The impact of response to iron therapy on maternal and neonatal outcomes among pregnant women with anemia

Association of antepartum anemia and red blood cell mass with racial and ethnic disparities in transfusion rates after cesarean delivery: A retrospective cohort study

BACKGROUND

Antepartum anemia among patients undergoing cesarean deliveries has increased over the past decades in the United States. We hypothesized that red blood cell (RBC) mass, reflecting both prepartum anemia and body mass index (BMI), predicts transfusion risk after cesarean delivery beyond racial/ethnic categories.

STUDY DESIGN AND METHODS

A retrospective analysis of cesarean deliveries from 2019 to 2021 was performed using the National Surgical Quality Improvement Program database. The outcome of interest was perioperative transfusion within 72 h of surgery. Multivariable logistic regression models evaluated the potential added predictive value of race and RBC mass, alongside other known predictors of transfusion.

RESULTS

Among 43,869 cesarean deliveries, the perioperative RBC transfusion rate was 3.3%. Anemia and high BMI were the most prominent in Blacks and Native Americans. These two racial groups had a significantly larger RBC mass difference between non-transfused and transfused individuals (ΔRBC mass, 360-400 mL). Cesarean deliveries for placental complications had six-fold higher transfusion odds than those with only a history of cesarean delivery. While race remained a significant predictor, a 400 mL increase in RBC mass was associated with a 35% decrease in transfusion odds.

DISCUSSION

Antepartum anemia prevalence and BMI varied significantly by race/ethnicity, influencing peripartum RBC mass and transfusion rates. Despite the association of races or placental factors, our predictive model demonstrated a significant reduction of transfusion odds with increased antepartum RBC mass. As a parameter that accounts for varied hemoglobin levels and BMI, estimated RBC mass may be a useful metric for assessing transfusion risk in diverse populations.

Does induction or augmentation of labor increase the risk of postpartum hemorrhage in pregnant women with anemia? A multicenter prospective cohort study in India

OBJECTIVE

To investigate whether induction/augmentation of labor in pregnant women with anemia increases the risk of postpartum hemorrhage (PPH) and whether this risk varied by indications for labor induction/augmentation and by anemia severity in pregnancy.

METHODS

In a prospective cohort study of 9420 pregnant women from 13 hospitals across India, we measured hemoglobin concentrations at recruitment (≥28 weeks of gestation) and blood loss after childbirth during follow-up and collected clinical information about PPH. Clinical obstetric and childbirth information at both visits were extracted from medical records. Anemia severity in the third trimester was categorized using hemoglobin concentrations (no/mild anemia: hemoglobin ≥10 g/dL; moderate: hemoglobin 7 to 9.9 g/dL; severe: hemoglobin <7 g/dL), while PPH was defined based on blood loss volume (vaginal births: ≥500 mL or cesarean sections: ≥1000 mL) and clinical diagnosis. Indications for labor induction/augmentation were classified as clinically indicated and elective as per guidelines. We performed multivariable modified Poisson regression analyses to investigate the associations of anemia severity and indications for labor induction/augmentation, including their interaction, with PPH, adjusted for potential confounders.

RESULTS

PPH was associated with anemia but not with indications for labor induction/augmentation. However, there was a significant interaction between the two factors in relation to PPH (P = 0.003). Among pregnant women with severe anemia, a higher risk of PPH was associated with elective (adjusted risk ratio, 3.44 [95% confidence interval, 1.29-9.18]) but not with clinically indicated (adjusted risk ratio, 1.22 [95% confidence interval, 0.42-3.55]) labor induction/augmentation. No associations were observed among pregnant women with no/mild and moderate anemia.

CONCLUSION

The risk of PPH is higher in women who have moderate-severe anemia in late pregnancy. Induction/augmentation of labor is generally safe for women with anemia, but it can increase the risk of PPH in women with severe anemia if performed electively.

