Reducing low birth weight: prioritizing action to address modifiable risk factors

Clinical value of prenatal screening markers in early pregnancy combined with perinatal characteristics to predict fetal growth restriction

Background

Due to the incomplete standardization of the etiology and diagnostic criteria for fetal growth restriction (FGR), there has been uncertainty in the early prediction of FGR. The comprehensive estimation of FGR was mainly based on various factors, such as maternal characteristics and medical history, nuchal translucency (NT), and serum biochemical markers [pregnancy-associated plasma protein-A (PAPP-A) and free beta human chorionic gonadotropin (free β-hCG)]. Herein, we performed a retrospective cohort study to investigate the correlation and diagnostic value of maternal markers such as PAPP-A, free β-hCG, and NT in the first trimester with maternal characteristics, so as to provide theoretical basis for perinatal care and the application of low-dose aspirin.

Methods

A retrospective cohort study was conducted to analyze the data of an FGR group and a non-FGR group. Chi-square test and Mann-Whitney U test were used for univariate analysis of qualitative or quantitative data, respectively. Modified Poisson regression calculated the relative risk (RR) and 95% confidence interval (CI) of perinatal variables; P<0.05 was considered statistically significant.

Results

The multiple of median (MoM) of PAPP-A level and NT in the FGR group were lower than those of the non-FGR group [0.63 (0.12-2.08) vs. 1.01 (0.28-2.41) MoM, 1.30 (0.80-2.07) vs. 1.40 (0.80-2.20) cm, P<0.05]. The weight, score, and length of newborns in the FGR group were lower than those in the non-FGR group (all P<0.001). Modified Poisson regression analysis showed that gestational hypertension (GH) [RR =1.836 (95% CI: 1.188-2.836)], oligohydramnios [1.420 (95% CI: 1.022-1.973)], premature rupture of membranes (PROM) [0.641 (95% CI: 0.425-0.969)], female infant [1.539 (95% CI: 1.098-2.157)], low infant length [5.700 (95% CI: 3.416-9.509)], low birth weight [1.609 (95% CI: 1.012-2.559), and increased PAPP-A MoM [0.533 (95% CI: 0.369-0.769)] were associated with FGR. The cut-off value of PAPP-A + free β-hCG + NT for predicting FGR was 0.190, with a sensitivity of 0.547 and a specificity of 0.778.

Conclusions

Early screening markers combined with perinatal characteristics have better diagnostic value in predicting FGR and provide a scientific basis for the clinical use of low-dose aspirin to prevent FGR.

Determinants of child stunting in the dryland area of East Nusa Tenggara Province, Indonesia: insights from a national-level survey

Stunting remains a critical public health issue in Indonesia, particularly in the province of East Nusa Tenggara. This region, characterized by its archipelagic dryland geography, has reported the highest prevalence of stunting among children under five from 2007 to 2021. The study aimed to examine the relationship between various characteristics of children under five and household factors with the occurrence of stunting. This observational study, with a cross-sectional design, used secondary data from the 2021 Indonesian Nutrition Status Survey, covering 7,835 children under five. We analyzed the data to identify patterns and relationships, using univariate analysis to display percentage distributions and bivariate analysis through multiple binary logistic regression tests. The results of the multiple logistic regression test showed that indicators of family characteristics such as age, gender, low birth weight, body length, possession of birth certificates, and receiving complementary feeding were all related to stunting. Additionally, household factors such as toilet type, National Health Insurance coverage, ownership of a Prosperous Family Card, and residential area were significant determinants. Factors contributing to stunting in dryland areas include a range of elements from both family characteristics-such as age, gender, birth certification, low birth weight, and initial body length, to the introduction of supplementary feeding-and household indicators, including the use of specific types of latrines (Plengsengan and Cemplung types without covers), health insurance coverage, possession of Prosperous Family Cards, and the family's residential area.

Birth weight and large for gestational age trends in offspring of pregnant women with gestational diabetes mellitus in southern China, 2012-2021

Background

With increasing prevalence of gestational diabetes mellitus (GDM) and changing management of GDM in pregnancy, it is imperative to understand the evolution of its current outcomes. The present study aimed to explore whether birth weight and large for gestational age (LGA) trends in women with GDM have changed over time in southern China.

Methods

In this hospital-based retrospective study, all singleton live births for the period 2012 to 2021 were collected from the Guangdong Women and Children Hospital, China. GDM was diagnosed following the criteria of the International Association of Diabetes and Pregnancy Study Group. The cutoff points for defining LGA (>90th centile) at birth based on INTERGROWTH-21st gender-specific standards. Linear regression was used to evaluate trends for birth weight over the years. Logistic regression analysis was used to determine the odds ratios (ORs) of LGA between women with GDM and those without GDM.

Results

Data from 115097 women with singleton live births were included. The total prevalence of GDM was 16.8%. GDM prevalence varied across different years, with the lowest prevalence in 2014 (15.0%) and the highest prevalence in 2021 (19.2%). The mean birth weight displayed decrease in women with GDM from 3.224kg in 2012 to 3.134kg in 2021, and the z score for mean birth weight decreased from 0.230 to -0.037 (P for trend < 0.001). Among women with GDM, the prevalence of macrosomia and LGA reduced significantly during the study period (from 5.1% to 3.0% in macrosomia and from 11.8% to 7.7% in LGA, respectively). Compared to women without GDM, women with GDM had 1.30 (95% CI: 1.23 - 1.38) times odds for LGA, and the ORs remained stable over the study period.

Conclusions

Among offspring of women with GDM, there are decreased trends of birth weight in parallel with reductions in LGA prevalence between 2012 and 2021. However, the risk of LGA in women with GDM remains stable at relatively high level over the 10-year period, and efforts are still needed to address regarding causes and effective intervention strategies.

