The impact of maternal anemia on perinatal mortality: a population-based, prospective cohort study in China

Non-invasive hemoglobin screening device: a promising digital method for reducing anemia prevalence through routine screening and timely intervention

BACKGROUND

Several non-invasive technologies are nowadays available in the market which claim to determine the hemoglobin levels instantly without the requirement of the blood sample. But no study has shown the significance of such non-invasive devices on a routine basis for determining their impact on anemia reduction programs. This study is conducted to determine the impact of regular hemoglobin screening on the women population to determine its potential in reducing anemia, using a digitalized non-invasive device.

METHOD

A cross-sectional study was conducted on 203 women of reproductive age group, residing in the Moradabad district. Repetitive readings were taken after a time interval of a minimum of 1 month for determining the impact of regular screening. The entire data collection process was carried out using the EzeCheck mobile app.

RESULTS

It was observed that the prevalence of anemia was reduced upon the second time screening and was accepted by the women population. Repetitive testing has a significant impact on reducing anemia prevalence. Also, the simplified non-invasive technology for estimating the hemoglobin values, makes the user more comfortable to take the test.

CONCLUSION

Non-invasive devices should be used regularly to keep track of hemoglobin levels which will help in the effective treatment of anemia. The mobile app-based testing could help to easily evaluate the reports of the patients from any remote location with instant result interpretation and health assistance.

Maternal anemia is associated with adverse maternal and neonatal outcomes in Mbarara, Uganda

PURPOSE

Maternal anemia is a significant risk factor for maternal morbidity and mortality, increasing risk of preterm birth, intrauterine growth restriction, stillbirth, and death. Moderate and severe anemia in pregnancy is defined as hemoglobin (Hb) <10 g/dl and Hb < 7 g/dl, respectively. We aimed to characterize the association of maternal anemia with maternal, neonatal, and placental outcomes in a resource-limited setting.

METHODS

Data were collected from a prospective cohort of 352 pregnant women at a tertiary academic Ugandan hospital. One hundred and seventy-six (50%) of women were living with HIV. Hemoglobin was measured in labor, and placentas were collected postpartum. Maternal outcomes included mode of delivery, hemorrhage, blood transfusion, intensive care unit admission, and maternal mortality. Neonatal outcomes included gestational age at delivery, birthweight, stillbirth, and neonatal mortality. Placental descriptors included weight and thickness. Categorical variables were analyzed using Chi-squared and Fisher's exact tests.

RESULTS

Hemoglobin < 10 g/dl, was present in 17/352 (5%) of women. Significantly more women with moderate or severe anemia were HIV-infected: 14/17 (82%) versus 162/335 (48%) (p = .006). Blood transfusions (2/17, 12% versus 5/335, 2%, p = .04) and neonatal deaths (2/17, 12% versus 9/335, 3%, p = .01) were more common in the anemia group. Placental thickness was lower in the anemia group (1.4 cm versus 1.7 cm, p = .04).

CONCLUSIONS

Moderate and severe anemia was associated with maternal HIV infection, maternal blood transfusion, neonatal death, and decreased placental thickness. The overall rate of moderate and severe anemia among this cohort was lower than previously reported.

Exploring the perspective of young adults about anaemia prevention; the contributions of knowledge about at-risk groups and consequences of anaemia

BACKGROUND

Anaemia persistently remains a grave public health challenge in most sub-Saharan African countries. Understanding the perspectives of young adults concerning the multi-factorial nature of anaemia may be an important step towards meeting the 2025 global nutrition target of halving anaemia since these individuals might be in the process of reproductive decisions.

AIM

To explore the relationship between students' knowledge about individuals at risk of developing anaemia, and anaemia consequences, and anaemia prevention strategies in a tertiary student cohort.

METHODS

This sequential exploratory study adopted a mixed-methods approach to triangulate the data collection. A semi-structured questionnaire was used to gather baseline data regarding students' perspective on anaemia. Themes that emerged from the initial questionnaire data analyses guided a focus group discussion (FGD) to further explore students' perspectives on anaemia. FGD data was thematically analysed to unearth reasons behind questionnaire item selection. Structural equation modeling (SEM) was used to explore the relationship between constructs in the anaemia knowledge questionnaire.

RESULTS

Overall, 543 students participated in the initial questionnaire data acquisition compared to 16 in the FGD. Our latent variable structural model showed that knowing the causes of anaemia did not significantly (p > 0.05) associate with either knowledge about anaemia consequences (b = 0.113) or knowledge about anaemia prevention strategies (b = 0.042). However, knowledge about individuals at-risk of anaemia was significantly positively associated with both anaemia prevention strategies (b = 0.306, p < 0.05) and knowledge about consequences of anaemia (b = 0.543, 95%). Moreover, knowing the consequences of anaemia seemed to significantly positively mediate the association between knowledge about at-risk groups and preventive measures that could be adopted (b = 0.410, p < 0.05).

CONCLUSIONS

Systems thinking public health educational campaigns that highlight the consequences of anaemia and at-risk groups are more likely to inspire the adoption of preventive strategies among young adults.

Effect of community based nutritional education on knowledge, attitude and compliance to IFA supplementation among pregnant women in rural areas of southwest Ethiopia: a quasi experimental study

BACKGROUND

Compliance with the iron folic acid supplementation is low and not at the required level to prevent anaemia during pregnancy in many countries, including Ethiopia, even though an iron-folic acid supplementation program is being implemented. The aims of this study were to determine the effect of community-based nutritional education on knowledge, attitude, and compliance to IFA supplementation in Ilu Aba Bor zone of southwest Ethiopia.

METHOD

A pretest-posttest quasi-experimental study design consisting of intervention and control group was conducted among pregnant women. The total sample size of 472, therefore, 236 pregnant women for each interventional and control group from 16 kebeles were randomly selected in two districts. A multi-stage sampling technique was used to select the study participants. Then, individual study units were selected using a simple random sampling technique and followed until the end of the study period. Effect of community-based nutritional education on knowledge, attitude, and compliance to IFA supplementation among pregnant women in rural areas were measured.

RESULTS

A total of 472 pregnant women participated in the study during the baseline and 437 (92.6%) were in the study until the end. The majority (49.2%) of respondents were 21-25 years of age, with a mean age of 23.4 (SD = 3.7) years. Community-based nutrition has resulted in a statistically significant increase in levels of maternal knowledge of IFAS by 15.2% in the intervention group compared to 5.1% in the control group. Similarly, the intervention group had odds of developing a positive attitude toward IFA 5.6 (4.01, 7.85) times higher than the control group. Moreover, in this study, the odds of compliance towards IFA supplementation were 3.9 (2.67, 5.57) times higher among those who received nutrition education than those women who did not.

CONCLUSION

This study revealed that community-based nutritional education can result in a significant change in knowledge, attitude, and compliance towards IFA supplementation and supports the literature suggesting the importance of the intervention to overcome the problem of poor compliance and its associated consequences.

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.

Variation Patterns of Hemoglobin Levels by Gestational Age during Pregnancy: A Cross-Sectional Analysis of a Multi-Center Retrospective Cohort Study in China

Background: Pregnancy anemia is a global health concern. However, to our knowledge, there still has little consensus on the reference value of hemoglobin levels. Particularly, little evidence from China was accessible in most existing guidelines. Objective: To evaluate hemoglobin levels and anemia prevalence of pregnant women in China and offer evidence for anemia and its reference values in China. Methods: A multi-center retrospective cohort study was conducted among 143,307 singleton pregnant women aged 15–49 at 139 hospitals in China, with hemoglobin concentrations routinely tested at each prenatal visit. Subsequently, a restricted cubic spline was performed to reveal a non-linear variation of hemoglobin concentrations during the gestational week. The Loess model was used to describe the changes in the prevalence of different degrees of anemia with gestational age. Multivariate linear regression model and Logistic regression model were applied to explore influencing factors of gestational changes in hemoglobin level and anemia prevalence, respectively. Results: Hemoglobin varied nonlinearly with gestational age, and the mean hemoglobin levels decreased from 125.75 g/L in the first trimester to 118.71 g/L in the third trimester. By analyzing hemoglobin levels with gestational age and pregnancy period, we proposed new criteria according to 5th percentile hemoglobin concentration in each trimester as a reference for anemia, with 108 g/L, 103 g/L, and 99 g/L, respectively. According to WHO’s criteria, the prevalence of anemia sustainably increased with gestational age, with 6.2% (4083/65,691) in the first trimester, 11.5% (7974/69,184) in the second trimester and 21.9% (12,295/56,042) in the third trimester, respectively. In subsequent analysis, pregnant women in non-urban residents, multiparity, and pre-pregnancy underweight tended to have lower hemoglobin levels. Conclusions: This research, the first large-sample study to present a set of gestational age-specific reference centiles for hemoglobin levels in China, could be used to obtain a better understanding of the overall levels of hemoglobin in Chinese healthy pregnant women and ultimately offer clues for a more precise hemoglobin reference value of anemia in China.

Maternal anemia and risk of adverse maternal health and birth outcomes in Bangladesh: A nationwide population-based survey

BACKGROUND

Maternal anemia is an ongoing public health challenge in low- and middle- income countries, including Bangladesh. The aim of this study was to explore the association of maternal anemia with a range of adverse maternal health and birth outcomes in Bangladesh.