Dietary supplements and prevention of preeclampsia

Preeclampsia (PE) is a common pregnancy complication characterized by hypertension, proteinuria, and end-organ dysfunction. However, to date, no effective treatment has been established other than iatrogenic delivery, and the importance of prevention as an alternative approach to addressing PE has been emphasized. There is growing evidence on the effectiveness of pharmacological and non-pharmacological prophylaxis in preventing PE. In this review, we focused on dietary supplements as non-pharmacological prophylaxis for PE. Calcium is a well-documented supplement for the prevention of PE. Daily 500 mg calcium supplementation can roughly halve the risk of PE in settings where calcium intake is low, including in Japan. According to recent systematic reviews and network meta-analyses, current evidence on the efficacy of vitamin D supplementation is inconsistent. Although vitamin D is a candidate for the prevention of PE, future large-scale randomized control trials are necessary to draw definitive conclusions. We also reviewed other dietary supplements, including vitamins (vitamins A, B6, C, and E, folic acid, and multivitamins), minerals (magnesium, zinc, and iron), amino acids (l-arginine and l-carnitine), anti-oxidants (lycopene, resveratrol, and astaxanthin), and other agents (omega-3 fatty acids, coenzyme Q10, melatonin, and s-equol). In this study, we provide a comprehensive approach to help develop better preventive strategies and ultimately reduce the burden of PE.

Association Between the Anemia During Pregnancy and Maternal Intensive Care Unit Admissions: A Systematic Review and Meta-Analysis

Anemia during pregnancy is one of the most common conditions that may have adverse consequences on maternal and fetal health. Current evidence is inconsistent with regards to the effects of anemia on maternal ICU admissions. This meta-analysis aimed to examine the overall effect of anemia during pregnancy on maternal ICU admissions. We searched PubMed, Embase, Cochrane Library, and Web of Science for observational studies that compared the risk of ICU admission between anemic and non-anemic pregnant women. We pooled the odds ratios (ORs) for ICU admission using a random-effects model. Heterogeneity among studies was assessed using prediction intervals (PIs), Tau2 and I2 statistics. Sensitivity analysis by excluding outlier studies, meta-regression by sample size and age, and publication bias detection by LFK index and Doi plot was undertaken. Eight studies with a total of 21,997,574 participants in both anemic and non-anemic groups were included. Of them, meta-analysis was conducted in seven studies which yielded a pooled OR for anemia and ICU admission as 1.32 (95% CI 0.62-2.81). There was also a very high level of heterogeneity among studies (PI: 0.10-18.16, I2 = 100%). When an influential study was omitted, the pooled OR 1.16 (95% CI - 1.13; 1.20) for ICU admission was significant. The LFK index was - 3.64, indicating publication bias. Anemia in pregnant women might be associated with a higher risk of ICU admission, but it is essential to interpret this cautiously due to significant heterogeneity and potential publication bias. Registration : PROSPERO database (CRD42023466529).

Supplementary Information

The online version contains supplementary material available at 10.1007/s12288-024-01849-0.

Risk Factors, Associations, and Outcomes of Reduced Fetal Movements: A Preliminary Cross-Sectional Study at Port Sudan Maternity Hospital

BACKGROUND

Reduced fetal movements (RFM) are a significant concern in obstetric care. They often indicate fetal distress and are associated with adverse perinatal outcomes such as stillbirth and intrauterine growth restriction (IUGR). While RFM is recognized as a critical marker of fetal well-being, there is a limit to the data available on its risk factors and outcomes in the Port Sudan region. This study aimed to estimate risk factors and outcomes of pregnancies at risk due to RFM.

METHODS

This was a cross-sectional hospital-based study, conducted from February to August 2022 at Port Sudan Maternity Hospital, focused on mothers with RFMs defined by the RCOG guidelines. A total of 33 cases were analyzed using a structured questionnaire, with data collected via direct interviews. Data analysis was performed using SPSS version 26.0 (IBM Corp., Armonk, NY), employing descriptive statistics, frequency tables, and cross-tabulations. Ethical approval was obtained, and participant confidentiality was ensured through anonymization.

RESULTS

Most participants were married women aged 18 to 29 years, primarily housewives with diverse educational backgrounds. A minority reported medical conditions like diabetes (6.1%) and hypertension (3%), while pregnancy complications included preeclampsia (10%) and anemia (6.7%). The first episode of RFM was commonly reported before 28 weeks of gestation (34.4%). Normal vaginal delivery was the most frequent mode of birth (48.4%), with a significant number of pregnancies resulting in intrauterine fetal demise (IUFD) (53.3%). Additionally, 77.8% of newborns had five-minute APGAR scores below 7, and 42.9% had birth weights between 2.5 kg and 3.5 kg. About 12.1% of births in our study were stillbirths and all of them were preterm babies.

