Several reviews have assessed the relationship between exposure to ambient air pollution and adverse birth outcomes during pregnancy, but the results remain controversial. The objective of this study was to assess this correlation quantitatively and to explore sources of heterogeneity. We included all published case-control or cohort studies that evaluated the correlation between ambient air pollution and low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA). Analytical methods and inclusion criteria were provided on the PROSPERO website (CRD42018085816). We evaluated pooled effects and heterogeneity. Subgroup analyses (grouped by exposure period, study settings, study design, exposure types, data source, Newcastle-Ottawa quality score (NOS), and adjustment for smoking or meteorological factors) were also conducted and publication bias was examined. The risk of bias in systematic reviews (ROBIS) tool was used to evaluate the overall risk of bias in this review. Forty studies met the inclusion criteria. We observed pooled odds ratios (ORs) of 1.03-1.21 for LBW and 0.97-1.06 for PTB when mothers were exposed to CO, NO 2 , NO x , O 3 , PM 2.5 , PM 10 , or SO 2 throughout their pregnancy. For SGA, the pooled estimate was 1.02 in relation to NO 2 concentrations. Subgroup analysis and sensitivity analysis decreased the heterogeneity to some extent, such as the subgroups of continuous measures (OR=0.98 (0.97-0.99), I 2 =0.0%) and NOS>7 (OR=0.98 (0.97-0.99), I 2 =0.0%) in evaluating the association between PTB and NO 2 . This review was completed with a low risk of bias. High concentrations of air pollution were significantly related to the higher risk of adverse birth outcomes. However, the sources of heterogeneity among studies should be further explored.

Prenatal health care interventions are effective ways to improve maternal and neonatal health. There have been few large investigations conducted on the inequalities in maternal health services utilization in Shaanxi Province of west China since the health care reform in 2009. This study examined the inequalities and determinants of maternal health services utilization in Shaanxi Province. A household survey was conducted from August to November in 2013. By using a multistage sampling method, local women aged 15–49 who had given birth in the preceding three years were recruited. Information including social-demographic characteristics and maternal health services utilization was collected through a face-to-face interview. A concentration index approach was used to measure inequalities in maternal health services utilization. A logistic regression model was employed to investigate the determinants of maternal health services utilization. There were 8,488 women from urban areas and 18,724 women from rural areas enrolled in this study. The concentration index for all the indicators of maternal health services utilization showed significance in these two areas. In urban areas, the concentration index of having 5 or more prenatal visits, receiving the first prenatal visit within 12 weeks, delivering at secondary- or higher-level health facilities and delivering by C-section were 0.0356, 0.0166, 0.0177 and 0.0591, respectively, while in rural areas, the corresponding figures were 0.0385, 0.0183, 0.0334 and 0.0566, respectively. The determinants related to maternal health services utilization were women’s age at delivery, educational level, employment status, parity, health problems during pregnancy and household income. Inequalities in maternal health services utilization still exist in Shaanxi Province. Providing maternal health services for younger, less educated, unemployed, high parity and poorer women, especially in rural areas, is expected to reduce the inequalities in maternal health services utilization.

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

The purpose of this study is to examine the relationship between infections and birth outcomes in pregnant Chinese women by using propensity score (PS) matching. The data used here was from a large population-based cross-sectional epidemiological survey on birth defects in Shaanxi province, Northwest China. The babies born during 2010–2013 and their mothers were selected with a stratified multistage sampling method. We used PS-matched (1:1) analysis to match participants with infections to participants without infections. Of 22916 rural participants, the overall prevalence of infection was about 39.96%. 5381 pairs were matched. We observed increased risks of birth defects with infections, respiratory infections and genitourinary infections during the pregnancy (OR, 1.59; 95% CI: 1.21–2.08; OR, 1.44; 95% CI: 1.10–1.87; OR, 3.11; 95% CI: 1.75–5.54). There was also a significant increase of low birth weight associated with respiratory infections (1.13(1.01–1.27)). The association of birth defect with the infection could be relatively stable but the effect could be mediated by some important factors such as mother’s age, education level and economic level. The infection during pregnancy is common in Chinese women and might increase the risk of offspring birth defects and low birth weight, especially in younger, lower education, poor pregnant women.

Background: The incidence of brucellosis, which is caused by the Brucella species of bacteria, is rapidly rising worldwide; however, few studies have investigated the immune response to this pathogen and clinical biochemical features. In this paper, we examined the levels of various cytokines and inflammatory factors as well as clinical course characteristics in patients with brucellosis, in order to provide evidence for the diagnosis, assessment, and prognosis of this infectious disease. Methods: A total of 191 brucellosis inpatients (50 acute cases and 141 chronic cases), as well as 60 healthy control subjects, were included in the analysis. We investigated changes in the levels of six cytokines (IL-4, IL-6, IL-10, IL-17, TNF-α, INF-γ) and related clinical biochemical markers in patients with acute and chronic brucellosis in Xinjiang, China. Possible factors were statistically analyzed using the t test, χ 2 test, z test and a multivariate logistic stepwise regression test. Results: We found that IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α levels were higher in those with brucellosis than in controls (P < 0.05). With regard to disease progression, procalcitonin (PCT) and C-reactive protein (CRP) levels were significantly higher in those with an acute infection compared to chronic cases (P < 0.05). We found that the expression of all six cytokines tested was closely related to the degree of brucellosis using univariate logistic regression; however, only IL-6 and INF-γ levels were independent factors associated with the severity of brucellosis. Conclusions: Assessing cytokine levels in patients with acute and chronic brucellosis is not only useful for detecting the immune response, but can also be indicative of the severity of brucellosis. In particular, we propose IL-6 and INF-γ levels may be useful independent predictive factors in the clinical evaluation and diagnosis of brucellosis.