METHODS

A total of 2,259 maternal women data was analyzed, extracted from the 2011 Bangladesh Demographic and Health Survey. Outcome variables considered were a range of maternal health and birth outcomes. Adverse maternal health outcomes were pregnancy complications, pregnancy termination, menstrual irregularities, cesarean delivery, diabetes, and hypertension. Adverse birth outcomes considered were low birth weight, stillbirths, early neonatal deaths, perinatal deaths, preterm birth, and prolonged labor. The main exposure variable was maternal anemia status. Mixed effect multilevel logistic/poisson regression model was used to determine the association between exposure and outcome variable adjusted for individual-, household-, and community-level factors.

RESULTS

The reported prevalence of anemia was 44%. A higher likelihoods pregnancy complication (AOR, 1.39, 95% CI, 1.09-2.41, p<0.05) and lower likelihoods of menstrual irregularities (AOR, 0.79, 95% CI, 0.58-0.94, p<0.05), diabetes (AOR, 0.78, 95% CI, 0.49-0.98, p<0.05) and hypertensive (AOR, 0.79, 95% CI, 0.60-0.96, p<0.05) were found among anemic maternal women as compared to the non-anemic maternal women. Adverse birth outcomes, including preterm birth (AOR, 2.03, 95% CI, 1.01-4.25, p<0.05), early neonatal mortality (AOR, 1.87, 95% CI, 1.06-5.10), and perinatal mortality (AOR, 1.54, 95% CI, 1.09-3.52, p<0.05), were also found higher among newborn of anemic maternal women as compared to the newborn of non-anemic maternal women.

CONCLUSION

Anemia during pregnancy increases the occurrence of adverse maternal health and birth outcomes. Strategies to reduce anemia, such as iron supplementation, during pregnancy and among reproductive-aged women need to be prioritized in the policies and programs.

Deworming program for women of reproductive age implemented through national iron folate supplementation program reduces prevalence of anemia: evidence from a community trial in rural Bangladesh

Background: Anemia causes debilitating outcomes for women and children, and can be of multifactorial etiology, soil transmitted helminth (STH) infection being one of them. The Bangladeshi government does not have any regular deworming program for women of reproductive age (WRAs), who constitute an important portion of the population. Hence, we conducted this study to generate evidence on the effect of regular deworming on STH infection status and anemia status of WRAs in rural Bangladesh. Methods: This was a quasi-experimental study conducted in rural Bangladesh using existing healthcare delivery platform (Community Clinics) for mass deworming of WRAs. Catchment areas of two community clinics constituted the intervention arm, where the WRAs received two cycles of deworming four months apart on top of government recommended iron-folate supplementation (IFA), and catchment areas of two different community clinics were considered as the control arm where the study population received IFA but no deworming medication. Baseline and endline surveys were conducted on randomly selected participants to measure prevalence of anemia and STH infection using HemoCue 201+ and Kato-Katz respectively. Results: The study area contained 4791 women aged 15-49 years. Among them, 2441 lived in the intervention area and 2350 lived in the control area. Compliance to deworming medication and IFA was 82% (2001 out of 2441) and 79% (1938 out of 2441) for the two cycles, respectively. In the baseline survey there was no significant difference in prevalence of anemia between the intervention and control arms (63.7% vs 65.7%; p=0.522). However, the endline survey yielded significant difference in anemia prevalence between the arms (47.5% vs 65.7%, p<0.001) rendering a 14% reduction in anemia due the intervention (p=0.004). Similarly, our intervention was shown to reduce STH infection by 16% (p<0.001) Conclusions: Our study clearly showed that regular deworming of WRA benefits their anemia and STH infection status.

Maternal hemoglobin levels and neonatal outcomes: the Japan Environment and Children's Study

BACKGROUND

Low birth weight (LBW), small for gestational age (SGA), and preterm birth (PTB) are important neonatal outcomes that may affect infant morbidity and mortality. The aim of this study is to investigate associations between maternal hemoglobin (Hb) concentrations and pregnancy outcomes of LBW, SGA, and PTB.

METHODS

This was a prospective birth cohort study using data of the Japan Environment and Children's Study. Participants were divided into five groups according to maternal Hb (g/dL) in the first and second trimesters: group 1, Hb < 9; group 2, 9 ≤ Hb < 11.0; group 3, 11.0 ≤ Hb < 13.0; group 4, 13.0 < Hb < 14.0; and group 5, 14.0 ≤ Hb. We examined the relationships between LBW, PTB, SGA, and maternal Hb in the first and second trimesters.

RESULTS

Excluding 29,673, a total of 74,392 newborns (first trimester: n = 39,084, second trimester: n = 35,308) were included. We obtained adjusted odds ratios (aORs) (95% confidence intervals (CIs)) using multivariate analysis; compared with group 3 in the first trimesters, women in group 1 were at increased risk of PTB (aOR, 3.20; 95% CI, 1.69-6.09), LBW (aOR, 2.21; 95% CI, 1.19-4.09). In the second trimester, multivariate analysis revealed that, compared with group 3 in the second trimester, women in group 1 were at increased risk of PTB (aOR, 2.30; 95% CI, 1.19-4.42) and women in group 5 were at increased risk of LBW (aOR, 1.87; 95% CI, 1.24-2.81) and PTB (aOR, 1.73; 95% CI, 1.06-2.83).

CONCLUSIONS

Elevated maternal Hb in the second trimester was associated with risks of PTB and LBW.

Effect of Intrapartum Maternal Hemoglobin on Mode of Delivery and Short-Term Neonatal Outcome: A Systematic Review

Importance

Maternal anemia in pregnancy is a common condition worldwide and is considered a risk factor for adverse neonatal and maternal outcome. Also high hemoglobin (Hb) levels are associated with adverse pregnancy outcomes. However, studies regarding the influence of intrapartum maternal Hb on mode of delivery and short-term neonatal outcome are limited and contradicting.

Objective

The aim of this study was to provide an overview of current evidence regarding associations between intrapartum maternal Hb levels and mode of delivery and short-term neonatal outcome. In addition, we propose directions for future research.

Evidence Acquisition

We systematically searched the electronic PubMed, EMBASE, and Cochrane databases for studies on maternal Hb levels and mode of delivery maternal and short-term neonatal outcome until January 2021. Eligible articles and their references were independently reviewed by 2 authors. Assessment was based on methodological quality and study results.

Results

We included 14 studies that evaluated the level of maternal pH in relation to clinical outcome, 6 studies on mode of delivery, 10 studies on Apgar score, 1 study on fetal distress, 2 studies on neonatal intensive care unit admission, 1 study on umbilical cord pH, and 5 studies on perinatal mortality.

Conclusions and Relevance

We found a trend toward an increased risk of cesarean delivery in anemic woman. Concerning the short-term neonatal outcomes, the evidence is conflicting, and included studies are too heterogenic to compare. Furthermore, various studies indicated a relation between high Hb levels and increased perinatal mortality. Therefore, we especially recommend attention to elevated Hb levels.

Target Audience

Obstetricians and gynecologists, family physicians.

Learning Objectives

After completing this activity, the learner should be better able to describe how Hb levels affect mode of delivery and short-term neonatal outcome, and identify abnormal Hb levels and propose appropriate treatment and monitoring recommendations.

Maternal Anemia during the First Trimester and Its Association with Psychological Health

Anemia during pregnancy is known to be associated with an increased risk of antenatal and/or postnatal depression, as well as adverse pregnancy outcomes. However, there are few studies evaluating psychological health throughout the antepartum and postpartum periods in women with anemia in early pregnancy. This study analyzed data collected by the Korean Pregnancy Outcome Study, a multicenter prospective cohort study conducted in South Korea, to determine the impact of anemia during the first trimester on birth outcomes and maternal mental health during pregnancy and postpartum. Hemoglobin levels were measured during the first trimester, and psychological health was evaluated at 12, 24, and 36 gestational weeks and 4−6 weeks postpartum. Anxiety and depression were defined using the Hospital Anxiety and Depression Scale and the Edinburgh Postnatal Depression Scale, respectively. Among 4067 Korean participants, 119 (2.9%) were diagnosed with anemia during the first trimester. Incidences of anxiety and depression did not differ over the pregnancy period between those with and without anemia during the first trimester. However, postpartum anxiety and depression were significantly more common in participants with anemia than in those without (p < 0.05, both). Hence, obstetricians should pay attention to postpartum mental health in women with anemia during the first trimester.

Diagnosis and Therapy of Iron Deficiency Anemia During Pregnancy: Recommendation of the Austrian Society for Gynecology and Obstetrics (OEGGG)

This overview analyzes the data on the controversial therapy of iron substitution during pregnancy, the diagnosis of iron deficiency anemia and the indication-related therapy, and is the first recommendation issued by the OEGGG on the appropriate therapy. The effects of anemia during pregnancy on postnatal outcomes have been intensively investigated with heterogeneous results. A final scientific conclusion with regards to the "optimal" maternal hemoglobin level is limited by the heterogeneous results of various studies, many of which were conducted in emerging nations (with different dietary habits and structural differences in the respective healthcare systems). The current literature even suggests that there may be a connection between both decreased and increased maternal serum hemoglobin concentrations and unfavorable short-term and long-term neonatal outcomes. In Austria, 67 percent of pregnant women take pharmacological supplements or use a variety of dietary supplements. Clinically, the prevalence of maternal anemia is often overestimated, leading to overtreatment of pregnant women (iron substitution without a medical indication). To obtain a differential diagnosis, a workup of the indications for treatment should be carried out prior to initiating any form of iron substitution during pregnancy. If treatment is medically indicated, oral iron substitution is usually sufficient. Because of the restricted approval and potential side effects, medical indications for intravenous iron substitution should be limited. Intravenous iron substitution without a prior detailed diagnostic workup is an off-label use and should only be used in very limited cases, and women should be advised accordingly.

