Maternal age, birth order, and race: differential effects on birthweight

Impact of Social Vulnerability, Race, and Urbanicity on Early Nutritional Outcomes in Patients With Cleft Palate

Patients with cleft palate experience early feeding difficulties, resulting in increased hospital utilization due to poor nutritional status. Sociodemographic factors may impact access and outcomes for cleft patients. This study investigates the association of social vulnerability, race, and urbanicity on birth encounter metrics and failure to thrive (FTT) rates for patients with cleft palate. Retrospective data from 2013 to 2023 was queried from Cosmos, a national deidentified database from Epic electronic health record. Birth metrics, the prevalence of FTT, and MyChart activation rates were compared across sociodemographic cohorts based on (1) social vulnerability index (SVI) quartiles, (2) patient race, and (3) USDA Rural-Urban Commuting Area (RUCA) codes using χ2 or Fisher exact tests. There were 92,437 patients diagnosed with cleft palate. Birth weight was lower in socially vulnerable and Black patients (SVI 75%: 101.50±1.57 oz; SVI 25%: 106.40±1.85 oz; Black: 95.3±2.63 oz; White: 104.90±1.02 oz; Other: 104.80±2.09 oz), and length of stay was longer (SVI 75%: 21±2.39 d; SVI 25%: 15±2.18 d; Black: 22±4 d). FTT related admissions increased with SVI quartile (Q25: 0.19%; Q25-50; 0.29%, Q50-75: 0.34%; Q75: 0.47%; P<0.001). An opposite trend was observed for MyChart activation rates (P<0.001). High SVI and Black patients are susceptible to unfavorable nutritional outcomes. Access disparities, such as direct-to-provider communication systems (ie, MyChart), may contribute. Awareness of social identities, geography, and community may assist in providing individualized care in early life.

The influence of birthweight on mortality and severe neonatal morbidity in late preterm and term infants: an Australian cohort study

Background

The aim of this study was to detail incidence rates and relative risks for severe adverse perinatal outcomes by birthweight centile categories in a large Australian cohort of late preterm and term infants.

Methods

This was a retrospective cohort study of singleton infants (≥34+0 weeks gestation) between 2000 and 2018 in Queensland, Australia. Study outcomes were perinatal mortality, severe neurological morbidity, and other severe morbidity. Categorical outcomes were compared using Chi-squared tests. Continuous outcomes were compared using t-tests. Multinomial logistic regression investigated the effect of birthweight centile on study outcomes.

Findings

The final cohort comprised 991,042 infants. Perinatal mortality occurred in 1944 infants (0.19%). The incidence and risk of perinatal mortality increased as birthweight decreased, peaking for infants <1st centile (perinatal mortality rate 13.2/1000 births, adjusted Relative Risk Ratio (aRRR) of 12.96 (95% CI 10.14, 16.57) for stillbirth and aRRR 7.55 (95% CI 3.78, 15.08) for neonatal death). Severe neurological morbidity occurred in 7311 infants (0.74%), with the highest rate (19.6/1000 live births) in <1st centile cohort. There were 75,243 cases of severe morbidity (7.59% livebirths), with the peak incidence occurring in the <1st centile category (12.3% livebirths). The majority of adverse outcomes occurred in infants with birthweights between 10 and 90th centile. Almost 2 in 3 stillbirths, and approximately 3 in 4 cases of neonatal death, severe neurological morbidity or other severe morbidity occurred within this birthweight range.

Interpretation

Although the incidence and risk of perinatal mortality, severe neurological morbidity and severe morbidity increased at the extremes of birthweight centiles, the majority of these outcomes occurred in infants that were apparently "appropriately grown" (i.e., birthweight 10th-90th centile).

Funding

National Health and Medical Research Council, Mater Foundation, Royal Australian College of Obstetricians and Gynaecologists Women's Health Foundation - Norman Beischer Clinical Research Scholarship, Cerebral Palsy Alliance, University of Queensland Research Scholarship.

Effect of maternal serum albumin level on birthweight and gestational age: an analysis of 39200 singleton newborns

Background

Serum albumin plays a pivotal role in regulating plasma oncotic pressure and modulating fluid distribution among various body compartments. Previous research examining the association between maternal serum albumin levels and fetal growth yielded limited and inconclusive findings. Therefore, the specific influence of serum albumin on fetal growth remains poorly understood and warrants further investigation.

Methods

A retrospective study involved 39200 women who had a singleton live birth at a tertiary-care academic medical center during the period from January 2017 to December 2020. Women were categorized into four groups according to the quartile of albumin concentration during early pregnancy: Q1 group, ≤41.0 g/L; Q2 group, 41.1-42.6 g/L; Q3 group, 42.7-44.3 g/L and Q4 group, >44.3 g/L. The main outcome measures were mid-term estimated fetal weight, birthweight and gestational age. Multivariate linear and logistic regression analysis were performed to detect the independent effect of maternal serum albumin level on fetal growth after adjusting for important confounding variables.

Results

In the crude analysis, a significant inverse correlation was found between early pregnancy maternal serum albumin levels and fetal growth status, including mid-term ultrasound measurements, mid-term estimated fetal weight, birthweight, and gestational age. After adjustment for a number of confounding factors, mid-term estimated fetal weight, birthweight, and birth height decreased significantly with increasing albumin levels. Compared to the Q2 group, the Q4 group had higher rates of preterm birth (aOR, 1.16; 95% CI, 1.01-1.34), small-for-gestational-age (aOR, 1.27; 95% CI, 1.11-1.45) and low birthweight (aOR, 1.41; 95% CI, 1.18-1.69), and lower rate of large-for-gestational-age (aOR, 0.85; 95% CI, 0.78-0.94). Moreover, to achieve the optimal neonatal outcome, women with higher early pregnancy albumin levels required a greater reduction in albumin levels in later pregnancy stages.

Conclusions

A higher maternal serum albumin level during early pregnancy was associated with poor fetal growth, with the detrimental effects becoming apparent as early as the mid-gestation period. These findings provided vital information for clinicians to predict fetal growth status and identify cases with a high risk of adverse neonatal outcomes early on.

Racial and ethnic disparities in premature births among pregnant women in the NISAMI cohort, Brazil

The incidence of premature birth has increased worldwide, unequally distributed by race/ethnicity. Racism generates economic inequalities, educational disparities, and differential access to health care, which increases the risk of preterm birth. Thus, this study aimed to evaluate the factors associated with preterm birth and racial and ethnic disparities in premature birth among pregnant women attending prenatal care at the Brazilian Unified Health System health units in the urban area of Santo Antônio de Jesus, Bahia, Brazil. This study used data from 938 pregnant women aged between 18 to 45 years within the NISAMI prospective cohort. Premature birth prevalence was 11.8%, with a higher prevalence among black than non-black women (12.9% versus 6.0%, respectively). Maternal age between 18 and 24 years was the only factor associated with premature birth. A higher risk of premature birth was found among black women than non-black women (RR 3.22; 95%CI 1.42-7.32). These results reveal the existence of racial and social inequalities in the occurrence of premature birth.

Influence of maternal age on birth and infant outcomes at 6 months: a cohort study with quantitative bias analysis

BACKGROUND

Maternal age is increasingly recognized as a predictor of birth outcomes. Given the importance of birth and growth outcomes for children's development, wellbeing and survival, this study examined the effect of maternal age on infant birth and growth outcomes at 6 months and mortality. Additionally, we conducted quantitative bias analysis (QBA) to estimate the role of selection bias and unmeasured confounding on the effect of maternal age on infant mortality.

