Predicting Postpartum Hemorrhage After Vaginal Birth by Labor Phenotype

New definitions, old complications: The association between duration of transition from latent to active labor and adverse obstetrical outcomes

OBJECTIVE

To explore the relationship between the duration of transition from latent to active labor and various obstetric, maternal, fetal, and neonatal outcomes.

METHODS

A retrospective cohort study was conducted on term, singleton deliveries at Soroka University Medical Center from 2013 to 2018. Data were extracted from electronic medical records. The exposure variable was defined as prolonged transition, which was itself defined as the upper 10th centile of dilation duration from 4 to 6 cm. Clinical and demographic characteristics were compared using χ2 test. Multivariate logistic regression was used to estimate the contribution of a prolonged transition with each adverse outcome adjusting for potential confounders.

RESULTS

In all, 12 104 deliveries met the inclusion criteria. The mean ± standard deviation of duration of dilation from 4 to 6 cm was 03:07:58 ± 03:03:42 (hours:minutes:seconds). Progress curves varied significantly among patients with different obstetrical and demographic characteristics. Prolonged transition was significantly linked to an increased risk of cesarean delivery (adjusted odds raito 2.607, 95% confidence interval 2.171-3.130, area under the curve 0.689) and higher rates of maternal and neonatal morbidity.

CONCLUSIONS

Patients experiencing transition phases exceeding the 90th centile faced an elevated risk of cesarean delivery and postpartum complications. Future studies should focus on interventions during the transition phase to improve pregnancy outcomes and enhance patient safety.

Impact of Race/Ethnicity and Insurance Status on Obstetric Outcomes: Secondary Analysis of the NuMoM2b Study

OBJECTIVE

This study aimed to investigate the impact of race/ethnicity and insurance status on obstetric outcomes in nulliparous women.

STUDY DESIGN

Secondary analysis of the Nulliparous Pregnancy Outcomes Study Monitoring Mothers-To-Be. Obstetric outcomes included the development of a hypertensive event during pregnancy, need for a cesarean section, delivery of a preterm neonate, and postpartum hemorrhage.

RESULTS

Of 7,887 nulliparous women, 64.7% were non-Hispanic White (White), 13.4% non-Hispanic Black (Black), 17.8% Hispanic, and 4.1% were Asian. Black women had the highest rates of developing new-onset hypertension (32%) and delivering preterm (11%). Cesarean deliveries were the highest in Asian (32%) and Black women (32%). Individuals with government insurance were more likely to deliver preterm (11%) and/or experience hemorrhage after delivery. In multivariable analyses, race/ethnicity was associated with hypertension and cesarean delivery. More important, the adjusted odds ratios for preventable risk factors, such as obesity, diabetes, and severe anemia were greater than the adjusted odds ratios for race/ethnicity in terms of poor maternal outcome.

CONCLUSION

Although disparities were observed between race/ethnicity and obstetric outcomes, other modifiable risk factors played a larger role in clinical differences.

KEY POINTS

· Race or insurance alone had mixed associations with maternal morbidities.. · Race and insurance had low associations with maternal morbidities.. · Other, modifiable risk factors may be more important.. · Both social and biological factors impact health disparities..

The infection, cervical and perineal lacerations in relation to postpartum hemorrhage following vaginal delivery induced by Cook balloon catheter

OBJECTIVE

To identify whether infection, cervical laceration and perineal laceration are associated with postpartum hemorrhage in the setting of vaginal delivery induced by Cook balloon catheter.

MATERIALS AND METHODS

The retrospective study included 362 women who gave birth vaginally at or beyond 37 weeks of gestation with a diagnosis of postpartum hemorrhage between February 2021 to May 2022, of which including 216 women with induction of labor (Cook balloon catheter followed by oxytocin or oxytocin) and 146 women with spontaneous delivery. Risk factors for postpartum hemorrhage were collected and compared.

RESULTS

362 women were divided into three groups, group 1 with spontaneous delivery, group 2 with oxytocin, group 3 with Cook balloon catheter followed by oxytocin. There was no significant difference in incidence of infection within three groups (P > 0.05). The rate of cervical laceration and perineal laceration was significantly higher in group 3 compared with groups 2 and 1 (P < 0.05); Multivariate logistic regression analysis found that compared with group 1, either group 3 or group 2 was associated with increased risks of cervical laceration and perineal laceration (P < 0.05), and compared with group 2, group 3 was not associated with increased risks of cervical laceration and perineal laceration (P > 0.05).