High hemoglobin level is a risk factor for maternal and fetal outcomes of pregnancy in Chinese women: A retrospective cohort study

BACKGROUND

To examine the association of hemoglobin (Hb) levels during gestation with the risk of selected adverse pregnancy outcomes such as preterm birth (PTB), low-birth-weight infants (LBW) and small-for-gestational-age infants (SGA) in Chinese women.

METHODS

This retrospective cohort study was conducted in the Department of Gynecology and Obstetrics at the Union Shenzhen Hospital of the Huazhong University of Science and Technology, using routinely collected maternity and hospital data on pregnancies (2015-2018). Hb levels were measured during the second (16-18th weeks) and third (28-30th weeks) trimesters of pregnancy, and pregnancy outcomes were recorded in the hospital information system. Hb levels were categorized into four groups as follows: < 110 g/L, 110-119 g/L, 120-130 g/L, and > 130 g/L. The second group (Hb 110-119 g/L) was defined as the reference group. Statistical analysis was performed using multivariate logistic regression.

RESULTS

A total of 1911 singleton mothers were included. After multivariable adjustment, Hb levels > 130 g/L in the second trimester increased the risk of LBW (odds ratio [OR], 2.54; 95% confidence interval [CI], 1.12-5.76). In the third trimester of gestation, compared with women whose Hb levels between 110 and 119 g/L, women with Hb levels > 130 g/L had an increased risk of LBW (OR, 2.20; 95% CI, 1.07-4.51) and SGA (OR, 2.00; 95% CI, 1.05-3.80). When we compared the highest and lowest quartiles of changes in the Hb across the second and third trimesters, the adjusted ORs were 0.35 (95% CI: 0.18-0.68) for PTB and 0.47 (95% CI: 0.23-0.98) for LBW.

CONCLUSION

Maternal Hb > 130 g/L was associated with increased risk of adverse pregnancy outcomes. Reduction of the risks of PTB and SGA were observed with the appropriate increase of Hb level during the third trimester.

Severity of Anemia During Pregnancy and Adverse Maternal and Fetal Outcomes

IMPORTANCE

Anemia is the most widespread nutritional deficiency among pregnant females in the world. Despite numerous studies on anemia, evidence is limited about the association of severity of anemia with maternal and fetal health.

OBJECTIVE

To investigate the association between severity of anemia during pregnancy and risk of maternal and fetal adverse outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used data from China's Hospital Quality Monitoring System from January 1, 2016, to December 31, 2019, for pregnant females aged 15 to 49 years with birth outcomes reported at 1508 hospitals with maternity services in mainland China.

EXPOSURES

Anemia of varying severity during pregnancy was identified from daily standardized electronic inpatient discharge records using corresponding codes of the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision. Mild anemia was defined as a hemoglobin concentration of 100 to 109 g/L (to convert g/L to g/dL, divide by 10.0); moderate anemia, as 70 to 99 g/L; and severe anemia, as less than 70 g/L.

MAIN OUTCOMES AND MEASURES

The main outcomes included 6 maternal outcomes (placental abruption, preterm birth, severe postpartum hemorrhage, shock, admission to the intensive care unit [ICU], and maternal mortality) and 3 neonatal outcomes (fetal growth restriction, malformation, and stillbirth). Multivariable logistic regression models were used to estimate the odds ratios (ORs) and 95% CIs of these outcomes among pregnant females with varying severity of anemia.

RESULTS

Among 18 948 443 pregnant females aged 15 to 49 years (mean [SD] age, 29.42 [4.87] years), 17.78% were diagnosed with anemia during pregnancy, including 9.04% with mild anemia, 2.62% with moderate anemia, 0.21% with severe anemia, and 5.90% with anemia of unknown severity. Compared with no anemia, anemia severity during pregnancy was associated with increased risks of placental abruption (mild: adjusted OR [aOR], 1.36 [95% CI, 1.34-1.38]; moderate: aOR, 1.98 [95% CI, 1.93-2.02]; severe: aOR, 3.35 [95% CI, 3.17-3.54]), preterm birth (mild: aOR, 1.08 [95% CI, 1.07-1.08]; moderate: aOR, 1.18 [95% CI, 1.17-1.19]; severe: aOR, 1.36 [95% CI, 1.32-1.41]), severe postpartum hemorrhage (mild: aOR, 1.45 [95% CI, 1.43-1.47]; moderate: aOR, 3.53 [95% CI, 3.47-3.60]; severe: 15.65 [95% CI, 15.10-16.22]), and fetal malformation (mild: aOR, 1.15 [95% CI, 1.14-1.17]; moderate: aOR, 1.19 [95% CI, 1.16-1.21]; severe: aOR, 1.62 [95% CI, 1.52-1.73]). Compared with no anemia, moderate or severe anemia were associated with increased risks of maternal shock (moderate: aOR, 1.50 [95% CI, 1.41-1.60]; severe: aOR, 14.98 [95% CI, 13.91-16.13]), ICU admission (moderate: aOR, 1.08 [95% CI, 1.01-1.16]; severe: aOR, 2.88 [95% CI, 2.55-3.25]), maternal death (moderate: aOR, 0.45 [95% CI, 0.30-0.65]; severe: aOR, 1.56 [95% CI, 0.97-2.48], fetal growth restriction (moderate: aOR, 0.80 [95% CI, 0.78-0.82]; severe: aOR, 1.08 [95% CI, 1.00-1.17]), and stillbirth (moderate: aOR,0.79 [95% CI, 0.76-0.81]; severe: aOR, 1.86 [95% CI, 1.75-1.98]), and mild anemia was associated with decreased risks (maternal shock: aOR, 0.67 [95% CI, 0.63-0.71]; ICU admission: aOR, 0.80 [95% CI, 0.76-0.84]; maternal death: aOR, 0.37 [95% CI, 0.29-0.49]; fetal growth restriction: aOR, 0.79 [95% CI, 0.77-0.80]; stillbirth: aOR, 0.59 [95% CI, 0.58-0.61]) after adjusting for sociodemographic characteristics and other complications during pregnancy.

CONCLUSIONS AND RELEVANCE

The findings suggest that anemia during pregnancy is associated with maternal and fetal health outcomes and that mild anemia is associated with improved maternal and fetal survival and fetal growth. Further work is needed to validate the concentration of hemoglobin at which optimal maternal and fetal health are achieved.

Iron status in late pregnancy is inversely associated with birth weight in Colombia

OBJECTIVE

Gestational anaemia (GA) is common in developing countries. This study assessed the relationship of late GA and negative perinatal outcomes in participants recruited in a reference maternity unit of the Caribbean region of Colombia.

DESIGN

Prospective analytical birth cohort study. Maternal Hb and serum ferritin (SF) levels were measured. GA was defined as Hb levels <6·82 mmol/l (<11 g/dl), SF depletion as SF levels <12 µg/l. Birth outcomes such as low birth weight (LBW), preterm birth (PB) and small for gestational age (SGA) were examined.

SETTING

Mothers in the first stage of labour, living in urban or rural areas of Bolívar, were enrolled in an obstetrical centre located in Cartagena, Colombia. Blood and stool samples were taken prior delivery. Maternal blood count, SF levels and infant anthropometric data were recorded for analysis.

PARTICIPANTS

1218 pregnant women aged 18-42 years and their newborns.

RESULTS

Prevalence of GA and SF depletion was 41·6 % and 41·1 %, respectively. GA was positively associated with poverty-related sociodemographic conditions. Prenatal care attendance lowered the risk of PB, LBW and SGA. Birth weight was inversely associated with Hb levels, observing a -36·8 g decrease in newborn weight per 0·62 mmol/l (or 1 g/dl) of maternal Hb. SF depletion, but not anaemia, was associated with PB. SGA outcome showed a significant association with anaemia, but not a significant relationship with SF depletion.

CONCLUSIONS

Birth weight and other-related perinatal outcomes are negatively associated with Hb and SF depletion. Prenatal care attendance reduced the risk of negative birth outcomes.

Perceptions and beliefs about anaemia: A qualitative study in three agroecological regions of Ghana

Little evidence exists concerning perceptions of anaemia in Ghanaian communities, which limits understanding of how to potentially improve health in settings with high anaemia prevalence. We explored lay perceptions of anaemia to understand local knowledge and beliefs and to provide an opportunity to inform interventions. A cross-sectional, qualitative study was conducted in selected communities in three regions of Ghana with high prevalence of anaemia. Forty-eight focus group discussions (FGDs) were conducted with adolescent girls, adult women of reproductive age and adult men (16 FGDs for each demographic group). Participants across the three demographic groups generally described anaemia as inadequate blood in the body and reported that poor diet, heat, alcohol intake, physiological factors and diseases such as malaria were the main causes of anaemia. Consequences of anaemia mentioned in the FGDs included dizziness, weight loss, loss of appetite and weakness. Prevention of anaemia was perceived to result from improved diet, avoidance of exposure to heat and improved sanitation to avoid diseases. The findings suggest that despite areas of convergence between lay and biomedical knowledge on the causes, consequences and prevention of anaemia, the burden of anaemia remains high in the study regions. This highlights a disconnect between local knowledge of anaemia and the health and nutrition behaviours needed to reduce its incidence. Effective interventions can be developed with and for communities that build upon existing knowledge while filling remaining knowledge gaps or misconceptions.