METHODS

We used data from randomized-controlled trials (RCTs) of 21 555 neonates in Burkina Faso conducted in 2019-2020. Newborns of mothers aged 13-19 years (adolescents) and 20-40 years (adults) were enrolled in the study 8-27 days after birth and followed for 6 months. Measurements of child's anthropometric measures were collected at baseline and 6 months. We used multivariable linear regression to compare child anthropometric measures at birth and 6 months, and logistic regression models to obtain the odds ratio (OR) of all-cause mortality. Using multidimensional deterministic analysis, we assessed scenarios in which the difference in selection probability of adolescent and adult mothers with infant mortality at 6 months increased from 0% to 5%, 10%, 15% and 20% if babies born to adolescent mothers more often died during the first week or were of lower weight and hence were not eligible to be included in the original RCT. Using probabilistic bias analysis, we assessed the role of unmeasured confounding by socio-economic status (SES).

RESULTS

Babies born to adolescent mothers on average had lower weight at birth, lower anthropometric measures at baseline, similar growth outcomes from enrolment to 6 months and higher odds of all-cause mortality by 6 months (adjusted OR = 2.17, 95% CI 1.35 to 3.47) compared with those born to adult mothers. In QBA, we found that differential selection of adolescent and adult mothers could bias the observed effect (OR = 2.24, 95% CI 1.41 to 3.57) towards the null [bias-corrected OR range: 2.37 (95% CI 1.49 to 3.77) to 2.84 (95% CI 1.79 to 4.52)], whereas unmeasured confounding by SES could bias the observed effect away from the null (bias-corrected OR: 2.06, 95% CI 1.31 to 2.64).

CONCLUSIONS

Our findings suggest that delaying the first birth from adolescence to adulthood may improve birth outcomes and reduce mortality of neonates. Babies born to younger mothers, who are smaller at birth, may experience catch-up growth, reducing some of the anthropometric disparities by 6 months of age.

Predictors of Low Birth Weight: A Study in a Health and Demographic Cohort from Assam, India

Low birth weight is associated with morbidities and mortality in the later life. Prevalence of anemia and under nutrition in Assam were reported to be high which may correlate with low birth weight of infants. The present study assessed prevalence and risk factors for low birth weight in a health and demographic cohort established in Dibrugarh district, Assam. A total of 1437 deliveries (580 from rural and 857 from tea garden) were recorded during March 2019 to February 2020. Prevalence of low birth weight was 30.34%. Tea-garden community [OR: 1.4 (1.06-1.79)], low levels of maternal education [OR: 1.57(1.12-2.13)], low monthly income [OR: 2.1 (1.1-3.9)], pre-term birth [OR: 4.1 (2.2-7.9)] and mother with low BMI [OR: 1.6 (1.3-2.07)] were found to be significantly associated with low birth weight. Intervention strategies to improve socioeconomic condition, promote antenatal checkup and alleviate under nutrition in pregnant mothers are warranted to reduce low birth weight.

Association between embryo morphological quality and birth weight for singletons conceived via autologous fresh embryo transfer: an analysis using Society for Assisted Reproductive Technology Clinical Outcomes Reporting System

OBJECTIVE

To determine if morphologically suboptimal embryo quality is associated with adverse perinatal outcomes.

DESIGN

A retrospective cohort.

SETTING

SART CORS database.

PATIENT(S)

Singletons conceived from autologous in vitro fertilization fresh cycles.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Birth weight (gram), birth weight z-score, low birth weight (LBW), small for gestational age (SGA), and large for gestational age (LGA).

RESULT(S)

Among 5,869 in vitro fertilization fresh cycles, 71.1% transferred morphologically good embryos, and 27.0% and 1.9% transferred fair and poor embryo(s), respectively. Compared with singletons conceived from good embryos, singletons from poor embryos had a higher birth weight (3,415.8 ± 562.0 vs. 3,202.7 ± 639.9). Proportions of LBW, SGA, and LGA were comparable across embryo quality groups. Multivariate regression analysis comparing perinatal outcomes from fair vs. good embryos showed no association for birth weight (0.69-gram difference; 95% CI, -24.30-25.68), birth weight z-score (Coefficient, 0.00; 95% CI, -0.07-0.08), LBW (adjusted odds ratio [aOR], 0.84; 95% CI, 0.63-1.11), SGA (aOR, 0.93; 95% CI, 0.78-1.11), and LGA (aOR, 1.07; 95% CI, 0.86-1.33). Stratified analysis, considering cleaved and blastocyst embryo transfers separately, confirmed these findings. Sensitivity analysis revealed increased odds of LGA (aOR, 1.53; 95% CI, 1.04-2.24) with fair-quality embryos only among single embryo transfer cycles.

CONCLUSION(S)

Once a singleton live birth from fresh embryo transfer is achieved, fair morphological embryo quality is not associated with a reduction in birth weight or increased risks of LBW, SGA, and LGA.

Determinants of very low birth weight in India: The National Family Health Survey – 4

Background

Low birth weight (LBW) is susceptible to neonatal complications, chronic medical conditions, and neurodevelopmental disabilities. We aim to describe the determinants of very low birth weight (VLBW) in India and compare it with the determinants of LBW based on the National Family Health Survey – 4 (NHFS-4)

Methods

Data from the NFHS-4 on birthweight and other socio-demographic characteristics for the youngest child born in the family during the five years preceding the survey were used. Data of 147,762 infant–mother pairs were included. Multiple logistic regression models were employed to delineate the independent predictors of VLBW (birth weight<1500 g) or LBW  (birth weight: 1500-2499 g).

Results

Of the 147,762 children included in the study, VLBW and LBW were observed in 1.2% and 15.8% of children, respectively. The odds of VLBW were higher in female children (aOR: 1.36, 95% CI: 1.15–1.60), among mothers aged 13–19 years (aOR: 1.58, 95% CI: 1.22–2.07), mothers with severe or moderate anaemia (aOR: 1.61, 95% CI: 1.34–1.94), mothers without recommended antenatal care (aOR: 1.47, 95% CI: 1.31–1.90), maternal height less than 150 cm (aOR: 1.54, 95% CI: 1.29–1.85) and among mothers with multiple pregnancy (aOR: 21.34, 95% CI: 14.70–30.96) in comparison to their corresponding counterparts. In addition to the variables associated with VLBW, educational status of mothers (no education; aOR: 1.08, 95% CI: 1.02–1.15 and primary education; aOR: 1.16, 95% CI: 1.08–1.25), caste of the children (scheduled tribe; aOR: 1.13, 95% CI: 1.03–1.24), and wealthiness of the family (poorest wealth quintiles; aOR: 1.11, 95% CI: 1.03–1.19) were associated with LBW.

Conclusions

Interventions targeting improvements in antenatal care access, maternal health, and nutritional status may reduce the number of VLBW infants. Social determinants of LBW require further detailed study to understand the high propensity of low birth-weight phenotypes in the disadvantaged communities in India.

Birth order differences in education originate in postnatal environments

Siblings share many environments and much of their genetics. Yet, siblings turn out different. Intelligence and education are influenced by birth order, with earlier-born siblings outperforming later-borns. We investigate whether birth order differences in education are caused by biological differences present at birth, that is, genetic differences or in utero differences. Using family data that spans two generations, combining registry, survey, and genotype information, this study is based on the Norwegian Mother, Father, and Child Cohort Study (MoBa). We show that there are no genetic differences by birth order as captured by polygenic scores (PGSs) for educational attainment. Earlier-born have lower birth weight than later-born, indicating worse uterine environments. Educational outcomes are still higher for earlier-born children when we adjust for PGSs and in utero variables, indicating that birth order differences arise postnatally. Finally, we consider potential environmental influences, such as differences according to maternal age, parental educational attainment, and sibling genetic nurture. We show that birth order differences are not biological in origin, but pinning down their specific causes remains elusive.

