Haemoglobin trajectories during pregnancy and associated outcomes using pooled maternity and hospitalization data from two tertiary hospitals

The fatigue after infusion or transfusion pilot trial and feasibility study: A three-armed randomized pilot trial of intravenous iron and blood transfusion for the treatment of postpartum anemia

BACKGROUND

Evidence for the management of moderate-to-severe postpartum anemia is limited. A randomized trial is needed; recruitment may be challenging.

STUDY DESIGN AND METHODS

Randomized pilot trial with feasibility surveys.

INCLUSION

hemoglobin 65-79 g/L, ≤7 days of birth, hemodynamically stable.

EXCLUSION

ongoing heavy bleeding; already received, or contraindication to intravenous (IV)-iron or red blood cell transfusion (RBC-T). Intervention/control: IV-iron; RBC-T; or IV-iron and RBC-T.

PRIMARY OUTCOME

number of recruits; proportion of those approached; proportion considered potentially eligible.

SECONDARY OUTCOMES

fatigue, depression, baby-feeding, and hemoglobin at 1, 6 and 12 weeks; ferritin at 6 and 12 weeks. Surveys explored attitudes to trial participation.

RESULTS

Over 16 weeks and three sites, 26/34 (76%) women approached consented to trial participation, including eight (31%) Māori women. Of those potentially eligible, 26/167 (15.6%) consented to participate. Key participation enablers were altruism and study relevance. For clinicians and stakeholders the availability of research assistance was the key barrier/enabler. Between-group rates of fatigue and depression were similar. Although underpowered to address secondary outcomes, IV-iron and RBC-T compared with RBC-T were associated with higher hemoglobin concentrations at 6 (mean difference [MD] 11.7 g/L, 95% confidence interval [CI] 2.7-20.7) and 12 (MD 12.8 g/L, 95% CI 1.5-24.2) weeks, and higher ferritin concentrations at 6 weeks (MD 136.8 mcg/L, 95% CI 76.6-196.9).

DISCUSSION

Willingness to participate supports feasibility for a future trial assessing the effectiveness of IV-iron and RBC-T for postpartum anemia. Dedicated research assistance will be critical to the success of an appropriately powered trial including women-centered outcomes.

Association of arsenic exposure and clinical hematological changes during pregnancy: Findings from a prospective Wuhan birth cohort study

BACKGROUND

Animal studies have reported arsenic-induced disturbed erythropoiesis parameters. However, the effects of exposure to arsenic on hematological parameters among pregnant women are unclear.

OBJECTIVES

We aimed to evaluate trimester-specific associations between arsenic metabolites and erythropoietic parameters measured repeatedly during pregnancy.

METHODS

A total of 1945 pregnant women from a birth cohort study were included. We detected arsenic species in urine sampled at each trimester and extracted erythropoietic parameters in different trimesters from the medical records. We used linear regressions with generalized estimating equations (GEEs) to examine the relationship between arsenic metabolites concentrations at different trimesters and erythropoietic parameters. We utilized GEEs to calculate the odds ratio (OR) for anemia during pregnancy.

RESULTS

Adjusted trimester-specific analysis showed that higher monomethylated arsenic (MMA) and %MMA were related to remarkably reduced hemoglobin (Hb) and mean corpuscular hemoglobin (MCH). Additionally, elevated urinary MMA concentration and %MMA in the early trimester were associated with an increased risk of microcytic anemias in the late trimester.

CONCLUSIONS

Our study demonstrated a significant inverse relationship between gestational arsenic exposure and Hb and MCH. Notably, higher MMA and lower methylation capacity to metabolize inorganic arsenic (iAs) in early pregnancy might increase the likelihood of microcytic anemia among pregnant women in late pregnancy.

Maternal low and high hemoglobin concentrations and associations with adverse maternal and infant health outcomes: an updated global systematic review and meta-analysis

BACKGROUND

Growing evidence suggests low and high maternal hemoglobin (Hb) concentrations may have adverse consequences for maternal and child health. There remain questions on specific Hb thresholds to define anemia and high Hb as well as how cutoffs may vary by anemia etiology and timing of assessment.

METHODS

We conducted an updated systematic review (using PubMed and Cochrane Review) on low (< 110 g/L) and high (≥ 130 g/L) maternal Hb concentrations and associations with a range of maternal and infant health outcomes. We examined associations by timing of Hb assessment (preconception; first, second, and third trimesters, as well as at any time point in pregnancy), varying cutoffs used for defining low and high hemoglobin concentrations and performed stratified analyses by iron-deficiency anemia. We conducted meta-analyses to obtain odds ratios (OR) and 95% confidence intervals.

