Recurrence of postpartum hemorrhage, maternal and paternal contribution, and the effect of offspring birthweight and sex: a population-based cohort study

Shoulder dystocia by severity in families: A nationwide population study

INTRODUCTION

Previous studies have established a history of shoulder dystocia as an important risk factor for shoulder dystocia, but studies on shoulder dystocia by severity are scarce. It is unknown if shoulder dystocia tends to be passed on between generations. We aimed to assess the recurrence risk of shoulder dystocia by severity in the same woman and between generations on both the maternal and paternal side. We also assessed the likelihood of a second delivery and planned cesarean section after shoulder dystocia.

MATERIAL AND METHODS

This was a population-based cohort study, using data from the Medical Birth Registry of Norway. To study recurrence in the same mother, we identified 1 091 067 pairs of first and second, second and third, and third and fourth births in the same mother. To study intergenerational recurrence, we identified an individual both as a newborn and as a mother or father in 824 323 mother-offspring pairs and 614 663 father-offspring pairs. We used Bayesian log-binomial multilevel regression to calculate relative risks (RR) with 95% credible intervals.

RESULTS

In subsequent deliveries in the same woman the unadjusted RR of recurrence was 7.05 (95% credible interval 6.39-7.79) and 2.99 (2.71-3.31) after adjusting for possible confounders, including current birthweight. The RRs were higher with severe shoulder dystocia as exposure or outcome. With severe shoulder dystocia as both exposure and outcome, unadjusted and adjusted RR was 20.42 (14.25-29.26) and 6.29 (4.41-8.99), respectively. Women with severe and mild shoulder dystocia and those without had subsequent delivery rates of 71.1, 68.9 and 69.0%, respectively. However, the rates of planned cesarean section in subsequent deliveries for those without shoulder dystocia, mild and severe were 1.3, 5.2 and 16.0%, respectively. On the maternal side the unadjusted inter-generational RR of recurrence was 2.82 (2.25-3.54) and 1.41 (1.05-1.90) on the paternal side. Corresponding adjusted RRs were 1.90 (1.51-2.40) and 1.19 (0.88-1.61), respectively.

CONCLUSIONS

We found a strong recurrence risk of shoulder dystocia, especially severe, in subsequent deliveries in the same woman. The inter-generational recurrence risk was higher on the maternal than paternal side. Women with a history of shoulder dystocia had more often planned cesarean section.

Trends in Postpartum Hemorrhage Prevalence and Comorbidity Burden: Insights from the ENACT Network Aggregated Electronic Health Record Data

The goal of this study was to assess trends in postpartum hemorrhage (PPH), its risk factors, and maternal comorbidity burden in the United States using aggregate data from the Evolve to Next-Gen Accrual to Clinical Trials (ENACT) network. This federated network employs interactive querying of electronic health record data repositories in academic medical centers nationwide. We conducted repeated annual cross-sectional analyses to evaluate PPH occurrence and comorbidities across various ethnoracial and sociodemographic groups, starting with a large cohort of 1,287,675 unique delivery hospitalizations collected from 22 ENACT sites between 2005 and 2022. During this time, there was a statistically significant increasing trend in the prevalence of PPH, rising from 5,634 to 10,504 PPH per 100,000 deliveries (P trend <0.001). Our findings revealed a continuous upward trend in PPH rates that remained consistent among women with ≥ 1 comorbid conditions (P trend <0.001) and those with ≥ 1 maternal risk factor (P trend <0.001). This result aligns with prior studies and extends beyond the time periods previously reported. Overall, Native Hawaiian or Other Pacific Islander women had the highest PPH prevalence (~ 13%), followed by Asian (9.8%), American Indian or Alaska Native (8.9%), multirace (8.6%), Black or African American (8.4%) and White (7.4%) women. The top PPH risk factor identified was placenta previa or accreta, while the top comorbidity was antepartum hemorrhage / placental abruption. The most common cause of PPH, namely uterine atony, was prevalent in ENACT data. Our analysis highlights significant ethnoracial disparities and underscores the need for targeted preventative interventions.

