Changes in Socioeconomic Inequality of Low Birth Weight and Macrosomia in Shaanxi Province of Northwest China, 2010-2013: A Cross-sectional Study

Multilevel multinomial regression analysis of factors associated with birth weight in sub-Saharan Africa

Birth weight significantly determines newborns immediate and future health. Globally, the incidence of both low birth weight (LBW) and macrosomia have increased dramatically including sub-Saharan African (SSA) countries. However, there is limited study on the magnitude and associated factors of birth weight in SSA. Thus, thus study investigated factors associated factors of birth weight in SSA using multilevel multinomial logistic regression analysis. The latest demographic and health survey (DHS) data of 36 sub-Saharan African (SSA) countries was used for this study. A total of a weighted sample of 207,548 live births for whom birth weight data were available were used. Multilevel multinomial logistic regression model was fitted to identify factors associated with birth weight. Variables with p-value < 0.2 in the bivariable analysis were considered for the multivariable analysis. In the multivariable multilevel multinomial logistic regression analysis, the adjusted Relative Risk Ratio (aRRR) with the 95% confidence interval (CI) was reported to declare the statistical significance and strength of association. The prevalence of LBW and macrosomia in SSA were 10.44% (95% CI 10.31%, 10.57%) and 8.33% (95% CI 8.21%, 8.45%), respectively. Maternal education level, household wealth status, age, and the number of pregnancies were among the individual-level variables associated with both LBW and macrosomia in the final multilevel multinomial logistic regression analysis. The community-level factors that had a significant association with both macrosomia and LBW were the place of residence and the sub-Saharan African region. The study found a significant association between LBW and distance to the health facility, while macrosomia had a significant association with parity, marital status, and desired pregnancy. In SSA, macrosomia and LBW were found to be major public health issues. Maternal education, household wealth status, age, place of residence, number of pregnancies, distance to the health facility, and parity were found to be significant factors of LBW and macrosomia in this study. Reducing the double burden (low birth weight and macrosomia) and its related short- and long-term effects, therefore, calls for improving mothers' socioeconomic status and expanding access to and availability of health care.

Child Nutrition Outcomes and Maternal Nutrition-Related Knowledge in Rural Localities of Mbombela, South Africa

Poor nutrition outcomes among children have become one of the major public health concerns in South Africa, attributed to poor feeding practices and maternal nutrition-related knowledge with conflicting data. In view of this, a cross-sectional study was conducted to determine the association of nutrition outcomes of children aged under two years with feeding practices and maternal nutrition-related knowledge in Mbombela, South Africa. Mothers' nutrition-related knowledge was estimated using an adapted structured questionnaire on colostrum, continued breastfeeding, diarrhea prevention and treatment using oral rehydration solution, immunization, and family planning, and scored as excellent (80-100), good (60-79), average (40-59), and fair (0-39). This was along with questions on socio-demographic factors and obstetric history, as well as anthropometric measurements. Child nutrition outcomes were estimated by WHO classification using z-scores for stunting (length-for-age (LAZ)), underweight (weight-for-age (WAZ)), and thinness (body mass index-for-age (BAZ)). Using STATA 17, 400 pairs of children (8 ± 6 months) and their mothers (29 ± 6 years) participated in the study and were living in a poor socio-economic status environment. Half of children were stunted (50%) and over half (54%) were obese, while mothers were underweight (39%) and overweight (34%). In addition to one third of mothers reporting obstetric complications, two thirds, initiated breastfeeding within one hour of delivery, 30% exclusively breastfed, 48% introduced early complementary feeding, and 70% practiced mixed feeding. Twenty-eight percent (28%) of mothers had fair nutrition-related knowledge, while 66% had average knowledge, 6% good knowledge, and none of the mothers had excellent knowledge. A chi-square test showed that mothers' nutrition-related knowledge was significantly associated with child stunting. The final hierarchical logistic regression showed significant associations of stunting with mothers' nutrition-related knowledge (average: AOR = 1.92, 95%CI: 1.12-3.29), child's age (6-11 months: AOR = 2.63, 95%CI: 1.53-4.53 and 12-23 months: AOR = 3.19, 95%CI: 1.41-7.25), and education (completing Grade 12: AOR = 0.36, 95%CI: 0.15-0.86). Contextual and intensified interventions on continued education for mothers to gain accurate information on nutrition-related knowledge and feeding practices could ultimately enhance child nutrition outcomes in poorer settings. Efforts should therefore be made to ensure that nutrition knowledge is appropriately provided based on the phases of child growth from 0 to 2 years, even beyond infancy into school age.

Facilitators and barriers associated with breastfeeding among mothers attending primary healthcare facilities in Mpumalanga, South Africa

Introduction

Despite the health benefits of breastfeeding for both the mother and the child, early cessation of breastfeeding remains a public health problem in South Africa, attributed to contextual barriers and facilitators. Within the context of Mpumalanga province, which is characterized by low breastfeeding rates and high infant mortality rates in children under 5 years, we explored the facilitators and barriers to breastfeeding among mothers attending the three primary health facilities in Ermelo.

Methods

Using a semi-structured interview guide suggested by the socio-ecological model, three focus group discussions and 12 in-depth interviews were conducted among mothers selected using a purposive sampling. Transcripts from audiotaped and transcribed verbatim interviews were assessed through thematic analysis using NVivo version 10.

Results

Mothers were aged between 18 and 42 years and from poor sociodemographic backgrounds. At the individual level, mothers valued breastfeeding facilitated by their commitment, maintaining it, eating healthy foods, and having sufficient breast milk. However, returning to work, insufficient breast milk, misconceptions about breastfeeding, and interference with social life were the barriers for mothers to breastfeed continuously. At the interpersonal level, the family was identified as the main form of support to breastfeeding mothers; however, family interference was also identified as a barrier. At the community level, mothers shared some family beliefs and practices but were still split between societal and cultural norms and traditional beliefs as facilitators or barriers to breastfeeding. At the organizational level, most mothers valued the support provided by healthcare workers on childcare and techniques for breastfeeding at the health facilities. They did however articulate concerns on the miscommunication some healthcare workers offered regarding breastfeeding, which negatively influenced their infant feeding practices.