RESULTS

The updated systematic review included 148 studies. Low maternal Hb at any time point in pregnancy was associated with: low birthweight, LBW (OR (95% CI) 1.28 (1.22-1.35)), very low birthweight, VLBW (2.15 (1.47-3.13)), preterm birth, PTB (1.35 (1.29-1.42)), small-for-gestational age, SGA (1.11 (1.02-1.19)), stillbirth 1.43 (1.24-1.65)), perinatal mortality (1.75 (1.28-2.39)), neonatal mortality (1.25 (1.16-1.34), postpartum hemorrhage (1.69 (1.45-1.97)), transfusion (3.68 (2.58-5.26)), pre-eclampsia (1.57 (1.23-2.01)), and prenatal depression (1.44 (1.24-1.68)). For maternal mortality, the OR was higher for Hb < 90 (4.83 (2.17-10.74)) than for Hb < 100 (2.87 (1.08-7.67)). High maternal Hb was associated with: VLBW (1.35 (1.16-1.57)), PTB (1.12 (1.00-1.25)), SGA (1.17 (1.09-1.25)), stillbirth (1.32 (1.09-1.60)), maternal mortality (2.01 (1.12-3.61)), gestational diabetes (1.71 (1.19-2.46)), and pre-eclampsia (1.34 (1.16-1.56)). Stronger associations were noted earlier in pregnancy for low Hb and adverse birth outcomes while the role of timing of high Hb was inconsistent. Lower Hb cutoffs were associated with greater odds of poor outcomes; for high Hb, data were too limited to identify patterns. Information on anemia etiology was limited; relationships did not vary by iron-deficiency anemia.

CONCLUSION

Both low and high maternal Hb concentrations during pregnancy are strong predictors of adverse maternal and infant health outcomes. Additional research is needed to establish healthy reference ranges and design effective interventions to optimize maternal Hb during pregnancy.

Latent Trajectories of Haematological, Hepatic, and Renal Profiles after Oil Spill Exposure: A Longitudinal Analysis

Exposure to polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) in crude oil has carcinogenic effects on various organ systems. This longitudinal cohort study examined the effects of oil spill exposure on the haematological, hepatic, and renal profiles of Rayong oil spill clean-up workers. The sample included 869 clean-up workers from the Rayong oil spill. Latent class mixture models were used to investigate and classify the longitudinal trajectories and trends of the haematological, hepatic, and renal indices. Subgroup analysis was used to evaluate the association between the urinary metabolites of PAHs and VOCs and haematological, hepatic, and renal parameters. Most clean-up workers (97.6%) had increasing levels of white blood cells (WBCs) (0.03 × 103 cells/µL), 94.90% of the workers had a significantly increasing trend of blood urea nitrogen (0.31 mg/dL per year), and 87.20% had a significantly increasing trend of serum creatinine (0.01 mg/dL per year). A high-decreasing trend of WBCs was seen in 2.42% (-0.73 × 103 per year). Post-exposure changes in haematological, renal, and hepatic profiles are present in workers exposed to the Rayong oil spill. This indicates possible long-term health complications and worsening renal function after exposure to PAHs and VOCs in crude oil.

Prepartum Anemia and Risk of Postpartum Hemorrhage: A Meta-Analysis and Brief Review

Postpartum hemorrhage (PPH) is responsible for 30% to 50% of maternal deaths. There is conflicting evidence if prepartum anemia facilitates PPH. A comprehensive analysis of studies describing their relation is missing. An extensive database search was conducted applying the terms "anemia" OR "hemoglobin" AND "postpartum hemorrhage." We used a random-effects meta-analysis model to estimate an overall odds ratio (OR) for PPH and prepartum anemia, separating studies that were conformant and non-conformant with the World Health Organization (WHO) definitions for anemia. The search yielded 2519 studies, and 46 were appropriate for analysis. The meta-analyses of WHO-conformant (n = 22) and non-conformant (n = 24) studies showed that the risk of PPH was increased when anemia was present. The ORs were 1.45 (CL: 1.23-1.71) for WHO-conformant studies, 2.88 (CL: 1.38-6.02) for studies applying lower thresholds for anemia, and 3.28 (CL: 2.08-5.19) for undefined anemia thresholds. PPH risk appeared to increase with lower anemia thresholds. Prepartum anemia is associated with an increased risk of PPH, an observation that is important regarding improved anemia correction strategies such as iron supplementation.

Maternal hemoglobin concentrations across pregnancy and child health and development from birth through 6-7 years

Background

The role of changes in maternal hemoglobin (Hb) across pregnancy on child health and development (CHD) remains unclear.

Objective

We examined the association between maternal Hb trajectories and CHD outcomes: (a) birth outcomes (birth weight, length, gestational age, preterm, and small for gestational age); (b) child Hb at 3, 6, 12, and 24 months; and (c) motor and mental development at 12 and 24 months and cognitive functioning at age 6-7 years.