The Prevalence of Low Birth Weight Among Newborn Babies and Its Associated Maternal Risk Factors: A Hospital-Based Cross-Sectional Study

Background Low birth weight (LBW) is at the forefront of 100 core health issues that are used as indicators to assess the global nutrition monitoring framework as reported by the World Health Organization (WHO). Several factors could contribute to LBW, which essentially include intrauterine growth retardation and premature delivery/birth. Moreover, LBW predisposes neonates to several developmental disturbances including both physical and mental disorders. Given that LBW is more common in poor and developing countries, there is not much reliable data that could be used to formulate strategies for controlling this problem. This study, therefore, attempts to assess the prevalence of LBW among newborn babies and its associated maternal risk factors. Methods This hospital-based cross-sectional study was carried out between June 2016 and May 2017 (one year) and included 327 LBW babies. A predefined and prevalidated questionnaire was used to obtain data for the study. The data collected included age, religion, parity, birth spacing, pre-pregnancy weight, weight gain during pregnancy, height, mother's education, occupation, family income, socioeconomic status, obstetric history, previous history of stillbirths and abortions, and history of any LBW baby. Results The prevalence of LBW was noted to be 36.33%. The occurrence of LBW babies was predominant among mothers who were aged <19 years (62.26%) and >35 years (57.14%). Grand multipara women showed the highest rates (53.70%) of LBW babies. Additionally, LBW was predominantly noticed among newborns (46.66%) with a birth spacing of <18 months, those born to mothers with pre-pregnancy weight of <40 Kg (94.04%), mothers with a height of <145 cm (83.46%), mothers who gained <7 kg during the pregnancy (82.20%), illiterate mothers (43.75%), and mothers who were agricultural workers (63.76%). Other maternal factors that could predispose to LBW included lower monthly income (66.25%), low socioeconomic status (52.90%), less number of antenatal visits (59.65%), low blood hemoglobin (100%), history of strenuous physical activities (48.66%), smoking and/or tobacco chewing habit (91.42%), alcoholism (66.66%), lack of iron and folic acid supplementation during pregnancy (64.58%), history of stillbirths (51.51%), and mothers suffering from chronic hypertension, preeclampsia, and eclampsia (47.61%), and tuberculosis (75%). Religion-wise, Muslim mothers revealed the highest prevalence (48.57%) of LBW, followed by Hindus (37.71%) and Christians (20%). The mother's age, pre-pregnancy weight, weight gain during pregnancy, height of the mother, hemoglobin concentration, weight of the baby, and length of the newborn (p≤0.05) could influence the health of the newborn. However, maternal infections, previous bad obstetrics history, presence of systemic illnesses, and protein and calorie supplementation (p≥0.05) had no significant impact on birth weight. Conclusions The results showed that multiple factors are responsible for LBW. Maternal factors such as weight, height, age, parity, weight gained during pregnancy, and anemia during pregnancy could predispose to delivering LBW babies. Additionally, other risk factors for LBW identified in this study were the literacy level of mothers, occupation, family income, socioeconomic status, antenatal care, strenuous physical activity during pregnancy, smoking/tobacco chewing, alcohol/toddy consumption, and iron and folic acid supplementation during pregnancy.

An exploration into the influence of birthweight and breastfeeding status on the weight status of 3-year-olds in an Irish cohort

BACKGROUND

Childhood obesity is a growing concern in Ireland. Childhood obesity can increase the risk of developing many non-communicable diseases and have lasting psychological and social consequences.

AIM

The aim of this study is to explore if weight at birth and breastfeeding status influence the weight status of 3-year-olds in an Irish cohort.

METHOD

This retrospective cohort study utilised data (National Child Health Screening Programme) on 3-year-olds born between 1 January 2011 and 3 March 2014 in the North West of Ireland.

RESULTS

Overall, 4144 children were included in the study. The main findings of this study were that 5.4% (n = 222) and 7.1% (n = 296) of the cohort were overweight or obese respectively with a higher percent of males than females in each category. Just under 55% (n = 2266) of the cohort were never breastfed, with only 7.4% breastfed for greater than 6 months. Those born with a high birthweight were more likely to be overweight or obese at 3 years (p ≤ 0.001).

CONCLUSION

These findings provide regionally specific data and highlight the need for focussed public health efforts to reduce the prevalence of overweight and obesity in children aged 3 years in this area. Interventions from pregnancy through childhood are warranted, with an initial emphasis on breast feeding initiation and maintenance.

Study on low birth weight and its associated factors among newborns delivered in a tertiary care hospital of Banda district, Uttar Pradesh

Background: Low birth weight is associated with higher morbidity and mortality including impaired growth and development, malnutrition etc. Worldwide, one- fifth of newborns delivered are low birth weight. Aims & objectives: To estimate frequency of low birth weight & its associated factors among newborns delivered in a tertiary care hospital. Materials & Methods: A cross sectional analysis of 290 newborns delivered in tertiary care hospital, Banda, Uttar Pradesh during period of 15th February 2021 to 31st December 2021 was done for estimating low birth weight frequency & its associated factors including child characteristics, mother characteristics & father characteristics using data from medical record section of hospital. Frequency, percentages, mean, standard deviation, chi square test & independent t- test was used. P value <0.05 was considered significant. Results: 91 out of 290 newborns delivered were low birth weight (27.9%, 95% CI- 23.1%- 33.4%). The following factors were shown to have a significant association with low birth weight: education of mother (p=0.04), education of father (p=0.03), occupation of father (p=0.02), and duration of pregnancy (p<0.001). Conclusion: This study demonstrated that education of mother, education of father, occupation of father, and duration of pregnancy had significant association with low birth weight frequency that suggests that improving literacy status can help in decreasing burden of low birth weight apart from other factors.

Pregnancy as a Fundamental Determinant of Child Health: a Review

PURPOSE OF REVIEW

Maternal conditions and exposures during pregnancy including over- and undernutrition are associated with poor childbirth outcomes, growth, development and chronic childhood diseases. We examined contemporary pregnancy-related determinants of child health.

RECENT FINDINGS

While maternal undernutrition remains a major contributor to low birth weight, maternal obesity affects foetal growth, birth weight, survival and is associated with childhood obesity, asthma and autistic spectrum disorders. Emerging evidence suggests that epigenetic changes, the prenatal microbiome and maternal immune activation (MIA), a neuroinflammatory process induced by diet and other exposures cause foetal programming resulting in these chronic childhood diseases. Maternal diet is potentially a modifiable risk factor for controlling low birth weight, obesity and chronic disease in childhood. Further studies are warranted to refine guidance on dietary restriction and physical activity during pregnancy and determine how MIA and prenatal microbiota can be applied to control childhood diseases arising from programming.