Intergenerational health effects of Medicaid

This paper investigates the effects of the introduction of Medicaid during the 1960s on next generations' birth outcomes. A federal mandate that all states must widen the coverage to all cash welfare recipients generated cross-state variations in Medicaid eligibility, specifically among nonwhites who largely overrepresented the target population. I implement a reduced-form difference-in-differences strategy that compares the birth outcomes of mothers born in states with higher cash welfare recipiency versus low welfare recipiency and different years relative to the Medicaid implementation year. Using Natality data (1970-2004), I find that Medicaid significantly improves birth outcomes. The effects are considerably larger among nonwhites, specifically blacks. The effects do not appear to be driven by preexisting trends in birth outcomes, preexisting trends in households' socioeconomic characteristics, changes in other welfare expenditures, and selective fertility. A back-of-an-envelope calculation points to a minimum of 3.9% social externality of Medicaid through income rises due to next generations' improvements in birth outcomes.

Determinant factors of low birth weight in Indonesia: Findings from the 2017 Indonesian demographic and health survey

BACKGROUND

Low birth weight (LBW) is still a significant problem in Indonesia because it affects the growth and development of infants. It is also one of the factors that increase the risk of developing chronic disease later in life.

PURPOSE

The study aimed to analyse the determinants of LBW in Indonesia.

METHODS

This cross-sectional analytic study used secondary data from the 2017 Indonesian Demographic and Health Survey (IDHS). Data on the maternal factors (maternal age, frequency of antenatal care (ANC) visits, education, and maternal smoking status), children's birth order, and socio-demographic factors of the 14,239 respondents were examined. The association between LBW and the independent variables was analysed using bivariate analysis with a chi-square test (X²), followed by multivariate analysis in the form of binary logistic regression.

RESULTS

LBW was identified in 960 infants (6.74%). Fewer than four ANC visits [AOR = 1.86; 95% CI = 1.44-2.42], uneducated mothers [AOR = 2.09; 95% CI = 1.00-4.37], and mothers who finished only primary school [AOR = 1.45; 95% CI = 1.05-2.00] were significantly associated with the incidence of LBW.

CONCLUSIONS

This study revealed that the frequency of ANC visits was a dominant factor in the incidence of LBW.

PRACTICE IMPLICATION

To reduce LBW in Indonesia, the government must increase ANC visits through health promotion programmes and maintain ANC facilities and quality.

Determinants of very low birth weight in India: The National Family Health Survey – 4

Background Low birth weight (LBW) is susceptible to neonatal complications, chronic medical conditions, and neurodevelopmental disabilities. We aim to describe the determinants of very low birth weight (VLBW) in India based on the National Family Health Survey – 4 (NHFS-4). Methods Data from the NFHS 4 on birthweight and other socio-demographic characteristics for the youngest child born in the family during the five years preceding the survey were used. Data of 147,762 infant–mother pairs were included. Multiple logistic regression models were employed to delineate the independent predictors of VLBW (birth weight<1500 g) or LBW (birth weight <2500 g). Results Of the 147,762 children included in the study, VLBW and LBW were observed in 1.2% and 15.8% of children, respectively. The odds of VLBW were higher in female children (aOR: 1.36, 95% CI: 1.15–1.60), among mothers aged 13–19 years (aOR: 1.58, 95% CI: 1.22–2.07), mothers with severe or moderate anaemia (aOR: 1.61, 95% CI: 1.34–1.94), mothers without recommended antenatal care (aOR: 1.47, 95% CI: 1.31–1.90), maternal height less than 150 cm (aOR: 1.54, 95% CI: 1.29–1.85) and among mothers with multiple pregnancy (aOR: 21.34, 95% CI: 14.70–30.96) in comparison to their corresponding counterparts. In addition to the variables associated with VLBW, educational status of mothers (no education; aOR: 1.08, 95% CI: 1.02–1.15 and primary education; aOR: 1.16, 95% CI: 1.08–1.25), caste of the children (scheduled tribe; aOR: 1.13, 95% CI: 1.03–1.24), and wealthiness of the family (poorest wealth quintiles; aOR: 1.11, 95% CI: 1.03–1.19) were associated with LBW. Conclusions Interventions targeting improvements in antenatal care access, maternal health, and nutritional status may reduce the number of VLBW infants. Social determinants of LBW require further detailed study to understand the high propensity of low birth-weight phenotypes in the disadvantaged communities in India.

Birth order revelations about managers

Purpose

This paper aims to reveal the effects of birth order in decision-making style, conflict handling style and propensity for participative decision-making. The intention is to open the perspective of birth order research in organizational studies, as an important individual difference of managers.

Design/methodology/approach

A survey was conducted with 230 managers from different industries in Kosovo. Self-report measures were used for decision-making style, conflict handling style and participatory decision-making constructs.

Findings

Results indicate that only children are more avoidant and spontaneous decision-makers. Firstborns are rational in decision-making and prefer problem-solving in conflict handling. Middleborns are intuitive decision-makers and use compromising in conflict handling. Lastborns make decisions rationally and use both compromising and problem-solving in conflicting situations. In addition, lastborns appeared to have a more positive attitude toward participative decision-making, followed by middleborns, firstborns and only children.

Research limitations/implications

Birth order affects managers’ behaviors in decision-making and conflict situations. Relationship dynamics in sibships are reflected in organizational settings, affecting how people behave in decision-making and conflict handling.

Originality/value

To the best of the authors’ knowledge, this is the first study to attest how birth order influences the ways managers make decisions, handle conflicts and involve others in decision-making. As birth order cannot be changed, such knowledge is critical.

Advanced trophectoderm quality increases the risk of a large for gestational age baby in single frozen-thawed blastocyst transfer cycles

STUDY QUESTION

Does trophectoderm (TE) quality affect birthweight after single frozen-thawed blastocyst transfer?

SUMMARY ANSWER

Transfer of single blastocyst with advanced TE quality was associated with higher birthweight and increased risk of a large for gestational age (LGA) baby.

WHAT IS KNOWN ALREADY

Transfer of blastocysts with advanced TE quality results in higher ongoing pregnancy rates and a lower miscarriage risk. However, data on the relationship between TE quality and birthweight are still lacking.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study at a tertiary-care academic medical center included 1548 singleton babies born from single frozen-thawed blastocyst transfer from January 2011 to June 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Babies were grouped into four groups according to embryo expansion (Stages 3, 4, 5 and 6), three groups according to inner cell mass (ICM) quality (A, B and C), and three groups according to TE quality (A, B and C). Main outcomes included absolute birthweight, Z-scores adjusted for gestational age and gender, and adverse neonatal outcomes. Multivariable linear and logistic regression analyses were performed to investigate the association of neonatal outcomes with expansion stage, ICM quality and TE quality.

MAIN RESULTS AND THE ROLE OF CHANCE

As TE quality decreased, birthweight (3468.10 ± 471.52, 3357.69 ± 522.06, and 3288.79 ± 501.90 for A, B and C, respectively, P = 0.002), Z-scores (0.59 ± 1.07, 0.42 ± 1.04, and 0.27 ± 1.06 for A, B and C, respectively, P = 0.002) and incidence of LGA (28.9%, 19.7% and 17.4% for A, B and C, respectively, P = 0.027) decreased correspondingly. After adjusting for confounders, compared with the Grade A group, blastocysts with TE Grade B (standardized coefficients (β): -127.97 g, 95% CI: -234.46 to -21.47, P = 0.019) and blastocysts with TE grade C (β: -200.27 g, 95% CI: -320.69 to -79.86, P = 0.001) resulted in offspring with lower birthweight. Blastocysts with TE grade C brought babies with lower Z-scores than TE Grade A (β: -0.35, 95% CI: -0.59 to -0.10, P = 0.005). Also, embryos with TE Grade B (adjusted odds ratio (aOR):0.91, 95% CI: 0.84 to 0.99, P = 0.033) and embryos with TE Grade C (aOR : 0.89, 95% CI: 0.81 to 0.98, P = 0.016) had lower chance of leading to a LGA baby than those with TE Grade A. No association between neonatal outcomes with embryo expansion stage and ICM was observed (all P > 0.05).

LIMITATIONS, REASONS FOR CAUTION

The retrospective design, lack of controlling for several unknown confounders, and inter-observer variation limited this study.

