Full-term Singleton Live Births Research Articles

Growth Status of Full-Term Infants with Different Sizes for Gestational Age During the First Year of Life.

This study aimed to assess the growth of full-term infants with different sizes at birth and examine catch-up and catch-down growth in their first year. This retrospective population-based cohort study was based on the Guangdong Provincial Women and Children Health Information System. 194797 full-term singleton live births were extracted. Measurements for weight and length were taken at birth, 6 months, and 12 months. The size-for-gestational age was categorized as small (SGA, <10th centile), appropriate (AGA, 10th-90th centiles), or large (LGA, >90th centile) based on the international newborn size for gestational age and sex INTERGROWTH-21st standards. Catch-up and catch- down growth were defined as a change in standard deviation in z-score greater than 0.67 in the growth curves. Of the 194797 full-term singletons, the average gestational age was 39.28 ± 1.03 weeks, and the average weight of the newborns was 3205 ± 383 grams. 15632 infants were identified as SGA (8.0%) and 12756 were LGA (6.5%). At 1 year of age, catch-up growth in weight was observed in 63.0% of SGA infants, 29.5% of AGA infants, and 5.4% of LGA infants. Conversely, catch-down growth occurred in 3.3% of SGA infants, 17.8% of AGA infants, and 54.7% of LGA infants. The proportions of catch-up growth in length for SGA, AGA, and LGA infants within the first year were 31.4%, 22.5%, and 17.1%, respectively. Catch-up or catch-down growth predominantly occurred before 6 months of age. However, from 6 to 12 months, there was no significant variation in WAZ among children with different birth sizes. In their first year of life, full-term singleton live births tend towards regression to the mean in their postnatal weight and length. The average delay in the growth of LGA is compensated by an increase in it of the SGA. Early monitoring and intervention are crucial for optimizing growth in infants with different birth sizes.

Obesity class I and II and IOM 2009 gestational weight gain recommendations 5–9 kg. An audit on 10,000 term singleton deliveries

Objectives To compare several maternal-fetal morbidities comparing the Institute of Medicine IOM 2009 recommendations (IOMR: 5–9 kg in all obese women) between women with adequate gestational weight gain (GWG) and Inadequate (less than 5 kg), and excessive those gaining more than 9 kg among obese women class I (30–34.9 kg/m2) and class II (35–39.9 kg/m2). Study design South-Reunion University’s maternity (Reunion Island, Indian Ocean). 21-Year-observational cohort study (2001–2021). Epidemiological perinatal database with information on obstetrical and neonatal risk factors. Main outcome measures Cesarean sections, preeclampsia, means birthweight, rate of small (SGA) or large (LGA) for gestational age newborns and macrosomic babies (≥4 kg). Results Among the singleton term live births (37 weeks onward) we could define the pre-pregnancy body mass index and GWG in 85.9% of cases. The final study population focused on 10,296 obese women (7138 obesity class I − 30–34.9 kg/m2, 3158 obesity class II – 35–39.9 kg/m2). Concerning inadequate GWG (less than 5 kg), respectively for obese I and II, IOMR babies were heavier (plus 90 and 104 g, p < .001), were more prone to be LGA OR 1.61 and 1.69, p < .001, macrosomic OR 1.49 and 2.21, p < .0001, IOMR women had more cesarean sections OR 1.33, OR 1.45, p = .001, and for obese II a tendency for more term preeclampsia OR 1.83, p = .06. Conclusion This study demonstrates that for obese women these IOMR (5–9 kg) are mildly but significantly too high if we consider obesity class I and obviously too high for obesity class II (35–39.9 kg/m2).

Racial Disparities in the Rates of and Indications for Cesarean Delivery in California: Are They Changing Over Time?