Leveraging a Longitudinally Linked Dataset to Assess Recurrence of Severe Maternal Morbidity

OBJECTIVES

Among those with a severe maternal morbidity (SMM) event and a subsequent birth, we examined how the risk of a second SMM event varied by patient characteristics and intrapartum hospital utilization.

METHODS

We used a Massachusetts population-based dataset that longitudinally linked in-state births, hospital discharge records, prior and subsequent births, and non-birth-related hospital utilizations for birthing individuals and their children from January 1, 1999, to December 31, 2018, representing 1,460,514 births by 907,530 birthing people. We restricted our study sample to 2,814 people who had their first SMM event associated with a singleton birth and gave birth a second time within the study period. Our outcome measure was recurrence of SMM in the second birth. We calculated the prevalence of SMM at second birth, compared SMM conditions between births, and estimated the adjusted risk ratios and 95% confidence intervals for having an SMM event at second birth among those who had an SMM at the first birth. We also examined overall hospital utilization including inpatient admissions, emergency room visits, and observational stays, and hospital utilization by interpregnancy intervals (IPIs) between the first and second birth.

RESULTS

There were 2,814 birthing people with at least one birth after the first SMM singleton birth. Among those, 198 (7.0%) had a subsequent SMM. The percentage of people with a second SMM event varied by age, race/ethnicity, insurance, IPI, and history of hypertension at first case of SMM (all p < .05). Between births, people with a second SMM event had significantly higher proportions of inpatient admissions (60.1% vs. 33.2.0%; p < .001), emergency room visits (71.7% vs. 57.7%; p < .001), and observational stays (35.4% vs. 19.5%; p < .001) compared with those who did not experience a second SMM event.

CONCLUSION

Hospital utilization after a birth with SMM might indicate an elevated risk of a second SMM event. Providers should counsel their patients about prevention and warning signs.

The association between unintended hysterotomy extensions with cesarean delivery and subsequent preterm birth

BACKGROUND

An increased risk for preterm birth has been observed among individuals with a previous second stage cesarean delivery when compared with those with a previous vaginal delivery. One mechanism that may contribute to the increased risk for preterm birth following a second stage cesarean delivery is the increased risk for cervical injury because of extension of the uterine incision (hysterotomy) into the cervix. The contribution of hysterotomy extension to the rate of preterm birth in a subsequent pregnancy has not been investigated and may shed light on the mechanism underlying the observed relationship between the mode of delivery and subsequent preterm birth.

OBJECTIVE

We aimed to quantify the association between unintended hysterotomy extension and preterm birth in a subsequent delivery.

STUDY DESIGN

We performed a retrospective cohort study using electronic perinatal data collected from 2 university-affiliated obstetrical centers. The study included patients with a primary cesarean delivery of a term, singleton live birth and a subsequent singleton birth in the same catchment (2005-2021). The primary outcome was subsequent preterm birth <37 weeks' gestation; secondary outcomes included subsequent preterm birth at <34, <32, and <28 weeks' gestation. We assessed crude and adjusted associations between unintended hysterotomy extensions and subsequent preterm birth with log binomial regression models using rate ratios and 95% confidence intervals. Adjusted models included several characteristics of the primary cesarean delivery such as maternal age, length of active labor, indication for cesarean delivery, chorioamnionitis, and maternal comorbidity.

RESULTS

A total 4797 patients met the study inclusion criteria. The overall rate of unintended hysterotomy extension in the primary cesarean delivery was 6.0% and the total rate of preterm birth in the subsequent pregnancy was 4.8%. Patients with an unintended hysterotomy extension were more likely to have a longer duration of active labor, chorioamnionitis, failed vacuum delivery attempt, second stage cesarean delivery, and persistent occiput posterior position of the fetal head in the primary cesarean delivery and higher rates of smoking in the subsequent pregnancy. Multivariable analyses that controlled for several confounders showed that a history of hysterotomy extension was not associated with a higher risk for preterm birth <37 weeks' gestation (adjusted rate ratio, 1.55; 95% confidence interval, 0.98-2.47), but it was associated with preterm birth <34 weeks' gestation (adjusted rate ratio, 2.49; 95% confidence interval, 1.06-5.42).

