Analysis of Factors Affecting Postpartum Hemorrhage in Twin Pregnancy

Research Article

Analysis of Factors Affecting Postpartum Hemorrhage in Twin Pregnancy

Zheng JS, Wang Y, Xu S, Hong HJ, Sun WJ, Xin G, Xiao J and Hong FZ*

The Second Hospital of Shandong University, Jinan, China

*Corresponding author: Hong FZ, The Second Hospital of Shandong University, 247 Beiyuan Road, Jinan 250010, China

Received: March 03, 2022; Accepted: March 29, 2022; Published: April 05, 2022


Objective: To explore the factors affecting postpartum hemorrhage in twin pregnancy.

Methods: The clinical data of 839 twin pregnancy patients who delivered at the Second Hospital of Shandong University from May 2010 to July 2020 were retrospectively analyzed. According to the amount of postpartum hemorrhage, patients were divided into postpartum hemorrhage group (PPH group) and non- PPH group. The basic population information and clinical data during pregnancy were compared between the two groups.

Results: A total of 839 women with twin pregnancy were included in this study, and hemorrhage occurred in 11% (n=96). The Binary logistic regression model predicts the risk of factor of postpartum hemorrhage in twin pregnancy: gestation week of delivery, placenta previa, polyhydramnios, acute delivery, anemia, placental adhesions and DIC (disseminated intravascular coagulation).

Conclusions: There are many factors that affect postpartum hemorrhage in twin pregnancy. Choosing the right gestational week for delivery, strengthening pregnancy management, and improving pregnancy complications can reduce the risk of postpartum hemorrhage in twin pregnancy.

Keywords: Postpartum hemorrhage; Pregnancy; Pregnancy; Twin; Retrospective studies; Risk factor


PPH: Postpartum Hemorrhage; DIC: Disseminated Intravascular Coagulation; BMI: Body Mass Index


Postpartum hemorrhage (PPH) is classically defined as a blood loss of >500mL after vaginal birth or that of >1000mL after cesarean delivery, with no adjustment for multiple pregnancies [1]. According to the World Health Organization, PPH is the leading cause of maternal mortality in developing countries (close to 30%) and the second leading cause of maternal mortality in developed countries (approximately 13%) [2]. PPH is responsible for approximately 68000 annual deaths in pregnant women, which means that one pregnant woman dies every 8 min due to PPH [3]. The 2014 National Maternal and Child Health Inspection Report described the main causes of maternal mortality in China. Although maternal mortality due to obstetric hemorrhage (more than 80% of PPH) has been declining for more than a decade, it is still the most common cause of maternal mortality [4]. Studies have reported uterine weakness, birth canal injury, placental factor, and coagulation dysfunction as the four major causes of PPH. Of these, uterine weakness is the most common cause of PPH that accounts for approximately 70%-80% of PPH [4,5]. Twin pregnancy leads to uterine smooth muscle overextension, which affects the uterine contraction after delivery and increases uterine weakness. Additionally, the circulating blood volume and uterine blood flow in women pregnant with twins increase to ensure adequate blood supply to the uterus, placenta, and fetal tissues. Thus, twin pregnancy is a significant risk factor for PPH [1,5-8]. With the wide application of assisted reproductive technology and the increase in maternal age, the twin pregnancy rate is increasing every year [9-11]. Factors affecting PPH in singleton pregnancy have been investigated in numerous studies [2,4]. However, the risk factors for PPH in twin pregnancy remain unknown. The present study attempts to explore the risk factors for PPH in twin pregnancy through a retrospective analysis of the clinical data of patients with twin pregnancy.

Materials and Methods

Study population

The present retrospective study analyzed the data of 839 patients after obtaining institutional ethical clearance. All the patients had twin pregnancy with >26 weeks of gestation, and they delivered at the Second Hospital of Shandong University between May 2010 and July 2020.

Diagnostic criteria and statistical indicators

The World Health Organization’s definition of PPH, that is, the bleeding volume of vaginal delivery exceeding 500mL or that of cesarean section delivery exceeding 1000mL, without adjusting for the bleeding volume of multiple pregnancy, was considered [1,3]. The diagnostic criteria of pregnancy complications were adopted from Gynecology and Obstetrics, edited by Xie Xing et al., 9th edition of Human Health Publishing House [4].

According to the estimated bleeding volume, the patients were divided into the PPH group (n=96) and the control group (non-PPH group; n=743). The basic information of the population included age, body mass index (BMI), number of pregnancies, number of miscarriages, and whether to having a live birth. Clinical data during pregnancy included pregnancy method, gestational week of delivery, delivery method, total fetal birth weight, and complications during pregnancy.

Statistical analysis

Statistical analysis was performed using the SPSS 22.0 software. The measurement data are expressed as percentiles, whereas the count data are expressed as percentages (%). The Kruskal–Wallis test was used to compare the means between the groups, and Chi-square test was used to compare the rates between the groups. Finally, the binary logistic regression model was used to predict the risk factors for PPH in twin pregnancy. A P value of <0.05 was considered statistically significant.


The present study was conducted in 839 patients, of which 96 patients exhibited PPH mainly due to uterine weakness, accounting for 71.88% of the PPH cases (Table 1).