WIDER IMPLICATIONS OF THE FINDINGS

The study extends our knowledge of the down-stream effect of TE quality on newborn birthweight and the risk of LGA.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by National Key R&D Program of China (2018YFC1003000), National Natural Science Foundation of China (81771533 to Y.P.K. and 31200825 to L.S.) and Innovative Research Team of High-level Local Universities in Shanghai (SSMU-ZLCX20180401), Shanghai Sailing Program(21YF1423200) and the Fundamental research program funding of Ninth People's Hospital affiliated to Shanghai Jiao Tong university School of Medicine (JYZZ117). The authors declare no conflict of interest in this present study.

TRIAL REGISTRATION NUMBER

N/A.

Exposure to ambient particulate matter and biomass burning during pregnancy: associations with birth weight in Thailand

BACKGROUND

There is a growing evidence that exposure to ambient particulate air pollution during pregnancy is associated with adverse birth outcomes, including reduced birth weight (BW). The objective of this study was to quantify associations between BW and exposure to particulate matter (PM) and biomass burning during pregnancy in Thailand.

METHODS

We collected hourly ambient air pollutant data from ground-based monitors (PM with diameter of <10 µm [PM₁₀], Ozone [O₃], and nitrogen dioxide [NO₂]), biomass burning from satellite remote sensing data, and individual birth weight data during 2015-2018. We performed a semi-ecological analysis to evaluate the association between mean trimester exposure to air pollutants and biomass burning with BW and low-birth weight (LBW) (<2500 g), adjusting for gestation age, sex, previous pregnancies, mother's age, heat index, season, year, gaseous pollutant concentrations, and province. We examined potential effect modification of PM₁₀ and biomass burning exposures by sex.

RESULTS

There were 83,931 eligible births with a mean pregnancy PM₁₀ exposure of 39.7 µg/m³ (standard deviation [SD] = 7.7). The entire pregnancy exposure was associated with reduced BW both for PM₁₀ (-6.81 g per 10 µg/m³ increase in PM₁₀ [95% CI = -12.52 to -1.10]) and biomass burning (-6.34 g per 1 SD increase in fires/km² [95% CI = -11.35 to -1.34]) only after adjustment for NO₂. In contrast with these findings, a reduced odds ratio (OR) of LBW was associated with PM₁₀ exposure only in trimesters one and two, with no relationship across the entire pregnancy period. Associations with biomass burning were limited to increased ORs of LBW with exposure in trimester three, but only for male births.

CONCLUSION

Based on our results, we encourage further investigation of air pollution, biomass burning and BW in Thailand and other low-income and middle-income countries.

Birth outcomes are superior after transfer of fresh versus frozen embryos for donor oocyte recipients

STUDY QUESTION

For donor oocyte recipients, are birth outcomes superior for fresh versus frozen embryos?

SUMMARY ANSWER

Among fresh donor oocyte recipients, fresh embryos are associated with better birth outcomes when compared with frozen embryos.

WHAT IS KNOWN ALREADY

Frozen embryo transfer (ET) with vitrification has been associated with improved pregnancy rates, but also increased rates of large for gestational age infants. Donor oocyte recipients represent an attractive biological model to attempt to isolate the impact of embryo cryopreservation on IVF outcomes, yet there is a paucity of studies in this population.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort of the US national registry, the Society for Assisted Reproductive Technology Clinic Outcome Reporting System, of IVF cycles of women using fresh donor oocytes resulting in ET between 2013 and 2015. Thawed oocytes were excluded.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Good obstetric outcome (GBO), defined as a singleton, term, live birth with appropriate for gestational age birth weight, was the primary outcome measure. Secondary outcomes included live birth, clinical pregnancy, spontaneous abortion, preterm birth, multiple births and gestational age-adjusted weight. Outcomes were modeled using the generalized estimating equation approach.

MAIN RESULTS AND THE ROLE OF CHANCE

Data are from 25 387 donor oocyte cycles, in which 14 289 were fresh and 11 098 were frozen ETs. A GBO was 27% more likely in fresh ETs (26.3%) compared to frozen (20.9%) (adjusted risk ratio 1.27; 95% confidence interval (CI) 1.21-1.35; P < 0.001). Overall, fresh transfer was more likely to result in a live birth (55.7% versus 39.5%; adjusted risk ratio 1.21; 95% CI 1.18-1.26; P < 0.001). Among singleton births, there was no difference in gestational age-adjusted birth weight between groups.

LIMITATION, REASONS FOR CAUTION

Our cohort findings contrast with data from autologous oocytes. Prospective studies with this population are warranted.

WIDER IMPLICATIONS OF THE FINDINGS

Among donor oocyte recipients, fresh ETs may be associated with better birth outcomes. Reassuringly, given its prevalent use, modern embryo cryopreservation does not appear to result in phenotypically larger infants.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Household food insecurity associations with pregnancy hypertension, diabetes mellitus and infant birth anthropometric measures: a cross-sectional study of Iranian mothers

Objective: The purpose of this study was to determine the associations between food insecurity on pregnancy and its outcomes.Materials and methods: This cross-sectional study was carried out on 700 Iranian mothers. Household socioeconomic status, prenatal information and household food security status were assessed using questionnaires. Data analysis was applied by SPSS version 22.Results: The results of the study showed a significant association between food insecurity with gestational diabetes mellitus. The results also showed a significant association between birth weight, and height with pregnancy-induced hypertension.Conclusion: food insecure women should be recognized, and receive appropriate training and assistance.

Investigating the linkages between pregnancy outcomes and climate in sub-Saharan Africa

Poor pregnancy outcomes include miscarriages, stillbirths, and low birth weights. Stress from heat and lack of resources play a potentially important role in producing these poor outcomes. Women and couples who experience these poor outcomes rather than a healthy birth suffer psychological, physical, social, and financial costs as well. We use detailed reproductive data in combination with fine-scale climate data to examine pregnancy outcomes among women in sub-Saharan Africa, a region that shelters some of the poorest families in the world. Fine-scale precipitation and temperature data allow each pregnancy to be matched to the relevant climate exposures. We investigate the linkages between climate and pregnancy outcomes using linear probability models with fixed effects to minimize confounding due to factors that vary by location, season, and year. We analyze retrospective pregnancy data from more than 65,000 pregnancies recorded in 23 surveys across 15 African countries. Our results indicate that pregnancy outcomes are indeed impacted by exposure to hot days even after considering other individual-level characteristics. This research provides insight into the linkages between climate and a major adverse health outcome faced by women. In doing so, this research expands scientific understanding of the impact of environmental factors on fertility outcomes.

Mother and Infant Predictors of Rapid Infant Weight Gain

Objective. To examine characteristics of the infant and mother associated with rapid infant weight gain (RIWG). Methods. Electronic health records (N = 4626) of term infants born were reviewed. Multivariable logistic regression examined the presence of RIWG (vs not) using participant characteristics in the whole sample and in stratified groups. Results. The prevalence of RIWG was 18.7%. Predictors of RIWG were infant male sex, younger infant gestational age, firstborn (vs later born) status, maternal Black or Other (Asian, American Indian, etc), non-Hispanic race/ethnicity (vs White non-Hispanic), Medicaid (vs non-Medicaid insurance), and maternal cigarette smoking status (vs never smoker). The regression model explained between 7.0% and 11.4% of the variance in RIWG. There were few differences in predictors of RIWG in stratified samples. Conclusions. Early childhood obesity intervention efforts may target the modifiable risk factors for RIWG starting prenatally.

Is maternal weight gain between pregnancies associated with risk of large-for-gestational age birth? Analysis of a UK population-based cohort

OBJECTIVE

Maternal overweight and obesity during pregnancy increases the risk of large-for-gestational age (LGA) birth and childhood obesity. We aimed to investigate the association between maternal weight change between subsequent pregnancies and risk of having a LGA birth.

DESIGN

Population-based cohort.