Prevention of iron deficiency anemia in infants and toddlers

Anemia, defined as a low blood hemoglobin concentration, is a major global public health problem. Identification of anemia is crucial to public health interventions. It is estimated globally that 273 million children under 5 years of age were anemic in 2011, and about ~50% of those cases were attributable to iron deficiency (Lancet Global Health 1:e16-e25, 2013). Iron-deficiency anemia (IDA) in infants adversely impacts short-term hematological indices and long-term neuro-cognitive functions of learning and memory that result in both fatigue and low economic productivity. IDA contributes to death and disability and is an important risk factor for maternal and perinatal mortality, including the risks for stillbirths, prematurity, and low birth weight (Comparative Quantification of Health Risks: Global and Regional Burden of Disease Attributable to Selected Major Risk Factors. Ch. 3 (World Health Organization, Geneva, 2004)). Reduction in early infantile anemia and newborn mortality rates is possible with easily implemented, low- to no-cost intervention such as delayed cord clamping (DCC). DCC until 1-3 min after birth facilitates placental transfusion and iron-rich blood flow to the newborn. DCC, an effective anemia prevention strategy, requires cooperation among health providers involved in childbirth, and a participatory culture change in public health. Public intervention strategies must consider multiple factors associated with anemia listed in this review before designing intervention studies that aim to reduce anemia prevalence in infants and toddlers. IMPACT: Anemia, defined as a low blood hemoglobin concentration, is a major global public health problem and identification of anemia is crucial to public health interventions. Delayed cord clamping (DCC) until 1-3 min after birth facilitates placental transfusion and iron-rich blood flow to the newborn. Reduction in early infantile anemia and newborn mortality rates is possible with easily implemented, low- to no-cost intervention such as DCC.

Healthcare at the Beginning of Life and Child Survival: Evidence from a Cash Transfer Experiment in Nigeria

Households in poor countries are encouraged (and sometimes coerced) to increase investments in formal health care services during pregnancy and childbirth. Is this good policy? The answer to a large extent depends on its effects on child welfare. We study the effects of a cash transfer program in Nigeria in which households were offered a payment of $14 conditioned on uptake of health services. We show that the transfer led to a large increase in uptake and a substantial increase in child survival driven by a decrease in in-utero child deaths. We present evidence suggesting that the key driver is prenatal health investments.

Anemia in Pregnancy is Still a Public Health Problem: A Single Center Study with Review of Literature

Anemia is a significant public health problem during pregnancy and its prevalence varies in different cohorts. Correct identification of this problem in a given population is important for implementation of various health schemes. This study was carried out at a tertiary care hospital in Haryana. The prevalence of anemia in females at the time pregnancy diagnosis during first trimester was studied. The study period was January 2018 to June 2019. Severity of anemia was categorized as mild (hemoglobin 10-10.9 gm/dl), moderate (hemoglobin 7-9.9 gm/dl) and severe (hemoglobin < 7 gm/dl) as per the WHO definition. Relevant review of literature on prevalence of anemia in pregnancy in different Indian states was done. The median age of 388 females with diagnosis of pregnancy during first trimester was 27 years. Mean hemoglobin concentration was 10.47 gm/dl. 264 (68%) females had anemia. Out of these 191 (72.3%) had mild anemia, 65 (24.6%) had moderate anemia and eight had severe anemia. Out of the total study population, 270 (69.58%) were from rural and 118 (30.41%) were from urban background. Among the anemic pregnant females, 179 (67.8%) belonged to rural areas and 85 (32.20%) belonged to urban areas. Out of 264 patients with anemia, 87 (32.95%) patients were primigravida and 177 (67.04%) were multiparous females. The results of literature review showed a high prevalence of anemia in the other Indian states also. There is high prevalence of anemia in females at the time of diagnosis of pregnancy. Rates of anemia are higher in females with higher parity.

Anemia and Dietary Behaviors among Young Adults in Riyadh, Saudi Arabia

Objective

The study sought to assess the prevalence and the risk factors associated with anemia among male and female young adults in (Riyadh city, Saudi Arabia).

Methods

A cross-sectional study was conducted at King Saud University and Alfaisal University in September 2016 among young adults aged 18 to 28 years old. Data were collected using an interview questionnaire. Additionally, the respondents were evaluated clinically and via laboratory testing for anemia.

Results

Our study population showed a higher percentage of men as compared to women participants. About half of our study sample had a lightly active lifestyle, and more than one-third of the study participants were overweight (34.7%). The average age of the respondents was 22.08 ± 1.98 years. The only factor significantly associated with anemia was gender, in that female gender showed a positive association with anemia.

Conclusion

The most explicit risk factor for anemia among Saudi individuals of college and young professional ages was the female gender. Dietary lifestyle, heavy menstruation, pregnancy, and intake of non-steroidal anti-inflammatory drugs were additional important risk factors among these individuals, but they were statistically not significant.

Maternal and severe anaemia in delivering women is associated with risk of preterm and low birth weight: A cross sectional study from Jharkhand, India

Background and objectives

Haemoglobin content is the well accepted indicator for anaemia assessment. The high prevalence of anaemia, maternal health care issues and adverse delivery outcome in Jharkhand, we investigated whether delivering women with anaemia would present a modifiable risk of preterm (PTB) and low birth weight (LBW).

Methods

A facility-based cross-sectional study involving pregnant women, with screening for pregnancy endpoints and haemoglobin assay, were conducted. Anaemia was classified according to World Health Organization's definition of anaemia in pregnancy. Confounding variables were adjusted in a logistic model. The adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were used for analyzing the association among maternal anaemia, PTB and LBW.

Results

We observed a high prevalence of anaemia (78.45%) in delivering women, whereas high prevalence of preterm birth (34.75%) and LBW (32.81%) in delivering women overall. In the adjusted analysis, overall anaemia in pregnancy was strongly associated with preterm birth (OR, 3.42; 95% CI, 1.98–5.88; P ≤ .0001) as compared to LBW (OR, 1.12; 95% CI, 0.65–1.61; P = .0003). The risk of PTB and LBW were dependent on the stratification of the anaemia group, as the strongest association was observed in severe (OR, 4.86) followed by mild (OR, 3.66) and moderate (OR, 3.18) anaemia in PTB; whereas risk of LBW was found in severe (OR, 2.5) followed by moderate (OR, 1.11) and mild (OR, 0.57) anaemia. The risk of PTB and LBW across six pregnancy haemoglobin groups were compared, haemoglobin of 10–10.9 g/dl (OR, 1.25) and ≤ 8 g/dl (OR, 1.03) have shown association with PTB and LBW, respectively. However, high haemoglobin concentration was not associated with either PTB or LBW.

Conclusions

Anaemia in delivering women was associated with an elevated risk of PTB and LBW and the risk increased with the severity of anaemia in pregnant women.

Iron deficiency in late pregnancy and its associations with birth outcomes in Chinese pregnant women: a retrospective cohort study

Background

Several biomarkers are used to measure iron deficiency (ID) during pregnancy, but the prevalence of ID and its association with adverse birth outcomes shows inconsistent results. The aim of this study was to examine the prevalence of ID in third trimester using multiple indicators of iron status and the relationship with birth outcomes in Chinese population.

Methods

We conducted a retrospective observational cohort study of 11,581 pregnant women between 2016 and 2017 in Changzhou City, Jiangsu Province, China. We obtained the data (maternal characteristics and birth outcomes) and the concentrations of ID biomarkers from our hospitalization information system and laboratory information system, respectively. Using serum ferritin (SF), serum transferrin (ST) and their ratio as criteria of ID, we investigated associations between birth outcomes and late pregnancy ID.

Results

The prevalence of ID in our study was 51.82% as defined by low SF (< 12 μg/L), 54.43% as defined by high ST (> 4 g/L) and 53.90% as defined by high ratio of ST/SF (Log 10 transform > 5.52). Maternal ST/SF ratio was associated with higher mean birth weight (97.04 g; 95% CI, 74.28, 119.81 for the highest vs. lowest quartile). Third trimester maternal ID, defined by ST/SF ratio, was associated with lower risks of preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA) infants, higher risks of macrosomia and large for gestational age (LGA) babies (for PTB: OR = 0.53, 95% CI, 0.36-0.77; for LBW: OR = 0.44, 95% CI, 0.31-0.62; for SGA: OR = 0.69, 95% CI, 0.57-0.83; for macrosomia: OR = 1.39, 95% CI, 1.13-1.70; for LGA: OR = 1.20, 95% CI, 1.04-1.39).

Conclusions

ID in the third-trimester of pregnancy are frequent in Chinese women. Our findings suggest that the ratio of ST/SF measured in late pregnancy could be useful as a significant predictor of unfavorable birth outcomes.

Maternal hemoglobin concentrations across pregnancy and maternal and child health: a systematic review and meta-analysis

Maternal anemia is a well‐recognized global health problem; however, there remain questions on specific hemoglobin (Hb) thresholds that predict health risk or protection for mother and child. We conducted a systematic review and meta‐analysis to examine the associations of maternal Hb concentrations with a range of maternal and infant health outcomes, accounting for the timing of measurement (preconception, and first, second, and third trimesters), etiology of anemia, and cutoff category. The systematic review included 272 studies and the meta‐analysis included 95 studies. Low maternal Hb (<110 g/L) was associated with poor birth outcomes (low birth weight, preterm birth, small‐for‐gestational‐age (SGA), stillbirth, and perinatal and neonatal mortality) and adverse maternal outcomes (postpartum hemorrhage, preeclampsia, and blood transfusion). High maternal Hb (>130 g/L) was associated with increased odds of SGA, stillbirth, preeclampsia, and gestational diabetes. Relationships varied by the timing of measurement and cutoff category (stronger associations with lower cutoffs); limited data were available on anemia etiology. There were insufficient data for other maternal outcomes and long‐term child health outcomes. Current data are insufficient for determining if revisions to current Hb cutoffs are required. Pooled high‐quality individual‐level data analyses, as well as prospective cohort studies, would be valuable to inform the reevaluation of Hb cutoffs.

