Extreme Birth Weight Research Articles

Comparing Fetal Ultrasound Biometric Measurements to Neonatal Anthropometry at the Extremes of Birth Weight.

Error in birthweight prediction by sonographic estimated fetal weight (EFW) has clinical implications, such as avoidable cesarean or misclassification of fetal risk in labor. We aimed to evaluate optimal timing of ultrasound and which fetal measurements contribute to error in fetal ultrasound estimations of birth size at the extremes of birthweight. We compared differences in head circumference (HC), abdominal circumference (AC), femur length, and EFW between ultrasound and corresponding birth measurements within 14 (n = 1,290) and 7 (n = 617) days of birth for small- (SGA, <10th percentile), appropriate- (AGA, 10th-90th), and large-for-gestational age (LGA, >90th) newborns. Average differences between EFW and birthweight for SGA neonates were: -40.2 g (confidence interval [CI]: -82.1, 1.6) at 14 days versus 13.6 g (CI: -52.4, 79.7) at 7 days; for AGA, -122.4 g (-139.6, -105.1) at 14 days versus -27.2 g (-50.4, -4.0) at 7 days; and for LGA, -242.8 g (-306.5, -179.1) at 14 days versus -72.1 g (-152.0, 7.9) at 7 days. Differences between fetal and neonatal HC were larger at 14 versus 7 days, and similar to patterns for EFW and birthweight, differences were the largest for LGA at both intervals. In contrast, differences between fetal and neonatal AC were larger at 7 versus 14 days, suggesting larger error in AC estimation closer to birth. Using a standardized ultrasound protocol, SGA neonates had ultrasound measurements closer to actual birth measurements compared with AGA or LGA neonates. LGA neonates had the largest differences between fetal and neonatal size, with measurements 14 days from delivery showing 3- to 4-fold greater differences from birthweight. Differences in EFW and birthweight may not be explained by a single fetal measurement; whether estimation may be improved by incorporation of other knowable factors should be evaluated in future research. · Ultrasound measurements may be inadequate to predict neonatal size at birth.. · Birthweight estimation error is higher for neonates >90th percentile.. · There is higher error in AC closer to birth..

ERRγ1 and Aromatase Expression in Human Placental Tissues from Term Deliveries of Large for Gestational Age Newborns

Plain Language SummaryEvents during fetal development are associated with susceptibility to chronic disease in adulthood. Extreme birth weight, for newborns of small for gestational age or large for gestational age (LGA), has been associated with an increased risk of developing metabolic syndrome in adulthood. Even though some intrauterine events during fetal development have been described, there is still a long way for identifying all the factors that are involved in fetal programming. The placenta has an important role in intrauterine programming because it controls the intrauterine environment by supplying oxygen, nutrients, and specific hormones involved in fetal development. Estrogens and androgens in maternal and fetal circulations play an important role in determining a physiological placental phenotype. ERRγ1 expression in placental tissues is involved in aromatase activity regulation and hence in intrauterine estrogen-androgen balance. In this study, we propose that the dysregulation of ERRγ1 in placental tissue might modify the estrogen-androgen balance in the intrauterine environment, representing one of the key factors in the regulation of fetal programming in LGA newborns.

Neonatal Birthweight Spectrum: Maternal Risk Factors and Pregnancy Outcomes in Saudi Arabia.