Methods

We used data from a randomized controlled trial (PRECONCEPT) conducted in Vietnam (N = 1,175 women enrolled during preconception with offspring follow-up through 6-7 years). Maternal Hb trajectories were developed using latent class analysis with Hb data at preconception, early (≤20 weeks), mid (21-29 weeks), and late (≥30 weeks) pregnancy. Multivariable linear and logistic regression models were used to assess the association between maternal Hb trajectories on CHD outcomes, adjusting for confounding variables at the maternal, child and household levels.

Results

Four distinct maternal Hb trajectories were identified. Track 1 (low initial Hb-decline) was associated with lower child Hb at 3 months (β [95% CI] -0.52 [-0.87, -0.16]), 6 months (-0.36 [-0.68, -0.05]), 12 months (-0.46 [-0.79, -0.13]), and 24 months (-0.44 [-0.72, -0.15]) and motor development at 12 months (-3.58 [-6.76, -0.40]) compared to track 4 (high initial Hb-decline). After adjustment for multiple testing, relationships remained robust with the exception of associations with child Hb at 6 months and motor development at 12 months. Track 2 (low initial Hb-improve) was the only Hb trajectory to increase across pregnancy; however, it was insufficiently powered. Track 3 (mid Hb-decline) was associated with lower child Hb at 12 months (-0.27 [-0.44, -0.10]) and 24 months (-0.20 [-0.34, -0.05]) compared to track 4 (high initial Hb-decline). Maternal Hb trajectories were not associated with birth outcomes or child development at 24 months or 6-7 years.

Conclusion

Maternal Hb trajectories during pregnancy are associated with child Hb concentrations across the first 1,000 days, but not with birth outcomes or later cognitive functioning. More work is needed to better understand and interpret changes in Hb levels during pregnancy especially in resource poor settings.

Maternal Hemoglobin Concentrations and Birth Weight, Low Birth Weight (LBW), and Small for Gestational Age (SGA): Findings from a Prospective Study in Northwest China

Birth weight and related outcomes have profound influences on life cycle health, but the effect of maternal hemoglobin concentration during pregnancy on birth weight is still unclear. This study aims to reveal the associations between maternal hemoglobin concentrations in different trimesters of pregnancy and neonatal birth weight, LBW, and SGA. This was a prospective study based on a cluster-randomized controlled trial conducted from July 2015 to December 2019 in rural areas of Northwest China. Information on maternal socio-demographic status, health-related factors, antenatal visits, and neonatal birth outcomes were collected. A total of 3748 women and their babies were included in the final analysis. A total of 65.1% and 46.3% of the participants had anemia or hemoglobin ≥ 130 g/L during pregnancy. In the third trimester, maternal hemoglobin concentration was associated with birth weight in an inverted U-shaped curve and with the risks of LBW and SGA in extended U-shaped curves. The relatively higher birth weight and lower risks for LBW and SGA were observed when hemoglobin concentration was 100–110 g/L. When maternal hemoglobin was <70 g/L or >130 g/L, the neonatal birth weight was more than 100 g lower than that when the maternal hemoglobin was 100 g/L. In conclusion, both low and high hemoglobin concentrations in the third trimester could be adverse to fetal weight growth and increase the risks of LBW and SGA, respectively. In addition to severe anemia, maternal hemoglobin >130 g/L in the third trimester should be paid great attention to in the practice of maternal and child health care.

Antepartum and postpartum anemia: a narrative review

Antepartum anemia impacts over a third of pregnant women globally and is associated with major maternal and perinatal morbidity, including peripartum transfusion, maternal death, maternal infection, preterm birth, and neurodevelopmental disorders among offspring. Postpartum anemia impacts up to 80% of women in low-income and rural populations and up to 50% of women in Europe and the United States, and is associated with postpartum depression, fatigue, impaired cognition, and altered maternal-infant bonding. Iron deficiency is the most common cause of maternal anemia because of insufficient maternal iron stores at the start of pregnancy, increased pregnancy-related iron requirements, and iron losses due to blood loss during parturition. Anemic women should undergo testing for iron deficiency; a serum ferritin cutoff level of 30 μg/L is commonly used to diagnose iron deficiency during pregnancy. The first-line treatment of iron deficiency is oral iron. Intravenous iron is a consideration in the following scenarios: a poor or absent response to oral iron, severe anemia (a hemoglobin concentration <80 g/L), rapid treatment for anemia in the third trimester, women at high risk for major bleeding (such as those with placenta accreta), and women for whom red blood cell transfusion is not an option. Given the high prevalence of antepartum and postpartum anemia, anesthesiologists are advised to partner with other maternal health professionals to develop anemia screening and treatment pathways.