Risk factors associated with low birth weight

OBJECTIVES

Low birth weight (LBW) is one of the major factors affecting child morbidity and mortality worldwide. Every day, approximately 800 women die from causes related to pregnancy and childbirth worldwide. Maternal ill health increases the risk of LBW. This study seeks to investigate determinants and incidence of LBW.

METHODS

This study was conducted based on the medical records of mothers and their 1,946 infants born in 2016-2019 at the Department of Gynaecology and Obstetrics of Louis Pasteur University Hospital in Košice. Data on mothers and newborn infants were obtained from the Reports on mothers at childbirth. The inclusion criteria were singleton births and birth weight > 500 g. The exclusion criteria were twins or multiple births, congenital anomalies and stillbirths, birth weight ≥ 4,000 g or ≤ 500 g, and Roma ethnicity. Roma children are more likely to be born prematurely, with low birth weight. Roma mothers have different lifestyle. Univariate analysis was employed to evaluate the association between the independent variables and LBW. Variables that were found to be statistically significant were then further analysed using multivariable logistic analysis for each dependent variable. The implementation of the research was approved by the Ethics Committee.

RESULTS

Of 1,946 newborns, 271 (13.90%) have low birth weight. The mean of birth weight at delivery was 3,068.62 (SD 671.16) grams. Factors that were associated with LBW were primary maternal education (OR = 2.98, 95% CI: 1.08-8.21, p = 0.034), marital status single (OR = 2.88, 95% CI: 1.68-4.94, p < 0.001), number of prenatal care visits less than 8 (OR = 1.62, 95% CI: 1.01-2.61, p = 0.047), and preterm birth (OR = 74.94, 95% CI: 45.44-123.61, p < 0.001).

CONCLUSION

The reducing of LBW requires strategies to improve maternal lifestyle, maternal care before, during and after birth and to strengthen social support.

Fast-track referral for health interventions during pregnancy: study protocol of a randomised pragmatic experimental study to reduce low birth weight in Portugal (STOP LBW)

INTRODUCTION

Low birth weight (LBW) is associated with a wide range of short-term and long-term consequences and is related to maternal psychosocial and behavioural determinants. The objective of this study is to estimate the effect of implementing fast-track referral for early intervention on psychosocial and behavioural risk factors-smoking, alcohol consumption, depression and physical violence-in reducing the incidence of LBW.

METHODS AND ANALYSIS

Parallel superiority pragmatic clinical trial randomised by clusters. Primary healthcare units (PHCU) located in Portugal will be randomised (1:1) to intervention or control groups. Pregnant women over 18 years of age attending these PHCU will be eligible to the study. Risk factors will be assessed through face-to-face interviews. In the intervention group, women who report at least one risk factor will have immediate access to referral services. The comparison group will be the local standard of care for these risk factors. We will use intention-to-treat analyses to compare intervention and control groups. We estimated a sample size of 2832 pregnant women to detect a 30% reduction in the incidence rate of LBW between the control and intervention groups. Secondary outcomes are the reduction of preterm births, reduction of the four risk factors and acceptance of the intervention.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of the Public Health Institute of the University of Porto (no CE20140). The findings will be disseminated to the public, the funders, health professionals, health managers and other researchers.

TRIAL REGISTRATION NUMBER

NCT04866277.

Determinants of low birth weight deliveries at five referral hospitals in Western Area Urban district, Sierra Leone

Background

Low birth weight (LBW) contributes significantly to infant and child mortality. Each year, about 20 1million deliveries are LBW with 96.5% occurring in developing countries. Whiles the incidence of LBW is reducing in other districts of Sierra Leone, it has been reported to be increasing in the Western Area Urban district. Determining the risk factors in a specific geographic area is important for identifying mothers at risk and thereby for planning and taking appropriate action. The current study sought to identify factors associated with LBW deliveries in the Western Area Urban district of Sierra Leone.

Methods

A hospital-based unmatched 1:2 case-control study was conducted among mothers who delivered live singleton babies from November, 2019 to February, 2020 in five referral health facilities. Mothers were conveniently sampled and sequentially enrolled into the study after delivery. Their antenatal care cards were reviewed and a pre-tested questionnaire administered to the mothers. Data analysis was done using Stata 15.0 and association between maternal socio-demographic, socio-economic, obstetric and lifestyle factors and LBW assessed using bivariable and multivariable logistic regression analyses.

Results

A total of 438 mothers (146 cases and 292 controls), mean age: 24.2 (±5.8) and 26.1 (±5.5) years for cases and controls respectively participated in the study. Multivariable analysis revealed that being unemployed (AoR = 2.52, 95% CI 1.16–5.49, p = 0.020), having anaemia during pregnancy (AoR = 3.88, 95% CI 1.90–7.90, p <  0.001), having less than 2 years inter-pregnancy interval (AoR = 2.53, 95% CI 1.11–5.73, p = 0.026), and smoking cigarettes during pregnancy (AoR = 4.36, 95% CI 1.94–9.80, p <  0.001) were significantly associated with having LBW babies.

Conclusion

Factors associated with LBW identified were unemployment, anaemia during pregnancy, < 2 years inter-pregnancy interval and cigarette smoking during pregnancy. Health care providers should screen and sensitize mothers on the risk factors of LBW during antenatal sessions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-021-01160-y.

What are the causes for low birthweight in Japan? A single hospital-based study

Low-birthweight (LBW; <2,500 g) babies are at a higher risk of poor educational achievement, disability, and metabolic diseases than normal-birthweight babies in the future. However, reliable data on factors that contribute to LBW have not been considered previously. Therefore, we aimed to examine the distribution of the causes for LBW. A retrospective review of cases involving 4,224 babies whose mothers underwent perinatal care at Keio University Hospital between 2013 and 2019 was conducted. The LBW incidence was 24% (1,028 babies). Of the 1,028 LBW babies, 231 babies were from multiple pregnancies. Of the 797 singleton LBW babies, 518 (65%) were born preterm. Obstetric complications in women with preterm LBW babies included premature rupture of membrane or labor onset (31%), hypertensive disorders of pregnancy (HDP, 64%), fetal growth restriction (24%), non-reassuring fetal status (14%), and placental previa/vasa previa (8%). Of the 279 term LBW babies, 109 (39%) were small for gestational age. Multiple logistic regression analyses revealed the following factors as LBW risk factors in term neonates: low pre-pregnancy maternal weight, inadequate gestational weight gain, birth at 37 gestational weeks, HDP, anemia during pregnancy, female sex, and neonatal congenital anomalies. HDP was an LBW risk factor not only in preterm births but also in term births. Our results suggest that both modifiable and non-modifiable factors are causes for LBW. It may be appropriate to consider a heterogeneous rather than a simple classification of LBW and to evaluate future health risks based on contributing factors.