The aim of this study was to assess whether racial disparities in rates of and indications for cesarean delivery (CD) between non-Hispanic Black and non-Hispanic White birthing people in California changed from 2011 to 2017. This was a retrospective cohort study using a database of birth certificates linked to discharge records. Singleton term live births in nulliparous Black and White birthing people in California between 2011 and 2017 were included. Those with noncephalic presentation, placenta previa, and placenta accreta were excluded. CD rate and indication were obtained from birth certificate variables and International Classification of Diseases codes. Differences in CD rate and indication were calculated for Black versus White individuals using univariable and multivariable logistic regression and adjusted for potential confounders. A total of 348,144 birthing people were included, 46,361 Black and 301,783 White. Overall, 30.9% of Black birthing people underwent CD compared with 25.3% of White (adjusted relative risk [aRR]: 1.2, 95% confidence interval [CI]: 1.2-1.3). From 2011 to 2017, the CD rate fell 11% (26.4-23.7%, p < 0.0001) for White birthing people and 1% for Black birthing people (30.4-30.1%, p = 0.037). Over the study period, Black birthing people had a persistent 1.2- to 1.3-fold higher risk of CD and were persistently more likely to undergo CD for fetal intolerance (aRR: 1.1, 95% CI: 1.1-1.2) and less likely for active phase arrest or arrest of descent (aRRs: 0.9 and 0.4; 95% CIs: 0.9-0.9 and 0.3-0.5). The CD rate decreased substantially for White birthing people and minimally for Black birthing people in our cohort over the study period. Meanwhile, disparities in CD rate and indications between the two groups persisted, despite controlling for confounders. Although care bundles for reducing CD may be effective among White birthing people, they are not associated with reduction in CD rates among Black birthing people nor improvements in racial disparities between Black and White birthing people. Despite increasing attention to racial inequities in obstetric outcomes, there were no changes in disparities in CD rates or indications in California from 2011 to 2017. · Black birthing people are more likely to undergo CD than White despite controlling for confounders.. · There are unexplained differences in CD indication among Black and White birthing people.. · These disparities persisted from 2011 to 2017 despite increasing efforts to decrease CD rates in CA..

Maternal exposure to traffic-related pollutants during pregnancy and birth weight: using machine-learning methods to achieve balance in inverse-probability weights

BACKGROUND AND AIM: Low birth weight (LBW) is associated with increased risks of health problems in infancy and later life. Among the current epidemiological analyses suggesting the association between air pollution and birth weight, few have specifically estimated the effects of traffic-related pollutants or used causal modelling. We aimed to investigate the causal association between prenatal exposure to black carbon (BC) and nitrogen dioxide (NO₂) and birth weight using machine learning methods to achieve balance in inverse-probability weights. METHODS: We examined 1,119,011 birth records between January 1, 2001 and December 31, 2015 from the Massachusetts Birth Registry. Mean residential BC and NO₂ exposure 0-30, 31-90, 91-280 days prior to birth were calculated using estimates from validated spatial-temporal models. We fit generalized propensity score models with gradient boosting tuned by a new algorithm to achieve covariate balance, then fit marginal structural models with stabilized inverse-probability weights calculated from those models. RESULTS:Over the entire pregnancy, average birth weight would drop by -31.2 g (95% CI: -35.5, -26.9) for an IQR increase of 0.145 μg/m3 in BC and would drop by -25.9 g (95% CI: -30.1, -21.7) for an IQR increase of 9.8 ppb in NO₂. The effect sizes are similar in the three averaging periods for BC but the effect in the 91-280 prior period for NO₂ is larger than the other two exposure windows. The estimated odds ratio of LBW (defined as birth weight less than 2,500 g) for every IQR increase during the entire pregnancy was 1.21 (95% CI: 1.13, 1.28) for BC and was 1.11 (95% CI: 1.05, 1.18) for NO₂. CONCLUSIONS:In full-term singleton live births in Massachusetts between 2001 and 2015, higher maternal exposure to traffic-related air pollution (BC and NO₂) during pregnancy resulted in lowering birth weight and increasing the odds of LBW. KEYWORDS: Air pollution, Traffic-related, Big data, Birth outcomes, Causal inference, Epidemiology

Epidemiological evidence that severe obese women (pre-pregnancy BMI ≥40 kg/m2) should lose weight during their pregnancy

Objectives Defining the optimal gestational weight gain (optGWG) allowing to have “normal shaped” babies (10% of Small for gestational age, SGA, and10% of large LGA babies) in severe obese women (pre-pregnancy BMI ≥40 kg/m2). Study design South-Reunion University’s maternity (Reunion Island, Indian Ocean). 20 year-observational cohort study (2001–2019). Epidemiological perinatal data base with information on obstetrical and neonatal risk factors. All consecutive term (37–42 weeks gestation) singleton pregnancies (>21 weeks) live birth pregnancies delivered in the maternity. Main outcome measures OptGWG to obtain newborns as close as possible of the 10% SGA/LGA goal for each BMI categories, 15–19.9, 20–24.9 …, as well as severe obese ≥40 kg/m2. Results Of the 71,318 singleton term live births (37 weeks onward), we could define the maternal pre-pregnancy body mass index and the GWG in of 61,764 patients (86.6%). Severe obese 40 kg/m2 losing 5–9.9 kg have 12.9% of LGA and 11.9% of SGA babies. Those losing 10 kg and more 12.7% of LGA and 7.3% of SGA. Our formerly proposed linear equation (validated from 15 to 40 kg/m2) may be prolonged at 45 kg/m2. opGWG ( kg ) = − 1.2 pp BMI ( Kg / m 2 ) + 42 ± 2 kg Conclusion In our population, a 32 kg/m2 obese should gain 3.6 kg (instead of 5–9 kg, IOM 2009). A very obese 40 kg/m2 should lose 6 kg, and a severe obese 45 kg/m2 lose 12 kg.