Repeated measures of prenatal phthalate exposure and maternal hemoglobin concentration trends: The Ma'anshan birth cohort (MABC) study

A prospective cohort study of a Chinese population was conducted to investigate the relationship between prenatal phthalates exposure and maternal hemoglobin or anemia. Based on the Ma'anshan Birth Cohort study, 7 phthalate metabolites were quantified in spot pregnancy urine samples (n = 9263) from 3269 pregnant women during each trimester. The maternal hemoglobin concentrations were obtained from electronic medical records at the same three time points for each participant during pregnancy. Anemia was defined as a hemoglobin concentration below 110 g/L in pregnant women. Repeated measures and trimester-specific analyses were used to estimate the effects of phthalates exposure on maternal hemoglobin and anemia. The prevalence of anemia was 3.6%, 27.0%, and 26.5% during the first, second and third trimester, respectively. Repeated measures analysis showed that hemoglobin concentrations decreased by 0.55, 0.19, 0.57, 0.49, and 0.54 g/L with each 1 ln-transformed concentration increase of MBP, MBzP, MEHP, MEOHP, and MEHHP, respectively. Exposure to MMP, MBP, MEHP, MEOHP, and MEHHP increased the risk of anemia by 1.11-fold, 1.21-fold, 1.20-fold, 1.13-fold, and 1.16-fold, respectively. Trimester-specific regression models stratified by the sample collection time during pregnancy generated consistent results. This is the first study focusing on the effect of prenatal phthalate exposures on hemoglobin or anemia in pregnant Chinese women. We found that prenatal phthalates exposure not only decreased the concentrations of hemoglobin but also showed associations with the prevalence of anemia. Associations appeared stronger for the subsample representing women pregnant with a male fetus than those pregnant with a female fetus. Anemia remains a moderate public health problem in China, and effective measures should be implemented.

The effect of first trimester hemoglobin levels on pregnancy outcomes

Objective

The relationship between hemoglobin levels and pregnancy outcomes is still a challenging issue. There is a supported opinion about the increased adverse pregnancy outcomes both with low and high hemoglobin levels. In this study, we aimed to evaluate this association for first trimester hemoglobin levels in a Turkish population.

Materials and Methods

In this retrospective study, 1306 women who were followed up during their pregnancy and gave birth in our clinic were enrolled. The patients were divided into three groups: hemoglobin <11 g/dL (n=490), 11≤ hemoglobin <13 g/dL (n=673), and hemoglobin ≥13 g/dL (n=143). The hemoglobin <11 g/dL group was classified into two subgroups as hemoglobin ≤9 g/dL (n=64) and hemoglobin >9 g/dL (n=426). Demographic characteristics, first trimester hemoglobin levels, gestational age at delivery and mode, birth weight, Apgar scores, and pregnancy outcomes were recorded and compared between the groups.

Results

Pregnancy-induced hypertension, preterm birth, neonatal intensive care unit admission, birth weight, gestational age at delivery, Apgar scores, and postpartum hemorrhage were significantly different between the three groups. In the pairwise comparison, gestational age at delivery, birth weight, and first minute Apgar scores were higher in the 11≤ hemoglobin <13 g/dL group, and pregnancy-induced hypertension was more common in the hemoglobin ≥13 g/dL group as compared with the others. Moreover, the preterm delivery rate was highest in the hemoglobin ≥13 g/dL (26.6%) group and lowest (7.3%) in the 11≤ hemoglobin <13 g/dL group. The neonatal intensive care unit admission rate was higher both the hemoglobin <11 g/dL and hemoglobin ≥13 g/dL groups. Postpartum hemorrhage was more common in the hemoglobin <11 g/dL group as compared with the other groups. Furthermore, pregnancy-induced hypertension was more common in the hemoglobin ≤9 g/dL subgroup (p=0.012).

Conclusion

In conclusion, both low and high hemoglobin levels are related with adverse pregnancy outcomes. We suggest that hemoglobin levels must be screened during pregnancy to provide maternal and fetal well-being.

U-shaped curve for risk associated with maternal hemoglobin, iron status, or iron supplementation

Both iron deficiency (ID) and excess can lead to impaired health status. There is substantial evidence of a U-shaped curve between the risk of adverse birth outcomes and maternal hemoglobin concentrations during pregnancy; however, it is unclear whether those relations are attributable to conditions of low and high iron status or to other mechanisms. We summarized current evidence from human studies regarding the association between birth outcomes and maternal hemoglobin concentrations or iron status. We also reviewed effects of iron supplementation on birth outcomes among women at low risk of ID and the potential mechanisms for adverse effects of high iron status during pregnancy. Overall, we confirmed a U-shaped curve for the risk of adverse birth outcomes with maternal hemoglobin concentrations, but the relations differ by trimester. For low hemoglobin concentrations, the link with adverse outcomes is more evident when hemoglobin concentrations are measured in early pregnancy. These relations generally became weaker or nonexistent when hemoglobin concentrations are measured in the second or third trimesters. Associations between high hemoglobin concentration and adverse birth outcomes are evident in all 3 trimesters but evidence is mixed. There is less evidence for the associations between maternal iron status and adverse birth outcomes. Most studies used serum ferritin (SF) concentrations as the indicator of iron status, which makes the interpretation of results challenging because SF concentrations increase in response to inflammation or infection. The effect of iron supplementation during pregnancy may depend on initial iron status. There are several mechanisms through which high iron status during pregnancy may have adverse effects on birth outcomes, including oxidative stress, increased blood viscosity, and impaired systemic response to inflammation and infection. Research is needed to understand the biological processes that underlie the U-shaped curves seen in observational studies. Reevaluation of cutoffs for hemoglobin concentrations and indicators of iron status during pregnancy is also needed.

Association between maternal haemoglobin and stillbirth: a cohort study among a multi-ethnic population in England

The study objectives were to examine the association of maternal haemoglobin with stillbirth and perinatal death in a multi‐ethnic population in England. We conducted a retrospective cohort analysis using anonymised maternity data from 14 001 women with singleton pregnancies ≥24 weeks’ gestation giving birth between 2013 and 2015 in two hospitals ‐ the Royal Wolverhampton NHS Trust and Guy's and St Thomas’ NHS Foundation Trust. Multivariable logistic regression analyses were undertaken to analyse the associations between maternal haemoglobin at first visit and at 28 weeks with stillbirth and perinatal death, adjusting for 11 other risk factors. Results showed that 46% of the study population had anaemia (haemoglobin <110 g/l) at some point during their pregnancy. The risk of stillbirth and perinatal death decreased linearly per unit increase in haemoglobin concentration at first visit (adjusted odds ratio [aOR] stillbirth = 0·70, 95% confidence interval [CI] 0·58–0·85, aOR perinatal death = 0·71, 95% CI 0·60–0·84) and at 28 weeks (aOR stillbirth = 0·83, 95% CI 0·66–1·04; aOR perinatal death = 0·86, 95%CI 0·67–1·12). Compared with women with haemoglobin ≥110 g/l, the risk of stillbirth and perinatal death was five‐ and three‐fold higher in women with moderate‐severe anaemia (haemoglobin <100 g/l) at first visit and 28 weeks, respectively. These findings have clinical and public health importance.

Association of Living Arrangement Conditions and Socioeconomic Differentials with Anemia Status among Women in Rural Bangladesh

In Bangladesh, iron deficiency is the most common cause of anemia and remains a significant public health concern. Being a high anemia prevalent country, numerous efforts have been made to confront the issue especially among women and children by both local and international actors. Though the situation has substantially improved in recent years, a staggering number of adult women are currently living with anemia. The etiology of anemia is a multifactorial problem and has been proposed to be associated with various household, societal, economic, cultural factors apart from dietary habits. However, evidence regarding the household arrangements and socioeconomic determinants of anemia is scarce, especially in the context of Bangladesh. To this end, we utilized the 2011 demographic and health survey data to explore the association between anemia status and selected demographic, socioeconomic, and household characteristics. Our result showed significant correlation of anemia with both sociodemographic and household characteristics. Among the sociodemographic variables the following were found to be significantly associated with anemia status: age (p = 0.014; OR = 1.195; 95% CI = 1.036-1.378) and microcredit membership (p = 0.014; OR = 1.19; 95% CI = 1.037-1.386). Regarding the household arrangements, women utilizing biomass fuel for cooking (p < 0.019; OR = 1.82; 95% CI = 0.981-2.460) were more likely to be anemic.

Maternal haemoglobin concentrations before and during pregnancy and stillbirth risk: a population-based case-control study

Background

Results of previous studies on the association between maternal haemoglobin concentration during pregnancy and stillbirth risk are inconclusive. It is not clear if haemoglobin concentration before pregnancy has a role. Using prospectively collected information from pre-pregnancy and antenatal visits, we investigated associations of maternal haemoglobin concentrations before and during pregnancy and haemoglobin dilution with stillbirth risk.

Methods

In a population-based case–control study from rural Golestan, a province in northern Iran, we identified 495 stillbirths (cases) and randomly selected 2,888 control live births among antenatal health-care visits between 2007 and 2009. Using logistic regression, we estimated associations of maternal haemoglobin concentrations, haemoglobin dilution at different stages of pregnancy, with stillbirth risk.