Maternal Obesity and Risk of Low Birth Weight, Fetal Growth Restriction, and Macrosomia: Multiple Analyses

The associations between maternal pre-pregnancy obesity and low birth weight (LBW, <2500 g) remain inconclusive. Therefore, birth weight in a Polish prospective cohort of 912 mothers was investigated depending on the pre-pregnancy body mass index (BMI). The whole cohort and the subgroup of gestational weight gain (GWG) in the range of the Institute of Medicine (IOM) recommendations, as well as 'healthy' women (who did not develop diabetes or hypertension in this pregnancy) were investigated. Adjusted odds ratios (AOR) of the newborn outcomes (with 95% confidence intervals, CI) for obesity (BMI ≥ 30 kg/m²) vs. normal BMI (18.5-24.9 kg/m²) were calculated using multiple logistic regression. Risk profiles (in the Lowess method) were presented for BMI values (kg/m²) and threshold BMI values were calculated. (1) In the cohort, LBW affected 6.6% of pregnancies, fetal growth restriction (FGR) 2.3%, and macrosomia 10.6%. (2) The adjusted risk of macrosomia was more than three-fold higher for obesity compared to normal BMI in the whole cohort (AOR = 3.21 (1.69-6.1), p < 0.001) and the result was maintained in the subgroups. A 17-fold higher adjusted LBW risk for obesity was found (AOR = 17.42 (1.5-202.6), p = 0.022), but only in the normal GWG subgroup. The FGR risk profile was U-shaped: in the entire cohort, the risk was more than three times higher for obesity (AOR = 3.12 (1.02-9.54), p = 0.045) and underweight (AOR = 3.84 (1.13-13.0), p = 0.031). (3) The risk profiles showed that the highest BMI values were found to be associated with a higher risk of these three newborn outcomes and the threshold BMI was 23.7 kg/m² for macrosomia, 26.2 kg/m² for LBW, and 31.8 kg/m² for FGR. These results confirm the multidirectional effects of obesity on fetal growth (low birth weight, fetal growth restriction, and macrosomia). The results for LBW were heavily masked by the effects of abnormal gestational weight gain.

Association between Adherence with Recommended Antenatal Care in Low-Risk, Uncomplicated Pregnancy, and Maternal and Neonatal Adverse Outcomes: Evidence from Italy

Antenatal care (ANC) aims of monitoring wellbeing of mother and foetus during pregnancy. We validate a set of indicators aimed of measuring the quality of ANC of women on low-risk, uncomplicated pregnancy through their relationship with maternal and neonatal outcomes. We conducted a population-based cohort study including 122,563 deliveries that occurred between 2015 and 2017 in the Lombardy Region, Italy. Promptness and appropriateness of number and timing of gynaecological visits, ultrasounds and laboratory tests were evaluated. We assessed several maternal and neonatal outcomes. Log-binomial regression models were used to estimate prevalence ratio (PR), and corresponding 95% confidence interval (95% CI), for the exposure→outcome association. Compared with women who adhered with recommendations, those who were no adherent had a significant higher prevalence of maternal intensive care units admission (PR: 3.1, 95%CI: 1.2-7.9; and 2.7, 1.1-7.0 respectively for promptness of gynaecological visits, and appropriateness of ultrasound examinations), low Apgar score (1.6, 1.1-1.2; 1.9, 1.3-2.7; and 2.1, 1.5-2.8 respectively for appropriateness and promptness of gynaecological visits, and appropriateness of ultrasound examinations), and low birth weight (1.8, 1.5-2.3 for appropriateness of laboratory test examinations). Benefits for mothers and newborn are expected from improving adherence to guidelines-driven recommendations regarding antenatal care even for low-risk, uncomplicated pregnancies.

Regional trends in birth weight in low- and middle-income countries 2013-2018

BACKGROUND

Birth weight (BW) is a strong predictor of neonatal outcomes. The purpose of this study was to compare BWs between global regions (south Asia, sub-Saharan Africa, Central America) prospectively and to determine if trends exist in BW over time using the population-based maternal and newborn registry (MNHR) of the Global Network for Women'sand Children's Health Research (Global Network).

METHODS

The MNHR is a prospective observational population-based registryof six research sites participating in the Global Network (2013-2018), within five low- and middle-income countries (Kenya, Zambia, India, Pakistan, and Guatemala) in threeglobal regions (sub-Saharan Af rica, south Asia, Central America). The birth weights were obtained for all infants born during the study period. This was done either by abstracting from the infants' health facility records or from direct measurement by the registry staff for infants born at home. After controlling for demographic characteristics, mixed-effect regression models were utilized to examine regional differences in birth weights over time.

RESULTS

The overall BW meanswere higher for the African sites (Zambia and Kenya), 3186 g (SD 463 g) in 2013 and 3149 g (SD 449 g) in 2018, ascompared to Asian sites (Belagavi and Nagpur, India and Pakistan), 2717 g (SD450 g) in 2013 and 2713 g (SD 452 g) in 2018. The Central American site (Guatemala) had a mean BW intermediate between the African and south Asian sites, 2928 g (SD 452) in 2013, and 2874 g (SD 448) in 2018. The low birth weight (LBW) incidence was highest in the south Asian sites (India and Pakistan) and lowest in the African sites (Kenya and Zambia). The size of regional differences varied somewhat over time with slight decreases in the gap in birth weights between the African and Asian sites and slight increases in the gap between the African and Central American sites.

CONCLUSIONS

Overall, BWmeans by global region did not change significantly over the 5-year study period. From 2013 to 2018, infants enrolled at the African sites demonstrated the highest BW means overall across the entire study period, particularly as compared to Asian sites. The incidence of LBW was highest in the Asian sites (India and Pakistan) compared to the African and Central American sites. Trial registration The study is registered at clinicaltrials.gov. ClinicalTrial.gov Trial Registration: NCT01073475.