CONCLUSION

Patients with a uterine incision extension have a 2.5 times higher rate of preterm birth <34 weeks' gestation when compared with patients who did not have this injury. This association was not observed for preterm birth <37 weeks' gestation. Future research should aim to replicate our analyses with incorporation of additional data to minimize the potential for residual confounding.

Same disease - different effect: maternal diabetes impact on birth weight stratified by fetal sex

BACKGROUND

Male-sex is an independent risk factor for adverse perinatal outcomes. One example is gestational diabetes mellitus (GDM), which is associated with large gestational age neonates. It was previously described that fetal glucose metabolism is affected by fetal sex.

PURPOSE

To examine whether the birth weight of neonates is affected differently by GDM according to fetal sex.

METHODS

A retrospective normalized cohort analysis, using the open database of 2017 Natality Data from the National Vital Statistics System in the US. We compared the delta in neonatal birth weight, according to fetal sex, between pregnancies with or without GDM. Linear regression was used to take into consideration the effect of multiple confounders. For evaluation whether fetal sex is an independent risk factor for macrosomia (> 4000 and > 4500 g) following pregnancies complicated by GDM we used multivariate logistic regression.

RESULTS

A significant relationship was found between the sex of the neonate and the delta in birth weight associated with GDM (P-value < 0.0001). The average weight gain in neonates to GDM pregnancies was 71 g in females, and 56 g in males. The prevalence of macrosomia above 4000 g and 4500 g that was attributed to GDM was higher in female-sex neonates compared to male-sex neonates (P < 0.05).

CONCLUSION

According to our study results, female sex is associated with higher fetal weight gain in pregnancies complicated by GDM. Moreover, macrosomia's rate (> 4000 g and > 4500 g) attributed to GDM raised in a more significant manner in female-sex neonates.

Incidence of postpartum hemorrhage and risk factors for recurrence in the subsequent pregnancy

PURPOSE

To assess incidence and risk factors for postpartum hemorrhage (PPH) and identify women at high risk of recurrence in the subsequent pregnancy.

METHODS

This register-based study includes data on women from the Capital Region of Denmark with two consecutive deliveries recorded in the Copenhagen Obstetric Database from 2007 to 2020. PPH, defined as a blood loss of 1000 mL or more within 24 h after delivery, was the primary outcome measure. We calculated incidence and recurrence rate of PPH and assessed possible risk factors at index and subsequent deliveries.

RESULTS

We included 44,800 women with 95,673 deliveries. The overall incidence of PPH was 6.3%. Women with previous PPH had a 3.5-fold increased risk of PPH in a subsequent delivery compared to unaffected women (19.1 vs. 5.4%; OR 4.1; 95% CI 3.7-4.5). Major risk factors for recurrence were PPH in combination with blood transfusion or manual removal of placenta at the index delivery. Labor induction in subsequent pregnancy increased the risk of recurrent PPH compared to spontaneous onset (OR 1.5; 95% CI 1.2-1.9), while planned caesarean section reduced the risk, compared to planned vaginal delivery (OR 0.6; 95% CI 0.4-0.7).

CONCLUSION

Previous PPH increases the risk of PPH in subsequent pregnancy 3.5-fold. The risk of recurrent PPH increases with labor induction and decreases with planned caesarean section in the subsequent pregnancy. To prevent recurrent PPH, personalized counseling based on risk factors, relevant labor history and maternal preferences is suggested.