Effects of maternal exposure to fine particulate matter on birth weight in 16 counties across China: a quantile regression analysis

The adverse effects of air pollution during pregnancy have been studied intensively, but mainly utilizing linear and logistic models, which generally yield little information about how air pollution may change the distribution of birth weight in populations. We aimed to examine the effects of fine particulate matter (PM2.5) on quantiles of birth weight, and if effects were heterogeneous in different populations and regions. We used a prospective cohort study of 196 283 singleton term live births from 16 counties across China during 2014–2018. PM2.5 exposure for full gestation, each trimester and last gestational month were assessed by Inverse Distance Weighting interpolation. Linear and quantile regression were conducted to estimate associations between PM2.5 exposure and mean birth weight, as well as birth weight distribution, with birthweight z-score as the main outcome. Stratified analyses and Cochran Q tests were conducted by maternal and geographical characteristics. Each 10 µg m−3 increase in average PM2.5 over the entire pregnancy was associated with reduced birthweight z-score (−0.010, 95% CI: −0.015, −0.005) and birth weight (−3.21 g, 95% CI: −5.27, −1.15). In quantile regression, more pronounced effects were observed in lower and intermediate quantiles, with a decrease of 0.021 (95% CI: 0.033, 0.009) and 0.009 (95% CI: 0.015, 0.002) in the 5th and 50th quantiles of birthweight z-score, respectively. Additionally, we observed stronger associations among well-educated, migrant and primiparous mothers as well as in coastal areas. Maternal exposure to PM2.5 was associated with reduction in birth weight, especially for those with very low birth weight. Well-educated, migrant and primiparous mothers, as well as births in coastal areas may be more sensitive to PM2.5 in our study population. The results may be relevant to targeted public health interventions to reduce maternal exposure to air pollution.

Maternal ADHD medication use during pregnancy and the risk of ADHD in children: Importance of genetic predispositions and impact of using a sibling analysis

Attention deficit with hyperactivity disorder (ADHD) medications in pregnancy would be associated with ADHD in children, however, estimates can be confounded by genetic predispositions and environmental factors related to the mother-child pair. We aim to quantify the risk of ADHD in children associated with ADHD medication exposures during pregnancy. A prospective cohort study and sibling analysis conducted within The Quebec Pregnancy/Child Cohort (QPC). All full-term singleton live births covered by the provincial prescription drug insurance in Quebec from 1998 to 2015 were included. ADHD medication exposure during pregnancy was defined according to trimester of use and class-specific medication. ADHD in children was defined as having at least one diagnosis or one prescription filled for an ADHD medication. Cox proportional hazards regression models were used to calculate crude and adjusted hazard ratios (aHR) with 95% confidence intervals (CIs) in the overall cohort, the sub-cohort and the sibling analysis. Of 166,047 full-term singleton live births included, 25,454 (15.3%) had ADHD. In the overall cohort, maternal exposure to ADHD medication during pregnancy was associated with ADHD in children (aHR= 1.96, 95% CI 1.22–3.15). In the ADHD pregnant women sub-cohort (aHR= 1.56; 95% CI 0.93–2.62) and the sibling control analysis (aHR= 1.14; 95% CI 0.62–1.98), ADHD medications during pregnancy was not associated with an increased risk of ADHD in children. Our findings suggest that in utero exposure to ADHD medications was not associated with an increased risk of ADHD in children. This suggests that the association is due to genetic and/or family environmental factors.

Changing trends of birth weight with maternal age: a cross-sectional study in Xi\u2019an city of Northwestern China

