Investigating the Relationships between Maternal Hemoglobin Concentration and Maternal Body Mass Index in Pregnancy and Neonatal Birth Weight

Document Type : Original Article


1 M.Sc. of Midwifery, Ardabil Health Care, Ardabil University of Medical Sciences, Ardabil, Iran

2 General Practitioner, Ardabil Health Care, Ardabil University of Medical Sciences, Ardabil, Iran.

3 M.Sc. of Midwifery, Ardabil Health Care, Ardabil University of Medical Sciences, Ardabil, Iran.

4 Assistant Professor of Occupational Health, Faculty of Health, Ardabil University of Medical Sciences, Ardabil, Iran.


Introduction: The rate of low birth weight has been reported to be 7.7% for singleton and multiple pregnancies for all races. About 56% of pregnant women in developing countries, 18% in developed countries and 80% in south Asia suffer from anemia. Controversial results have been reported concerning the effects of maternal hemoglobin concentration on neonatal birth weight. The purpose of this study is investigating the relationships between hemoglobin and maternal Body mass index (BMI) in pregnancy and neonatal birth weight.
Methods: This analytical cross-sectional study was conducted on all medical records of pregnant women (6685 records) who referred to Ardabil health centers and had labor in 2009. Twin deliveries, still births, smokers and mothers with severe chronic disease were excluded. Pearson correlation, T- test, ANOVA, and were applied for statistical analysis using SPSS software.
Data were analyzed using SPSS software (version 16), Pearson correlation test, T-test, ANOVA and MANOVA tests. P less than 0.05 was considered statistically significant.
Results: No significant relationship was found between maternal hemoglobin concentration in first and third trimester of pregnancy and neonatal birth weight (p=0.33, p=0.98). No significant difference was found in mean of neonatal weight based on stratified hemoglobin concentration in different groups of BMI (p=0.25). There was a significant relationship between parental age and birth weight (p<0.001). Moreover, statistically significant difference was observed in birth weight between different genders (p=0.001). Frequency of low birth weight and macrosomia were respectively 3.5% and 5.2%.
Conclusion: No significant relationship was found between maternal hemoglobin concentration and neonatal birth weight. But, neonatal weight is associated with other factors such as birth weight, parental age, number of prenatal care, infant gender and maternal body mass index.


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