Results

Compared with normal maternal haemoglobin concentration (110–120 g/l) at the end of the second trimester, high maternal haemoglobin concentration (≥140 g/l) was associated with a more than two-fold increased stillbirth risk (OR = 2.31, 95 % CI [1.30–4.10]), while low maternal haemoglobin concentration (<110 g/l) was associated with a 37 % reduction in stillbirth risk. Haemoglobin concentration before pregnancy was not associated with stillbirth risk. Decreased haemoglobin concentration, as measured during pregnancy (OR = 0.61, 95 % CI [0.46, 0.80]), or only during the second trimester (OR = 0.75, 95 % CI [0.62, 0.90]), were associated with reduced stillbirth risk. The associations were essentially similar for preterm and term stillbirths.

Conclusions

Haemoglobin concentration before pregnancy is not associated with stillbirth risk. High haemoglobin level and absence of haemoglobin dilution during pregnancy could be considered as indicators of a high-risk pregnancy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-0924-x) contains supplementary material, which is available to authorized users.

Association between maternal anaemia and pregnancy outcomes: a cohort study in Assam, India

Objectives

To examine the association between maternal anaemia and adverse maternal and infant outcomes, and to assess the feasibility of conducting epidemiological studies through the Indian Obstetric Surveillance System–Assam (IndOSS-Assam).

Design

Retrospective cohort study using anonymised hospital records. Exposure: maternal iron deficiency anaemia; outcomes: postpartum haemorrhage (PPH), low birthweight, small-for-gestational age babies, perinatal death.

Setting

5 government medical colleges in Assam.

Study population

1007 pregnant women who delivered in the 5 medical colleges from January to June 2015.

Main outcome measures

ORs with 95% CIs to estimate the association between maternal iron deficiency anaemia and the adverse maternal and infant outcomes. Potential interactive roles of infections and induction of labour on the adverse outcomes were explored.

Results

35% (n=351) pregnant women had moderate–severe anaemia. Women with severe anaemia had a higher odds of PPH (adjusted OR (aOR) =9.45; 95% CI 2.62 to 34.05), giving birth to low birthweight (aOR=6.19; 95% CI 1.44 to 26.71) and small-for-gestational age babies (aOR=8.72; 95% CI 1.66 to 45.67), and perinatal death (aOR=16.42; 95% CI 4.38 to 61.55). Odds of PPH increased 17-fold among women with moderate–severe anaemia who underwent induction of labour, and 19-fold among women who had infection and moderate–severe anaemia.

Conclusions

Maternal iron deficiency anaemia is a major public health problem in Assam. Maternal anaemia was associated with increased risks of PPH, low birthweight, small-for-gestational age babies and perinatal death. While the best approach is prevention, a large number of women present with severe anaemia late in pregnancy and there is no clear guidance on how these women should be managed during labour and delivery.

Mild anemia as a protective factor against pregnancy loss

BACKGROUND

Iron deficiency anemia is traditionally considered to be a pathological condition during pregnancy. According to the standards, prescription of iron supplements to pregnant women is required at hemoglobin levels of 110 g/l and lower. Numerous studies at different periods showed the relationship of anemia and premature birth [5], preeclampsia [1], low birth-weight [2]. Meanwhile, physiological hemodilution carries in pregnancy an important adaptive function. It is well known, that in the second half of pregnancy physiological hypercoagulability develops (increased activity of the plasma clotting factors, platelet aggregation, decreased activity and blood concentrations of physiological anticoagulants) aimed at implementing adequate hemostasis in labor. Under these conditions, moderate hemodilution is an effective mechanism for preventing the development of severe disseminated intravascular coagulation (DIC) in labor, during surgery, in various forms of obstetric pathology.

OBJECTIVE

To study the effect of anemia of varying severity on the pregnancy course and outcomes.

METHODS

We conducted a "case-control" study based on cohort. The study included 421 pregnant women who received outpatient care under the monitoring of pregnancy in the antenatal clinic of the South Ural State Medical University and the antenatal clinic of Chelyabinsk Clinical Hospital №6. The inclusion period was from January to March 2014. Inclusion criteria were: confirmed pregnancy, informed consent to participate in the study. Exclusion criteria were multiple pregnancy, induced pregnancy, late first appearance in the antenatal clinic (after 25 weeks' gestation), change of residence and medical supervision during pregnancy, the presence of severe mental disorders, severe somatic diseases in decompensation stage, HIV infection, cancer, active tuberculosis. Study design complies with the legislation of the Russian Federation, international ethical standards and was approved by the Ethics Committee of the South Ural State Medical University. Prospective observation was conducted. All pregnancy complications were registered, in particular, preeclampsia, placental insufficiency (violation of utero-placental blood flow), the presence and severity of anemia during pregnancy, as well as outcomes: the duration and mode of delivery, fetal weight at birth. The criteria for the diagnosis of anemia during pregnancy were: decrease of hemoglobin levels below 110 g/l. All pregnant women with confirmed anemia were treated with iron supplements. After the completion of follow-up the odds ratios analysis of presenting anemia was performed in subgroups: 1) a patient gave birth to a live child, and patient with the loss of the fetus at various stages of gestation; 2) patients who have given birth in time, and patients with premature birth; 3) patients with placental insufficiency (violation of utero-placental blood flow) during pregnancy and patients without placental insufficiency; 4) patients with preeclampsia and patients without pre-eclampsia; 5) patients who have delivered live births weighing less than 2,500 grams and birth weight over 2500. In each case, odds ratios (ORs) and confidence intervals (95% CI) were calculated. Statistical calculations were performed using the software package SPSS 22.0.

RESULTS

Among all patients (n = 421) anemia of varying severity has been diagnosed in 190 (45.13%), including mild anemia in 161 (38.24%), moderate or severe anemia - in 29 patients (6.88%). In 16 (3.8%) cases, the pregnancy resulted in miscarriage or fetal death. Premature birth of live fetus before 34 weeks of gestation was recorded in 13 cases (3.2%; n = 405). Preeclampsia was diagnosed in 15 women (3.56%). Live births with weights less than 2,500 g were registered in 23 cases (5.67%; n = 405).An analysis of odds ratios was performed to compare the groups of women with anemia of any severity and without anemia, with mild anemia compared with women without anemia, and moderate/severe anemia compared to women with mild anemia or without anemia.According to our results, there was a statistically significant reduction in the chance of having anemia of any severity in patients whose pregnancy was completed by fetal loss. For mild anemia odds ratio in these subgroups was even lower. Thus, the odds of having mild anemia in the group of women who completed a pregnancy to a live birth, was 90.3%, which may indicate a protective role of mild anemia against the loss of the fetus.In all other cases, statistically significant results were not received. Thus, we didn't receive significant positive association between anemia and development of preeclampsia, placental insufficiency during pregnancy, low birth weight and premature birth. There are other publications that show a protective role of anemia in pregnancy. Case control study [3] showed a protective role of anemia against the development of pre-eclampsia (n = 636, p = 0,01). In [4] anemia was a protective factor against stillbirth. There is evidence [6] of the higher risk of stillbirth in women with high hemoglobin level (146 g/l and above), while the link of the risk of stillbirth with anemia has not been confirmed (n = 1404).

CONCLUSIONS

Our data suggest a protective role of mild anemia during pregnancy in relation to pregnancy loss.

Maternal anemia and risk of adverse birth and health outcomes in low- and middle-income countries: systematic review and meta-analysis

BACKGROUND

Anemia is a leading cause of maternal deaths and adverse pregnancy outcomes in developing countries.

OBJECTIVES

We conducted a systematic review and meta-analysis to estimate the pooled prevalence of anemia, the association between maternal anemia and pregnancy outcomes, and the population-attributable fraction (PAF) of these outcomes that are due to anemia in low- and middle-income countries.

DESIGN

PubMed, EMBASE, CINAHL, and the British Nursing Index were searched from inception to May 2015 to identify cohort studies of the association between maternal anemia and pregnancy outcomes. The anemic group was defined as having hemoglobin concentrations <10 or <11 g/dL or hematocrit values <33% or <34% depending on the study. A metaregression and stratified analysis were performed to assess the effects of study and participant characteristics on adverse pregnancy risk. The pooled prevalence of anemia in pregnant women by region and country-income category was calculated with the use of a random-effects meta-analysis.

RESULTS

Of 8182 articles reviewed, 29 studies were included in the systematic review, and 26 studies were included in the meta-analysis. Overall, 42.7% (95% CI: 37.0%, 48.4%) of women experienced anemia during pregnancy in low- and middle-income countries. There were significantly higher risks of low birth weight (RR: 1.31; 95% CI: 1.13, 1.51), preterm birth (RR: 1.63; 95% CI: 1.33, 2.01), perinatal mortality (RR: 1.51; 95% CI: 1.30, 1.76), and neonatal mortality (RR: 2.72; 95% CI: 1.19, 6.25) in pregnant women with anemia. South Asian, African, and low-income countries had a higher pooled anemia prevalence than did other Asian and upper-middle-income countries. Overall, in low- and middle-income countries, 12% of low birth weight, 19% of preterm births, and 18% of perinatal mortality were attributable to maternal anemia. The proportion of adverse pregnancy outcomes attributable to anemia was higher in low-income countries and in the South Asian region.

CONCLUSION

Maternal anemia remains a significant health problem in low- and middle-income countries.