Smoking and Smoking Cessation in the Risk for Fetal Growth Restriction and Low Birth Weight and Additive Effect of Maternal Obesity

Many studies have shown that neonates of smoking mothers have a lower birth weight, but several issues remain poorly studied, e.g., the effects of giving up smoking or the combined effects of smoking and maternal obesity. Therefore, we evaluated a prospective cohort of 912 mothers in a single pregnancy, recruited in Poland, in 2015−2016. In the cohort, we recorded 72 (7.9%) newborns with birth weight <10th percentile, 21 (2.3%) fetal growth restriction (FGR) cases, and 60 (6.6%) low birth weight (LBW, <2500 g) newborns. In the cohort, 168 (18.4%) women smoked before pregnancy; the mean number of cigarettes/day was 10.8 (1–30), and the mean number of years of cigarette smoking was 8.5 (1–25). Among smokers, 57 (6.3%) women smoked in the first trimester. Adjusted odds ratio (AOR) of newborn outcomes (with 95% confidence intervals, CI) was calculated in multi-dimensional logistic regressions. Compared to participants who had never smoked, smoking before pregnancy was associated with a higher odds ratio of birth weight <10th percentile (AOR = 1.93, CI: 1.08–3.44, p = 0.027), but the result for LBW (AOR = 2.76, CI: 1.05–7.26, p = 0.039) and FGR (AOR = 1.13, CI: 0.38–3.36, p = 0.822) had the wider confidence interval or was insignificant. Effects of smoking cessation before pregnancy were statistically insignificant for the studied outcomes. Smoking in the first trimester was associated with a higher risk of birth weight <10th percentile (AOR = 4.68, CI: 2.28–9.62, p < 0.001), LBW (AOR = 6.42, CI: 1.84–22.36, p = 0.004), and FGR (AOR = 3.60, CI: 0.96–13.49, p = 0.057). Smoking cessation in the second/third trimester was associated with a higher odds ratio of birth weight <10th percentile (AOR = 4.54, CI: 1.58–13.02, p = 0.005), FGR (AOR = 3.36, CI: 0.6–18.74, p = 0.167), and LBW (AOR = 2.14, CI: 0.62–7.36), p = 0.229), to a similar degree to smoking in the first trimester. The odds ratios were higher in the subgroup of pre-pregnancy body mass index ≥25 kg/m² for the risk of birth weight <10th percentile (AOR = 6.39, CI: 2.01–20.34, p = 0.002) and FGR (AOR = 6.25, CI: 0.86–45.59, p = 0.071). The length of cigarette smoking time was also the risk factor for studied outcomes. Conclusions: Smoking in the first trimester increased the studied risks, and the coexistence of excessive maternal weight increased the effects. Smoking cessation during the second/third trimester did not have a protective effect.

Factors associated with low birth weight at term: a population-based linkage study of the 100 million Brazilian cohort

BACKGROUND

Factors associated with low birth weight at term (TLBW), a proxy for intrauterine growth restriction (IUGR), are not well-elucidated in socioeconomically vulnerable populations. This study aimed to identify the factors associated with TLBW in impoverished Brazilian women.

METHODS

Records in the 100 Million Brazilian Cohort database were linked to those in the National System of Information on Live Births (SINASC) to obtain obstetric, maternal, birth and socioeconomic data between 2001 and 2015. Multivariate logistic regression was performed to investigate associations between variables of exposure and TLBW.

RESULTS

Of 8,768,930 term live births analyzed, 3.7% presented TLBW. The highest odds of TLBW were associated with female newborns (OR: 1.49; 95% CI: 1.47-1.50), whose mothers were black (OR: 1.20; 95% CI: 1.18-1.22), had a low educational level (OR: 1.57; 95% CI: 1.53-1.62), were aged ≥35 years (OR: 1.44; 95% CI: 1.43-1.46), had a low number of prenatal care visits (OR: 2.48; 95% CI: 2.42-2.54) and were primiparous (OR: 1.62; 95% CI: 1.60-1.64). Lower odds of TLBW were found among infants whose mothers lived in the North, Northeast and Center-West regions of Brazil compared to those in the South.

CONCLUSION

Multiple aspects were associated with TLBW, highlighting the need to comprehensively examine the mechanisms underlying these factors, especially in more vulnerable Brazilian populations, in order to contribute to the elaboration of health policies and promote better conditions of life for poor and extremely poor mothers and children.

Spatial Interaction Model for Healthcare Accessibility: What Scale Has to Do with It

This manuscript develops a theoretical spatial interaction model using the entropy approach to relax the assumption of the deterministic utility function. The spatial healthcare accessibility improves as the demand for healthcare increases or the opportunity cost of traveling to and from healthcare providers decreases. The empirical application used different spatial econometric techniques and multilevel modeling to evaluate the spatial distribution of existing hospitals in Texas and their social and economic correlates. To control for spatial autocorrelation, spatial autoregressive regression models were estimated, and geographically weighted regression models examined potential spatial non-stationarity. The multilevel modeling controlled for spatial autocorrelation and also allowed local variation and spatial non-stationarity. The empirical analysis showed that healthcare accessibility was not stationary in Texas in 2015, with areas of poor accessibility in rural and peripheral areas in Texas, when using hospitals’ location and county data. The model of spatial interaction applied to healthcare accessibility can be used to evaluate policies aiming at the provision of health services, such as closures of hospitals and capacity increases.

Asthma and/or hay fever as predictors of fertility/impaired fecundity in U.S. women: National Survey of Family Growth

This study addresses whether asthma and/or hay fever predict fertility and impaired fecundity. The lifetime number of pregnancies (fertility) and spontaneous pregnancy losses (impaired fecundity) in 10,847 women representative of the U.S. population 15 to 44 years of age with histories of diagnosed asthma and/or hay fever are analyzed in the 1995 National Survey of Family Growth using multivariable Poisson regression with multiple covariates and adjustments for complex sampling. Smokers have significantly increased fertility compared to nonsmokers. Smokers with asthma only have significantly increased fertility compared to other smokers. Higher fertility is associated with impaired fecundity (ectopic pregnancy, miscarriage, stillbirth). Women with asthma (with and without hay fever) have significantly higher pregnancy losses than women without asthma. With increasing number of pregnancies, smokers have increased pregnancy losses compared to nonsmokers. Smokers, especially those with asthma only, have increased fertility and require special attention as to their family planning needs, reproductive health, and smoking cessation. Women with asthma, regardless of number of pregnancies, and smokers with higher numbers of pregnancies have high risk pregnancies that require optimal asthma/medical management prenatally and throughout pregnancy. Whether a proinflammatory asthma endotype underlies both the increased fertility and impaired fecundity associated with age and smoking is discussed.

