Introduction

Postpartum hemorrhage (PPH) is the leading cause of maternal mortality worldwide^1,2 and contributes 19.7% of maternal deaths³. In Peru, 264 maternal deaths occurred in 2023, of which 21.8% were due to obstetric hemorrhage⁴.

The definition of PPH is not yet fully standardized mainly due to the difficulty of blood quantification⁵. The World Health Organization (WHO), in 2014 classically defined PPH as blood loss of 500 mL consecutive to vaginal delivery or more than 1,000 mL after cesarean section, within 24 hours after delivery. It is also defined as any postpartum bleeding with hemodynamic changes requiring blood transfusion, a drop in hematocrit of more than 10%⁶⁾ and/or 2.9 mg/ dL in hemoglobin⁷. In 2007, the American College of Obstetrics and Gynecology defined it as a loss greater than or equal to 1,000 mL associated with signs or symptoms of hypovolemia, independent of the type of delivery⁵. The global prevalence of PPH, independent of the route of delivery, in observational studies is 10.8%, in Africa 25.7% and in Latin America and the Caribbean 8.2%⁸. In Peru, Cabrera et al. published a prevalence of 10%^9).

The main cause of PPH is uterine atony², which is conditioned by various characteristics of pregnancy, delivery and puerperium. The most representative risk factors for PPH due to uterine atony are multiparity¹⁰, previous cesarean section¹¹, hypertensive disorders associated with pregnancy¹², polyhydramnios¹³, chorioamnionitis¹³, multiple pregnancy¹⁰, fetal macrosomia^10,12, body mass index ≥ 28 kg/ m2¹⁰, maternal age greater than or equal to 35 years¹⁴, among others. Therefore, PPH prevention should focus on the early detection of risk factors and the planning of specific measures within delivery care.

The management of PPH recommended by various organizations includes intravenous isotonic crystalloids, uterine massage, uterotonic drugs and the use of tranexamic acid as initial measures¹⁵. When medical treatment fails, the use of conservative surgical measures such as B-Lynch and Hayman compressive sutures¹⁶, which generate mechanical compression of the uterine walls, significantly reducing postpartum hemorrhage bleeding and preventing its recurrence, is recommended. Compressive sutures have also been recommended as PPH prophylaxis in highrisk cesarean section patients, achieving a lower drop in hemoglobin level compared to those receiving medical treatment¹⁷.

PPH is one of the main causes of postpartum anemia, with a prevalence of 10% to 30% in high-income countries and more than 50% in low-resource countries¹⁸. Postpartum anemia leads to symptoms such as fatigue, palpitations, dyspnea, and infections¹⁹ and may affect the mother-child relationship and care²⁰. The use of compressive sutures could be a preventive measure for postpartum anemia in patients with specific risk factors, such as antepartum anemia. Therefore, it would contribute to improve the quality of life of these postpartum women, avoiding compromising the affective bonds between the mother and the newborn and even avoiding blood transfusions.

The aim of the present study was to determine the association between the use of compressive suture and the level of hemoglobin decrease in patients who underwent cesarean section and who presented postpartum hemorrhage due to uterine atony.

Methodology

This was an analytical retrospective cohort study that included all patients who were delivered by cesarean section and had PPH due to uterine atony at the Instituto Nacional Materno Perinatal (INMP) in Lima-Peru, in the period between July and December 2020. The INMP is a tertiary care hospital whose mission is to provide highly specialized care to women, particularly high-risk pregnant women and their newborns. It attends about 16,500 deliveries per year and is a reference center in Peru. The inclusion criteria for the study were: 1) patient whose cesarean delivery took place at the INMP in the determined period; 2) pregnancy greater than 22 weeks; 3) PPH that met one of the following criteria: uterine atony, Hb decrease of 2.9 mg/dL measured at 24 hours postpartum, hematocrit decrease of 10% or intraoperative bleeding of 1,000 mL. Exclusion criteria were placenta previa, placenta accreta spectrum, placental abruption, uterine rupture, coagulation disorders, perineal tear or major vaginal laceration causing PPH, collagenopathies or connective tissue diseases, or diagnoses other than uterine atony; in addition, incomplete medical history records. The present study had the institutional approval of the Ethics Committee with Report N°050-2021-CIE/INMP.