Development of a novel smartphone-based application for accurate and sensitive on-field hemoglobin measurement

A smartphone-based app for the accurate and sensitive measurement of hemoglobin was developed.

Smartphone dongle for simultaneous measurement of hemoglobin concentration and detection of HIV antibodies

It is traditionally difficult to incorporate two classes of diagnostic tests into a single platform. In this work, we demonstrate a microfluidic-based smartphone dongle that simultaneously measures concentration of hemoglobin and detects HIV antibodies. Specifically, we demonstrate how a previously published immunoassay device, which measured optical density of silver precipitation on gold colloids, can be expanded to quantitatively measure hemoglobin concentration via a colorimetric assay. By lysing whole blood components with CHAPS detergent, we achieved highly reproducible measurement of hemoglobin concentration with the device. We tested this dual test on 38 patient samples from Columbia University Medical Center. Compared with the Hemocue Hb 201+ analyzer, hemoglobin concentrations from our device were accurate within 1.2 g dL(-1), while the HIV immunoassay (in the presence of CHAPS detergent) showed 95% sensitivity and 95% specificity, comparable to our previous studies. This work demonstrates the feasibility of integrating two classes of diagnostic tests (a colorimetric-based quantitative measurement and an immunoassay based on silver precipitation on gold colloids) into a low-cost, fast, and low-power dongle that works with smartphones, and creates a novel dual panel with clinical utility for antenatal-care settings.

Nutritional determinants of anemia among adults in Eastern China

Historically, Eastern China has the highest prevalence of anemia among adults in China. It is commonly believed that iron deficiency is the main cause of anemia in China. Iron fortified soysauce is used to prevent anemia. Findings from Jiangsu Nutrition Study suggest that diet is related to anemia in this region. However, iron deficiency is not the main cause. Micronutrients other than iron (e.g., riboflavin) need to be considered in the prevention of anemia in the region.

How can formative research inform the design of an iron-folic acid supplementation intervention starting in first trimester of pregnancy in Bangladesh?

Background

The study objective was to understand community preparedness for iron and folic acid (IFA) supplementation early in pregnancy and to inform the design of a large-scale trial of early introduction of IFA supplementation in rural Bangladesh.

Methods

66 in-depth interviews (pregnant women, husbands, and older women in the household), 20 key-informant interviews, 3 focus-group discussions (community health workers and adolescent female students), and observation of two community-based clinics were conducted.

Results

Most of the women who used IFA tablets during pregnancy reported better health and physical strength after taking them. Women perceived that IFA increased blood volume, leading to foetal nourishment and compensated for blood loss during delivery. However, a culturally informed perceived barrier was the belief that IFA supplementation will increase foetus size, leading to birth complications, hospitalisation, caesarean section and financial burden for the family. Community health workers (CHWs) of BRAC (a non-government organisation) were the main sources of IFA information and supplements, although knowledge of IFA tablets among women’s social networks also helped to make it acceptable. Pregnant women felt that they could start taking IFA during the first trimester of pregnancy if advised by the CHWs. Programme managers and healthcare providers expressed concern about starting IFA supplementation early.

Conclusion

Our study suggests that introduction of IFA supplementation early in pregnancy is feasible with support from CHWs. Promotion of IFA could benefit from efforts to include culturally sensitive reasons for usage; improvement of the CHW training modules; targeted home visits and counselling; and outreach to standardize messages.

Causes of and factors associated with stillbirth in low- and middle-income countries: a systematic literature review

BACKGROUND

Annually, 2.6 million stillbirths occur worldwide, 98% in developing countries. It is crucial that we understand causes and contributing factors.

METHODS

We conducted a systematic review of studies reporting factors associated with and cause(s) of stillbirth in low- and middle-income countries (2000-13). Narrative synthesis to compare similarities and differences between studies with similar outcome categories.

MAIN RESULTS

A total of 142 studies with 2.1% from low-income settings were investigated; most report on stillbirths occurring at health facility level. Definition of stillbirth varied; 10.6% of studies (mainly upper middle-income countries) used a cut-off point of ≥22 weeks of gestation and 32.4% (mainly lower income countries) used ≥28 weeks of gestation. Factors reported to be associated with stillbirth include poverty and lack of education, maternal age (>35 or <20 years), parity (1, ≥5), lack of antenatal care, prematurity, low birthweight, and previous stillbirth. The most frequently reported cause of stillbirth was maternal factors (8-50%) including syphilis, positive HIV status with low CD4 count, malaria and diabetes. Congenital anomalies are reported to account for 2.1-33.3% of stillbirths, placental causes (7.4-42%), asphyxia and birth trauma (3.1-25%), umbilical problems (2.9-33.3%), and amniotic and uterine factors (6.5-10.7%). Seven different classification systems were identified but applied in only 22% of studies that could have used a classification system. A high percentage of stillbirths remain 'unclassified' (3.8-57.4%).

CONCLUSION

To build capacity for perinatal death audit, clear guidelines and a suitable classification system to assign cause of death must be developed. Existing classification systems may need to be adapted. Better data and more data are urgently needed.

First- and second-trimester tests to predict stillbirth in unselected pregnant women: a systematic review and meta-analysis

BACKGROUND

Several biophysical and biochemical tests have been proposed to predict stillbirth but their predictive ability remains unclear.

OBJECTIVE

To assess the accuracy of tests performed during the first and/or second trimester of pregnancy to predict stillbirth in unselected women with singleton, structurally and chromosomally normal fetuses through use of formal methods for systematic reviews and meta-analytic techniques.

SEARCH STRATEGY

Electronic databases, bibliographies and conference proceedings.

SELECTION CRITERIA

Observational studies that evaluated the predictive accuracy for stillbirth of tests performed during the first two trimesters of pregnancy.

DATA COLLECTION AND ANALYSIS

Two reviewers selected studies, assessed risk of bias and extracted data. Summary receiver operating characteristic curves, pooled sensitivities, specificities and likelihood ratios (LRs) were generated. Data were synthesised separately for stillbirth as a sole category and for specific stillbirth categories.

MAIN RESULTS

Seventy-one studies, evaluating 16 single and five combined tests, met the inclusion criteria. A uterine artery pulsatility index >90th centile during the second trimester and low levels of pregnancy-associated plasma protein A (PAPP-A) during the first trimester had a moderate to high predictive accuracy for stillbirth related to placental abruption, small-for-gestational-age or pre-eclampsia (positive and negative LRs from 6.3 to 14.1, and from 0.1 to 0.4, respectively). All biophysical and biochemical tests assessed had a low predictive accuracy for stillbirth as a sole category.

CONCLUSIONS

Currently, there is no clinically useful first-trimester or second-trimester test to predict stillbirth as a sole category. Uterine artery pulsatility index and maternal serum PAPP-A levels appeared to be good predictors of stillbirth related to placental dysfunction disorders.

Maternal haemoglobin and short-term neonatal outcome in preterm neonates

Objective

To determine whether there is a significant association between maternal haemoglobin measured before delivery and short-term neonatal outcome in very preterm neonates.

Study design

We included prospectively all live births occurring from 25 to 32+6 weeks of gestation in a tertiary care centre between January 1^st 2009 and December 31^st 2011. Outborn infants and infants presenting with lethal malformations were excluded. Three hundred and thirty-nine mothers and 409 infants met the inclusion criteria. For each mother-infant pair a prospective record of epidemiologic data was performed and maternal haemoglobin concentration recorded within 24 hours before delivery was retrospectively researched. Maternal haemoglobin was divided into quartiles with the second and the third one regarded as reference as they were composed of normal haemoglobin values. Short-term outcome was defined as poor in case of death during hospital stay and/or grades III/IV intraventricular haemorrhage and/or periventricular leukomalacia and/or necessity of ventriculoperitoneal shunt.

Results

The global rate of poor short-term neonatal outcome was 11.4% and was significantly associated with low maternal haemoglobin values. This association remained significant after adjustment for antenatal corticosteroids therapy, gestational age, parity, mechanism of preterm birth, mode of delivery and birth weight (aOR = 2.97 CI 95% [1.36–6.47]). There was no relation between short-term neonatal outcome and high maternal haemoglobin concentration values.

Conclusion

We show that low maternal haemoglobin concentration at delivery is an independent risk factor for poor short-term neonatal outcome in very preterm neonates. This study is one of the first to show such an association within the preterm population.

Prevalence of anemia and associated factors in child bearing age women in riyadh, saudi arabia

Objective. To determine the prevalence and risk factors for anemia in child bearing age women in Riyadh, Saudi Arabia. Design. Cross-sectional survey was conducted using two-stage cluster sampling. 25 clusters (primary health care centers (PHCC)) were identified from all over Riyadh, and 45–50 households were randomly selected from each cluster. Eligible women were invited to PHCC for questionnaire filling, anthropometric measurements, and complete blood count. Blood hemoglobin was measured with Coulter Cellular Analysis System using light scatter method. Setting. PHCC. Subjects. 969 (68%) women out of 1429 women were included in the analysis. Results. Mean hemoglobin was 12.35 (±1.80) g/dL, 95% CI 12.24–12.46 with interquartile range of 1.9. Anemia (Hb <12 g/dL) was present in 40% (390) women. Mean (±SD) for MCH, MCV, MCHC, and RDW was 79.21 (±12.17) fL, 26.37 (±6.21) pg, 32.36 (±4.91) g/dL, and 14.84 (±4.65)%, respectively. Multivariate logistic regression revealed that having family history of iron deficiency anemia (OR 2.91, 95% CI 1.78–4.76) and infrequent intake of meat (OR 1.54, 95%CI 1.15–2.05) were associated with increased risk of anemia, whereas increasing body mass index (OR 0.95, 95% CI 0.92–0.97) was associated with reduced risk of anemia. Conclusion. Women should be educated about proper diet and reproductive issues in order to reduce the prevalence of anemia in Saudi Arabia.