BackgroundMost studies have shown that maternal age is associated with birth weight. However, the specific relationship between each additional year of maternal age and birth weight remains unclear. The study aimed to analyze the specific association between maternal age and birth weight.MethodsRaw data for all live births from 2015 to 2018 were obtained from the Medical Birth Registry of Xi’an, China. A total of 490,143 mother-child pairs with full-term singleton live births and the maternal age ranging from 20 to 40 years old were included in our study. Birth weight, gestational age, neonatal birth date, maternal birth date, residence and ethnicity were collected. Generalized additive model and two-piece wise linear regression model were used to analyze the specific relationships between maternal age and birth weight, risk of low birth weight, and risk of macrosomia.ResultsThe relationships between maternal age and birth weight, risk of low birth weight, and risk of macrosomia were nonlinear. Birth weight increased 16.204 g per year when maternal age was less than 24 years old (95%CI: 14.323, 18.086), and increased 12.051 g per year when maternal age ranged from 24 to 34 years old (95%CI: 11.609, 12.493), then decreased 0.824 g per year (95% CI: -3.112, 1.464). The risk of low birth weight decreased with the increase of maternal age until 36 years old (OR = 0.917, 95%CI: 0.903, 0.932 when maternal age was younger than 27 years old; OR = 0.965, 95%CI: 0.955, 0.976 when maternal age ranged from 27 to 36 years old), then increased when maternal age was older than 36 years old (OR = 1.133, 95%CI: 1.026, 1.250). The risk of macrosomia increased with the increase of maternal age (OR = 1.102, 95%CI: 1.075, 1.129 when maternal age was younger than 24 years old; OR = 1.065, 95%CI: 1.060, 1.071 when maternal age ranged from 24 to 33 years old; OR = 1.029, 95%CI: 1.012, 1.046 when maternal age was older than 33 years old).ConclusionsFor women of childbearing age (20–40 years old), the threshold of maternal age on low birth weight was 36 years old, and the risk of macrosomia increased with the increase of maternal age.

Estimated prenatal exposure to nitrate in drinking water and body length and head circumference at birth: A population-based prospective cohort study from Denmark, 1991-2011

Background/Aim: Findings from studies examining the effects of prenatal exposure to nitrate from drinking water on fetal growth have been inconsistent, small, and mostly ecologic in nature and none have explicitly examined infant size as measured by body length (BL) or head circumference (HC) at birth. The aim of this study was to assess maternal exposure to nitrate in drinking water and BL and HC at birth in a large population-based cohort.Methods: Estimates of water contamination by nitrate at each maternal address during pregnancy were linked with individual-level birth registry data to create a cohort of full-term singleton live births in Denmark from Danish parents during 1991-2011, with 848,106 measures of BL and 588,981 of HC. Exposures were modeled both categorically and as log-transformed continuous estimates. Multivariate linear regression with generalized estimating equations was used to assess associations.Results: A negative trend in BL was observed in both categorical (p&lt;0.001) and continuous models (p=0.01) of nitrate exposure. When comparing the European Union action level of 25mg/L to 0mg/L NO3- exposure, a 0.3mm reduction in BL was estimated. There was no evidence of an exposure-response relationship in either categorical (p=0.52) or continuous (p=0.69) models of nitrate exposure for HC. Conclusions: To the best of our knowledge, our study is the first to examine the relationship between nitrate in drinking water and body length and head circumference. Estimated maternal nitrate exposure was associated with decreased BL, but not HC at birth. However, HC was not recorded until 1997 and has less overall variation, making it harder to observe effects of environmental exposures. While the reduction in BL is not clinically relevant at the individual level, it may important from a public health point of view given the widespread exposure to nitrate in drinking water worldwide.

Beyond adequate: Factors associated with quality of antenatal care in western Tanzania.

To determine quality of antenatal care (ANC). Most literature focuses on ANC attendance and services. Less is known about quality of care (QoC). Data were analyzed from the 2016 Kigoma Reproductive Health Survey, a population-based survey of reproductive-aged women. Women with singleton term live births were included and principal component analysis (PCA) was used to create an ANC quality index using linear combinations of weights of the first principal component. Nineteen variables were selected for the index. The index was then used to assign a QoC score for each woman and linear regression used to identify factors associated with receiving higher QoC. A total of 3178 women received some ANC. Variables that explained the most variance in the QoC index included: gave urine (0.35); gave blood (0.34); and blood pressure measured (0.30). In multivariable linear regression, factors associated with higher QoC included: ANC at a hospital (versus dispensary); older age; higher level of education; working outside the home; higher socioeconomic status; and having lower parity. Using PCA methods, several basic components of ANC including maternal physical assessment were identified as important indicators of quality. This approach provides an affordable and effective means of evaluating ANC programs.