CONCLUSION

The study underscores the frequent serious implications of RFM on pregnancy outcomes with the majority presenting as low APGAR scores and IUFD. Early detection and timely management of RFM are crucial for improving maternal and neonatal outcomes. Tailored antenatal care (ANC) is needed to address the diverse risks associated with RFM.

Accelerating adverse pregnancy outcomes research amidst rising medication use: parallel retrospective cohort analyses for signal prioritization

BACKGROUND

Pregnant women are significantly underrepresented in clinical trials, yet most of them take medication during pregnancy despite the limited safety data. The objective of this study was to characterize medication use during pregnancy and apply propensity score matching method at scale on patient records to accelerate and prioritize the drug effect signal detection associated with the risk of preterm birth and other adverse pregnancy outcomes.

METHODS

This was a retrospective study on continuously enrolled women who delivered live births between 2013/01/01 and 2022/12/31 (n = 365,075) at Providence St. Joseph Health. Our exposures of interest were all outpatient medications prescribed during pregnancy. We limited our analyses to medication that met the minimal sample size (n = 600). The primary outcome of interest was preterm birth. Secondary outcomes of interest were small for gestational age and low birth weight. We used propensity score matching at scale to evaluate the risk of these adverse pregnancy outcomes associated with drug exposure after adjusting for demographics, pregnancy characteristics, and comorbidities.

RESULTS

The total medication prescription rate increased from 58.5 to 75.3% (P < 0.0001) from 2013 to 2022. The prevalence rate of preterm birth was 7.7%. One hundred seventy-five out of 1329 prenatally prescribed outpatient medications met the minimum sample size. We identified 58 medications statistically significantly associated with the risk of preterm birth (P ≤ 0.1; decreased: 12, increased: 46).

CONCLUSIONS

Most pregnant women are prescribed medication during pregnancy. This highlights the need to utilize existing real-world data to enhance our knowledge of the safety of medications in pregnancy. We narrowed down from 1329 to 58 medications that showed statistically significant association with the risk of preterm birth even after addressing numerous covariates through propensity score matching. This data-driven approach demonstrated that multiple testable hypotheses in pregnancy pharmacology can be prioritized at scale and lays the foundation for application in other pregnancy outcomes.

Screening and Supplementation for Iron Deficiency and Iron Deficiency Anemia During Pregnancy: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Importance

In 2015 the US Preventive Services Task Force (USPSTF) found insufficient evidence to assess the balance of benefits and harms of routine screening and supplementation for iron deficiency anemia during pregnancy.

Objective

To update the 2015 review on screening for iron deficiency anemia, in addition to iron deficiency during pregnancy, to inform the USPSTF.

Data Sources

Ovid MEDLINE and Cochrane databases through May 24, 2023; surveillance through May 24, 2024.

Study Selection

Randomized clinical trials of iron supplementation, screening effectiveness, treatment, and harms; observational studies of screening.

Data Extraction and Synthesis

Dual review of abstracts, full-text articles, study quality, and data abstraction. Data were pooled using a random-effects model.

Main Outcomes and Measures

Maternal and infant clinical outcomes, hematologic indices, and harms.

Results

Seventeen trials (N = 24 023) on maternal iron supplementation were included. Iron supplementation was associated with decreased risk of maternal iron deficiency anemia at term (4 trials, n = 2230; 8.6% vs 19.8%; relative risk, 0.40 [95% CI, 0.26-0.61]; I2 = 20.5%) and maternal iron deficiency at term (6 trials, n = 2361; 46% vs 70%; relative risk, 0.47 [95% CI, 0.33-0.67]; I2 = 81.9%) compared with placebo or no iron supplement. There were no statistically significant differences in maternal quality of life, rates of gestational diabetes, maternal hemorrhage, hypertensive disorders of pregnancy, cesarean delivery, preterm birth, infant low birth weight, or infants small for gestational age for maternal iron supplementation compared with placebo or no supplementation. Harms of iron supplementation included transient gastrointestinal adverse effects. No studies evaluated the benefits or harms of screening for iron deficiency or iron deficiency anemia during pregnancy. Data on the association between iron status and health outcomes, such as hypertensive disorders of pregnancy and preterm birth, were very limited.