CONCLUSION

Infection, cervical laceration and perineal laceration are identified not to be independent risk factors for postpartum hemorrhage for women undergoing labor with Cook balloon catheter; Cervical laceration and perineal laceration increase the risk of postpartum hemorrhage in women with labor induction.

A prolonged latent phase: An early career in oxytocin during birth

•The author, a nurse-midwife scientist, shares her path to the study of the causes and consequences of clinical oxytocin use.•This paper highlights mentors and key research that informed new thinking about the role of oxytocin during parturition.•Future directions for improving maternal care during childbirth are presented, including genetic and epigenetic perspectives.

Health care provider decision-making and the quality of maternity care: An analysis of postpartum care in Kenyan hospitals

Evidence suggests that health care providers' non-adherence to clinical guidelines is widespread and contributes to poor patient outcomes across low- and middle-income countries. Through observations of maternity care in Kenya, we found limited adherence to guideline-recommended active monitoring of patients for signs of postpartum hemorrhage, the leading cause of maternal mortality, despite providers' having the necessary training and equipment. Using survey vignettes conducted with 144 maternity providers, we documented evidence consistent with subjective risk and perceived uncertainty driving providers' decisions to actively monitor patients. Motivated by these findings, we introduced a simple model of providers' decision-making about whether to monitor a patient, which may depend on their perceptions of risk, diagnostic uncertainty, and the value of new information. The model highlights key trade-offs between gathering diagnostic information through active monitoring versus waiting for signs and symptoms of hemorrhage to manifest. Our work provides a template for understanding provider decision-making and could inform interventions to encourage more proactive obstetric care.

Low-dose aspirin in the prevention of pre-eclampsia in China: postpartum hemorrhage in subgroups of women according to their characteristics and potential bleeding risk

BACKGROUND

The APPEC study is a large-population randomized controlled trial in China evaluating the role of low-dose aspirin prophylactic treatment for pre-eclampsia. There was no statistically significant difference in postpartum hemorrhage (PPH) incidence between the aspirin and control groups. This study aimed to evaluate the potential bleeding risk of 100 mg aspirin in high-risk pregnant women and the difference in the incidence of PPH according to maternal characteristics.

METHODS

This is a secondary data analysis of the APPEC study. Platelet counts and coagulation test results were collected at five follow-up visits. Subgroups defined by maternal age (<35 years and ≥35 years), pre-pregnancy body mass index (pre-BMI, <28 kg/m 2 and ≥28 kg/m 2 ), parity, gestational age at enrollment, and medical history, including pre-eclampsia, chronic hypertension, and diabetes mellitus, were analyzed. Logistic regression analysis was used to determine the statistical significance of the difference in the incidence of PPH after aspirin administration in pregnant women in each subgroup. Adjustment using multiple logistic regression models followed these analyses. Binary logistic regression was used to determine the relationship between pre-BMI and PPH.

RESULTS

There was no significant difference between the aspirin and control groups in bleeding risk (3.4% [16/464] vs. 3.0% [13/434], T = 0.147, P  = 0.701). No significant difference was found in the incidence of PPH in total (relative risk  = 1.220, 95% confidence interval [CI] = 0.720-2.067, P  = 0.459; aspirin group vs. control group, 6.5% [30/464] vs. 5.3% [23/434], P  = 0.459) or in subgroup analysis. A significant correlation between pre-BMI and PPH was found in the aspirin group, while in the control group there was no significant correlation (aspirin group, odds ratio [OR] = 1.086, 95% CI = 1.004-1.175, P  = 0.040; control group, OR = 1.060, 95% CI = 0.968-1.161, P  = 0.209).

CONCLUSIONS

A dosage of 100 mg of aspirin per day, initiated from 12 to 20 gestational weeks until 34 weeks of gestation, did not increase the risk of potential bleeding and PPH regardless of the maternal characteristic. In the aspirin group, the positive correlation between BMI and PPH was significant.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01979627.

Oxytocin receptor single nucleotide polymorphism predicts atony-related postpartum hemorrhage

BACKGROUND

Postpartum hemorrhage remains a key contributor to overall maternal morbidity in the United States. Current clinical assessment methods used to predict postpartum hemorrhage are unable to prospectively identify about 40% of hemorrhage cases. Oxytocin is a first-line pharmaceutical for preventing and treating postpartum hemorrhage, which acts through oxytocin receptors on uterine myocytes. Existing research indicates that oxytocin function is subject to variation, influenced in part by differences in the DNA sequence within the oxytocin receptor gene. One variant, rs53576, has been shown to be associated with variable responses to exogenous oxytocin when administered during psychological research studies. How this variant may influence myometrial oxytocin response in the setting of third stage labor has not been studied. We tested for differences in the frequency of the oxytocin receptor genotype at rs53576 in relationship to the severity of blood loss among a sample of individuals who experienced vaginal birth.