Background and Objectives: Low-birth-weight (LBW) neonates are at increased risk of morbidity and mortality which are inversely proportional to birth weight, while macrosomic babies are at risk of birth injuries and other related complications. Many maternal risk factors were associated with the extremes of birthweight. The objectives of this study are to investigate maternal risk factors for low and high birthweight and to report on the neonatal complications associated with abnormal birth weights. Materials and Methods: We conducted a retrospective analysis of medical records of deliveries ≥ 23 weeks. We classified the included participants according to birth weight into normal birth weight (NBW), LBW, very LBW (VLBW), and macrosomia. The following maternal risk factors were included, mother's age, parity, maternal body mass index (BMI), maternal diabetes, and hypertension. The neonatal outcomes were APGAR scores < 7, admission to neonatal intensive care unit (NICU), respiratory distress (RD), and hyperbilirubinemia. Data were analyzed using SAS Studio, multivariable logistic regression analyses were used to investigate the independent effect of maternal risk factors on birthweight categories and results were reported as an adjusted odds ratio (aOR) and 95% Confidence Interval (CI). Results: A total of 1855 were included in the study. There were 1638 neonates (88.3%) with NBW, 153 (8.2%) with LBW, 27 (1.5%) with VLBW, and 37 (2.0%) with macrosomia. LBW was associated with maternal hypertension (aOR = 3.5, 95% CI = 1.62-7.63), while increasing gestational age was less likely associated with LBW (aOR = 0.51, 95% CI = 0.46-0.57). Macrosomia was associated with maternal diabetes (aOR = 3.75, 95% CI = 1.67-8.41), in addition to maternal obesity (aOR = 3.18, 95% CI = 1.24-8.14). The odds of VLBW were reduced significantly with increasing gestational age (aOR = 0.41, 95% CI = 0.32-0.53). In total, 81.5% of VLBW neonates were admitted to the NICU, compared to 47.7% of LBW and 21.6% of those with macrosomia. RD was diagnosed in 59.3% of VLBW neonates, in 23% of LBW, in 2.7% of macrosomic and in 3% of normal-weight neonates. Hyperbilirubinemia was reported in 37.04%, 34.21%, 22.26%, and 18.92% of VLBW, LBW, NBW, and macrosomic newborns, respectively. Conclusions: Most neonates in this study had normal birthweights. Maternal hypertension and lower gestational age were associated with increased risk of LBW. Additionally, maternal obesity and diabetes increased the risk of macrosomia. Neonatal complications were predominantly concentrated in the LBW and VLBW, with a rising gradient as birthweight decreased. The main complications included respiratory distress and NICU admissions.

Association of maternal birth weight and maternal preterm birth with subsequent risk for adverse reproductive outcomes: The Women's Health Initiative

BackgroundAdvancements in medical technology and pharmacologic interventions have drastically improved survival of infants born preterm and low birth weight, but knowledge regarding the long-term health impacts of these individuals is limited and inconsistent. AimTo investigate whether an individual's birthweight or history of being born preterm increases the risk of an adverse reproductive outcome. Study designNested case-control study within the Women's Health Initiative. Subjects79,934 individuals who self-reported their personal birthweight category and/or preterm birth status. Outcomes measuresSelf-reported pregnancy outcomes: subfertility, miscarriage, stillbirth, preeclampsia, gestational diabetes, gestational hypertension, preterm birth, low birthweight infant, high birthweight infant. Logistic regression models were used to estimate unadjusted and adjusted odds ratios (OR). ResultsAfter adjustments, individuals reporting their birthweight <6lbs. were 20 % more likely to have a stillbirth or 70 % more likely to have a low birthweight infant and were less likely to have a full-term birth or high birthweight infant during their pregnancy. Individuals reporting a birthweight ≥10 lbs. were more likely to have a high birthweight infant (OR 3.49, 95 % CI 2.73–4.39) and less likely to have a low birthweight infant (OR 0.64, 95 % CI 0.47–0.82). Individuals born preterm were at increased risk for infertility, miscarriage, preeclampsia, gestational diabetes, and delivering a preterm or low birthweight infant. ConclusionsAs more individuals born preterm and/or low birthweight survive to adulthood, the incidence and prevalence of poor reproductive outcomes may increase. Women born at extremes of birthweight and prematurity may need to be monitored more closely during their own pregnancies.

Letter to the Editor: Influence of maternal NAFLD on infant weight-the real precursor to NAFLD in offspring?