Conclusions and Relevance

Routine prenatal iron supplementation reduces the incidence of iron deficiency and iron deficiency anemia during pregnancy, but evidence on health outcomes is limited or indicates no benefit. No studies addressed screening for iron deficiency or iron deficiency anemia during pregnancy. Research is needed to understand the association between changes in maternal iron status measures and health outcomes.

Daily oral iron supplementation during pregnancy

BACKGROUND

Iron and folic acid supplementation have been recommended in pregnancy for anaemia prevention, and may improve other maternal, pregnancy, and infant outcomes.

OBJECTIVES

To examine the effects of daily oral iron supplementation during pregnancy, either alone or in combination with folic acid or with other vitamins and minerals, as an intervention in antenatal care.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Trials Registry on 18 January 2024 (including CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, WHO's International Clinical Trials Registry Platform, conference proceedings), and searched reference lists of retrieved studies.

SELECTION CRITERIA

Randomised or quasi-randomised trials that evaluated the effects of oral supplementation with daily iron, iron + folic acid, or iron + other vitamins and minerals during pregnancy were included.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed trial eligibility, ascertained trustworthiness based on pre-defined criteria, assessed risk of bias, extracted data, and conducted checks for accuracy. We used the GRADE approach to assess the certainty of the evidence for primary outcomes. We anticipated high heterogeneity amongst trials; we pooled trial results using a random-effects model (average treatment effect).

MAIN RESULTS

We included 57 trials involving 48,971 women. A total of 40 trials compared the effects of daily oral supplements with iron to placebo or no iron; eight trials evaluated the effects of iron + folic acid compared to placebo or no iron + folic acid. Iron supplementation compared to placebo or no iron Maternal outcomes: Iron supplementation during pregnancy may reduce maternal anaemia (4.0% versus 7.4%; risk ratio (RR) 0.30, 95% confidence interval (CI) 0.20 to 0.47; 14 trials, 13,543 women; low-certainty evidence) and iron deficiency at term (44.0% versus 66.0%; RR 0.51, 95% CI 0.38 to 0.68; 8 trials, 2873 women; low-certainty evidence), and probably reduces maternal iron-deficiency anaemia at term (5.0% versus 18.4%; RR 0.41, 95% CI 0.26 to 0.63; 7 trials, 2704 women; moderate-certainty evidence), compared to placebo or no iron supplementation. There is probably little to no difference in maternal death (2 versus 4 events, RR 0.57, 95% CI 0.12 to 2.69; 3 trials, 14,060 women; moderate-certainty evidence). The evidence is very uncertain for adverse effects (21.6% versus 18.0%; RR 1.29, 95% CI 0.83 to 2.02; 12 trials, 2423 women; very low-certainty evidence) and severe anaemia (Hb < 70 g/L) in the second/third trimester (< 1% versus 3.6%; RR 0.22, 95% CI 0.01 to 3.20; 8 trials, 1398 women; very low-certainty evidence). No trials reported clinical malaria or infection during pregnancy. Infant outcomes: Women taking iron supplements are probably less likely to have infants with low birthweight (5.2% versus 6.1%; RR 0.84, 95% CI 0.72 to 0.99; 12 trials, 18,290 infants; moderate-certainty evidence), compared to placebo or no iron supplementation. However, the evidence is very uncertain for infant birthweight (MD 24.9 g, 95% CI -125.81 to 175.60; 16 trials, 18,554 infants; very low-certainty evidence). There is probably little to no difference in preterm birth (7.6% versus 8.2%; RR 0.93, 95% CI 0.84 to 1.02; 11 trials, 18,827 infants; moderate-certainty evidence) and there may be little to no difference in neonatal death (1.4% versus 1.5%, RR 0.98, 95% CI 0.77 to 1.24; 4 trials, 17,243 infants; low-certainty evidence) or congenital anomalies, including neural tube defects (41 versus 48 events; RR 0.88, 95% CI 0.58 to 1.33; 4 trials, 14,377 infants; low-certainty evidence). Iron + folic supplementation compared to placebo or no iron + folic acid Maternal outcomes: Daily oral supplementation with iron + folic acid probably reduces maternal anaemia at term (12.1% versus 25.5%; RR 0.44, 95% CI 0.30 to 0.64; 4 trials, 1962 women; moderate-certainty evidence), and may reduce maternal iron deficiency at term (3.6% versus 15%; RR 0.24, 95% CI 0.06 to 0.99; 1 trial, 131 women; low-certainty evidence), compared to placebo or no iron + folic acid. The evidence is very uncertain about the effects of iron + folic acid on maternal iron-deficiency anaemia (10.8% versus 25%; RR 0.43, 95% CI 0.17 to 1.09; 1 trial, 131 women; very low-certainty evidence), or maternal deaths (no events; 1 trial; very low-certainty evidence). The evidence is uncertain for adverse effects (21.0% versus 0.0%; RR 44.32, 95% CI 2.77 to 709.09; 1 trial, 456 women; low-certainty evidence), and the evidence is very uncertain for severe anaemia in the second or third trimester (< 1% versus 5.6%; RR 0.12, 95% CI 0.02 to 0.63; 4 trials, 506 women; very low-certainty evidence), compared to placebo or no iron + folic acid. Infant outcomes: There may be little to no difference in infant low birthweight (33.4% versus 40.2%; RR 1.07, 95% CI 0.31 to 3.74; 2 trials, 1311 infants; low-certainty evidence), comparing iron + folic acid supplementation to placebo or no iron + folic acid. Infants born to women who received iron + folic acid during pregnancy probably had higher birthweight (MD 57.73 g, 95% CI 7.66 to 107.79; 2 trials, 1365 infants; moderate-certainty evidence), compared to placebo or no iron + folic acid. There may be little to no difference in other infant outcomes, including preterm birth (19.4% versus 19.2%; RR 1.55, 95% CI 0.40 to 6.00; 3 trials, 1497 infants; low-certainty evidence), neonatal death (3.4% versus 4.2%; RR 0.81, 95% CI 0.51 to 1.30; 1 trial, 1793 infants; low-certainty evidence), or congenital anomalies (1.7% versus 2.4; RR 0.70, 95% CI 0.35 to 1.40; 1 trial, 1652 infants; low-certainty evidence), comparing iron + folic acid supplementation to placebo or no iron + folic acid. A total of 19 trials were conducted in malaria-endemic countries, or in settings with some malaria risk. No studies reported maternal clinical malaria; one study reported data on placental malaria.