Discussion

Intervention efforts should focus on behaviour change to educate and equip mothers to overcome the barriers that are within their control. Such interventions should further focus on family-centered education and strengthening the proficiency of healthcare workers on advising breastfeeding mothers.

Secular trends and age-period-cohort effect on adverse perinatal outcomes in Hubei, China (2011-2019)

The increasing trend in the incidence of adverse perinatal outcomes is a public health concern globally as well as in China. However, the causes of the increasing trend are not well understood. The present tertiary-hospital-based retrospective study (2011-2019) aims to determine the secular trends and age-period-cohort effect on adverse perinatal outcomes in Hubei, China. The age-standardized incidence rates of adverse perinatal outcomes significantly decreased such as preterm births by 22% [AAPC - 3.4% (95% CI - 7.8, - 1.2)], low birth weight (LBW) by 28.5% [AAPC - 4.7% (95% CI - 6.0, - 3.3)], and fetal distress by 64.2% [AAPC - 14.0% (95% CI - 17.8, - 10.0)] during 2011-2019. Both extremes of maternal age groups (18-20 years and 42-44 years) had a higher risk ratio for adverse perinatal outcomes including preterm birth, perinatal mortality, LBW, low ponderal index (LPI), low Apgar score, and congenital defect compared to the reference age group (30-32 years). A higher risk ratio for perinatal mortality, intrauterine growth restriction (IUGR), and fetal distress and a lower risk ratio for preterm births and LBW were observed in the period 2017-2019. Both the young cohort (1997-1999) and the old cohort (1976-1969) had a higher risk ratio for preterm birth, perinatal mortality, macrosomia, and congenital defect compared to the reference cohort (1982-1984). In conclusion, some of the adverse perinatal outcomes incidence significantly decreased in the last 9 years in Hubei. However, extremes of maternal age groups and both young and old cohorts were associated with a higher risk of preterm birth, perinatal mortality, and congenital defect.

A Comprehensive Review on Social Inequalities and Pregnancy Outcome-Identification of Relevant Pathways and Mechanisms

Scientific literature tends to support the idea that the pregnancy and health status of fetuses and newborns can be affected by maternal, parental, and contextual characteristics. In addition, a growing body of evidence reports that social determinants, measured at individual and/or aggregated level(s), play a crucial role in fetal and newborn health. Numerous studies have found social factors (including maternal age and education, marital status, pregnancy intention, and socioeconomic status) to be linked to poor birth outcomes. Several have also suggested that beyond individual and contextual social characteristics, living environment and conditions (or "neighborhood") emerge as important determinants in health inequalities, particularly for pregnant women. Using a comprehensive review, we present a conceptual framework based on the work of both the Commission on Social Determinants of Health and the World Health Organization (WHO), aimed at describing the various pathways through which social characteristics can affect both pregnancy and fetal health, with a focus on the structural social determinants (such as socioeconomic and political context) that influence social position, as well as on intermediary determinants. We also suggest that social position may influence more specific intermediary health determinants; individuals may, on the basis of their social position, experience differences in environmental exposure and vulnerability to health-compromising living conditions. Our model highlights the fact that adverse birth outcomes, which inevitably lead to health inequity, may, in turn, affect the individual social position. In order to address both the inequalities that begin in utero and the disparities observed at birth, it is important for interventions to target various unhealthy behaviors and psychosocial conditions in early pregnancy. Health policy must, then, support: (i) midwifery availability and accessibility and (ii) enhanced multidisciplinary support for deprived pregnant women.

The association between adverse pregnancy outcomes with genital Chlamydia Trachomatis infection among pre-pregnancy couples in Shenzhen, China: A cross-sectional study

Objectives

To investigate the prevalence of adverse pregnancy outcomes (APOs) in women and the impact of pre-pregnancy couples' genital Chlamydia Trachomatis (GCT) infection and other infections on APOs.

Study design

Data on genital infections were collected from the Free Pre-pregnancy Health Check (FPHC) in Shenzhen, China. Data on APOs were collected from a 1-year telephone follow-up of pregnancy status and subsequent pregnancy outcomes.

Methods

APO data were used to count adverse outcomes, and logistic regression was conducted to determine the association between APOs and GCT infection.

Results

From December 2018 to December 2019, among 4,429 couples who underwent FPHC; 1,925 were pregnant, and 1,816 couples were tracked for pregnancy outcomes, including 1,471 normal pregnancies and 345 (19.00%) APOs. The rest of 109 pregnant couples did not answer the phone or refused to answer the pregnancy outcome during the follow-up. Among APOs, the number of spontaneous abortions was 122 (35.36%), the number of macrosomia was 85 (24.64%), the number of low birth weight (LBW) & preterm births (PTB) was 39 (11.30%), the number of LBW was 34 (9.86%), and the number of PTB was 31 (8.99%). The prevalence of GCT infection in females and males was 4.24% [95% Confidence Interval, (CI): 3.41-5.27%] and 3.58% (95% CI: 2.79-4.57%), respectively. More than half (52.69%, 49/93) of the couples were GCT-concordant. The prevalence of APOs in couples without GCT infection was 18.74% (332/1,772). The prevalence of APOs in female GCT-discordant was 32.14% (9/28), and the prevalence of APOs in male GCT-discordant was 25% (4/16). The prevalence of APOs in GCT-concordant was 12.24% (6/49). Multivariable analysis indicated that females 30-35 years old [adjusted Odds Ratio (aOR) = 1.08, 95% CI: 1.01-1.17] and over 35 years old (aOR = 1.16, 95% CI: 1.03-1.32) were more likely to experiencing APOs.

