of the Affiliated Hospital of Jining Medical University from January 1, 2020, to December 31, 2020. The data included maternal age, pre-pregnancy body mass index (BMI), gravidity, gestational age at delivery, weight gain during pregnancy, common pregnancy complications (such as gestational hypertension, gestational diabetes, hypothyroidism, and pregnancy-related anemia), types of uterotonics, duration of each stage of labor, delivery outcomes, perineal conditions, postpartum hemorrhage within 2 hours, and neonatal birth length and weight. The exposure variable was the duration of the second stage of labor, and the outcome was the amount of postpartum hemorrhage within 2 hours. Potential risk factors were analyzed using univariate analysis. After adjusting for potential confounding factors, a generalized additive model was used for linear regression analysis, smooth curve fitting, and threshold effect analysis to observe the relationship between the duration of the second stage of labor and postpartum hemorrhage within 2 hours.Results:A total of 2 067 primiparas were included in the study. The mean age of the participants was 26.5±3.6 years, the median duration of the second stage of labor was 54 min (range: 35-81 min), and the median amount of postpartum hemorrhage within 2 hours was 230 ml (range: 200-300 ml). After adjusting for factors such as maternal age, pre-pregnancy BMI, gestational age at delivery, vaginal delivery, duration of the first and third stages of labor, perineal conditions, types of uterotonics used within 2 hours postpartum, and neonatal birth length and weight, a positive relationship was found between the duration of the second stage of labor and the amount of postpartum hemorrhage within 2 hours ( ?=0.20, 95% CI: 0.00-0.30, P<0.05). The smooth curve fitting results showed a non-linear relationship between the duration of the second stage of labor and postpartum hemorrhage within 2 hours. Threshold effect analysis indicated that the two-segment regression model (Model Ⅱ) was more suitable for fitting the correlation compared to the univariate linear regression model (Model Ⅰ), with a log-likelihood ratio test P-value of 0.001, and the inflection point was 115 min for the second stage of labor (95% CI: 99-125 min). Conclusions:In primiparas using epidural analgesia, there is a non-linear relationship and threshold effect between the duration of the second stage of labor and the amount of postpartum hemorrhage within 2 hours. When the second stage of labor exceeds 115 min, the extension of the second stage may increase the amount of postpartum hemorrhage within 2 hours.