AUTHORS' CONCLUSIONS

Daily oral iron supplementation during pregnancy may reduce maternal anaemia and iron deficiency at term. For other maternal and infant outcomes, there was little to no difference between groups or the evidence was uncertain. Future research is needed to examine the effects of iron supplementation on other maternal and infant health outcomes, including infant iron status, growth, and development.

Effects of Maternal Anemia Affecting Fetal Outcomes: A Narrative Review

This review's main objective was to assess the obstacles to anemia prevention, as well as the attitudes and behaviors of anemic women toward their condition. Since iron is crucial for neurodevelopment, iron deficiency anemia (IDA) accounts for the majority of pregnant mothers having anemia. In India and other developing countries, anemia is a serious health problem. More than half of pregnant women have anemia. The search strategy was conducted in PubMed. Few of the articles were searched without using MeSH terms. Strong correlations between mothers' anemia and that of their offspring point to intergenerational anemia with lasting consequences. Children who were underweight at birth and those who were malnourished had a higher risk of having anemia. Clinicians usually evaluate anemia, and the criteria for determining the cause of anemia are outlined in this brief review.

A meta-analysis of ferric carboxymaltose versus other intravenous iron preparations for the management of iron deficiency anemia during pregnancy

Objective

We conducted a meta-analysis of randomized clinical trials evaluating the clinical effects of ferric carboxymaltose therapy compared to other intravenous iron in improving hemoglobin and serum ferritin in pregnant women. We also assessed the safety of ferric carboxymaltose vs. other intravenous iron.

Data source

EMBASE, PubMed, and Web of Science were searched for trials related to ferric carboxymaltose in pregnant women, published between 2005 and 2021. We also reviewed articles from google scholar. The keywords "ferric carboxymaltose," "FCM," "intravenous," "randomized," "pregnancy," "quality of life," and "neonatal outcomes" were used to search the literature. The search was limited to pregnant women.

Selection of studies

Studies related to ferric carboxymaltose in pregnancy were scanned. Observational studies, review articles, and case reports were excluded. Randomized studies in pregnant women involving ferric carboxymaltose and other intravenous iron formulations were shortlisted. Of 256 studies, nine randomized control trials were selected.