Conclusion

Although only women's age was found to be associated with APOs, the prevalence of APOs with GCT-discordant in couples, especially female GCT-discordant, was higher than in those without infection or who were GCT-concordant, suggesting that these groups, especially in older women, should be paid more attention to in follow-ups to improve reproductive health.

Machine learning algorithms for predicting low birth weight in Ethiopia

Background

Birth weight is a significant determinant of the likelihood of survival of an infant. Babies born at low birth weight are 25 times more likely to die than at normal birth weight. Low birth weight (LBW) affects one out of every seven newborns, accounting for about 14.6 percent of the babies born worldwide. Moreover, the prevalence of LBW varies substantially by region, with 7.2 per cent in the developed regions and 13.7 per cent in Africa, respectively. Ethiopia has a large burden of LBW, around half of Africa. These newborns were more likely to die within the first month of birth or to have long-term implications. These are stunted growth, low IQ, overweight or obesity, developing heart disease, diabetes, and early death. Therefore, the ability to predict the LBW is the better preventive measure and indicator of infant health risks.

Method

This study implemented predictive LBW models based on the data obtained from the Ethiopia Demographic and Health Survey 2016. This study was employed to compare and identify the best-suited classifier for predictive classification among Logistic Regression, Decision Tree, Naive Bayes, K-Nearest Neighbor, Random Forest (RF), Support Vector Machine, Gradient Boosting, and Extreme Gradient Boosting.

Results

Data preprocessing is conducted, including data cleaning. The Normal and LBW are the binary target category in this study. The study reveals that RF was the best classifier and predicts LBW with 91.60 percent accuracy, 91.60 percent Recall, 96.80 percent ROC-AUC, 91.60 percent F1 Score, 1.05 percent Hamming loss, and 81.86 percent Jaccard score.

Conclusion

The RF predicted the occurrence of LBW more accurately and effectively than other classifiers in Ethiopia Demographic Health Survey. Gender of the child, marriage to birth interval, mother’s occupation and mother’s age were Ethiopia’s top four critical predictors of low birth weight in Ethiopia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-022-01981-9.

Changes in adverse pregnancy outcomes in women with advanced maternal age (AMA) after the enactment of China's universal two-child policy

The universal two-child policy (TCP; 2016) in China has affected many aspects of maternal-neonatal health. A tertiary hospital-based retrospective study (2011–2019) was used to find the association of these policy changes with maternal age and pregnancy outcomes in women with AMA (≥ 35 years) in the Hubei Province, China. The proportion of neonatal births to women with AMA increased by 68.8% from 12.5% in the one-child policy (OCP) period to 21.1% in the universal TCP period [aOR 1.76 (95% CI: 1.60, 1.93)]. In the univariate analysis, the proportion of preterm births (29.4% to 24.1%), low birth weight (LBW) (20.9% to 15.9%), and hypertensive disorders of pregnancy (HDP) (11.5% to 9.2%) significantly (p < 0.05) decreased in women with AMA from the OCP period to universal TCP period. However, the proportion of intrauterine growth restriction (IUGR) (0.2% to 0.7%) and gestational diabetes mellitus (GDM) (1.7% to 15.6%) was significantly (p < 0.05) increased over the policy changes. After adjusting for confounding factors, only the risk of GDM increased [aOR 10.91 (95% CI: 6.05, 19.67)] in women with AMA from the OCP period to the universal TCP period. In conclusion, the risk of GDM increased in women with AMA from the OCP period to the universal TCP period.

Associations of B Vitamin-Related Dietary Pattern during Pregnancy with Birth Outcomes: A Population-Based Study in Northwest China

This study aimed to derive a maternal dietary pattern to explain the variation in B vitamins during pregnancy and to investigate this pattern in relation to birth outcomes. A total of 7347 women who gave birth to live newborns less than one year were included. Their dietary pattern during pregnancy was derived using the reduced-rank regression method with six B vitamins as response variables. Associations between dietary pattern score and birth weight, gestational age at delivery, birth weight Z score, low birth weight, preterm, and small-for-gestational-age (SGA) were estimated using generalised linear mixed models. We identified a high B-vitamin dietary pattern characterised by high intakes of animal foods, vegetables, fungi and algae, legumes, and low intakes of oils and cereals. Women in the highest quartile of this pattern score had newborns with a 44.5 g (95% CI: 13.8, 75.2 g) higher birth weight, 0.101 (95% CI: 0.029, 0.172) higher birth weight Z score, and 27.2% (OR: 0.728; 95% CI: 0.582, 0.910) lower risk of SGA than those in the lowest quartile. Our study suggested that adherence to the high B-vitamin dietary pattern during pregnancy was associated with a higher birth weight and a lower risk of SGA.

Trends of Adverse Pregnancy Outcomes in a High Prevalence Region of Birth Defects - Shanxi Province, China, 2007-2019

What is already known about this topic?

Shanxi Province in northern China has been identified as a region with the highest prevalence of birth defects nationwide. With large amounts of financial support devoted for prevention and related interventions for birth defects, huge progress has been made as a 60% decrease in its prevalence was observed from 2009 to 2014.

What is added by this report?

The study presented a recent trend of adverse pregnancy outcomes (APOs) in Shanxi Province, a region with high prevalence of birth defects in China from 2007–2019. The prevalence of serious APOs including birth defects, stillbirths, and neonatal deaths remained at a relatively low level, yet macrosomia, low birth weight (LBW), preterm births, and spontaneous abortion comprised a majority of all APOs, with macrosomia showing an obvious upward trend from 2007 to 2012.

What are the implications for public health practice?

These findings provide new evidence for prevention and intervention strategies of APOs in northern China. Future research should focus on comprehensive interventions for multiple APOs, especially macrosomia, LBW, preterm births, and spontaneous abortion.

