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

Abstract

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.

The Association between Iron and Folic Acid Supplementation and Malaria Prophylaxis and Linear Growth among Children and Neonatal Mortality in Sub-Saharan Africa—A Pooled Analysis

“…The findings from this study diverge from the results of similar studies in South Asia, where IFA supplementation and the timing of its initiation were found to be significantly associated with linear growth [ 13 , 14 ] and neonatal mortality [ 7 , 19 , 20 , 21 ]. This contrast that also highlights the importance of context may be explained by the high prevalence of malaria in SSA.…”

“…Multiple studies have shown a positive association of iron and folic acid (IFA) supplementation during pregnancy with fetal growth [ 6 ] and low birth weight [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. However, very few have analyzed the association with a child’s linear growth beyond birth.…”

A Critical Analysis of the Automated Hematology Assessment in Pregnant Women at Low and at High Altitude: Association between Red Blood Cells, Platelet Parameters, and Iron Status

“…Anemia during pregnancy is considered an adverse condition that can affect the health of the maternal–fetal unit according to the World Health Organization (WHO), generally defined with hemoglobin values <11 g/dL. Several studies have demonstrated that hemoglobin values in pregnant women between 9 g/dL and 13 g/dL are not associated with adverse neonatal outcomes [ 12 , 13 , 14 , 15 ]. This is an important question for populations living at HA since they have normally increased Hb levels [ 2 ].…”

Interaction effects of MTHFR C677T and A1298C polymorphisms with maternal glycated haemoglobin levels on adverse birth outcomes

“…(2016) observed a significant interaction between the MTHFR 677TT genotype and being overweight/obesity on the risk of developing type 2 diabetes, with the attributable proportion due to interaction being 0.40 (95% CI: 0.05–0.76) 14 . Similarly, our previous studies had indicated that pregnant women who were obese, with the CT + TT genotype, were 2.40 times more likely to have GDM, whereas no significant association was observed in those with the CC genotype 31 . In addition, an Italian study demonstrated that participants with the C677T CT or TT genotype had a high body weight, BMI, and other anthropometrics at baseline, and lost less weight in the mutated genotype group after dietary intervention 32 .…”