To the editor, We read with enthusiasm the publication by Amadou et al.1 demonstrating that within a large French cohort, extremes of birthweight increased the risk for NAFLD in adulthood. On mediation analysis, findings for low birthweight were explained by prematurity. As the authors’ highlight, an important limitation was unavailable maternal data, including maternal weight. Beyond maternal obesity, there remains a knowledge gap regarding the in-utero influence of maternal NAFLD on infant outcomes. NAFLD rates in pregnancy have nearly tripled over the past decade, and NAFLD cirrhosis is also rising in pregnant women.2,3 In pediatric populations, NAFLD can develop even in utero, and by school-age 10% of all children, and 30%–40% of those with obesity have NAFLD.4 Thus, there is an urgent need to identify early and modifiable risk factors in pregnant women with NAFLD and their offspring. Though prior data link maternal obesity to childhood NAFLD, the influence of maternal NAFLD on long-term metabolic outcomes has not been elucidated. In a large US study we evaluated NAFLD in pregnancy and maternal and perinatal outcomes at delivery.2 Importantly, maternal NAFLD increased risk for both large-for-gestational age infants (adjusted OR of 1.8, 95% CI: 1.4–2.5) and preterm birth (adjusted OR: 1.60, 95% CI: 1.3–2.0), independent of maternal metabolic comorbidities. Likewise, in our Canadian study of cirrhosis in pregnancy, maternal NAFLD independently increased arge-for-gestational age risk as compared with other etiologies of cirrhosis (RR: 1.6, 95% CI: 1.3–2.1).3 These data suggest a direct influence of in utero NAFLD exposure as a contributor to prematurity and arge-for-gestational age infants, key risk factors for long-term NAFLD risk in offspring as demonstrated by Amoudou and colleagues. Although the underlying mechanisms have not been elucidated, independent of diabetes and obesity the liver plays a critical role in the regulation of glucose and lipid metabolism. NAFLD-specific effects beyond the liver include peripheral insulin resistance, systemic inflammation, and dysregulated lipid metabolism, which may help to explain our findings of increased arge-for-gestational age risk in infants of mothers with NAFLD. In summary, we applaud the work by Amadou and colleagues and emerging literature evaluating early influencers of NAFLD. An even earlier focus on preconception through postpartum periods may further define contributors to NAFLD in offspring, and support interventions among expectant mothers to help mitigate rising NAFLD rates in young populations.

Echocardiographic nomograms and Z-scores for term Indian neonates.

The availability of nomograms is crucial for the correct interpretation of pediatric and neonatal echocardiograms. Echocardiographic Z-score applications/websites use Western nomograms as reference, which may not be an appropriate standard for gauging Indian neonates. Currently available Indian pediatric nomograms either have not included neonates or have not been specifically designed for neonates. This gross underrepresentation of neonates renders available nomograms unreliable for use as standards for comparison. The objective of this study was to collect normative data for the measurement of various cardiac structures using M-Mode and two-dimensional (2D) echo in healthy Indian neonates and to derive Z-scores for each measured parameter. Echocardiograms were performed on healthy term neonates (within first 5 days of life). Birth weight and length were recorded, and body surface area was calculated using Haycock's formula. Twenty M-mode and 2D-echo parameters were measured (including left ventricular dimensions, atrioventricular valves, and semilunar valves' annuli sizes, pulmonary artery and branches, aortic root, and arch). We studied 142 neonates (73 males) with a mean age of 1.83 ± 1.12 days and mean birth weight of 2.89 ± 0.39 Kg. Regression equations with linear, logarithmic, exponential and square root models were tested to select the best model of fit for the relationship between birth weight and each echocardiographic parameter. Scatter plots and nomogram charts with Z-scores were prepared for each echocardiographic parameter. Our study provides nomograms with Z-scores for term Indian neonates weighing between 2 kg and 4 kg at birth, within first 5 days of life, for a set of echocardiographic parameters that are frequently used in clinical practice. This nomogram has poor predictability for babies at extremes of birth weight. There is a need for further indigenous studies to include neonates at extremes of weight, both term, and preterm.