Causal Association Between Birth Weight and Adult Diseases: Evidence From a Mendelian Randomization Analysis

Purpose: Birth weight has a profound long-term impact on individual’s predisposition to various diseases at adulthood—a hypothesis commonly referred to as the fetal origins of adult diseases. However, it is not fully clear to what extent the fetal origins of adult diseases hypothesis holds and it is also not completely known what types of adult diseases are causally affected by birth weight.

Materials and methods: Mendelian randomization using multiple genetic instruments associated with birth weight was performed to explore the causal relationship between birth weight and adult diseases. The causal relationship between birth weight and 21 adult diseases as well as 38 other complex traits was examined based on data collected from 37 large-scale genome-wide association studies with up to 340,000 individuals of European ancestry. Causal effects of birth weight were estimated using inverse-variance weighted methods. The identified causal relationships between birth weight and adult diseases were further validated through extensive sensitivity analyses, bias calculation, and simulations.

Results: Among the 21 adult diseases, three were identified to be inversely causally affected by birth weight after the Bonferroni correction. The measurement unit of birth weight was defined as its standard deviation (i.e., 488 g), and one unit lower birth weight was causally related to an increased risk of coronary artery disease (CAD), myocardial infarction (MI), type 2 diabetes (T2D), and BMI-adjusted T2D, with the estimated odds ratios of 1.34 [95% confidence interval (CI) 1.17–1.53], 1.30 (95% CI 1.13–1.51), 1.41 (95% CI 1.15–1.73), and 1.54 (95% CI 1.25–1.89), respectively. All these identified causal associations were robust across various sensitivity analyses that guard against various confounding due to pleiotropy or maternal effects as well as reverse causation. In addition, analysis on 38 additional complex traits did not identify candidate traits that may mediate the causal association between birth weight and CAD/MI/T2D.

Conclusions: The results suggest that lower birth weight is causally associated with an increased risk of CAD, MI, and T2D in later life, supporting the fetal origins of adult diseases hypothesis.

Gestational Age, Birth Weight, and Outcomes Six Years After the Norwood Procedure

BACKGROUND

Preterm delivery and low birth weight (LBW) are generally associated with worse outcomes in hypoplastic left heart syndrome (HLHS), but an individual preterm or small neonate may do well. We sought to explore the interactions between gestational age, birth weight, and birth weight for gestational age with intermediate outcomes in HLHS.

METHODS

We analyzed survival, growth, neurodevelopment, length of stay, and complications to age 6 years in subjects with HLHS from the Single Ventricle Reconstruction trial. Univariate and multivariable survival and regression analyses examined the effects and interactions of LBW (<2500 g), weight for gestational age, and gestational age category.

RESULTS

Early-term delivery (n = 234) was more common than term (n = 219) delivery. Small for gestational age (SGA) was present in 41% of subjects, but only 14% had LBW. Preterm, compared with term, delivery was associated with an increased risk of death or transplant at age 6 years (all: hazard ratio = 2.58, confidence interval = 1.43-4.67; Norwood survivors: hazard ratio = 1.96, confidence interval = 1.10-3.49) independent of LBW and weight for gestational age. Preterm delivery, early-term delivery, LBW, and SGA were each associated with lower weight at 6 years. Neurodevelopmental outcomes were worst in the LBW cohort.

CONCLUSIONS

Preterm delivery in HLHS was associated with worse survival, even beyond Norwood hospitalization. LBW, SGA, and early-term delivery were associated with worse growth but not survival. LBW was associated with worse neurodevelopment, despite similar length of stay and complications. These data suggest that preterm birth and LBW (although often concomitant) are not equivalent, impacting clinical outcomes through mechanisms independent of perioperative course complexity.

Additive drug-specific and sex-specific risks associated with co-use of marijuana and tobacco during pregnancy: Evidence from 3 recent developmental cohorts (2003-2015)

BACKGROUND

Methodologic challenges related to the concomitant use (co-use) of substances and changes in policy and potency of marijuana contribute to ongoing uncertainty about risks to fetal neurodevelopment associated with prenatal marijuana use. In this study, we examined two biomarkers of fetal neurodevelopmental risk-birth weight and length of gestation-associated with prenatal marijuana use, independent of tobacco (TOB), alcohol (ALC), other drug use (OTH), and socioeconomic risk (SES), in a pooled sample (N = 1191) derived from 3 recent developmental cohorts (2003-2015) with state-of-the-art substance use measures. We examined differential associations by infant sex, and multiplicative effects associated with co-use of MJ and TOB.

METHODS

Participants were mother-infant dyads with complete data on all study variables derived from Growing Up Healthy (n = 251), Behavior and Mood in Babies and Mothers (Cohorts 1 and 2; n = 315), and the Early Growth and Development Study (N = 625). We estimated direct effects on birth weight and length of gestation associated with MJ, TOB, and co-use (MJ x TOB), using linear regression analysis in the full sample, and in male (n = 654) and female (n = 537) infants, separately.

RESULTS

Mean birth weight and length of gestation were 3277 g (SD = 543) and 37.8 weeks (SD = 2.0), respectively. Rates of prenatal use were as follows: any use, n = 748 (62.8%); MJ use, n = 273 (22.9%); TOB use, n = 608 (51.0%); co-use of MJ and TOB, n = 230 (19.3%); ALC use, n = 464 (39.0%); and OTH use n = 115 (9.7%.) For all infants, unique effects on birth weight were observed for any MJ use [B(SE) = -84.367(38.271), 95% C.I. -159.453 to -9.281, p = .028], any TOB use [B(SE) = -0.99.416(34.418), 95% C.I. -166.942 to -31.889, p = .004], and each cigarette/day in mean TOB use [B(SE) = -12.233(3.427), 95% C.I. -18.995 to -5.510, p < .001]. Additional effects of co-use on birth weight, beyond these drug-specific effects, were not supported. In analyses stratified by sex, while TOB use was associated with lower birth weight in both sexes, MJ use during pregnancy was associated with lower birth weight of male infants [B(SE) = -153.1 (54.20); 95% C.I. -259.5 to -46.7, p = .005], but not female infants [B(SE) = 8.3(53.1), 95% C.I. -96.024 to 112.551, p = .876]. TOB, MJ, and their co-use were not associated with length of gestation.

