IMPACT OF PRENATAL MATERNAL FACTORS AND BIRTH ORDER ON THE ANTHROPOMETRIC STATUS OF NEWBORNS IN IRAN

Dose-response relationships of maternal height and weight with risk of low birthweight neonates: a meta-analysis

INTRODUCTION

The development of novel methods to identify pregnant women at increased risk of low birthweight neonates before delivery is required to improve pre- and periconceptional strategies to reduce the prevalence of low birthweight neonates. A dose-response meta-analysis was performed to examine the adjusted relationships of maternal height and weight with risk of low birthweight neonates.

EVIDENCE ACQUISITION

PubMed (Medline), CINAHL, PsycINFO, Wiley Online Library, ProQuest, Web of Science, Google Scholar, and Sage Journals Online were searched. There were no restrictions regarding publication date. English-language cohort studies involving singleton births that provided adjusted relative risks or Odds Ratios for low birthweight neonates at two or more values of maternal height or weight compared to the reference and numbers of low birthweight neonates and numbers of normal birthweight neonates in these values and the reference are included.

EVIDENCE SYNTHESIS

From the five finally eligible studies, four good-quality studies evaluating the relationship of maternal height with risk of low birthweight neonates and three good-quality studies evaluating the relationship of maternal weight with risk of low birthweight neonates were extracted. Both of these relationships were non-linear rather than linear (P values for non-linearity <0.05). Based on the non-linear dose-response model, maternal height limited to below 160 cm and maternal weight with no restrictions regarding the range were significantly and negatively related to risk of low birthweight neonates.

CONCLUSIONS

Risk of low birthweight neonates may decrease with increasing maternal height from below 160 cm to 160 cm and by increasing maternal weight regardless of above or below 55 kg.

Maternal risk factors associated with term low birth weight in India: A review

Low birth weight is one of the leading factors for infant morbidity and mortality. To a large extent affect, various maternal risk factors are associated with pregnancy outcomes by increasing odds of delivering an infant with low birth weight. Despite this association, understanding the maternal risk factors affecting term low birth weight has been a challenging task. To date, limited studies have been conducted in India that exert independent magnitude of these effects on term low birth weight. The aim of this review is to examine the current knowledge of maternal risk factors that contribute to term low birth weight in the Indian population. In order to identify the potentially relevant articles, an extensive literature search was conducted using PubMed, Goggle Scholar and IndMed databases (1993 – Dec 2020). Our results indi­cate that maternal age, educational status, socio-economic status, ethnicity, parity, pre-pregnancy weight, maternal stature, maternal body mass index, obstetric history, maternal anaemia, gestational weight gain, short pregnancy outcome, hypertension during pregnancy, infection, antepartum haemorrhage, tobacco consumption, maternal occupation, maternal psychological stress, alcohol consumption, antenatal care and mid-upper arm circumference have all independent effects on term low birth weight in the Indian pop­ulation. Further, we argue that exploration for various other dimensions of maternal factors and underlying pathways can be useful for a better understanding of how it exerts independent association on term low birth weight in the Indian sub-continent.

Birth weight increases with birth order despite decreasing maternal pregnancy weight gain

AIM

We investigated whether birth order is an influencing factor for birth weight independent from maternal factors.

METHODS

Data were obtained from the longitudinal cohort study LIFE Child and included 1864 children, of which 526 were only children. The 1338 siblings were ranked into first-borns (n = 570), second-borns (n = 606) and third-or-later-borns (n = 162). Children born prematurely, suffering from chronic or syndromic diseases, were excluded. We performed intra-family comparisons to reduce bias and assessed the impact of perinatal parameters, such as birth order on birth weight, using mixed models.

RESULTS

Birth weight increased with birth order. In univariate analyses, birth order had a significant effect on birth weight-SDS with second-borns having 0.29 SDS (app. 130 g) and third-borns 0.40 SDS (app. 180 g) higher values than first-borns (P < .001). Maternal pregnancy weight gain was associated with higher birth weight-SDS (P < .01) in univariate analysis, though maternal pregnancy weight gain was lower for higher birth orders. Multivariate analyses revealed that being a second or third-or-later-born child had a stronger impact on birth weight than all maternal factors.