SETTING

Routinely collected antenatal healthcare data between January 2003 and September 2017 at University Hospital Southampton, England.

PARTICIPANTS

Health records of women with their first two consecutive singleton live-birth pregnancies were analysed (n=15 940).

PRIMARY OUTCOME MEASURE

Risk of LGA, recurrent LGA and new LGA births in the second pregnancy.

RESULTS

Of the 15 940 women, 16.0% lost and 47.7% gained weight (≥1 kg/m²) between pregnancies. A lower proportion of babies born to women who lost ≥1 kg/m² (12.4%) and remained weight stable between -1 and 1 kg/m² (11.9%) between pregnancies were LGA compared with 13.5% and 15.9% in women who gained 1-3 and ≥3 kg/m², respectively. The highest proportion was in obese women who gained ≥3 kg/m² (21.2%). Overweight women had a reduced risk of recurrent LGA in the second pregnancy if they lost ≥1 kg/m² (adjusted relative risk (aRR) 0.69, 95% CI 0.48 to 0.97) whereas overweight women who gained ≥3 kg/m² were at increased risk of new LGA after having a non-LGA birth in their first pregnancy (aRR 1.35, 95% CI 1.05 to 1.75). Normal-weight women who gained weight were also at increased risk of new LGA in the second pregnancy (aRR 1.26, 95% CI 1.06 to 1.50 with gain of 1-3 kg/m² and aRR 1.34, 95% CI 1.09 to 1.65 with gain of ≥3 kg/m²).

CONCLUSIONS

Losing weight after an LGA birth was associated with a reduced LGA risk in the next pregnancy in overweight women, while interpregnancy weight gain was associated with an increased new LGA risk. Preventing weight gain between pregnancies is an important measure to achieve better maternal and offspring outcomes.

The weathering hypothesis as an explanation for racial disparities in health: a systematic review

PURPOSE

The weathering hypothesis states that chronic exposure to social and economic disadvantage leads to accelerated decline in physical health outcomes and could partially explain racial disparities in a wide array of health conditions. This systematic review summarizes the literature empirically testing the weathering hypothesis and assesses the quality of the evidence regarding weathering as a determinant of racial disparities in health.

METHODS

Databases (Web of Science, Ovid MEDLINE, PubMed, and Embase) were searched for studies published in English up to July 1, 2017. Studies that tested the weathering hypothesis for any physical health outcome and included at least one socially or economically disadvantaged group (e.g., Blacks) for whom the weathering hypothesis applies were assessed for eligibility. Threats to validity were assessed using the Quality in Prognostic Studies tool.

RESULTS

The 41 included studies were rated as having overall good methodological quality. Most studies found evidence in support of the weathering hypothesis, although the magnitude of support varied by the health outcome and population studied.

CONCLUSIONS

Future evaluations of the weathering hypothesis should include an examination of additional health outcomes and interrogate mechanisms that could link weathering to poor health.

A large-scale population study of early life factors influencing left-handedness

Hand preference is a conspicuous variation in human behaviour, with a worldwide proportion of around 90% of people preferring to use the right hand for many tasks, and 10% the left hand. We used the large cohort of the UK biobank (~500,000 participants) to study possible relations between early life factors and adult hand preference. The probability of being left-handed was affected by the year and location of birth, likely due to cultural effects. In addition, hand preference was affected by birthweight, being part of a multiple birth, season of birth, breastfeeding, and sex, with each effect remaining significant after accounting for all others. Analysis of genome-wide genotype data showed that left-handedness was very weakly heritable, but shared no genetic basis with birthweight. Although on average left-handers and right-handers differed for a number of early life factors, all together these factors had only a minimal predictive value for individual hand preference.

Birth weight and maternal age among American Indian/Alaska Native mothers: A test of the weathering hypothesis

Substantial research has examined birth outcomes by race/ethnicity, noting not only disparities by race/ethnicity, but different maternal age patterns in low birth weight (LBW) prevalence. Few studies have examined these disparities among American Indian/Alaska Native (AI/AN) mothers, whose LBW prevalence is below the national average, despite substantial socioeconomic disadvantage among the population. Prior work has hypothesized that AI/AN mothers should exhibit LBW age patterns similar to those seen in NH black mothers as a result of exposure to cumulative stress, trauma, and socioeconomic disadvantage, but this has not been empirically tested. This paper uses data from the 2014–2016 U.S. Birth File, which contains records of all U.S. births for those years to examine maternal age patterns in birth weight among AI/AN mothers. Importantly, this study also considers high birth weight (HBW) births, given higher prevalence of diabetes in the AI/AN population, and proposes that if “weathering” is occurring in this population, HBW prevalence likely will influence the observed maternal age patterns in birth weight, such that prevalence of births in normal range may resemble NH blacks, even if LBW prevalence does not. Findings suggest modest evidence of weathering in AI/AN populations for LBW. Examination of normal birth weight births suggests that inclusion of HBW to the risk profile of AI/AN births better defines birth outcome risk in this population relative to white mothers. Smoking during pregnancy and gestational diabetes were particularly prevalent among AI/AN mothers and present reason for concern in spite of relatively favorable birth outcomes.

•

American Indian/Alaska Native (AI/AN) birth outcomes resemble white mothers, despite substantially higher rates of gestational diabetes.

•

Age patterns of low birth weight in AI/AN mothers modestly suggest patterns in line with the weathering hypothesis.

•

AI/AN birth outcomes and risks have been ignored in research literature because of relatively small population size.

•

AI/AN mothers have higher rates of gestational diabetes than other groups, and higher smoking rates at older ages.

BIRTH ORDER, STAGE OF INFANCY AND INFANT MORTALITY IN INDIA

Using data from India's National Family Health Survey, 2005-06 (NFHS-3), this article examines the patterns of relationship between birth order and infant mortality. The analysis controls for a number of variables, including mother's characteristics such as age at the time of survey, current place of residence (urban/rural), years of schooling, religion, caste, and child's sex and birth weight. A modest J-shaped relationship between birth order of children and their risk of dying in the neonatal period is found, suggesting that although both first- and last-born children are at a significantly greater risk of dying compared with those in the middle, last-borns (i.e. fourth and higher order births) are at the worst risk. However, in the post-neonatal period first-borns are not as vulnerable, but the risk increases steadily with the addition of successive births and last-borns are at much greater risk, even worse than those in the neonatal period. Although the strength of relationship between birth order and mortality is attenuated after the potential confounders are taken into account, the relationship between the two variables remains curvilinear in the neonatal period and direct in the post-neonatal period. There are marked differences in these patterns by the child's sex. While female children are less prone to the risk of dying in the neonatal period in comparison with male children, the converse is true in the post-neonatal period. Female children not only run higher risks of dying in the post-neonatal period, but also become progressively more vulnerable with an increase in birth order.

Disparities in the Context of Opportunities for Cancer Prevention in Early Life

Persistent health disparities are a major contributor to disproportionate burden of cancer for some populations. Health disparities in cancer incidence and mortality may reflect differences in exposures to risk factors early in life. Understanding the distribution of exposures to early life risk and protective factors for cancer across different populations can shed light on opportunities to promote health equity at earlier developmental stages. Disparities may differentially influence risk for cancer during early life and create opportunities to promote health equity. Potential risk and protective factors for cancer in early life reveal patterns of disparities in their exposure. These disparities in exposures can manifest in downstream disparities in risk for cancer. These risk and protective factors include adverse childhood experiences; maternal alcohol consumption in pregnancy; childhood obesity; high or low birth weight; benzene exposure; use of assisted reproductive technologies; pesticide and insecticide exposure; isolated cryptorchidism; early pubertal timing; exposure to radiation; exposure to tobacco in utero and in early life; allergies, asthma, and atopy; and early exposure to infection. Disparities on the basis of racial and ethnic minority status, economic disadvantage, disability status, sex, geography, and nation of origin can occur in these risk and protective factors. Vulnerable populations experience disproportionally greater exposure to risk factors in early life. Addressing disparities in risk factors in early life can advance opportunities for prevention, promote health equity, and possibly reduce risk for subsequent development of cancer.