Risk of hypoglycemia by anthropometric measurements in neonates of mothers with diabetes

Macrosomia in neonates of diabetic women is a risk factor for neonatal hypoglycemia, with an over-risk for asymmetric macrosomia. This study aimed to study the association between anthropometric measurements and hypoglycemia in neonates of mothers treated for gestational diabetes. This is a secondary analysis of the INDAO trial study conducted between May 2012 and November 2016 in 13 French tertiary care university hospitals in 890 pregnant women with gestational diabetes treated with either insulin or glyburide. Neonatal anthropometric measurements were birthweight and weight-length ratio (WLR, defined as birth weight/length). Neonatal hypoglycemia was defined as capillary blood glucose below 36mg/dL (2mmol/L) or below 45mg/dL (2.5mmol/L) associated with clinical signs after 2h of life. Their relationships were modeled with logistic regressions using fractional polynomials. Extreme categories of birthweight or WLR adjusted for gestational age at birth and sex were defined as Z-score < -1.28 or > 1.28. These categories were compared to Z-score between -1.28 and 1.28 by estimating odds ratios and confidence intervals for neonatal hypoglycemia. Neonatal hypoglycemia occurred in 9.1% of cases. The relationship between birthweight and WLR Z-scores and neonatal risk of hypoglycemia adjusted for maternal treatment was a U-shaped curve. Adjusted odds ratios for the risk of hypoglycemia were 9.6 (95% CI 3.5, 26.8) and 2.3 (95% CI 1.1, 4.9) for WLR Z-score below -1.28 and above 1.28, respectively, compared with WLR Z-score between -1.28 and 1.28. Conclusion: Birthweight Z-score was associated with the risk of neonatal hypoglycemia in neonates from mothers treated for gestational diabetes. The risk of neonatal hypoglycemia was increased for both extreme birthweight Z-scores, regardless of maternal treatment. Small for gestational age neonates of diabetic mothers require special attention for the risk of neonatal hypoglycemia. What is Known: • Macrosomia in neonates of diabetic women is a risk factor for neonatal hypoglycemia, with an over-risk for asymmetric macrosomia. Few retrospective studies have assessed the risk for neonatal hypoglycemia among small for gestational age neonates born to diabetic mothers. What is New: • The risk of neonatal hypoglycemia among neonates of diabetic mothers increased for both low and high weight-length ratio, regardless of maternal medicinal treatment, gestational age at birth, and sex of the newborn.

Extreme Birth Weight and Metabolic Syndrome in Children.

Small and large birth weights (BWs) for gestational age (GA) represent extremes, but the correlation between extreme BW and metabolic syndrome (MetS) has not been fully elucidated. In this study, we examined this correlation in obese children based on changes in their metabolic profile from childhood to adolescence. A retrospective observational study was performed on 535 obese patients aged 0–18 years in the Clinical and Emergency Hospital for Children “Louis Turcanu” in Timisoara, Romania, based on clinical and biological data from January 2015 to December 2019. We emphasized the links between extreme BW and obesity, extreme BW and cardiometabolic risk, obesity and cardiometabolic risk, and extreme BW, obesity and MetS. Children born large for gestational age (LGA) predominated over those born small for gestational age (SGA). Our findings showed that BW has an independent effect on triglycerides and insulin resistance, whereas obesity had a direct influence on hypertension, impaired glucose metabolism and hypertriglyceridemia. The influences of BW and obesity on the development of MetS and its components are difficult to separate; therefore, large prospective studies in normal-weight patients are needed.

Impact of mode of conception on early pregnancy human chorionic gonadotropin rise and birth weight

ObjectiveTo assess whether the mode of conception and embryo biopsy impact first-trimester human chorionic gonadotropin (hCG) dynamics and subsequent risk of small for gestational age (SGA) or large for gestational age (LGA).DesignRetrospective cohort study.SettingUniversity fertility center.Patient(s)Six hundred-two pregnant patients with singleton live births.Intervention(s)Serial serum hCG measurements were obtained between 10 and 28 days postconception to determine the within-woman rate of change in hCG (slope) by mode of conception (unassisted pregnancy, fresh embryo transfer (ET), frozen ET, and frozen ET following preimplantation genetic testing for aneuploidy (PGT-A).Main Outcome Measure(s)Primary outcomes included birth weight, SGA, and LGA.Result(s)Mode of conception is not independently associated with birth weight, SGA, or LGA. Mediation analysis revealed an expected one-day increase in log-transformed hCG varied by mode of conception: unassisted (0.41), fresh ET (0.39), frozen ET (0.42), PGT-A (0.44). Human chorionic gonadotropin rise has a positive effect on birth weight (55 g per SD increase in hCG slope) and is associated with SGA (odds ratio, 0.65), but not with LGA (odds ratio, 1.18).Conclusion(s)Human chorionic gonadotropin rise is an important mediator of the mode of conception/birth weight relationship. Preimplantation genetic testing for aneuploidy has the highest rate of hCG rise, followed by frozen ET, unassisted, and fresh ET. Faster rise is associated with higher birth weight and lower risk of SGA but does not impact LGA risk. Importantly, PGT-A does not increase the risk of extreme birth weight relative to other modes of conception evaluated.