A total of 625 medical records with a diagnosis of PPH according to ICD-10 corresponding to the study period and which met the inclusion criteria and did not have any exclusion criteria were evaluated. Of the total, 461 patients did not meet the inclusion criteria, six patients had a diagnosis of PPH other than uterine atony and one patient was excluded due to incomplete data. An electronic data collection instrument constructed in Microsoft Excel version 16.61.1 was applied. The following variables were collected: age, body mass index (BMI), number of adequate prenatal controls greater than or equal to 6 (aPNC)^21), hemoglobin decrease as a result of the difference between antepartum hemoglobin and postpartum hemoglobin at 24 hours, fetal macrosomia (weight ≥4,000 g), twin pregnancy, previous cesarean section, previous postpartum hemorrhage, poor attitude of presentation, uteroplacental insufficiency, severe preeclampsia, eclampsia, cephalopelvic incompatibility, premature detachment of ovarian membranes, use of compressive suture, surgical reintervention, need for prepartum and intrapartum transfusion, need for postpartum transfusion, and operative time.

Continuous variables were presented as mean and standard deviation if they met the normal distribution and median with interquartile ranges if they did not meet the normal distribution. Categorical variables were education, prenatal care (adequate, inadequate PNC), gestational age (preterm or term), categorized body mass index (BMI), parity, use of compressive sutures, number of pregnancies (primigestation, multigestation), number of cesarean sections (primary, equal to or greater than one cesarean section), and surgical reintervention. The variables expressed as continuous variables were age, BMI in kg/m2, number of PNC, preand intrapartum globular pack transfusions, postpartum globular pack transfusions and surgical time.

The bivariate analysis was performed with T student with equal variances for numerical independent variables and chi-square for categorical independent variables. Multivariate linear regression controlled for confounding variables according to epidemiological criteria was applied in the analysis. A 95% significance level and Stata statistical software version 17.0 were used for the analysis. In addition, we evaluated multicollinearity in the final model. It should be noted that the study variables complied with the assumptions established in multivariate linear regression: 1) linearity between hemoglobin reduction and the use of compressive sutures was assessed; 2) normality was assessed using Kendall's standard residual density and graphical methods; 3) independence of observations was described; and 4) homoscedasticity was assessed.

Results

The analysis included 157 patients with a diagnosis of PPH due to uterine atony. Table 1 describes the characteristics of the included patients. The mean age was 29.1 years and median BMI 30.5 kg/m2 (type I obesity). Only 12.1% of patients had adequate prenatal care with a median of 2 controls per pregnant woman. The frequency of compressive suture use was 59.9% and no complications directly associated with the surgical procedure were reported. The mean decrease in hemoglobin at 24 hours was 3.25 ± 1.2 mg/ dL. The 7 patients who were reoperated did not undergo compressive suturing. Eleven patients (7.0%) were admitted to the intensive care unit (ICU), of whom 63.6% required the use of compressive suturing.

Table 1 Sociodemographic and obstetric characteristics (n=157). 

SD=standard deviation, BMI=body mass index, PNC=prenatal care, wk=weeks, ICU=intensive care unit

* Variables do not meet normal distribution

** Some variables may add up to less than 157 due to missing data

Table 2 shows the main causes of cesarean section in the study. Fetal macrosomia was the most frequent reason with 27 cases (17.2%). Other factors were fetal distress in 26 cases (16.6%) and severe preeclampsia with 23 cases (14.7%).

Table 2 leading cause of cesarean section (n=157). 

* Other causes of cesarean section: oligohydramnios, preterm labor, placenta previa, narrow pelvis, chorioamnionitis, prolapsed fetal parts, funicular dystocia and dysfunctional labor.

Table 3 shows the crude and adjusted association of the use of compressive suture and hemoglobin decrease at 24 h. At 24 h, there was less hemoglobin loss. At 24 h, there was lower mean Hb loss of 0.38 mg/dL (95% CI: -0.75, -0.10, p=0.044) in those patients who underwent compression suturing controlled for surgical reintervention, preand cesarean pack transfusions, post-cesarean pack transfusions, age, BMI and number of prenatal controls.

Table 3  multiple linear regression of the association between hb decrease (24 h) and the use of compressive suture. 