Hemoglobin concentration and pregnancy outcomes: a systematic review and meta-analysis

Objective. To conduct a systematic review and meta-analysis of hemoglobin effect on the pregnancy outcomes. Methods. We searched MEDLINE and SCOPUS from January 1, 1990 to April 10, 2011. Observational studies addressing association between hemoglobin and adverse pregnancy outcomes were selected. Two reviewers independently extracted data. A mixed logistic regression was applied to assess the effects of hemoglobin on preterm birth, low birth weight, and small for gestational age. Results. Seventeen studies were included in poolings. Hemoglobin below 11 g/dL was, respectively, 1.10 (95% CI: 1.02–1.19), 1.17 (95% CI: 1.03–1.32), and 1.14 (95% CI: 1.05–1.24) times higher risk of preterm birth, low birth weight, and small for gestational age than normal hemoglobin in the first trimester. In the third trimester, hemoglobin below 11 g/dL was 1.30 (95% CI: 1.08–1.58) times higher risk of low birth weight. Hemoglobin above 14 g/dL in third trimester decreased the risk of preterm term with ORs of 0.50 (95% CI: 0.26–0.97), but it might be affected by publication bias. Conclusions. Our review suggests that hemoglobin below 11 g/dl increases the risk of preterm birth, low birth weight, and small gestational age in the first trimester and the risk of low birth weight in the third trimester.

Global, regional, and national trends in haemoglobin concentration and prevalence of total and severe anaemia in children and pregnant and non-pregnant women for 1995-2011: a systematic analysis of population-representative data

Background

Low haemoglobin concentrations and anaemia are important risk factors for the health and development of women and children. We estimated trends in the distributions of haemoglobin concentration and in the prevalence of anaemia and severe anaemia in young children and pregnant and non-pregnant women between 1995 and 2011.

Methods

We obtained data about haemoglobin and anaemia for children aged 6–59 months and women of childbearing age (15–49 years) from 257 population-representative data sources from 107 countries worldwide. We used health, nutrition, and household surveys; summary statistics from WHO's Vitamin and Mineral Nutrition Information System; and summary statistics reported by other national and international agencies. We used a Bayesian hierarchical mixture model to estimate haemoglobin distributions and systematically addressed missing data, non-linear time trends, and representativeness of data sources. We quantified the uncertainty of our estimates.

Findings

Global mean haemoglobin improved slightly between 1995 and 2011, from 125 g/L (95% credibility interval 123–126) to 126 g/L (124–128) in non-pregnant women, from 112 g/L (111–113) to 114 g/L (112–116) in pregnant women, and from 109 g/L (107–111) to 111 g/L (110–113) in children. Anaemia prevalence decreased from 33% (29–37) to 29% (24–35) in non-pregnant women, from 43% (39–47) to 38% (34–43) in pregnant women, and from 47% (43–51) to 43% (38–47) in children. These prevalences translated to 496 million (409–595 million) non-pregnant women, 32 million (28–36 million) pregnant women, and 273 million (242–304 million) children with anaemia in 2011. In 2011, concentrations of mean haemoglobin were lowest and anaemia prevalence was highest in south Asia and central and west Africa.

Interpretation

Children's and women's haemoglobin statuses improved in some regions where concentrations had been low in the 1990s, leading to a modest global increase in mean haemoglobin and a reduction in anaemia prevalence. Further improvements are needed in some regions, particularly south Asia and central and west Africa, to improve the health of women and children and achieve global targets for reducing anaemia.

Funding

Bill & Melinda Gates Foundation, Grand Challenges Canada, and the UK Medical Research Council.

Anaemia, prenatal iron use, and risk of adverse pregnancy outcomes: systematic review and meta-analysis

OBJECTIVES

To summarise evidence on the associations of maternal anaemia and prenatal iron use with maternal haematological and adverse pregnancy outcomes; and to evaluate potential exposure-response relations of dose of iron, duration of use, and haemoglobin concentration in prenatal period with pregnancy outcomes.

DESIGN

Systematic review and meta-analysis

DATA SOURCES

Searches of PubMed and Embase for studies published up to May 2012 and references of review articles.

STUDY SELECTION CRITERIA

Randomised trials of prenatal iron use and prospective cohort studies of prenatal anaemia; cross sectional and case-control studies were excluded.

RESULTS

48 randomised trials (17 793 women) and 44 cohort studies (1 851 682 women) were included. Iron use increased maternal mean haemoglobin concentration by 4.59 (95% confidence interval 3.72 to 5.46) g/L compared with controls and significantly reduced the risk of anaemia (relative risk 0.50, 0.42 to 0.59), iron deficiency (0.59, 0.46 to 0.79), iron deficiency anaemia (0.40, 0.26 to 0.60), and low birth weight (0.81, 0.71 to 0.93). The effect of iron on preterm birth was not significant (relative risk 0.84, 0.68 to 1.03). Analysis of cohort studies showed a significantly higher risk of low birth weight (adjusted odds ratio 1.29, 1.09 to 1.53) and preterm birth (1.21, 1.13 to 1.30) with anaemia in the first or second trimester. Exposure-response analysis indicated that for every 10 mg increase in iron dose/day, up to 66 mg/day, the relative risk of maternal anaemia was 0.88 (0.84 to 0.92) (P for linear trend<0.001). Birth weight increased by 15.1 (6.0 to 24.2) g (P for linear trend=0.005) and risk of low birth weight decreased by 3% (relative risk 0.97, 0.95 to 0.98) for every 10 mg increase in dose/day (P for linear trend<0.001). Duration of use was not significantly associated with the outcomes after adjustment for dose. Furthermore, for each 1 g/L increase in mean haemoglobin, birth weight increased by 14.0 (6.8 to 21.8) g (P for linear trend=0.002); however, mean haemoglobin was not associated with the risk of low birth weight and preterm birth. No evidence of a significant effect on duration of gestation, small for gestational age births, and birth length was noted.

CONCLUSIONS

Daily prenatal use of iron substantially improved birth weight in a linear dose-response fashion, probably leading to a reduction in risk of low birth weight. An improvement in prenatal mean haemoglobin concentration linearly increased birth weight.

Moderate to severe, but not mild, maternal anemia is associated with increased risk of small-for-gestational-age outcomes

Anemia is highly prevalent globally, estimated at 40-50% in women of reproductive age. Prior studies have produced inconclusive evidence as to the association between maternal anemia and intrauterine growth restriction (IUGR). We conducted a systematic review of the literature containing associations between maternal anemia and small for gestational age (SGA) outcomes (as a proxy for IUGR). A meta-analysis was performed to pool associations, categorized by the hemoglobin cutoffs presented by the authors. We identified 12 studies reporting associations between maternal anemia and SGA. For the meta-analysis, there were 7 associations with a hemoglobin cutoff <110 g/L, 7 with a cutoff <100 g/L, and 5 with a cutoff <90 or <80 g/L. Although the <110- and <100-g/L categories showed no significant relationship with SGA, the <90- or <80-g/L category was associated with a 53% increase in risk of the newborn being SGA [pooled OR = 1.53 (95% CI: 1.24-1.87); P < 0.001]. Moderate to severe, but not mild, maternal anemia appears to have an association with SGA outcomes, but the findings must be viewed with caution due to the great heterogeneity of the studies. Further examination should be conducted using datasets with better standardized definitions and measurements of exposure and outcome.

Anaemia in low-income and middle-income countries

Anaemia affects a quarter of the global population, including 293 million (47%) children younger than 5 years and 468 million (30%) non-pregnant women. In addition to anaemia's adverse health consequences, the economic effect of anaemia on human capital results in the loss of billions of dollars annually. In this paper, we review the epidemiology, clinical assessment, pathophysiology, and consequences of anaemia in low-income and middle-income countries. Our analysis shows that anaemia is disproportionately concentrated in low socioeconomic groups, and that maternal anaemia is strongly associated with child anaemia. Anaemia has multifactorial causes involving complex interaction between nutrition, infectious diseases, and other factors, and this complexity presents a challenge to effectively address the population determinants of anaemia. Reduction of knowledge gaps in research and policy and improvement of the implementation of effective population-level strategies will help to alleviate the anaemia burden in low-resource settings.

Perinatal outcomes in native Chinese and Chinese-American women

This study aimed to compare perinatal outcomes in native Chinese, foreign-born and US-born Chinese-American women by analysing a cohort of 950,624 singleton pregnancies in south-east China and 293,849 singleton births from the US live and stillbirth certificates from 1995 to 2004. Only births at 28 weeks or later were included. Compared with US-born Chinese-American women, native Chinese and foreign-born Chinese-American women had substantially lower risks of having a small-for-gestational age (SGA) infant (adjusted relative risk [aRR] ranging from 0.46 to 0.66) or preterm birth (aRR ranging from 0.53 to 0.82). While having a White or Black father had a reduced risk of SGA (aRR=0.45 and 0.62, respectively), it has an increased risk for preterm birth (aRR=1.13 and 1.57, respectively). Infants with Chinese father and foreign-born mother were heavier than those with Chinese father and US-born mothers. All findings were statistically significant. Our findings demonstrated the protective role of foreign-born status on low birthweight and preterm delivery. The paternal contribution to fetal size is substantial.