Birth weight and prediabetes in a nationally representative sample of US adolescents.

Prediabetes affects about 20% of adolescents in the United States. Previous studies have shown that low and high birth weight impairs glucose homeostasis in adults; however, limited research has examined this relationship in adolescents. To investigate association of birthweight with prediabetes in US adolescents using data from NHANES 2005-2016 and examine whether sex and obesity moderate this relationship. Adolescents, aged 12-15 years without diagnosed/undiagnosed diabetes and extreme birthweight (n=1396), were classified as low birth weight (LBW), normal birthweight (NBW) and high birth weight (HBW). Logistic regression examined relationship of birthweight with odds of prediabetes. Likelihood ratio test tested interactions of birthweight with sex and obesity measures. In this nationally representative cross-sectional study, LBW adolescents had significantly higher odds of prediabetes compared to NBW counterparts (Odds ratio [95% confidence interval]=1.93 (1.10, 3.38); p < .05). Sex and obesity moderated the association, such that the strength of the relationship of LBW with increased prediabetes odds was greater among male adolescents (Odds ratio [95% confidence interval]=2.40 (1.02, 5.67); p < .05) and those with overweight/obesity (Odds ratio [95% confidence interval]=2.13 (1.01, 4.49); p < .05). Findings imply that the adverse effects of LBW on glucose homeostasis could be manifested early in life. Further, the higher odds of prediabetes among LBW adolescents who are male or have overweight/obesity underscore the heightened need for prediabetes screening of these subgroups.

Characteristics and outcomes of pregnant women with type 1 or type 2 diabetes: a 5-year national population-based cohort study