CONCLUSION

Birth order must be considered a potential risk factor for higher birth weight. Maternal pregnancy weight gain is not the driving factor for higher birth weight in siblings.

Frequency of Normal Birth Length and Its Determinants: A Cross-Sectional Study in Newborns

Objectives

There are several factors that may affect the length and height of the infant. Maternal factors include a wide array of factors (anthropometric, hematological, or genetic), which can affect newborn health determinants. The objective of this study was to evaluate the frequency of normal birth length and its determinants in newborns.

Methods

This retrospective cross-sectional study was carried out at the Obstetrics and Gynaecological Department of Hamdard Hospital, Karachi, Pakistan, from March 1, 2019, to August 31, 2019. The relevant data were gathered by trained data collectors with the help of a structured questionnaire designed specifically for the study after taking written informed consent from all the participants. Data analysis was performed using Statistical Package for Social Sciences Version 20. Binary logistic regression was applied to develop a risk assessment model for the study outcome.

Results

Out of 195 pregnant mothers, 57 (29.2%) had low birth weight infants. Mean age of mothers was 29.29±5.22 years, 142 (72.8%) had BMI of 25.0 or more, 102 (52.3%) had hemoglobin between 10 to 11 mg/dL, 172 (88.2%) used to take vitamin C and iron during pregnancy, 136 (69.7%) consumed extra meals during pregnancy, and only 5 (2.6%) were tobacco smokers/chewers. Hundred (51.3%) newborns had normal birth length, i.e., >48 cm. The mother's mid-arm circumference > 22 cm (adjusted odds ratio [AOR]: 4.719; 95% CI: 2.337-9.527; p<0.001), consumption of extra meals during pregnancy (AOR: 3.947; 95% CI: 1.627-9.574; p=0.002), hemoglobin > 11 mg/dL (AOR: 4.314; 95% CI: 1.779-10.463; p=0.001), and adequate rest during pregnancy (AOR: 3.798; 95% CI: 1.464-9.848; p=0.006) were significantly associated with normal birth length of the infants, i.e., >48 cm.

Conclusions

Mother's mid-arm circumference > 22 cm, consumption of extra meals during pregnancy, hemoglobin > 11 mg/dL, and adequate rest during pregnancy were found to be significant predictors of normal birth length of the infants.

Gender inequality and sexual height dimorphism in Chile

Chile has experienced significant improvements in its economy; thus, a secular trend in height has been observed in its population. Gender equality has also improved hand in hand with active policies addressing the gender gap in several dimensions (work, education, health) and overall economic improvement. This study examined changes in sexual height dimorphism in four samples of Chilean male and female working-age subjects and attempted to establish associations with gender equality and welfare. Sexual height dimorphism was calculated and compared with gender equality and overall welfare indicators between 1955 and 1995. Sexual height dimorphism reduction was seen to be strongly associated with greater gender equality and some general welfare indicators, such as the infant mortality rate. Gross domestic product per capita was not associated with sexual height dimorphism, but it showed significant associations with gender equality indicators. Overall, the gender gap has been reduced in Chile, which can be observed through improvements in gender equality indicators and a reduction in height dimorphism, mainly in areas associated with women's health. However, gender equality is still far behind in terms of female labour participation and women in political power, which require attention and further improvements.

The contribution of prenatal maternal factors to maternal gestational weight gain

Data from 807 mothers in Iran delivering a singleton live infant and their offspring-during the last 2 years up to August 2014-were collected from eight public health care centers and analyzed. Of the women, 46.2% gained weight within the recommended range, 29.4% had inadequate gestational weight gain (GWG), and 24.4% had excessive GWG. Excessive GWG was more common among overweight and obese women, whereas inadequate GWG was prevalent among 50% of under and normal weight women. A significant correlation was found between maternal anthropometric characteristics, folic acid intake during pregnancy, and birth order with GWG. Maternal GWG was positively correlated with neonates' weight and height.