Development and validation of nomogram for prediction of low birth weight: a large-scale cross-sectional study in northwest China

BACKGROUND

Birth weight is closely related to infant survival and future health, growth and development. In developing countries, the incidence of low birth weight is twice as high as in developed countries. Due to the low economic and medical level in northwest China, the problem of low birth weight needs to be solved urgently.

METHODS

We developed the predictive model based on data sets from a cross-sectional study conducted in northwest China, and data were collected from August 2013 to November 2013. A total of 27,233 patients were included in the study. Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to select the optimal predictive characteristics among risk factors. The selected characteristics in the LASSO regression were used in multivariate logistic regression to build the prediction model. C-index and calibration plot were used to evaluate the degree of discrimination and calibration of the model. The decision curve is used to evaluate the net benefit rate of the application of the predictive tool. Bootstrapping validation was used for internal validation.

RESULTS

Nomogram included gestational age, the sex of the attendance, the mother's education level, antenatal care, the mother's occupation, pregnancy-induced hypertension, family income, exposure to pesticides and nutritional supplements. The C-index of the predicted nomogram was 0.698(95% confidence interval: 0.671-0.725), C-index of internal verification was 0.694, indicating that the model had a good identification ability. Calibration plot showed that the model had good calibration. Decision curve indicated that patients with a threshold probability of low birth weight between 1% and 71% would benefit more from using the prediction tool.

CONCLUSION

The use of this predictive model will contribute to clinicians and pregnant women to make personalized predictions easily and quickly so that early lifestyle detection and medical intervention can be undertaken by physicians and patients.

Macrosomia and large for gestational age in Asia: One size does not fit all

Macrosomia, usually defined as infant birth weight of ≥4000 g, does not consider gestational age, sex, or country/region-specific differences in mean birth weight and maternal body weight. This issue is particularly relevant for Asia, where 60% of the world's population lives, due to variations in maternal size and birth weights across populations. Large for gestational age (LGA), defined as birth weight > 90th centile, is a more sensitive measure as it considers gestational age and sex, though it is dependent on the choice of growth charts. We aimed to review reporting of macrosomia and LGA in Asia. We reviewed the literature on prevalence and risk of macrosomia and LGA in Asia over the last 29 years. Prevalence of macrosomia ranged from 0.5% (India) to 13.9% (China) while prevalence of LGA ranged from 4.3% (Korea) to 22.1% (China), indicating substantial variation in prevalence within and between Asian countries. High pre-pregnancy body mass index, excessive gestational weight gain, and impaired glucose tolerance conferred risk of macrosomia/LGA. Incidence of macrosomia and LGA varies substantially within and between Asian countries, as do the growth charts and definitions. The latter makes it impossible to make comparisons but suggests differences in intrauterine growth between populations. Reporting LGA, using standardized country/regional growth charts, would better capture the incidence of high birth weight and allow for comparison and identification of contributing factors. Better understanding of local drivers of excessive intrauterine growth could enable development of improved strategies for prevention and management of LGA.

Association between maternal iron supplementation and newborn birth weight: a quantile regression analysis

Objective

Our study aimed to explore the association between maternal iron supplementation and newborn birth weight (BW) in Shaanxi Province using quantile regression (QR).

Method

The data used in this study were derived from a large cross-sectional survey of a population in Shaanxi Province, Northwest China. A total of 28,209 women and their infants were selected using a stratified multistage random sampling method. The effect of iron supplementation on the newborn BW was assessed by a multiple linear regression model and QR.

Results

A total of 5.15% of the women took iron supplements during pregnancy. Multiple linear regression showed that the iron supplementation during pregnancy had positive effects on the BW, with an average increase of 43.07 g (β = 43.07, t = 3.55, and p < 0.001). The QR showed that the iron supplementation during pregnancy was associated with an increased newborn BW from very low to higher percentiles (quantiles: 0 ~ 0.40), with the β ranging from 136.51 to 43.86. As the percentiles of the BW increased, the neonatal BW gain gradually declined in the iron supplementation group compared with the group that did not receive iron supplementation (quantiles: 0 ~ 0.40, with the β ranging from 136.51 to 43.86). Iron supplementation was more effective among women who suffered from anemia during pregnancy (β = 45.84, t = 2.05, and p = 0.04; quantiles: 0 ~ 0.15, 0.30, 0.80, with β ranging from 150.00 to 39.29) than it was in any other group (β = 38.18, t = 2.62, and p = 0.009; quantiles: 0 ~ 0.15, with β ranging from 133.33 to 28.32).

Conclusions

Iron supplementation during pregnancy is associated with an increased newborn BW, and the effect was more obvious in the newborns with the lower BW and newborns whose mothers suffered from anemia during pregnancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-021-01084-7.

Influence of family resources on secondhand smoking in pregnant women: a cross-sectional study in the border and minority urban areas of Northwest China

BACKGROUND

Pregnant women's exposure to secondhand smoke is a very serious health issue in China. The purpose of our research is to identify factors that predict the probability of exposure to secondhand smoke among pregnant women from the perspective of a family-based open system.

METHODS

From September 2014 to August 2015, Urumqi City, Shihezi City, and Shawan County-level City were sampled according to population characteristics. A revised structured questionnaire based on family resources was adapted for use in this study. Questionnaires were collected via convenience sampling at the hospitals with the largest number of local antenatal clients. A total of 1249 pregnant women of age 18-51 years were investigated. Descriptive statistics were calculated to characterize the participants and study variables. Binary logistic regression was performed to assess the impact of family resources corresponding variables on the likelihood that participants would be exposed to SHS. Both unadjusted and adjusted odds ratios (OR/AOR) [with 95% confidence intervals (CI)] were reported.