CI=95% confidence interval, PG pre/intra SOP=transfusions of globular packs intra or pre operating room, PG post SOP=transfusions of globular packs post operating room

*Adjusted for preoperative/intraoperative PG transfusions, postoperative transfusions, operative time, age, BMI and categorized PNC

Compressive suture was the independent variable and explained approximately 3% of the variability of hemoglobin decrease. However, when confounding variables were added according to epidemiological criteria -such as transfusion of globular packet before and during cesarean sectionthey increased by 15.9%, transfusion of globular packet after cesarean section by 15.4%, surgical time 14.9%, age 14.5%, categorized BMI by 14.1% and adequate prenatal controls by 13.7%, as the final model. In this final model, multicollinearity was evaluated, which resulted in 1.08, determining that there was no multicollinearity. Finally, homogeneity of variances was tested.

Discussion

In our study we determined the association of lower hemoglobin decrease at 24 hours with the use of a compressive suture surgical technique (B-Lynch or Hayman) in post-cesarean patients with PPH due to uterine atony.

The prevalence of PPH, considering 2,394 cesarean deliveries due to uterine atony between July and December 2020, was 6.6%, similar to other studies performed in Peru⁹. The COVID-19 pandemic that conditioned less access to health services among pregnant women does not seem to have affected this prevalence. PPH represented 36.2% in the INMP, being the main cause of extreme maternal morbidity²².

Only 12.1% of patients in our study had adequate PNC; however, this differs greatly from the 88.9% reported in the 2017 ENDES²³. This could reflect pandemic-specific limitations that restricted access to care in health facilities. Ninety-three percent of patients diagnosed with PPH were overweight or had a degree of obesity, and 21% of patients had type II or III obesity, similar to other studies²⁴. Liu et al. in 2021 published that 36.9% of patients who had PPH were aged 35 years or older; in our study it was 22.3%^25).

Compressive sutures type B-Lynch and Hayman are widespread, easy and reproducible surgical techniques because no special materials are needed for their development, so they can be used in low-resource settings. Basic training given in a standard obstetric medical residency program is required. However, Bouet et al. in 2019 reported that 79% of resident physicians surveyed in France did not effectively master the technique of compressive sutures and 55% had no technique for PPH resolution²⁶. Therefore, training programs should ensure that resident physicians attain the necessary competencies in surgical techniques for the management of PPH. Both B-Lynch and Hayman compression sutures are considered to have equal efficacy in the management of PPH²⁷. Our study achieved 100% efficacy similar to publications such as the original study by B-Lynch et al²⁸.

PPH and puerperal anemia constitute a public health problem worldwide and in our country. In addition to causing maternal mortality, puerperal anemia conditions the reduction of quality of life due to the increase of symptoms such as fatigue, palpitations and risk of infections such as those of the urinary tract¹⁹. In addition, cognitive performance is affected, and there is an increased risk of emotional instability and depression²⁹. Therefore, the application of all strategies to prevent, diagnose and treat PPH should be considered. The application of medical treatment with uterotonics is essential; however, Ahmed et al. reported a better effectiveness of compressive suture (B Lynch) compared to medical treatment in terms of hemoglobin and hematocrit reduction in patients with risk factors¹⁷. Furthermore, it should be noted that Kwong et al. in a prospective study in 2023 concluded that compressive sutures do not alter fertility or menstruation³⁰. Consequently, the use of accessible surgical techniques could be to reduce postpartum anemia in patients with risk factors and will be treatment in patients with PPH due to atony.

Among our limitations we consider: 1) The present study is a retrospective cohort, whose data collection depends largely on what is recorded by the treating physicians; 2) There is difficulty in correctly accounting for intraoperative and postoperative bleeding in operative reports and medical records; this could lead to underestimated or overestimated diagnoses; 3) The decrease of 0.3 mg/dL is not clinically significant; but this amount could be related to the difficulty to adequately account for bleeding and the recommendation of a control hemoglobin sample at 48 hours¹⁹; 4) The statistical power found was around 60%. Therefore, we consider that prospective cohort studies are necessary, with a larger population and study time, with a correct accounting of intraoperative and postoperative bleeding, properly filled out operative reports and data adequately recorded in a validated data collection form.

Conclusions

Compressive suture is a first-line surgical procedure for the treatment of PPH, which would achieve a lower decrease in hemoglobin in postcesarean patients diagnosed with PPH due to uterine atony.