Association of maternal perfluoroalkyl substance exposure with postpartum haemorrhage in Guangxi, China

Postpartum haemorrhage (PPH) is the leading cause of maternal death worldwide, and it may be caused by environmental endocrine disruptors. Prenatal exposure to perfluoroalkyl substances (PFASs) in women has been linked to pregnancy disorders and adverse birth outcomes, but no data are available on the relationship between PFAS exposure during pregnancy and postpartum haemorrhage. This study aimed to explore the associations of maternal PFAS exposure with the postpartum haemorrhage risk and total blood loss. A total of 1496 mother-infant pairs in the Guangxi Zhuang birth cohort were included between June 2015 and May 2018. The concentration of PFASs in serum was detected using ultrahigh liquid chromatography-tandem mass spectrometry. Multiple binomial regression and linear regression models were used to analyse individual PFAS exposures. The mixture of PFASs was analysed using Bayesian Kernel Machine Regression (BKMR). In single substance exposure models, exposure to perfluorohexanesulfonic acid (PFHxS) increased the risk of postpartum haemorrhage (OR: 3.42, 95 % CI: 1.45, 8.07), while exposure to perfluorododecanoic acid (PFDoA) was inversely associated with the risk of postpartum haemorrhage (OR: 0.42, 95 % CI: 0.22, 0.80). The concentrations of perfluoroundecanoic acid (PFUnA) (β: 0.06, 95 % CI: 12.32, 108.82) and perfluorononanoic acid (PFNA) (β: 0.05, 95 % CI: 0.40, 88.95) exposure were positively correlated with the amount of postpartum haemorrhage; this result occurred only in the absence of covariate adjustment. In BKMR models, the risk of postpartum haemorrhage increased with increasing exposure to a PFAS mixture. In conclusion, our study suggested that maternal serum PFAS exposure during pregnancy was associated with the risk of postpartum haemorrhage.

Risk factors and recurrence of cause-specific postpartum hemorrhage: A population-based study

OBJECTIVE

To explore risk profiles of the different types of postpartum hemorrhage (PPH >500ml or severe PPH >1500ml) and their recurrence risks in a subsequent delivery.

METHODS

With data from The Medical Birth Registry of Norway and Statistics Norway we performed a population-based cohort study including all singleton deliveries in Norway from 1967-2017. Multilevel logistic regression was used to calculate odds ratio (OR), with 95% confidence interval (CI), with different PPH types (PPH >500ml or PPH >1500ml (severe PPH) combined with retained placenta, uterine atony, obstetric trauma, dystocia, or undefined cause) as outcomes.

RESULT

We identified 277 746 PPH cases of a total of 3 003 025 births (9.3%) from 1967 to 2017. Retained placenta (and/or membranes) was most often registered as severe PPH (29.3%). Maternal, fetal, and obstetric characteristics showed different associations with the PPH types. Male sex of the neonate was associated with reduced risk of PPH. This effect was strongest on PPH due to retained placenta (adjusted OR, (aOR): 0.80, 95% CI 0.78-0.82), atony (aOR 0.92, 95% CI: 0.90-0.93) and PPH with undefined cause (aOR 0.96, 95% CI: 0.95-0.97). Previous cesarean section showed a strong association with PPH due to dystocia (aOR of 13.2, 95% CI: 12.5-13.9). Recurrence risks were highest for the same type: PPH associated with dystocia (aOR: 6.8, 95% CI: 6.3-7.4), retained placenta and/or membranes (aOR: 5.9, 95% CI: 5.5-6.4), atony (aOR: 4.0, 95% CI: 3.8-4.2), obstetric trauma (aOR: 3.9, 95% CI: 3.5-4.3) and PPH of undefined cause (aOR: 2.2, 95% CI: 2.1-2.3).

CONCLUSION

Maternal, fetal and obstetric characteristics had differential effects on types of PPH. Recurrence differed considerably between PPH types. Retained placenta was most frequently registered with severe PPH, and showed strongest effect of sex; delivery of a boy was associated with lower risk of PPH. Previous cesarean increased the risk of PPH due to dystocia.