Ambient air pollution and markers of fetal growth: A retrospective population-based cohort study of 2.57 million term singleton births in China

BackgroundsEvidence is scarce on the relation between maternal exposure to ambient air pollution during pregnancy and fetal growth in developing countries. Moreover, the current evidence is inconsistent. We aimed to investigate the association of trimester-specific exposure to air pollution with risk of being born small for gestational age (SGA) and birth weight-markers of fetal growth-among Chinese term births. MethodsThis retrospective population-based cohort study consisted of 2,567,457 singleton term live-births from January 1, 2014 to December 31, 2017 across 123 Chinese districts and counties. Personal exposure to ambient air pollutants including carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), particulate matter with aerodynamic diameter < 2.5 μm (PM2.5), and PM10 was assigned using the inverse distance weighting spatial interpolation algorithm. Generalized estimating equations (GEE) logistic regression models were performed to estimate the associations between trimester-specific exposure to air pollution and risk of SGA or low birth weight (LBW), and GEE linear regression to examine the associations between the exposure and term birth weight, adjusting for maternal demographics, maternal cigarette smoking status during pregnancy, mode of delivery, gravidity, gestational age, year and month of conception, neonate’s sex, and meteorological factors. Stratified and sensitivity analyses were also performed. ResultsWhen mother exposed to ambient air pollutants over the entire pregnancy, per IQR increment (0.122 mg/m3) in ambient CO concentrations was associated with higher risk of SGA (odds ratio (OR) = 1.04, 95% confidence interval (CI): 1.02, 1.05) and reduced birth weight among term births (−5.95 g, 95% CI: −8.01, −3.89). This association was also pronounced in the second and third trimesters. Term birth weight was negatively associated with per IQR increase of O3 (−3.52 g, 95% CI: −6.23, −0.81), PM2.5 (−5.93 g, 95% CI: −8.36, −3.49) and PM10 (−7.78 g, 95% CI: −10.41, −5.16) during the entire pregnancy, respectively. No significant association was detected between maternal exposure to air pollutants and term LBW. Effect estimates of heterogeneity suggested that maternal age and infant sex modified the impact of air pollution on birth weight. ConclusionsThe findings suggest that maternal exposure to air pollution during pregnancy is adversely affecting fetal growth. Further studies are warranted to integrate these findings and take clinical or public health interventions in pregnancy.

Determinants of low birth weight in India: An investigation from the National Family Health Survey.

This study aimed to estimate the change in prevalence of low birth weight (LBW) over the last decade in India and to identify its associated factors-biological, demographic, socio-economic, and programmatic. We used the data from the National Family Health Survey of 2005-2006 (NFHS-3) and 2015-2016 (NFHS-4). The sample of this study included 11 300 children from NFHS-3 and 99 894 from NFHS-4 data; all these children were the last full-term singleton live-births, born within the last 3 years prior to the survey. In India, the prevalence of LBW has significantly declined from 20.4% (95%CI 19.4-21.4) to 16.4% (95% CI 16.1-16.8) in the last decade. The prevalence of LBW remained high in girl children (OR = 1.2, 95% CI 1.2-1.3; P < .001), whose mothers were adolescent (OR = 1.2, 95% CI 1.1-1.3; P < .001), and were stunted (OR = 1.3, 95% CI 1.3-1.3; P < .001). Prevalence of LBW declined among second or higher birth order child (OR = 0.8, 95% CI 0.8-0.9; P < .001), whose mothers educated up to secondary level and above (OR = 0.6 to 0.8), belonged to rich wealth quintiles (OR = 0.9 to 0.8), were from rural area (OR = 0.9, 95% CI 0.9-1.0; P < .001), received better nutrition and adequate antenatal care (OR = 0.8, 95% CI 0.8-0.8; P < .001), and were from eastern, northeastern, and southern regions of India (OR = 0.9 to 0.5). Although the prevalence of LBW in India has declined over the past decade, the extent of the decline is modest. In the coming years, health programs in India need to gear up with greater convergence between maternal health services and maternal nutrition to reduce LBW.

Relationship between pre-pregnancy maternal BMI and optimal weight gain in singleton pregnancies

BackgroundThere is a peculiar phenomenon: two separate individuals (mother and foetus) have a mutually interactive dependency concerning their respective weight. Very thin mothers have a higher risk of small for gestational age (SGA) infants, and rarely give birth to a large for gestational age (LGA) infant. While morbidly obese women often give birth to LGA infants, and rarely to SGA. Normal birthweight (AGA) infants (>10th and <90th centile of a neonatal population) typically have the lowest perinatal and long-term morbidity. The aim of the current study is (1) to determine the maternal body mass index (BMI) range associated with a balanced risk (10% SGA, 10% LGA), and (2) to investigate the interaction between maternal booking BMI, gestational weight gain (GWG) and neonatal birthweight centiles. Methods16.5 year-observational cohort study (2001–2017). The study population consisted of all consecutive singleton term (37 weeks onward) live births delivered at University's maternity in Reunion island, French Overseas Department. FindingsOf the 59,717 singleton term live births, we could define the booking BMI and the GWG in 52,092 parturients (87.2%). We had 2 major findings (1) Only women with a normal BMI achieve an equilibrium in the SGA/LGA risk (both 10%). We propose to call this crossing point the Maternal Fetal Corpulence Symbiosis (MFCS). (2) This MFCS shifts with increasing GWG. We tested the MFCS by 5 kg/m2 incremental BMI categories. The result is a linear law:opGWG (kg) = −1.2 ppBMI (Kg/m²) + 42 ± 2 kg InterpretationIOM-2009 recommendations are adequate for normal and over-weighted women but not for thin and obese women: a thin woman (17 kg/m2) should gain 21.6 ± 2 kg (instead of 12.5–18). An obese 32 kg/m2 should gain 3.6 kg (instead of 5–9). Very obese 40 kg/m2 should lose 6 kg.