Depression Trajectories of Antenatally Depressed and Nondepressed Young Mothers: Implications for Child Socioemotional Development

OBJECTIVES

This study explores the longitudinal trajectories of depressive symptoms in young mothers and investigate the consequences of maternal depression for children's birth outcomes and behavioral adjustment.

HYPOTHESIS

Antenatal depression puts children of young mothers at risk for adjustment difficulties by adversely impacting birth outcomes and maternal symptoms after birth.

METHODS

Data were drawn from a three-wave randomized, controlled trial of a statewide home visiting program for young primiparous women. A subsample of women (n = 400) who were prenatal at intake was used in the analysis. Mothers were divided into an antenatally depressed group (ADG; 40%) and a healthy group (HG) based on their symptoms at intake. Mothers reported depressive symptoms at intake and 12- and 24-month follow-up, and filled out a checklist of child behavior problems at 24 months follow-up. Perinatal and birth outcomes were derived from the Electronic Birth Certificate collected by the State Department of Public Health at discharge from the hospital.

RESULTS

ADG and HG had similar pregnancy characteristics and birth outcomes, but ADG reported more child behavioral problems. Multigroup latent growth curve analysis provided evidence for distinct depression trajectories. A mediation hypothesis was not supported. In both groups, steeper increase in symptoms over time predicted more mother-reported child behavioral problems.

CONCLUSIONS

Findings are consistent with studies linking antenatal depression with post-birth symptoms, underscoring the importance of prenatal screening for depression.

Perinatal characteristics, older siblings, and risk of ankylosing spondylitis: a case-control study based on national registers

Background

The effect of circumstances and exposures early in life on the risk of developing ankylosing spondylitis (AS) is largely unknown. The purpose of this study was to determine whether perinatal characteristics predict development of AS.

Methods

AS cases (n = 1960; 59 % men) were defined as listed with a diagnosis of AS at least once in the Swedish National Patient Register and registered in the Swedish Medical Birth Register (born ≥1973). Population controls were retrieved from the Swedish Population Register (n = 8378; mean 4.3 controls/case), matched on birth year, sex and county. Odds ratios (OR) for developing AS were determined through conditional logistic regression, with regard to: birth weight, birth order, season of birth, maternal age, gestational length, size for gestational age, type of birth, mode of delivery, congenital malformations, mothers’ country of birth, mothers’ civil status and size of delivery unit.

Results

In the univariate analyses statistically significant increases in risk for developing AS were observed for having older siblings (OR 1.18; 95 % Cl 1.06–1.30). No association was observed for the remainder of analysed exposures, although there was a weak association with birth weight below 3000 g (OR 1.19; 95 % CI 1.04–1.37), though not for “low birth weight” <2500 g (OR 0.90; 95 % CI 0.70–1.16). The increase in risk associated with having older siblings was consistent in a multivariate analysis adjusting for possible confounders (OR 1.23; 95 % Cl 1.09–1.39). The direction and magnitude of the point estimates were also consistent in several sensitivity analyses and when stratifying by sex.

Conclusions

Having older siblings was associated with an increased risk for developing AS. These results need to be repeated and confirmed in other cohorts.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-0917-1) contains supplementary material, which is available to authorized users.

Analysis of hospital cost outcome of DHA-rich fish-oil supplementation in pregnancy: Evidence from a randomized controlled trial

OBJECTIVE

Recent research emphasized the nutritional benefits of omega-3 long chain polyunsaturated fatty acids (LCPUFAs) during pregnancy. Based on a double-blind randomised controlled trial named "DHA to Optimize Mother and Infant Outcome" (DOMInO), we examined how omega 3 DHA supplementation during pregnancy may affect pregnancy related in-patient hospital costs.

METHOD

We conducted an econometric analysis based on ordinary least square and quantile regressions with bootstrapped standard errors. Using these approaches, we also examined whether smoking, drinking, maternal age and BMI could influence the effect of DHA supplementation during pregnancy on hospital costs.

RESULTS

Our regressions showed that in-patient hospital costs could decrease by AUD92 (P<0.05) on average per singleton pregnancy when DHA supplements were consumed during pregnancy. Our regression results also showed that the cost savings to the Australian public hospital system could be between AUD15 - AUD51 million / year.

CONCLUSION

Given that a simple intervention like DHA-rich fish-oil supplementation could generate savings to the public, it may be worthwhile from a policy perspective to encourage DHA supplementation among pregnant women.

A Genetically Informed Study of the Associations Between Maternal Age at Childbearing and Adverse Perinatal Outcomes

We examined associations of maternal age at childbearing (MAC) with gestational age and fetal growth (i.e., birth weight adjusting for gestational age), using two genetically informed designs (cousin and sibling comparisons) and data from two cohorts, a population-based Swedish sample and a nationally representative United States sample. We also conducted sensitivity analyses to test limitations of the designs. The findings were consistent across samples and suggested that, associations observed in the population between younger MAC and shorter gestational age were confounded by shared familial factors; however, associations of advanced MAC with shorter gestational age remained robust after accounting for shared familial factors. In contrast to the gestational age findings, neither early nor advanced MAC was associated with lower fetal growth after accounting for shared familial factors. Given certain assumptions, these findings provide support for a causal association between advanced MAC and shorter gestational age. The results also suggest that there are not causal associations between early MAC and shorter gestational age, between early MAC and lower fetal growth, and between advanced MAC and lower fetal growth.

Factors influencing reproduction in captive-bred cynomolgus monkeys (Macaca fascicularis) from Mauritius

The cynomolgus monkey is widely used in reproductive research. However, the effects on their reproductive parameters of infant and maternal factors such as birth order, sex of infants, twin births, maternal age and lactation status have not been fully examined. The aim of this retrospective study was to determine how such infant and maternal factors impact on infant birth weight, birth viability, neonatal loss and retained placenta in cynomolgus monkeys. The study was based on birth data from a cohort of 789 females over an eight-year period. Consistent with reports made in other macaque species, female offspring had lower birth weight compared with males. Birth weights of firstborn infants were lower compared with birth weights of higher birth order infants. Results from the logistic regression analysis showed that the risk of non-viable births was increased by advancing maternal age and retained placenta. As in other non-human primates, maternal age had predictive value for non-viable births in cynomolgus monkeys. The risk of neonatal loss decreased with advancing maternal age but was not affected by birth order. Firstborn offspring did not have an increased risk for neonatal loss, possibly from the practice of retaining mothers in their natal groups, which improved maternal skills in primiparous females. However, infant low birth weight and non-lactating females increased the risk of neonatal loss, and the delivery of low birth weight infants was associated with retained placenta. The results from this study can be useful for scientists conducting reproductive studies and for colony managers in maximizing fertility and infant survival of cynomolgus monkeys.

1,5-Anhydroglucitol: a new predictor of neonatal birth weight in diabetic pregnancies

OBJECTIVE

To determine whether 1,5-anhydroglucitol is predictive of neonatal birth weight.

STUDY DESIGN

A retrospective cohort study including 85 pregnancies complicated by diabetes (Type 1=37, Type 2=24, gestational=24). Women had simultaneous hemoglobin A1c and 1,5-anhydroglucitol measurements every 4-8 weeks throughout pregnancy until delivery. Neonatal birth weight was evaluated by standardized z-scores. Linear regression analysis was performed to determine an association of 1,5-anhydroglucitol with neonatal birth weight z-score.