RESULTS

The secondhand smoke exposure rate found in this study was 54.6%. Having good knowledge of the dangers of secondhand smoke had no effect on reducing the prevalence of exposure (P > 0.05). Even pregnant women whose husbands who did not use tobacco or never smoked nearby had a risk of exposure to secondhand smoke [adjusted odds ratio (AOR) 1.568, 95% CI 1.205-2.041] when the data were adjusted for age, gravidity, gestational weeks, knowledge of the dangers of secondhand smoke, location, and work status. Home smoking bans were confirmed to be an important protective factor (AOR 1.710, 95% CI 1.549-1.918); however, only one-third (33.5%) of participants reported having a smoking ban at home. Religion (mainly Islam), as a special external family resource, was a protective factor that reduced secondhand smoke exposure in pregnant women (AOR 0.399, 95% CI 0.312-0.510).

CONCLUSIONS

The effect of family resources on tobacco control should be considered in the development of effective and enduring strategies for indoor smoking bans and smoking cessation.

Prevalence of and socioeconomic gradient in low birth weight in Ethiopia: further analysis of the 2016 demographic and health survey data

Background

Evidence suggests appearance of socioeconomic gradient in the probability of low birth weight (LBW). Such evidence, however, is scanty in Ethiopia. The study aimed to examine the prevalence of and socioeconomic gradient in LBW in Ethiopia.

Method

Data for the study were drawn from the Ethiopia Demographic and Health Survey conducted in 2016. The 2016 EDHS is the fourth wave in the series of nationally representative household surveys carried out in the country to deliver up-to-date health and demographic indicators for the Ethiopian population. Women aged 15 to 49 years were the main focus of the survey, with data also gathered from men aged 15 to 59 years and under five children. The study pursued complex sampling strategy to draw samples representative at national as well as at urban and rural levels. The data are available to the public domain and were accessed from the MEASURE DHS following registration. Multivariable logistic regression model and marginal standardization were used to estimate socioeconomic gradient in the probability of LBW. We performed sensitivity analysis to evaluate variation of LBW according to different categories of socioeconomic position. Maternal education and household wealth were used as measures of the socioeconomic position in the study.

Results

13.2% (95% confidence interval = 10.73, 15.65) of births were complicated by LBW. The findings showed that socioeconomic gradient was evident between maternal education and LBW; as education increases from no education to secondary education, the probability of occurrence of LBW consistently declined. However, no gradient in LBW was detected for household wealth.

Conclusions

We have identified education gradient in LBW, with the highest burden of LBW occurring among the non-educated women. To redress the observed education disparity in LBW, targeted interventions need to be implemented with greater emphasis placed on illiterate women.

Association between maternal lifestyle factors and low birth weight in preterm and term births: a case-control study

Background

It has been reported that lifestyle factors may affect birth weight; however, few studies have explored the association between lifestyle factors and low birth weight in preterm and term births in China. The objective of this study was to explore the effect of lifestyle on low birth weight in preterm and term births.

Methods

This case-control study was conducted in fourteen hospitals in Jiangmen, Guangdong Province. Data were collected from August 2015 to May 2016 using a standard questionnaire. Data were analysed using logistic regression.

Results

Women who delivered preterm and were physically active (1–3 times per week and ≥ 4 times per week) had reduced odds of having low birth weight babies (aOR = 0.584, 95%CI = 0.394–0.867 and, aOR = 0.516, 95%CI = 0.355–0.752, respectively). Pregnant women who had insufficient gestational weight gain had increased odds of having low birth weight babies (aOR = 2.272, 95%CI = 1.626–3.176). Women exposed to passive smoking had an increased risk of delivering low birth weight infants (aOR = 1.404, 95%CI = 1.057–1.864). Insufficient gestational weight gain and excessive gestational weight gain were both significantly associated with low birth weight (aOR = 1.484, 95%CI = 1.103–1.998 and aOR = 0.369, 95%CI = 0.236–0.577, respectively) for term deliveries. In addition, parity, history of low birth weight, antenatal care and gestational hypertension were significantly associated with the likelihood of low birth weight.

Conclusion

Pregnant women without exercise contraindications should remain physically active. Pregnant women should be aware of the negative effects of smoke and be aware of strategies to protect themselves from passive smoke exposure. Hospitals should inform pregnant women of the importance appropriate gestational weight gain. These recommendations should be put into practice to decrease the prevalence of low birth weight infants.

Association between parity and macrosomia in Shaanxi Province of Northwest China

OBJECTIVE

To explore the relationship between parity and macrosomia and provide the necessary reference for the maternal and children health service.

METHOD

A cross-sectional epidemiological survey with the purpose to assess the birth outcomes was conducted in Shaanxi province, China.

RESULTS

The incidence of macrosomia in multiparas was higher than that in primiparas. Univariate analysis showed that maternal age < 25 years, peasant/housework, living in rural areas and female infants were the protective factors of macrosomia. The possibility of having a macrosomic infant also increased with gestational age, maternal education level, household wealth index, living in Central Shaanxi and gestational diabetes. The generalized linear mixed models represented the association between parity and macrosomia. After adjusting for statistically significant factors in univariate analysis from model 1 to model 3, the risk of being born macrosomia was 1.26 times higher for a multipara compared to that for a primipara.

CONCLUSIONS

Present study indicated parity of two children was associated with increased risk for macrosomic births compared with parity of one child. Compared to primiparas, multiparas should far strengthen the pre-pregnancy education and the guidance during pregnancy to control pre-pregnancy body mass index and pregnancy weight, and keep the appropriate exercise and balanced diet.

When and How Should Chinese Pregnant Women Exercise? A Longitudinal Study in China

This study aimed to examine when and how physical activity (PA) influences gestational weight gain (GWG) and infant birthweight (BW) by considering the PA’s total volume, timing, intensity, and type, controlling for the influence of energy intake. A total of 1272 participants in different stages of pregnancy were recruited from hospital. The associations between PA and GWG or BW in the latter half of pregnancy were significant. Women with the highest PA volume in the third trimester had significantly lower risks of inadequate and excessive GWG by 69% (OR = 0.31, 95%CI: 0.10–0.91) and 67% (OR = 0.33, 95% CI: 0.12–0.91), respectively, compared to women in the lowest quartile. Women who achieved the recommended moderate intensity of PA during their second and third trimesters, independent of total volume of PA, had infants with significantly lower BWs compared to those who did not (β = −0.15, SE = 66.33, p = 0.04; β = −0.20, SE = 64.54, p = 0.01, respectively). Therefore, the effects of total volume and intensity of PA on GWG and BW were different. Interventions to prevent inappropriate GWG and macrosomia may need to set different priorities and timing regarding total volume or intensity of PA.