METHODS

A case-control prospective design was used to enroll 119 postpartum participants who underwent vaginal birth who were at least 37 weeks of gestation. Cases were defined by either a 1000 mL or greater blood loss or instances of heavier bleeding where parturients were given additional uterotonic treatment due to uterine atony. Controls were matched to cases on primiparity and labor induction status. Genotype was measured from a maternal blood sample obtained during the 2^nd postpartum month from 95 participants. Statistical analysis included bivariate tests and generalized linear and Poisson regression modeling.

RESULTS

The distribution of the genotype across the sample of 95 participants was 40% GG (n = 38), 50.5% AG (n = 48) and 9.5% AA (n = 9). Blood loss of 1000 mL or greater occurred at a rate of 7.9% for GG, 12.5% for AG and 55.6% for AA participants (p = 0.005). Multivariable models demonstrated A-carriers (versus GG) had 275.2 mL higher blood loss (95% CI 96.9-453.4, p < 0.01) controlling for parity, intrapartum oxytocin, self-reported ancestry, active management of third stage or genital tract lacerations. Furthermore, A-carrier individuals had a 79% higher risk for needing at least one second-line treatment (RR = 1.79, 95% CI = 1.08-2.95) controlling for covariates. Interaction models revealed that A-carriers who required no oxytocin for labor stimulation experienced 371.4 mL greater blood loss (95% CI 196.6-546.2 mL).

CONCLUSIONS

We provide evidence of a risk allele in the oxytocin receptor gene that may be involved in the development of postpartum hemorrhage among participants undergoing vaginal birth, particularly among those with fewer risk factors. The findings, if reproducible, could be useful in studying pharmacogenomic strategies for predicting, preventing or treating postpartum hemorrhage.

Patterns in Second Stage Labor Care Practices Associated With Genital Tract Injury and Postpartum Hemorrhage During Physiologic Birth: A Latent Mixture Model Analysis

INTRODUCTION

Genital tract injury during childbirth contributes to short and long-term problems, including postpartum hemorrhage, incontinence, and pelvic organ prolapse. The purpose of this study was to examine which sets of second stage management techniques employed by midwives attending births in the community setting are associated with genital tract injury and subsequent postpartum hemorrhage.

METHODS

Data from primiparous individuals within the Midwives Alliance of North America (MANA) Stats 2.0 (2004–2009) database were used for this analysis. Latent mixture modeling identified classes (groups) within the sample that are most similar based on 11 different characteristics of second stage management as noted by midwives in their birth notes, including hands-on management techniques during birth, maternal positioning at birth, and water birth.

RESULTS

Three classes of second stage management techniques best fit this complex dataset. The patterns of techniques used by midwives were only marginally associated with better or worse genital tract outcomes independent of other factors. Two covariables, however, advanced maternal age (OR1.60, 95% CI 1.09–2.34) and births with low fetal heart rate during second stage (OR2.82, 95% CI 1.93–4.10)—were associated with severe genital tract injury. Postpartum hemorrhage was more likely for the two classes where midwives used more hands-on management during second stage, even when considering presence of genital tract injury (OR1.33, 95% CI 1.09–1.63). This study highlights the complex second stage circumstances that interact with management techniques, which together shape or contribute to both genital tissue and hemorrhage outcomes.

Diagnosis and Management of Perinatal Depression

Perinatal depression is a mood disorder that may occur during pregnancy or within a year after childbirth. It can be disabling for the birthing parent and cause attachment and developmental problems for the infant. A host of risk factors, including genetics, reproductive history, and life experiences, are associated with perinatal depression. With validated screening tools, health care providers can assess individuals, initiate treatment, and/or refer as appropriate. Successful treatment, which may include modalities such as cognitive behavioral therapy and/or pharmacologic therapies, helps individuals maintain a sense of control, develop self-confidence, take control of their thinking, and learn coping skills. Integrative therapies and lifestyle changes have some success but may not be adequate for many individuals. Patients may benefit from providers learning and initiating cognitive behavioral therapy techniques while awaiting therapy.

