Interaction of body mass index and hemoglobin concentration on blood pressure among pregnant women in Guangxi, China

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.

Detrimental Effects of Higher Body Mass Index and Smoking Habits on Menstrual Cycles in Korean Women

BACKGROUND

Alteration of menstrual cycle by individual lifestyles and unfavorable habits may cause menstrual irregularity. We aimed to investigate the relationship between lifestyle factors and menstrual irregularity in Korean women using data from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES) 2010-2012.

MATERIALS AND METHODS

This cross-sectional study included 3779 nondiabetic Korean women aged 19-49 years who did not take any oral contraceptives or sex hormonal compounds. We examined the association of menstrual irregularity with age, body mass index (BMI), drinking experience, and smoking habits.

RESULTS

Age, Asian BMI, marriage status, age at menarche, and smoking habits were significantly associated with menstrual cycle irregularity (p < 0.01). The prevalence of menstrual irregularity was significantly increased at younger ages: 18.4%, 10.3%, and 10.5% at 19-29, 30-39, and 40-49 years, respectively. Moreover, obesity groups, defined as per Asian BMI using modified WHO criteria, were strongly associated with menstrual irregularity. BMI 25.0-29.9 [obesity class I] (adjusted odds ratios [OR], 1.94; 95% confidence intervals [CI], 1.37-2.74) and ≥30.0 [obesity class II] (adjusted OR, 2.18; 95% CI, 1.22-3.91) presented significantly higher risk of menstrual irregularity compared with BMI 18.5-22.9 [normal weight]. Multivariable analysis revealed that high BMI in younger women aged 19-29 years (p < 0.001) and smoking habits in middle-aged women aged 30-39 years (p < 0.005) significantly predicted menstrual irregularity.

CONCLUSION

This study substantiated that menstrual irregularity was closely associated with higher BMI and smoking habits in nondiabetic Korean women. Weight loss and smoking cessation should be recommended to promote women's reproductive health.