Family socioeconomic position and abnormal birth weight: evidence from a Chinese birth cohort

BACKGROUND

Birth weight is a strong determinant of infant short- and long-term health outcomes. Family socioeconomic position (SEP) is usually positively associated with birth weight. Whether this association extends to abnormal birth weight or there exists potential mediator is unclear.

METHODS

We analyzed data from 14,984 mother-infant dyads from the Born in Guangzhou Cohort Study. We used multivariable logistic regression to assess the associations of a composite family SEP score quartile with macrosomia and low birth weight (LBW), and examined the potential mediation effect of maternal pre-pregnancy body mass index (BMI) using causal mediation analysis.

RESULTS

The prevalence of macrosomia and LBW was 2.62% (n = 392) and 4.26% (n = 638). Higher family SEP was associated with a higher risk of macrosomia (OR 1.30, 95% CI 0.93-1.82; OR 1.53, 95% CI 1.11-2.11; and OR 1.59, 95% CI 1.15-2.20 for the 2nd, 3rd, and 4th SEP quartile respectively) and a lower risk of LBW (OR 0.69, 95% CI 0.55-0.86; OR 0.76, 95% CI 0.61-0.94; and OR 0.61, 95% CI 0.48-0.77 for the 2nd, 3rd, and 4th SEP quartile respectively), compared to the 1st SEP quartile. We found that pre-pregnancy BMI did not mediate the associations of SEP with macrosomia and LBW.

CONCLUSIONS

Socioeconomic disparities in fetal macrosomia and LBW exist in Southern China. Whether the results can be applied to other populations should be further investigated.

Physical activity and dietary intake among Chinese pregnant women: an observational study

BACKGROUND

Physical activity (PA) and dietary intake are important modifiable factors associated with health outcomes. However, Chinese pregnant women's PA and dietary intake are only vaguely understood. The aim of this study was to reveal the characteristics of PA and dietary intake of Chinese women in different trimesters as well as the associations between PA and dietary intake.

METHODS

This is a cross-sectional observational study. PA, dietary intake, and demographics of 1077 Chinese pregnant women were measured. The Chi-square test, Kruskal-Wallis test, multiple logistic regression, and multiple linear regression were used for data analysis.

RESULTS

About 57.1% of the participants met the international guideline for PA. Household activity and occupational activity contributed the most to the total PA, while sports/exercise contributed little. The mean energy intake of the participants was 2008 ± 748.0 kcal. Most participants had normal energy intake, but they obtained excessive energy from fat (mean = 41.7 ± 8.7%). PA was not found to be significantly associated with dietary intake. Further, the participants who were unemployed during pregnancy (OR = 0.72, 95% CI: 0.55-0.95; p < 0.05) or had no exercise habits before pregnancy (OR = 0.62, 95% CI: 0.47-0.80; p < 0.01) were less likely to meet the PA guideline. The participants in the third trimester (OR = 1.43, 95% CI: 1.03-1.99; p < 0.05) were more likely to meet the PA guideline compared to those in the first trimester. The older participants (> 30 years) showed higher dietary intake than the younger (< 25 years) participants (p < 0.01).

CONCLUSIONS

The total PA of Chinese women during pregnancy mostly consists of household and occupational activities, but little sports/exercise. Starting exercise before pregnancy may help women achieve adequate PA during pregnancy. Moreover, these women consumed an excessive amount of fat and their diet intake varies by age.

The association of maternal dietary folate intake and folic acid supplementation with small-for-gestational-age births: a cross-sectional study in Northwest China

The effect of maternal folate intake on small-for-gestational-age (SGA) births remains inconclusive. The present study aimed to investigate the associations of maternal folate intake from diet and supplements with the risk of SGA births using data from a cross-sectional study in Shaanxi Province of Northwest China. A total of 7307 women who were within 12 months (median 3; 10th–90th percentile 0–7) after delivery were included. Two-level models were adopted to examine the associations of folate (dietary folate, supplemental folic acid and total folate) intake with the risk of SGA births and birth weight Z score, controlling for a minimum set of confounders that were identified in a directed acyclic graph. Results showed that a higher supplemental folic acid intake during the first trimester was negatively associated with the risk of SGA births (≤60 d v. non-use: OR 0·80; 95 % CI 0·66, 0·96; &gt;60 d v. non-use: OR 0·78; 95 % CI 0·65, 0·94; Ptrend = 0·010; per 10-d increase: OR 0·97; 95 % CI 0·95, 0·99). A higher total folate intake during pregnancy was associated with a reduced risk of SGA births (highest tertile v. lowest tertile: OR 0·77; 95 % CI 0·64, 0·94; Ptrend = 0·010; per one-unit increase in the log-transformed value: OR 0·81; 95 % CI 0·69, 0·95). A similar pattern was observed for the birth weight Z score. Our study suggested that folic acid supplementation during the first trimester and a higher total folate intake during pregnancy were associated with a reduced risk of SGA births.

Association of low birth weight with thinness and severe obesity in children aged 3-12 years: a large-scale population-based cross-sectional study in Shanghai, China

OBJECTIVES

Low birth weight (BW) is a general symbol of inadequate intrauterine conditions that elicit abnormal fetal growth and development. The aim of current study is to investigate the relationship between low BW and thinness or severe obesity during maturation.

DESIGN

A large-scale cross-sectional population-based survey.

SETTING

134 kindergartens and 70 elementary schools.

PARTICIPANTS

70 284 Chinese children aged 3-12 years.