Data collection

Two reviewers independently extracted data from nine selected trials.

Data synthesis

The final effect size for increase in hemoglobin after treatment was significant for ferric carboxymaltose vs. iron sucrose/iron polymaltose (standard mean difference 0.89g/dl [95% confidence interval 0.27,1.51]). The final effect size for the increase in ferritin after treatment was more for ferric carboxymaltose vs. iron sucrose/iron polymaltose (standard mean difference 22.53µg/L [-7.26, 52.33]). No serious adverse events were reported with ferric carboxymaltose or other intravenous iron.

Conclusion

Ferric carboxymaltose demonstrated better efficacy than other intravenous iron in increasing hemoglobin and ferritin levels in treating iron deficiency anemia in pregnant women.

Temporal trends of hemoglobin among pregnant women: The Mutaba'ah study

BACKGROUND

Low hemoglobin (Hb) level is a leading cause of many adverse pregnancy outcomes. Patterns of changes in Hb levels during pregnancy are not well understood.

AIM

This study estimated Hb levels, described its changing patterns across gestational trimesters, and identified factors associated with these changes among pregnant women.

MATERIALS AND METHODS

Data from the ongoing maternal and child health cohort study-The Mutaba'ah Study, was used (N = 1,120). KML machine learning algorithm was applied to identify three distinct cluster trajectories of Hb levels between the first and the third trimesters. Descriptive statistics were used to profile the study participants. Multinomial multivariable logistic regression was employed to identify factors associated with change patterns in Hb levels.

RESULTS

The three identified clusters-A, B and C-had, respectively, median Hb levels (g/L) of 123, 118, and 104 in the first trimester and 119, 100, and 108 in the third trimester. Cluster 'A' maintained average normal Hb levels in both trimesters. Cluster 'B', on average, experienced a decrease in Hb levels below the normal range during the third trimester. Cluster 'C' showed increased Hb levels in the third trimester but remained, on average, below the normal range in both trimesters. Pregnant women with higher gravida, diabetes mellitus (type 1 or 2), nulliparity or lower level of education were more likely to be in cluster 'B' than the normal cluster 'A'. Pregnant women who reported using iron supplements before pregnancy or those with low levels of education. were more likely to be in cluster 'C' than the normal cluster 'A'.

CONCLUSION

The majority of pregnant women experienced low Hb levels during pregnancy. Changes in Hb levels during pregnancy were associated with parity, gravida, use of iron before pregnancy, and the presence of diabetes mellitus (type 1 or 2).

Racial and Ethnic Disparities in Anemia and Severe Maternal Morbidity

OBJECTIVE

To evaluate antepartum anemia prevalence by race and ethnicity, to assess whether such differences contribute to severe maternal morbidity (SMM), and to estimate the contribution of antepartum anemia to SMM and nontransfusion SMM by race and ethnicity.

METHODS

We conducted a population-based cohort study using linked vital record and birth hospitalization data for singleton births at or after 20 weeks of gestation in California from 2011 through 2020. Pregnant patients with hereditary anemias, out-of-hospital births, unlinked records, and missing variables of interest were excluded. Antepartum anemia prevalence and trends were estimated by race and ethnicity. Centers for Disease Control and Prevention criteria were used for SMM and nontransfusion SMM indicators. Multivariable logistic regression modeling was used to estimate risk ratios (RRs) for SMM and nontransfusion SMM by race and ethnicity after sequential adjustment for social determinants, parity, obstetric comorbidities, delivery, and antepartum anemia. Population attributable risk percentages were calculated to assess the contribution of antepartum anemia to SMM and nontransfusion SMM by race and ethnicity.