Maternal Morbidity Predicted by an Intersectional Social Determinants of Health Phenotype: A Secondary Analysis of the NuMoM2b Dataset

Maternal race, ethnicity and socio-economic position are known to be associated with increased risk for a range of poor pregnancy outcomes, including maternal morbidity and mortality. Previously, researchers seeking to identify the contributing factors focused on maternal behaviors and pregnancy complications. Less understood is the contribution of the social determinants of health (SDoH) in observed differences by race/ethnicity in these key outcomes. In this secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b) dataset, latent mixture modeling was used to construct groups of healthy, nulliparous participants with a non-anomalous fetus in a cephalic presentation having a trial of labor (N = 5763) based on SDoH variables. The primary outcome was a composite score of postpartum maternal morbidity. A postpartum maternal morbidity event was experienced by 350 individuals (6.1%). Latent class analysis using SDoH variables revealed six groups of participants, with postpartum maternal morbidity rates ranging from 8.7% to 4.5% across groups (p < 0.001). Two SDoH groups had the highest odds for maternal morbidity. These higher-risk groups were comprised of participants with the lowest income and highest stress and those who had lived in the USA for the shortest periods of time. SDoH phenotype predicted MM outcomes and identified two important, yet distinct groups of pregnant people who were the most likely have a maternal morbidity event.

Is the increase in postpartum hemorrhage after vaginal birth because of altered clinical practice?: A register-based cohort study

BACKGROUND

To identify risk factors for severe postpartum hemorrhage (PPH) ≥1000 ml in women giving birth vaginally.

METHOD

A register-based cohort study including women with singleton pregnancies giving birth vaginally at term to a live-born child at Aarhus University Hospital, Denmark, from January 1, 2004, to December 31, 2012. Logistic multivariable regression was used to analyze data.

RESULTS

In 31 837 births, 1832 women (5.7%) experienced severe PPH. Maternal age, smoking during pregnancy, and prepregnancy body mass index did not increase the risk of severe PPH. However, nulliparous and multiparous women with a previous cesarean birth had an increased risk of severe PPH. Antepartum and intrapartum risk factors for severe PPH included gestational age >40 weeks, induction of labor, augmentation of labor, irregular fetal position, instrumental birth, and birthweight >4000 g. In particular, the combination of induction and augmentation of labor doubled the risk of severe PPH. Among genital tract tears, vaginal tears >3 cm were associated with the highest risk of severe PPH.

CONCLUSIONS

Maternal characteristics did not increase the risk of severe PPH, except for nulliparous and multiparous women with a previous cesarean birth. Obstetric interventions such as induction of labor, augmentation of labor, and a birthweight higher than 4000 g increased the risk of severe PPH. Larger vaginal tears presented the highest risk of severe PPH. Clinical practice with rigorous indications for obstetric interventions and timely identification and management of genital tract tears may reduce risk of severe PPH.

Factors affecting third-stage management and postpartum hemorrhage in planned midwife-led home and birth center births in the United States

BACKGROUND

Postpartum hemorrhage (PPH) is a potential childbirth complication. Little is known about how third-stage labor is managed by midwives in the United States, including use of uterotonic medication during community birth. Access to uterotonic medication may vary based on credentials of the midwife or state regulations governing midwifery.

METHODS

Using data from the Midwives of North America 2.0 database (2004-2009), we describe the PPH incidence for women giving birth in the community, their demographic and clinical characteristics, and methods used by midwives to address PPH. We also examined PPH rates by midwifery credentials and by the presence of regulations for legal midwifery practice.

RESULTS

Of the 17 836 vaginal births, 15.9% had blood loss of over 500 mL and 3.3% had 1000 mL or greater blood loss. Midwives used pharmaceuticals to prevent or treat postpartum bleeding in 6.3% and 13.9% of births, respectively, and the rate of hospital transfer after birth was 1.4% (n = 247). In adjusted analyses, PPH was less likely when births occurred at home vs a birth center, if the midwife had a CNM/CM credential vs a CPM/LM/LDM credential, or if the woman was multiparous without a history of PPH or prior cesarean birth. PPH was more likely in states with barriers to midwifery practice compared with regulated states (OR: 1.26; 95% CI, 1.16-1.38).

CONCLUSIONS

Women giving birth in the community experienced low overall incidence of PPH-related hospital transfer. However, the occurrence of PPH itself would likely be reduced with improved legal access to uterotonic medication.