OUTCOME MEASURES

International Obesity Task Force body mass index (BMI) cut-offs were used to define grade 1, grade 2 and grade 3 thinness, overweight, obesity and severe obesity. Multinomial logistic regression was used to estimate the association between BW and BMI category.

RESULTS

A total of 70 284 children participated in the survey. The percentage of grade 1 thinness and severe obesity in children with low BW is significantly higher than that in children with normal BW (p<0.05). Low BW was associated with an increased risk of grade 1 thinness (OR 1.56, 95% CI 1.38 to 1.75), grade 2 thinness (OR 1.34, 95% CI 1.10 to 1.64), grade 3 thinness (OR 1.99, 95% CI 1.63 to 2.42) and severe obesity (OR 1.27, 95% CI 1.03 to 1.55) but was not associated with obesity (OR 0.85, 95% CI 0.67 to 1.06).

CONCLUSION

There is a positive association between low BW and thinness or severe obesity risk.

Factors associated with low birth weight in Afghanistan: a cross-sectional analysis of the demographic and health survey 2015

OBJECTIVES

This study aimed to investigate the factors associated with low birth weight (LBW) in Afghanistan.

DESIGN

Cross-sectional study.

SETTING

This study used data collected from the Afghanistan Demographic and Health Survey 2015.

PARTICIPANTS

Facility-based data from 2773 weighted live-born children enrolled by a two-stage sampling strategy were included in our analysis.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was LBW, defined as birth weight <2.5kg.

RESULTS

Out of 2773 newborns, 15.5% (n=431) had LBW. Most of these newborns were females (58.3%, n=251), had a mother with no formal schooling (70.5%, n=304), lived in urban areas (63.4%, n=274) or lived in the Central region of Afghanistan (59.7%, n=257). In multivariable analysis, residence in Central (adjusted OR (AOR): 3.4; 95% CI 1.7 to 6.7), Central Western (AOR: 3.0; 95% CI 1.5 to 5.8) and Southern Western (AOR: 4.0; 95% CI 1.7 to 9.1) regions had positive association with LBW. On the other hand, male children (AOR: 0.5; 95% CI 0.4 to 0.8), newborns with primary maternal education (AOR: 0.5; 95% CI 0.3 to 0.8), birth interval ≥48 months (AOR: 0.4; 95% CI 0.1 to 0.8), belonging to the richest wealth quintile (AOR: 0.2; 95% CI 0.1 to 0.6) and rural residence (AOR: 0.3; 95% CI 0.2 to 0.6) had decreased odds of LBW.

CONCLUSIONS

Multiple factors had association with LBW in Afghanistan. Maternal, Neonatal and Child Health programmes should focus on enhancing maternal education and promoting birth spacing to prevent LBW. To reduce the overall burden of LBW, women of the poorest wealth quintiles, and residents of Central, Central Western and South Western regions should also be prioritised. Further exploration is needed to understand why urban areas are associated with higher likelihood of LBW. In addition, research using nationally representative samples are required.

Low birth weight in Jordan: a hospital-based study

Background: Low birth weight (LBW) is one of the leading causes of neonatal and infant morbidity and mortality.Objective: To determine the prevalence and possible risk factors associated with LBW in four regional hospitals in Jordan.Methods: This retrospective study analyzed the medical records of all singleton live births for the period 2011-2015.Results: A total of 22,789 singleton live births were included for this study. Of these, 4133 (18%) had a LBW. Rates of LBW increased over the 5 years study period. Factors associated with LBW were preterm birth, pregnancy complications or comorbidities, older maternal age (≥35 years), first-born infants, and having a female baby.Conclusion: Midwives' assessment and health education messages to mothers included awareness of risk factors associated with LBW of neonates in Jordan. Effective public health interventions need to highlight the importance of a healthy diet and valuing female off-spring.

The Association between Household Socioeconomic Status, Breastfeeding, and Infants' Anthropometric Indices

Background:

The growth, learning, and contribution to active life in the communities are better in well-nourished children, and various factors influence infants' feeding. In this study, we assessed whether household socioeconomic status (SES) affects infants' length-for-age, weight-for-age (indicators of health and nutritional status) and breastfeeding (BF) (a necessity for optimal growth and health) status.

Methods:

In this cross-sectional study, 150 households with infants of 1–1.5 years old were interviewed on these variables: family size, dwelling ownership, duration of BF, exclusive BF (EBF) for 6 months, parents' age, parents' ethnicity, birth order, delivery type, and parents' education. Weight and length at 4 and 12 months were obtained from centers' records. To determine SES, we assessed total years of parents' education and household asset ownership by an index of nine owned assets.

Results:

The average of 4-month length in the low SES group was significantly lower than the two others (P < 0.05). In middle socioeconomic group, duration of BF was significantly higher (19.5 ± 7.3 months vs. 18.0 ± 8.0 months in low and 17.5 ± 7.9 months in high SES groups) (P < 0.05). Comparing illiterate mothers, university degree holders and university students were 73% less likely to not having EBF. Moreover, those with middle SES showed to be about 40% less likely to not having EBF.

Conclusions:

Nutritional status, duration of BF, and EBF might be determined by household SES and maternal education. Therefore, these findings can be used to decide how to focus on appropriate target groups in family education planning to improve children's development to its most possible.