Five successful pregnancies with antenatal anakinra exposure.

Our aim is to add to the limited existing prospective data on IL-1 inhibitor use in pregnancy. Data were obtained from the Organization of Teratology Information Specialists Autoimmune Disease in Pregnancy Project, a prospective cohort study of pregnancy outcomes in the USA and Canada. Eligible women were enrolled prior to 19 weeks' gestation between 2004 and 2017. Outcomes were obtained by maternal interview and medical record abstraction. Five pregnancies with anakinra exposure were identified, all resulting in full-term singleton live births with no major or long-term complications. Three maternal subjects used anakinra for adult-onset Still's disease and two for systemic JIA. For all individuals who discontinued anakinra, some amount of steroid medication was necessary for treatment of disease flare. Two maternal subjects developed oligohydramnios, one also with pregnancy-induced hypertension. Two women had Caesarian sections, one medically indicated and one scheduled. One infant had low birth weight, but follow-up records indicated normal adjusted weight at 1 year. Three women successfully breastfed their infants, at least two of whom continued anakinra while breastfeeding. Anakinra was used successfully in five full-term pregnancies; however, two subjects developed oligohydramnios, a process that can be linked to fetal renal anomalies. Given previously reported cases of congenital renal anomalies associated with both antenatal anakinra use and maternal hyperthermia, the relationship between maternal IL-1 inhibitor use, uncontrolled maternal febrile disease and fetal outcomes should be further explored.

Birth weight influences the kidney size and function of Bangladeshi children.

Early-life conditions influence organ growth patterns and their functions, as well as subsequent risk for non-communicable chronic diseases in later life. A limited number of studies have determined that in Bangladesh, kidney size relates to its function among children as a consequence of the maternal and postnatal conditions. The present study objectives were to determine early-life conditions in relation to childhood kidney size and to compare their influences on kidney function. The study was embedded in a population-based prospective cohort of 1067 full-term singleton live births followed from fetal life onward. Kidney volume was measured by ultrasound in children at the age of 4.5 years (range 45-64 months), and the estimated glomerular filtration rate (eGFR) was assessed at the age of 9 years (range 96-116 months). The mean (s.d.) kidney volume of children at 4.5 years was 64.2 (11.3) cm3, with a significant mean difference observed between low birth weight and normal birth weight children (P<0.001). The multivariable model showed, changes in status from low birth weight to normal birth weight children, with kidney volume increases of 2.92 cm3/m2, after adjusting for the child's age, sex, maternal age and early pregnancy body mass index, and socio-economic index variables. One-unit change in kidney volume (cm3/m2) improved the eGFR to 0.18 ml/min/1.73 m2. The eGFR in low birth weight children was 5.44 ml/min/1.73 m2 less than that in normal birth weight children after adjustments. Low birth weight leads to adverse effects on kidney size and function in children.

Risk factors for maternal anaemia and low birth weight in pregnant women living in rural India: a prospective cohort study

ObjectiveThe aim of this prospective study was to estimate the prevalence and risk factors for maternal anaemia and low birth weight (LBW) in pregnant women living in Maharashtra state, India. Study designThis is a prospective study. MethodsWomen between 3 and 5 months of pregnancy were recruited from 34 villages based in Maharashtra state. Baseline data collection, anthropometric measurements and blood investigations were performed. Participants were followed-up to record birth weight. ResultsIn total, 303 women were eligible, and 287 (95%) provided data. 77% were anaemic, defined as haemoglobin less than 11.0 g/dl at the time of recruitment, with a mean corpuscular volume of 80.5 fl/cell (standard deviation: 7.22, range: 53.4–93.8). The increased risk of anaemia was seen in women with consanguineous marriages (odds ratio [OR]: 2.41, 95% confidence interval [CI]: 1.16–5.01, P = 0.01) after adjustment for potential confounding factors. Postdelivery data from full-term singleton live births demonstrated a 7% prevalence of LBW. Consanguineous marriage was a major risk factor for LBW (OR: 4.10, 95% CI: 1.25–13.41, P = 0.02). The presence of maternal anaemia during 3–5 months of pregnancy was associated with lower risk of LBW (unadjusted OR: 0.34, 95% CI: 0.13–0.92, P = 0.03). ConclusionAbout 30% of our study participants were in a consanguineous marriage, which was identified as a potentially avoidable risk factor for both anaemia and LBW.