CONCLUSIONS

In this sample, intrauterine co-exposure to MJ and TOB was associated with an estimated 18% reduction in birth weight not attributable to earlier delivery, exposure to ALC or OTH drugs, nor to maternal SES. We found evidence for greater susceptibility of male fetuses to any prenatal MJ exposure. Examination of dose-dependence in relationships found in this study, using continuous measures of exposure, is an important next step. Finally, we underscore the need to consider (a) the potential moderating influence of fetal sex on exposure-related neurodevelopmental risks; and (b) the importance of quantifying expressions of risk through subtle alterations, rather than dichotomous outcomes.

Positive parenting behaviors in women who spontaneously quit smoking during pregnancy: Clues to putative targets for preventive interventions

BACKGROUND

While the majority of pregnant smokers do not respond to intervention, little is known about how a subset of pregnant smokers known as spontaneous quitters achieve sustained biologically-confirmed abstinence through delivery in the absence of intervention. We explore a developmental framework to address this question by viewing spontaneous quitting as an adaptive parenting behavior, facilitated by abilities necessary for sensitive parenting, or responsiveness. Utilizing existing data, we examined responsiveness from parenting assessments in women who exhibited a variety of smoking patterns during pregnancy, including spontaneous quitting.

METHODS

Participants were N = 305 pregnant women assessed for smoking prospectively and biochemically at 16 weeks, 28 weeks, delivery, and 4 weeks postpartum, then reassessed with their children 5 years later with directly-observed home- and lab-based measures of parenting. We used linear regression analysis to compare spontaneous quitters with women who exhibited other prenatal smoking patterns on parenting responsiveness, controlling for potential confounders.

RESULTS

In home-based observations, spontaneous quitters (n = 22) exhibited greater responsiveness with their children relative to intermittent pregnancy smokers [n = 70; β = 0.258, p = .022]; persistent pregnancy smokers [n = 66; β = 0.228, p = .040]; former smokers (quit before pregnancy) [n = 78; β = 266, p = .028]; and never smokers [n = 69; β = 0.312, p = .009]. Hypothesized differences were not observed in lab-based and self-report measures.

CONCLUSIONS

Putative protective characteristics in spontaneous quitters were captured in mother-child interactions at home, but not in lab-based and maternal report measures of responsiveness. Specification of these characteristics using prospective designs that oversample for spontaneous quitters is recommended to enable translation to preventive interventions.

Predictors of low birth weight and 24-hour perinatal outcomes at Muhimbili National Hospital in Dar es Salaam, Tanzania: a five-year retrospective analysis of obstetric records

Introduction

The global prevalence of low birth weight (LBW) is 16%, representing more than 20 million infants worldwide, of which 96% are born in low-income countries. This study aimed to determine the prevalence, predictors and perinatal outcomes of LBW newborns.

Methods

We conducted a retrospective analysis of data obtained from the hospital's obstetric and neonatal database. Descriptive statistics and multivariate logistic regression were performed with 95% confidence intervals (CI).

Results

The prevalence of LBW was 21% (n = 8,011) and two-thirds of these were delivered at term. Seven percent of newborns were stillbirths and 2% died within 24hrs after birth. Logistic regression revealed that primigravida and grand multiparity were associated with LBW (OR: 1.25, 95%CI: 1.15-1.37; and OR: 1.21, 95%CI: 1.01-1.25, respectively). Having <4 antenatal care (ANC) visits was associated with increased odds of LBW (OR: 1.74, 95%CI: 1.59-1.87). Regression models revealed an independent association between LBW and increased odds of stillbirths (OR = 7.20, 95%CI 6.71-7.90), low Apgar score (OR = 3.42, 95%CI: 3.12-3.76) and early neonatal deaths (OR = 1.82, 95%CI: 1.51-2.19).

Conclusion

The prevalence of LBW was high and was associated with extreme maternal age groups, grand multiparity, low maternal education, low number of ANC visits and obstetrics risks factors and complications. Both LBW and prematurity were independently associated with poor perinatal outcome. Future interventions should focus on improving the quality of ANC and integrating peripartum emergency obstetric and neonatal care.

A Population-based Prospective Study to Identify Contributors to Mother and Child Health in Suburban Communities: The Cohort Profile

BACKGROUND

Following community health assessment Project (CHAP) in suburbs of Bandar Abbas city, health problems in women and children such as pregnancy complications and infant/child impaired growth are highly prevalent. Therefore, the present population-based prospective cohort study investigated the effects of a wide range of modifiable exposures during pregnancy and postpartum on mother and child health.

METHODS

The sample comprised of 1000 pregnant women in their first gestational trimester, who live in the three most socially and economically vulnerable neighborhoods of Bandar Abbas, are under recruitment during Feb 2016-18. Four structured questionnaires are being carried out from pregnancy to 30 d, 6 months, and 12 months postpartum. Biologic and ultrasound results are also gathered through hospital and health center records. The study is currently close to the end of the recruitment phase.

CONCLUSION

The results of the interim and final analyses are being translated into applicable preventive action plans aiming to reduce and control modifiable risk factors for ill-health in mothers and children in suburb communities in South of Iran.

WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Adverse Birth Outcomes

Introduction: Three recent systematic reviews suggested a relationship between noise exposure and adverse birth outcomes. The aim of this review was to evaluate the evidence for the World Health Organization (WHO) noise guidelines and conduct an updated systematic review of environmental noise, specifically aircraft and road traffic noise and birth outcomes, such as preterm birth, low birth weight, being small for gestational age and congenital malformations. Materials and methods: We reviewed again all the papers on environmental noise and birth outcomes included in the previous three systematic reviews and conducted a systematic search on noise and birth outcomes to update previous reviews. Web of Science, PubMed and Embase electronic databases were searched for papers published between June 2014 (end date of previous systematic review) and December 2016 using a list of specific search terms. Studies were also screened in the reference list of relevant reviews/articles. Further inclusion and exclusion criteria for the studies provided by the WHO expert group were applied. Risk of bias was assessed according to criteria from the Newcastle-Ottawa quality assessment scale for case-control and cohort studies. Finally, we applied the GRADE principles to our systematic review in a reproducible and appropriate way for judgment about quality of evidence. Results: In total, 14 studies are included in this review, six studies on aircraft noise and birth outcomes, five studies (two with more or less the same population) on road traffic noise and birth outcomes and three related studies on total ambient noise that is likely to be mostly traffic noise that met the criteria. The number of studies on environmental noise and birth outcomes is small and the quality of evidence generally ranges from very low to low, particularly in case of the older studies. The quality is better for the more recent traffic noise and birth outcomes studies. As there were too few studies, we did not conduct meta-analyses. Discussion: This systematic review is supported by previous systematic reviews and meta-analyses that suggested that there may be some suggestive evidence for an association between environmental noise exposure and birth outcomes, although they pointed more generally to a stronger role of occupational noise exposure, which tends to be higher and last longer. Very strict criteria for inclusion and exclusion of studies, performance of quality assessment for risk of bias, and finally applying GRADE principles for judgment of quality of evidence are the strengths of this review. Conclusions: We found evidence of very low quality for associations between aircraft noise and preterm birth, low birth weight and congenital anomalies, and low quality evidence for an association between road traffic noise and low birth weight, preterm birth and small for gestational age. Further high quality studies are required to establish such associations. Future studies are recommended to apply robust exposure assessment methods (e.g., modeled or measured noise levels at bedroom façade), disentangle associations for different sources of noise as well as daytime and nighttime noise, evaluate the impacts of noise evens (that stand out of the noise background), and control the analyses for confounding factors, such as socioeconomic status, lifestyle factors and other environmental factors, especially air pollution.

Evaluation of Health in Pregnancy grants in Scotland: a natural experiment using routine data

Background

Pregnancy and the period around birth are critical for the development and improvement of population health as well as the health of mothers and babies, with outcomes such as birthweight influencing adult health.

Objectives

We evaluated the clinical effectiveness and cost-effectiveness of the Health in Pregnancy (HiP) grants in Scotland, looking for differential outcomes when the scheme was in place, as well as before its implementation and after its withdrawal.

Design

The HiP grants were evaluated as a natural experiment using interrupted time series analysis. We had comparison groups of women who delivered before the grants were introduced and after the grants were withdrawn.

Setting

Scotland, UK.

Participants

A total of 525,400 singleton births delivered between 24 and 44 weeks in hospitals across Scotland between 1 January 2004 and 31 December 2014.

Intervention

The HiP grant was a universal, unconditional cash transfer of £190 for women in Great Britain and Northern Ireland reaching 25 weeks of pregnancy if they had sought health advice from a doctor or midwife. The grant was introduced for women with a due date on or after 6 April 2009 and subsequently withdrawn for women reaching the 25th week of pregnancy on or after 1 January 2011. The programme was paid for by Her Majesty’s Treasury.

Main outcome measures

Our primary outcome measure was birthweight. Secondary outcome measures included maternal behaviour, measures of size, measures of stage and birth outcomes.

Data sources

The data came from the Scottish maternity and neonatal database held by the Information and Services Division at the NHS National Services Scotland.

Results

There was no statistically significant effect on birthweight, with births during the intervention period being, on average, 2.3 g [95% confidence interval (CI) –1.9  to 6.6 g] lighter than would have been expected had the pre-intervention trend continued. Mean gestational age at booking (i.e. the first antenatal appointment with a health-care professional) decreased by 0.35 weeks (95% CI 0.29 to 0.41 weeks) and the odds of booking before 25 weeks increased by 10% [odds ratio (OR) 1.10, 95% CI 1.02 to 1.18] during the intervention but decreased again post intervention (OR 0.91, 95% CI 0.83 to 1.00). The odds of neonatal death increased by 84% (OR 1.84, 95% CI 1.22 to 2.78) and the odds of having an emergency caesarean section increased by 7% (OR 1.07, 95% CI 1.03 to 1.10) during the intervention period.

Conclusions

The decrease in the odds of booking before 25 weeks following withdrawal of the intervention makes it likely that the HiP grants influenced maternal health-care-seeking behaviour. It is unclear why neonatal mortality and emergency caesarean section rates increased, but plausible explanations include the effects of the swine flu outbreak in 2009 and the global financial crisis. The study is limited by its non-randomised design. Future research could assess an eligibility threshold for payment earlier than the 25th week of pregnancy.

Funding

The National Institute for Health Research Public Health Research programme. The Social and Public Health Sciences Unit is core funded by the Medical Research Council (MC_UU_12017/13) and the Scottish Government Chief Scientist Office (SPHSU13).

Specification of Change Mechanisms in Pregnant Smokers for Malleable Target Identification: A Novel Approach to a Tenacious Public Health Problem

Maternal smoking during pregnancy (MSDP) continues to be a leading modifiable risk factor for perinatal complications and a range of neurodevelopmental and cardio-metabolic outcomes across the lifespan. Despite 40 years of intervention research less than one in five pregnant smokers who receive an intervention quit by delivery. Within this context, recognition of pregnancy is commonly associated with abrupt suspension or reduction of smoking in the absence of intervention, yet has not been investigated as a volitional target. The goal of this article is to provide the empirical foundation for a novel direction of research aimed at identifying malleable targets for intervention through the specification of behavior change mechanisms specific to pregnant women. To do so, we: (1) summarize progress on MSDP in the United States generated from conventional empirical approaches to health behavior change; (2) discuss the phenomenon of spontaneous change in the absence of intervention among pregnant smokers to illustrate the need for mechanistic specification of behavior change motivated by concern for fetal well-being; (3) summarize component processes in neurobiological models of parental and non-parental social behaviors as a conceptual framework for understanding change mechanisms during pregnancy; (4) discuss the evidence for the malleability of these processes to support their translational relevance for preventive interventions; and (5) propose a roadmap for validating the proposed change mechanism using an experimental medicine approach. A greater understanding of social and interpersonal processes that facilitate health behavior change among expectant mothers and how these processes differ interindividually could yield novel volitional targets for prenatal interventions. More broadly, explicating other-oriented mechanisms of behavior change during pregnancy could serve as a paradigm for understanding how social and interpersonal processes positively influence health behaviors across the lifespan.