RESULTS

In total, 3,863,594 births in California were included. In 2020, Black pregnant patients had the highest incidence of antepartum anemia (21.5%), followed by Pacific Islander (18.2%), American Indian-Alaska Native (14.1%), multiracial (14.0%), Hispanic (12.6%), Asian (10.6%), and White pregnant patients (9.6%). From 2011 to 2020, the prevalence of anemia increased more than100% among Black patients, and there was a persistent gap in prevalence among Black compared with White patients. Compared with White patients, the adjusted risk for SMM was high among most racial and ethnic groups; adjustment for anemia after sequential modeling for known confounders decreased SMM risk most for Black pregnant patients (approximated RR 1.47, 95% CI 1.42-1.53 to approximated RR 1.27, 95% CI 1.22-1.37). Compared with White patients, the full adjusted nontransfusion SMM risk remained high for most groups except Hispanic and multiracial patients. Within each racial and ethnic group, the population attributable risk percentage for antepartum anemia and SMM was highest for multiracial patients (21.4%, 95% CI 17.5-25.0%), followed by Black (20.9%, 95% CI 18.1-23.4%) and Hispanic (20.9%, 95% CI 19.9-22.1%) patients. The nontransfusion SMM population attributable risk percentages for Asian, Black, and White pregnant patients were less than 8%.

CONCLUSION

Antepartum anemia, most prevalent among Black pregnant patients, contributed to disparities in SMM by race and ethnicity. Nearly one in five to six SMM cases among Black, Hispanic, American Indian-Alaska Native, Pacific Islander, and multiracial pregnant patients is attributable in part to antepartum anemia.

Association of adverse outcomes with three-tiered risk assessment tool for obstetrical hemorrhage

BACKGROUND

Guidelines promote stratification for the risk for postpartum hemorrhage among parturients, although the evidence for the associated differential morbidity among the groups remains inconsistent among published reports.

OBJECTIVE

Using the California Maternal Quality Care Collaborative schema modified by the American College of Obstetrics and Gynecology, we compared the composite maternal hemorrhagic outcome and the composite neonatal adverse outcome among singletons who were categorized after delivery by the researchers as low-, medium-, or high-risk for postpartum hemorrhage. We hypothesized that the composite outcomes would be significantly different among the individuals in the different 3-tiered categories.

STUDY DESIGN

This was a retrospective cohort study of all singleton parturients with a gestational age of at least 14 weeks who delivered at a single site within 1 year. The composite maternal hemorrhagic outcome included any of the following: estimated blood loss ≥1000 mL, use of uterotonics (excluding prophylactic oxytocin) or Bakri balloon, surgical management of postpartum hemorrhage, blood transfusion, hysterectomy, thromboembolism, admission to the intensive care unit, or maternal death. The composite neonatal adverse outcome included Apgar score <7 at 5 minutes, birth injury, bronchopulmonary dysplasia, intraventricular hemorrhage, neonatal seizure, sepsis, ventilation > 6 hrs., brachial plexus palsy, hypoxic-ischemic encephalopathy, or neonatal death. Multivariable Poisson regression models with robust error variance were used to estimate the adjusted relative risks with 95% confidence intervals.

RESULTS

Of the 4544 deliveries in the study period, 4404 (96.7%) met the inclusion criteria, and among them, 1745 (39.6%) were categorized as low, 1376 (31.2%) as medium, and 1283 (29.1%) as high risk. Overall, 941 (21.4%) participants experienced the composite maternal hemorrhagic outcome with 285 (16.4%) of those being in the low-risk group, 319 (23.2%) in the medium-risk group, and 337 (26.3%) in the high-risk group. Among all parturients, 95.7% in the low-, 89.4% in the medium-, and 85.3% in the high-risk group neither had an estimated blood loss or a quantified blood loss ≥1000 mL nor were transfused. After multivariable adjustment and when compared with the low-risk group, there was a significantly higher risk for the composite maternal hemorrhagic outcome in the medium-risk group (adjusted relative risk, 1.23; 95% confidence interval, 1.05-1.43) and in the high-risk group (adjusted relative risk, 1.51; 95% confidence interval, 1.31-1.75). Overall, 366 newborns (8.4%) developed the composite neonatal adverse outcome with 76 (4.2%) in of those being in the low-risk group, 153 (11.3%) in the medium-risk group, and 140 (11.1%) in the high-risk group. After multivariable adjustment and when compared with the low-risk group, there were no significant differences in the composite neonatal adverse outcome in the medium- (adjusted relative risk, 1.27; 95% confidence interval, 0.97-1.68) or the high-risk group (adjusted relative risk, 1.29; 95% confidence interval, 0.98-1.68).

CONCLUSION

Although 8 of 10 parturients categorized as high risk neither had blood loss ≥1000 mL nor underwent transfusion, the risk stratification provides information regarding the composite maternal hemorrhagic outcome.