Gestational weight gain rate in third trimester relates to maternal and neonatal outcomes in pregnancies with normal glucose tolerance

Objective To investigate the association between third-trimester gestational weight gain rate (GWGR) and both maternal and neonatal health outcomes in a normal glucose tolerance obstetric population. Methods This was a retrospective cohort study of full-term singleton live births (n=1 967) in women with a normal oral glucose tolerance test (OGTT) tested at 24-28 gestational weeks, who gave birth at Beijing Obstetrics and Gynecology Hospital, Capital Medical University, between January and December in 2013. The subjects were divided into three groups based on third-trimester GWGR category of the 2009 Institute of Medicine (IOM) guidelines. Each group was divided into three subgroups by pre-pregnancy body mass index (BMI): low (<18.5), normal (≥18.5-<25.0), and high (≥25.0). One-way analysis of variance, Chi-square or Fisher's exact test, Logistic regression and corrected analysis were performed for statistical analysis. Results (1) Of the 1 967 women analyzed, third-trimester weight gain distribution was normal in 575(29.2%), excessive in 982(49.9%), and insufficient in 410(20.8%). No significant differences were found in terms of age, parity, education level, family history of diabetes or hypertension among the GWGR groups (all P>0.05). (2) The mean third-trimester weight gain in the 1 967 normal OGTT women was (0.56±0.23) kg/week and the mean neonatal birth weight was (3 442±396) g. The above two parameters were linearly correlated (Y=103.839X+3383.752, r=0.621, P 0.05). (3) Compared to the normal GWGR group, the excessive GWGR group had an increased incidence of cesarean section [30.2% (297/982) vs 22.2% (128/575)] and hypertensive disorders of pregnancy [4.0% (39/982) vs 1.9% (11/575)] (all P 0.05). (4) In the normal and insufficient GWGR groups, no differences in neonatal birth weight or risk of small-for-gestational age (SGA) or large-for-gestational age (LGA) were seen in any of the BMI subgroups (all P>0.05). In the excessive GWGR group, the high pre-pregnant BMI subgroup showed higher neonatal birth weight than the normal pre-pregnant BMI subgroup [(3 552.3±445.0) vs (3 481.8±416.1) g, P<0.01], and the low pre-pregnant BMI subgroup showed lower neonatal birth weight (3 352.7±371.2) g than the normal pre-pregnant BMI subgroup (P<0.01). Moreover, the high pre-pregnant BMI subgroup in the excessive GWGR group had an increased risk of fetal macrosomia (OR=1.60, 95%CI: 1.11-2.81). Conversely, the low pre-pregnant BMI subgroup in the excessive GWGR group had a decreased risk of fetal macrosomia (OR=0.52, 95%CI: 0.29-0.97) (all P<0.05). The high BMI subgroup had a greater risk of hypertensive disorders of pregnancy than the normal BMI subgroup in all GWGR groups (all P<0.05). The incidence of surgical delivery or NICU admission was not significantly different among the three GWGR subgroups. Conclusions Excessive weight gain in third-trimester is common in normal OGTT women. Excessive gestational weight gain is associated with adverse maternal and neonatal outcomes. Thus, gestational weight gain in the third-trimester should be adequately monitored and a balance in weight gain within the range recommended by the 2009 IOM guidelines should be established in normal OGTT pregnant women. Key words: Pregnancy; Weight gain; Pregnancy trimester, third; Body mass index; Birth weight; Infant, newborn; Pregnancy outcome

Parental Characteristics can Explain Why Japanese Women Give Birth to the Smallest Infants in the United States.