RESULTS

Type 1 diabetic patients had the lowest mean 1,5-anhydroglucitol of 3.5mcg/mL (SD=1.6mcg/mL) and highest mean hemoglobin A1c of 6.5% (SD=0.74%) compared to gestational diabetic patients who had the highest mean 1,5-anhydroglucitol of 6.7mcg/mL (SD=3.8mcg/mL) and lowest mean hemoglobin A1c of 6.0% (SD=0.94%). Mean 1,5-anhydroglucitol values were significantly different between diabetes types (p<0.01). Mean neonatal birth weight was above population averages for all diabetes classifications, although mean birth weight z-scores did not differ significantly between diabetic types (p=0.38). Multivariate linear regression showed a negative association between log-transformed 1,5-anhydroglucitol and birth weight (coefficient -0.82, 95% CI -1.19, -0.46).

CONCLUSION

In pregnancies complicated by diabetes, low 1,5-anhydroglucitol was associated with increased neonatal birth weight. 1,5-Anhydroglucitol may be useful in the assessment of glycemic control in pregnancy in addition to A1c.

[Study of low birth weight associated with maternal age and parity in a population of mother and children in Lubumbashi]

Introduction

Evaluer l'influence de l’âge maternel et de la parité sur la naissance d'un faible poids de naissance (FPN) à Lubumbashi.

Méthodes

Il s'agit d'une étude basée sur une analyse documentaire des dossiers médicaux des accouchées enregistrées dans les maternités des 10 hôpitaux généraux de référence (HGR) de la ville de Lubumbashi en République Démocratique du Congo entre le 1er décembre 2013 et le 31 mars 2014. Ces accouchées ont été réparties en deux groupes, en fonction du poids de naissance de leurs enfants: groupe I (femmes ayant accouché de nouveau-nés vivants dont le poids était inférieur à 2500 grammes) et groupe II (femmes ayant accouché de nouveau-nés vivants dont le poids était supérieur ou égal à 2500 grammes). Il s'agissait dans tous les cas de grossesses monofoetales âgées de 28 semaines ou plus. L’âge maternel et la parité ont été étudiés et comparés dans les deux groupes. Les données ont été analysées à l'aide des logiciels Épi info version 7.0 et SPSS version 19. Les différences étaient jugées significatives pour un seuil p < 0,05.

Résultats

La prévalence du FPN chez les nouveau-nés issus de ces accouchées était ainsi de 6,4% (71/1112). En analyse univariée, les femmes d’âge < 20 ans présentent un risque multiplié par 2,47 fois d'avoir un nouveau-né de FPN comparativement à celles de ≥20 ans (OR = 2,47; IC95%: 1,26-4,78) et celui pour les primipares d'avoir un enfant de FPN est 2,3 fois supérieur à celui de multipares (OR = 2,32; IC95%: 1,34-3,99). En faisant la régression logistique, nous avons observé que seule la parité est significativement corrélée au poids de naissance (OR ajusté = 2,61; IC95%: 1,43-4,74).

Conclusion

L’étude que nous avons menée montre que le taux de FPN diminue considérablement avec l’âge de la mère à partir de 20 ans et la multiparité.

Racial and ethnic disparities in extremes of fetal growth after gestational diabetes mellitus

AIMS/HYPOTHESIS

The aim of this study was to assess and compare risks of having large- or small-for gestational age (LGA and SGA, respectively) infants born to women with gestational diabetes mellitus (GDM) from ten racial/ethnic groups.

METHODS

LGA and SGA were defined as birthweight >90th and <10th percentile, respectively, specific to each racial/ethnic population and infant sex. Risks of LGA and SGA were compared among a retrospective cohort of 29,544 GDM deliveries from Hispanic, non-Hispanic white (NHW), non-Hispanic black (NHB), Filipino, Chinese, Asian Indian, Vietnamese, Korean, Japanese and Pacific Islander (PI) groups of women.

RESULTS

Unadjusted LGA and SGA risks varied among the ten groups. For LGA, the highest risk was in infants born to NHB women (17.2%), followed by those born to PI (16.2%), Hispanic (14.5%), NHW (13.1%), Asian Indian (12.8%), Filipino (11.6%) and other Asian (9.6-11.1%) women (p < 0.0001). Compared with NHW, the LGA risk was significantly greater for NHB women with GDM (RR 1.25 [95% CI 1.11-1.40]; p = 0.0001 after adjustment for maternal characteristics). Further adjustment for maternal pre-pregnancy BMI and gestational weight gain in the sub-cohort with available data (n = 8,553) greatly attenuated the elevated LGA risk for NHB women. For SGA, the risks ranged from 5.6% to 11.3% (p = 0.003) where most groups (8/10) had risks that were lower than the population-expected 10% and risks were not significantly different from those in NHW women.

CONCLUSIONS/INTERPRETATION

These data suggest that variation in extremes of fetal growth associated with GDM deliveries across race/ethnicity can be explained by maternal characteristics, maternal obesity and gestational weight gain. Women should be advised to target a normal weight and appropriate weight gain for pregnancies; this is particularly important for NHB women.

Is the fetoplacental ratio a differential marker of fetal growth restriction in small for gestational age infants?

Higher placental weight relative to birthweight has been described as an adaptive mechanism to fetal hypoxia in small for gestational age (SGA) infants. However, placental weight alone may not be a good marker reflecting intrauterine growth restriction. We hypothesized that fetoplacental ratio (FPR)-the ratio between birthweight and placental weight-may serve as a good marker of SGA after adjustment for surrogates of fetal hypoxemia (maternal iron deficiency anemia, smoking and choriodecidual necrosis). We conducted a within-sibling analysis using data from the US National Collaborative Perinatal Project (1959-1966) of 1,803 women who delivered their first two (or more) consecutive infants at term (n = 3,494). We used variance-component fixed-effect linear regression models to explore the effect of observed time-varying factors on placental weight and conditional logistic regression to estimate the effects of the tertiles of FPRs (1st small, 2nd normal and 3rd large) on the odds of SGA infants. We found placental weights to be 15 g [95 % confidence interval (CI) 8, 23] higher and -7 g (95 % CI -13, -2) lower among women that had anemia and choriodecidual necrosis, respectively. After multivariable adjustment, newborns with a small FPR (1st-tertile ≤7) had twofold higher odds of being SGA (OR 2.0, 95 % CI 1.2, 3.5) than their siblings with a large FPR (3nd-tertile ≥9). A small FPR was associated with higher odds of SGA, suggesting that small FPR may serve as an indicator suggestive of adverse intrauterine environment. This observation may help to distinguish pathological from constitutional SGA.

Mediation analysis of gestational age, congenital heart defects, and infant birth-weight

BACKGROUND

In this study we assessed the mediation role of the gestational age on the effect of the infant's congenital heart defects (CHD) on birth-weight.

METHODS

We used secondary data from the Baltimore-Washington Infant Study (1981-1989). Mediation analysis was employed to investigate whether gestational age acted as a mediator of the association between CHD and reduced birth-weight. We estimated the mediated effect, the mediation proportion, and their corresponding 95% confidence intervals (CI) using several methods.

RESULTS

There were 3362 CHD cases and 3564 controls in the dataset with mean birth-weight of 3071 (SD = 729) and 3353 (SD = 603) grams, respectively; the mean gestational age was 38.9 (SD = 2.7) and 39.6 (SD = 2.2) weeks, respectively. After adjusting for covariates, the estimated mediated effect by gestational age was 113.5 grams (95% CI, 92.4-134.2) and the mediation proportion was 40.7% (95% CI, 34.7%-46.6%), using the bootstrap approach.

CONCLUSIONS

Gestational age may account for about 41% of the overall effect of heart defects on reduced infant birth-weight. Improved prenatal care and other public health efforts that promote full term delivery, particularly targeting high-risk families and mothers known to be carrying a fetus with CHD, may therefore be expected to improve the birth-weight of these infants and their long term health.

Paternal race/ethnicity and very low birth weight

BACKGROUND

The purpose was to examine the association between paternal race/ethnicity and very low birth weight stratified by maternal race/ethnicity.