Study on the influence of pregnancy-induced hypertension on neonatal birth weight

To explore the effect of pregnancy-induced hypertension (PIH) on neonatal birth weight and provide the necessary reference value for the maternal and children health service. A cross-sectional study was carried out in Shaanxi Province of China in 2013. And a total of 28 045 singleton live infants and their mothers were recruited using a stratified, multistage, probability-proportional-to-size sampling method. Among the 28 045 women of childbearing age surveyed, multiple linear regression and quantile regression analysis all showed that the birth weight of newborns whose mothers had suffered from PIH during pregnancy was significantly lower than those whose mothers had not suffered from PIH during pregnancy from very low to higher birth weight percentiles (q=0-0.85), an average decrease of 137.45 g (β=-137.45, t=-5.77 and p<0.001). When birth weight was at q=0.90-1.00 percentiles, there was no birth weight difference between two groups. The present cross-sectional study indicated that PIH had an effect of on neonatal birth weight. When pregnant women with PIH are identified then the healthcare professional initiates a closer supervision of their pregnancy in order to ameliorate the status of BP and provide a good intrauterine environment for the fetus. In addition, the gynecologists should admonish the pregnant women that their health is related to the health of their fetus, then gravidas may be more engaged to alert their physician and accept early or preventative interventions. And the healthcare professional should ask and be alert to the issues of hypertension during pregnancy.

Reliability and Validity of a Chinese-Translated Version of a Pregnancy Physical Activity Questionnaire

Objectives The objectives of the present study were to translate the English version of the Pregnancy Physical Activity Questionnaire into Chinese (PPAQ-C) and to determine its reliability and validity for use by pregnant Chinese women. Methods The study included 224 pregnant women during their first, second, or third trimesters of pregnancy who completed the PPAQ-C on their first visit and wore a uniaxial accelerometer (Lifecorder; Suzuken Co. Ltd) for 7 days. One week after the first visit, we collected the data from the uniaxial accelerometer records, and the women were asked to complete the PPAQ-C again. Results We used intraclass correlation coefficients to determine the reliability of the PPAQ-C. The intraclass correlation coefficients were 0.77 for total activity (light and above), 0.76 for sedentary activity, 0.75 for light activity, 0.59 for moderate activity, and 0.28 for vigorous activity. The intraclass correlation coefficients were 0.74 for "household and caregiving", 0.75 for "occupational" activities, and 0.34 for "sports/exercise". Validity between the PPAQ-C and accelerometer data was determined by Spearman correlation coefficients. Although there were no significant correlations for moderate activity (r = 0.19, P > 0.05) or vigorous activity (r = 0.15, P > 0.05), there were significant correlations for total activity [light and above; r = 0.35, P < 0.01)] and for light activity (r = 0.33, P < 0.01). Conclusions for Practice The PPAQ-C is reliable and moderately accurate for measuring physical activity in pregnant Chinese women.

Birth weight changes in a major city under rapid socioeconomic transition in China

Estimates of trends in birth weight may be useful in evaluating population health. We aimed to determine whether temporal changes in birth weight have occurred amongst 2.3 million neonates born in Guangzhou, China, during 2001-2015 and investigate the socioeconomic determinants of any changes. Trends in mean birth weight and annualized changes with the associated 95% confidence intervals (CIs) in the incidence of small for gestational age (SGA) and large for gestational age (LGA), defined as birth weight <10^th or >90^th centile respectively for gestational age and sex, were examined using linear and Poisson regression models. We found that mean birth weight declined by 1.07 grams/year from 2001 to 2015. After adjustment for gestational length, the decline in birth weight was attenuated (0.37 grams/year). The incidence of both SGA and LGA significantly decreased during the study period (annual decrease of 1.6% [95% CI, 1.5% to 1.7%] for SGA, 1.6% [95% CI, 1.5% to 1.8%] for LGA). We found a narrowing of disparities in SGA and LGA incidence across different maternal educational levels and residence location. Our results demonstrate that there has been an increase in the proportion of neonates born in the healthy birth weight range in Guangzhou.

Factors associated with spontaneous abortion: a cross-sectional study of Chinese populations

Background

Spontaneous abortion (SA) is one of the prevalent negative reproductive outcomes among women around the world, which is a great challenge faced by maternal health promotion. The present study is aimed to explore the association between SA and socioeconomic status (SES) and provides reference for policy makers to improve strategies on maternal health promotion.

Methods

A cross-sectional analysis was conducted with baseline data from a large-scale population-based cohort study of 0.5 million people from 10 geographically diverse areas of China recruited from 2004 to 2008. The study collected data from 84,531 women aged 35–45 years old in the baseline survey of China Kadoorie Biobank. Participants were interviewed using a standardized questionnaire, and information on demographic-socioeconomic as well as reproductive health status was collected. Odds ratios (OR) with 95% CI, estimated by a multistep logistic regression, were used to approximate the associations between SA occurrence and characteristics of SES. A stratification analysis was also applied to find out how SES influenced women’s reproductive health outcomes differently between rural and urban areas. The model was adjusted for age at study date, tea consumption, alcohol consumption, cigarette smoking, and number of induced abortion.

Results

The risk of SA in rural was 1.68 times greater than in urban (AOR = 1.68, 95%CI: 1.54–1.84). Women with high income had a decreased risk of SA when compared with that of women with low income (AOR = 0.90, 95%CI: 0.84–0.97). Compared with women in low educational attainment, women in higher educational attainment had a lower prevalence of SA (AOR = 0.90, 95%CI: 0.82–0.98). The risk of SA only reduced in factory worker (AOR = 0.59, 95%CI: 0.53–0.66) and professional worker (AOR = 0.75, 95%CI: 0.66–0.84) compared with agriculture and related workers. After stratifying by rural/urban, the association between income and SA in urban (AOR = 0.88, 95%CI: 0.78–0.99) was stronger than that in rural (AOR = 0.92, 95%CI: 0.84–1.00). Association between education and SA was found in urban (AOR = 0.66, 95%CI: 0.55–0.78) but not in rural (AOR = 1.05, 95%CI: 0.34–1.17), and there was no difference on how occupation impacted SA among women between the two subgroups.

Conclusions

Generally women with lower SES status had a higher risk of SA. Lower income and educational attainment were inversely associated with the risk of SA. Women with agricultural and related work had a significantly higher prevalence of SA. Interventions could be targeted more on women with low SES to increase both health profits as well as economic gains for health programs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12978-017-0297-2) contains supplementary material, which is available to authorized users.