Whether birthweight differences observed between races are due to modifiable factors remains controversial. In the United States, Asian infants weigh less than white infants and Japanese infants weigh the least. Using US Natality data, we evaluated 4132319 singleton term livebirths to parents of non-Hispanic white or Japanese race/ethnicity from 2009 to 2012. Infants were categorised by parental race/ethnicity (both white, n=4116637; Japanese father/white mother, n=2377; white father/Japanese mother, n=7478; both Japanese, n=5827). We used multivariable regression to sequentially adjust for maternal characteristics to determine to what extent they explained differences in fetal growth due to maternal race/ethnicity. Infants born to Japanese mothers were smaller by 132 (95% CI 101, 122) grams, with higher risk of small for gestational age (relative risk ratio (RRR) 1.56 (95% CI 1.47, 1.65) and lower risk of large for gestational age RRR 0.49, 95% CI 0.44, 0.54), compared to infants of white mothers. Differences in social factors and in maternal age, parity, and gestational age only minimally explained this difference. However, additionally adjusting for maternal height, body mass index and gestational weight gain substantially attenuated this difference to 20 (95% CI 12, 29) grams in birthweight, 0.91 (95% CI 0.86, 0.97) times risk of small for gestational age, and 1.06 (95% CI 0.96, 1.17) times risk of large for gestational age, with the effect similar across strata of paternal race/ethnicity. Differences in fetal growth between infants from Japanese and white mothers could be explained by differences in maternal height, pre-pregnancy weight, and gestational weight gain. Fetal growth potential appears to be similar across racial/ethnic groups when parental sizes are similar.

Low birth weight at term and the presence of fine particulate matter and carbon monoxide in the Brazilian Amazon: a population-based retrospective cohort study.

BackgroundAlthough studies have shown an association between air pollutants from anthropogenic sources and pregnancy outcomes, little is known regarding the association between low birth weight (LBW) and exposure to emissions of biomass burning.MethodsThis population-based retrospective cohort study assessed the effect of exposure to particulate matter and carbon monoxide (CO) from biomass burning in the Amazon and cerrado (Brazilian savanna) biomes on term LBW (<2500 g) in cities of Mato Grosso, Brazil. Data on births were obtained from the Information System on Live Births of the Ministry of Health. The exclusion criteria were a twin pregnancy, gestational age of less than 37 weeks, and congenital malformation diagnosed at birth. For exposure variables, we used a historical series of daily average concentrations of particulate matter with a diameter less than 2.5 μm (PM2.5) and CO provided by Coupled Aerosol and Trace Gases Transport Model for the Brazilian Development of the Regional Atmospheric Modeling System developed at the National Institute for Space National Center for Weather Forecasts and Climate Studies, National Institute for Space Research. Maternal exposure was estimated by the average amount of pollutants for each trimester and for the entire period of gestation. The association between air pollutants and LBW was analyzed by multiple logistic regression, adjusting for the newborn’s sex, mother’s age and education, and prenatal care.ResultsA total of 6147 full-term singleton live births were included in the study and 193 (3.1%) were LBW. In adjusted analysis, the number of prenatal visits and maternal education with 8 years or more were associated with LBW. The association between exposure to air pollutants and the risk of LBW was significant for the 4th quartile of PM2.5 concentrations in the 2nd trimester (OR = 1.51, 95% CI = 1.04 to 2.17) and in the 3rd trimester, and for the 4th quartile of CO concentrations in the 2nd trimester only, in adjusted analysis.ConclusionsThis study provides further evidence of the effect of smoke from biomass burning on the occurrence of LBW in cities of the Brazilian Amazon.

Yearly Trends in Fetal Macrosomia among Hospital Births in Enugu, South East Nigeria

Fetalmacrosomia is associated with higher risks of maternal and neonatal complications and with health risks in adulthood. Trends in fetal macrosomia could indicate fetal growth patterns and its knowledge could be useful for prenatalcare and maternal health education. The objective of the study was to describe the yearly trends in the prevalence of fetal macrosomia among singleton live term hospital births in Enugu, South East Nigeria. Routinely collected delivery data of three major maternity centres in Enugu were reviewed for the period January 2003 to December 2013. All singleton term live births that took place at the three centres during the study period were analysed and the yearly prevalences of fetal macrosomia were determined. Statistical analysis involved descriptive and inferential statistics at 95% level of confidence. A total of 22,628 singleton live term deliveries were studied. There were 2116 births of macrosomic babies giving a prevalence rate of 9.3% of singleton term deliveries. The mean weight of all macrosomic babies was 4.42kg ± 0.38. The prevalence rates of macrosomia showed a small, but significant decreasing trend over the period of study. The likelihood of fetal macrosomia was increased by male births (aOR 1.64, 95% confidence interval [C.I.] 1.10, 3.20); postdate births (aOR 2.1, 95% C.I. 1.4, 4.1) and multiparity (aOR 8.0, 95% C.I. 3.2, 16.4). It was concluded that there was a decreasing trend in the prevalence of fetal macrosomia in the study centres,and factors such as the prevalences of male births, postdate pregnancies and multiparity could have influenced this, at least in part. However, population based studies incorporating prenatal weight and medical complication data would be needed to establish the factors responsible for the actual trend in macrosomic births in the general population in this area.