METHODS

Birth data for Tarrant County, Texas 2006-2010 were analyzed. Very low birth weight was dichotomized as yes (<1,500 g) and no (≥1,500 g). Paternal race/ethnicity was categorized as Caucasian, African American, Hispanic, other, and missing. Missing observations (14.7%) were included and served as a proxy for fathers absent during pregnancy. Potential confounders included maternal age, education, and marital status, plurality, previous preterm birth, sexually transmitted disease during pregnancy, smoking during pregnancy, and Kotelchuck Index of prenatal care. Logistic regressions were stratified by maternal race/ethnicity. Odds ratios and 95% confidence intervals were calculated.

RESULTS

Of 145,054 births, 60,156 (41.5%) were Caucasian, 22,306 (15.4%) African American, 54,553 (37.6%) Hispanic, and 8,039 (5.5%) other mothers. There were 2,154 (1.5%) very low birth weights total, with 3.1% for African American mothers and 1.2% for all other race/ethnicities. Among Caucasian mothers, African American paternal race was associated with increased odds of very low birth weight (OR = 1.52; 95% CI:1.08-2.14). Among Hispanic mothers, African American paternal race (OR = 1.66; 95% CI:1.01-2.74) and missing paternal race/ethnicity (OR = 1.65; 95% CI:1.15-2.36) were associated with increased odds of very low birth weight.

CONCLUSIONS

Paternal race/ethnicity is an important predictor of very low birth weight among Caucasian and Hispanic mothers. Future research should consider paternal race/ethnicity and further explore the association between paternal characteristics and very low birth weight.

Birth weight reference percentiles for Chinese

Objective

To develop a reference of population-based gestational age-specific birth weight percentiles for contemporary Chinese.

Methods

Birth weight data was collected by the China National Population-based Birth Defects Surveillance System. A total of 1,105,214 live singleton births aged ≥28 weeks of gestation without birth defects during 2006–2010 were included. The lambda-mu-sigma method was utilized to generate percentiles and curves.

Results

Gestational age-specific birth weight percentiles for male and female infants were constructed separately. Significant differences were observed between the current reference and other references developed for Chinese or non-Chinese infants.

Conclusion

There have been moderate increases in birth weight percentiles for Chinese infants of both sexes and most gestational ages since 1980s, suggesting the importance of utilizing an updated national reference for both clinical and research purposes.

Factors associated with birth weight inequalities in Jordan

BACKGROUND

Birth weight is a good indicator of mothers' and neonates' nutritional status, and it contributes to the newborn baby's survival, health, growth and development.

AIM

This study identified social factors associated with differences in the mean birth weight of newborn babies in Jordan.

METHODS

This retrospective study analysed medical records to determine possible risk factors associated with differences in newborn BW in the Irbid governorate of Jordan. All full-term singleton births during the year 2010 were reviewed. Abstracted data included mother's age, educational level, and monthly family income. Newborn information included birth weight, gender and birth order.

RESULTS

A total of 5414 full-term singleton births were included. Of these, 15.1% were low birth weight, 73.6% were normal birth weight, and 11.3% were high birth weight. Bivariate analysis of variance revealed that low mean birth weight was associated with female gender, first-born babies, higher maternal age (>35 years), lower educational level and lower income (<500 JD). Multivariate analysis of variance revealed that mean birth weight was lower in female infants, first-born infants, infants of less educated mothers, higher age and low monthly income.

LIMITATIONS

The findings can be generalized to full-term singleton pregnancies in countries who share similar cultural and traditional values.

CONCLUSION

Education of mothers is a modifiable variable that can positively influence birth weight, particularly in the case of female and first-born infants.

IMPLICATION FOR NURSING AND HEALTH POLICY

The findings inform our understanding of some social factors affecting birth weights of neonates in Jordan and development of effective public health interventions that could reduce the adverse effects of such factors on newborn birth weight. Preconception and antenatal care is also important for early detection of such possible risk and targeting mothers who require early interventions and support.

Applying measures of discriminatory accuracy to revisit traditional risk factors for being small for gestational age in Sweden: a national cross-sectional study

OBJECTIVES

Small for gestational age (SGA) is considered as an indicator of intrauterine growth restriction, and multiple maternal and newborn characteristics have been identified as risk factors for SGA. This knowledge is mainly based on measures of average association (ie, OR) that quantify differences in average risk between exposed and unexposed groups. Nevertheless, average associations do not assess the discriminatory accuracy of the risk factors (ie, its ability to discriminate the babies who will develop SGA from those that will not). Therefore, applying measures of discriminatory accuracy rather than measures of association only, our study revisits known risk factors of SGA and discusses their role from a public health perspective.

DESIGN

Cross-sectional study. We measured maternal (ie, smoking, hypertension, age, marital status, education) and delivery (ie, sex, gestational age, birth order) characteristics and performed logistic regression models to estimate both ORs and measures of discriminatory accuracy, like the area under the receiver operating characteristic curve (AU-ROC) and the net reclassification improvement.

SETTING

Data were obtained from the Swedish Medical Birth Registry.

PARTICIPANTS

Our sample included 731 989 babies born during 1987-1993.

RESULTS

We replicated the expected associations. For instance, smoking (OR=2.57), having had a previous SGA baby (OR=5.48) and hypertension (OR=4.02) were strongly associated with SGA. However, they show a very small discriminatory accuracy (AU-ROC≈0.5). The discriminatory accuracy increased, but remained unsatisfactorily low (AU-ROC=0.6), when including all variables studied in the same model.

CONCLUSIONS

Traditional risk factors for SGA alone or in combination have a low accuracy for discriminating babies with SGA from those without SGA. A proper understanding of these findings is of fundamental relevance to address future research and to design policymaking recommendations in a more informed way.

Fundal height growth curve for underweight and overweight and obese pregnant women in Thai population

Objectives. To develop fundal height growth curves for underweight and overweight and obese pregnant women based on gestational age from last menstrual period and/or ultrasound. Methods. A retrospective study was conducted at four hospitals in the northern part of Thailand between January 2009 and March 2011. Fundal height, gestational age, height, and prepregnancy weight were extracted from antenatal care and delivery records. Fundal height growth curves were presented as smoothed function of the 10th, 50th, and 90th percentiles between 20 and 40 weeks of gestation, derived from multilevel models. Results. Fundal height growth curve of the underweight was derived from 1,486 measurements (208 women) and the overweight and obese curve was derived from 1,281 measurements (169 women). The 50th percentile line of the underweight was 0.1-0.4 cm below the normal weight at weeks 23-31 and 0.5-0.8 cm at weeks 32-40. The overweight and obese line was 0.1-0.4 cm above the normal weight at weeks 22-29 and 0.6-0.8 cm at weeks 30-40. Conclusions. Fundal height growth curves of the underweight and overweight and obese pregnant women were different from the normal weight. In monitoring or screening for abnormal intrauterine growth in these women, fundal height growth curves specifically developed for such women should be applied.

Sibship size, birth order, family structure and childhood mental disorders

PURPOSE

The aim of this study was to determine the role that birth order, sibship size and family structure have as risk factors in the development of common childhood mental disorders.

METHOD

A case-control study design was conducted (N = 16,823). The group under study consisted of all those subjects who had consulted with a psychiatrist/psychologist and had received a clinical diagnosis at public mental health centres within the Region of Madrid (Spain), between 1980 and 2008. A multiple logistic regression was used to explore the independent association with each diagnosis: emotional disorders (ED) with onset specific to childhood, attention deficit hyperactivity disorder (ADHD), conduct disorder (CD), mental retardation (MR), and pervasive developmental disorder (PDD).

RESULTS

Birth order and family structure significantly predicted the risk of being diagnosed with ED or ADHD. In addition, sibship size and sex predicted the risk of being diagnosed with a childhood mental disorder.

CONCLUSIONS

We concluded that being the middle child and living with both biological parents appear to be protective factors against the development of ED or ADHD. Living in large families appears to increase the risk of receiving a CD, MR, or PDD diagnosis. Further research is warranted.