Diabetes in pregnancy is associated with preterm delivery, birthweight extremes, and increased rates of congenital anomaly, stillbirth, and neonatal death. We aimed to identify and compare modifiable risk factors associated with adverse pregnancy outcomes in women with type 1 diabetes and those with type 2 diabetes and to identify effective maternity clinics. In this national population-based cohort study, we used data for pregnancies among women with type 1 or type 2 diabetes collected in the first 5 years of the National Pregnancy in Diabetes audit across 172 maternity clinics in England, Wales, and the Isle of Man, UK. Data for obstetric complications (eg, preterm delivery [<37 weeks' gestation], large for gestational age [LGA] birthweight [>90th percentile]) and adverse pregnancy outcomes (congenital anomaly, stillbirth, neonatal death) were obtained for pregnancies completed between Jan 1, 2014, and Dec 31, 2018. We assessed associations between modifiable (eg, HbA1c, BMI, pre-pregnancy care, maternity clinic) and non-modifiable risk factors (eg, age, ethnicity, deprivation, duration of type 1 diabetes) with pregnancy outcomes in women with type 1 diabetes compared with those with type 2 diabetes. We calculated associations between maternal factors and perinatal deaths using a regression model, including diabetes type and duration, maternal age, BMI, deprivation quintile, first trimester HbA1c, preconception folic acid, potentially harmful medications, and third trimester HbA1c. Our dataset included 17 375 pregnancy outcomes in 15 290 pregnant women. 8690 (50·0%) of 17 375 pregnancies were in women with type 1 diabetes (median age at delivery 30 years [10-90th percentile 22-37], median duration of diabetes 13 years [3-25]) and 8685 (50·0%) were in women with type 2 diabetes (median age at delivery 34 years [27-41], median duration of diabetes 3 years [0-10]). The rates of preterm delivery (3325 [42·5%] of 7825 pregnancies among women with type 1 diabetes, 1825 [23·4%] of 7815 with type 2 diabetes; p<0·0001), and LGA birthweight (4095 [52·2%] of 7845 with type 1 diabetes, 2065 [26·2%] of 7885 with type 2 diabetes; p<0·0001) were higher in type 1 diabetes. The prevalence of congenital anomaly (among women with type 1 diabetes: 44·8 per 1000 livebirths, terminations, and fetal losses; among women with type 2 diabetes: 40·5 per 1000 livebirths, terminations, and fetal losses; p=0·17) and stillbirth (type 1 diabetes: 10·4 per 1000 livebirths and stillbirths; type 2 diabetes: 13·5 per 1000 livebirths and stillbirths; p=0·072) did not significantly differ between diabetes types, but rates of neonatal death were higher in mothers with type 2 diabetes than in those with type 1 diabetes (type 1 diabetes: 7·4 per 1000 livebirths; type 2 diabetes 11·2 per 1000 livebirths; p=0·013). Across the whole study population, independent risk factors for perinatal death (ie, stillbirth or neonatal death) were third trimester HbA1c of 6·5% (48 mmol/mol) or higher (odds ratio 3·06 [95% CI 2·16-4·33] vs HbA1c <6·5%), being in the highest deprivation quintile (2·29 [1·16-4·52] vs the lowest quintile), and having type 2 diabetes (1·65 [1·18-2·31] vs type 1 diabetes). Variations in HbA1c and LGA birthweight were associated with maternal characteristics (age, diabetes duration, deprivation, BMI) without substantial differences between maternity clinics. Our data highlight persistent adverse pregnancy outcomes in women with type 1 or type 2 diabetes. Maternal glycaemia and BMI are the key modifiable risk factors. No maternity clinics were had appreciably better outcomes than any others, suggesting that health-care system changes are needed across all clinics. None.

Maternal cardiac adaptation and fetal growth

Pregnancies with small-for-gestational-age fetuses are at increased risk of adverse maternal-fetal outcomes. Previous studies examining the relationship between maternal hemodynamics and fetal growth were mainly focused on high-risk pregnancies and those with fetuses with extreme birthweights, such as less than the 3rd or 10th percentile and assumed a similar growth pattern in fetuses above the 10th percentile throughout gestation. This study aimed to evaluate the trends in maternal cardiac function, fetal growth, and oxygenation with advancing gestational age in a routine obstetrical population and all ranges of birthweight percentiles. This was a prospective, longitudinal study assessing maternal cardiac output and peripheral vascular resistance by bioreactance at 11+0 to 13+6, 19+0 to 24+0, 30+0 to 34+0, and 35+0 to 37+0 weeks' gestation, sonographic estimated fetal weight in the last 3 visits and the ratio of the middle cerebral artery by umbilical artery pulsatility indices or cerebroplacental ratio in the last 2 visits. Women were divided into the following 5 groups according to birthweight percentile: group 1, <10th percentile (n=261); group 2, 10 to 19.9 percentile (n=180); group 3, 20 to 29.9 percentile (n=189); group 4, 30 to 69.9 percentile (n=651); and group 5, ≥70th percentile (n=508). The multilevel linear mixed-effects model was performed to compare the repeated measures of hemodynamic variables and z scores of the estimated fetal weight and cerebroplacental ratio. In visit 2, compared with visit 1, in all groups, cardiac output increased, and peripheral vascular resistance decreased. At visit 3, groups 1, 2, and 3, compared with 4 and 5, demonstrated an abrupt decrease in cardiac output and increase in peripheral vascular resistance. From visit 2, group 1 had a constant decline in estimated fetal weight, coinciding with the steepest decline in maternal cardiac output and rise in peripheral vascular resistance. In contrast, in groups 4 and 5, the estimated fetal weight had a stable or accelerative pattern, coinciding with the greatest increase in cardiac output and lowest peripheral vascular resistance. Groups 2 and 3 showed a stable growth pattern with intermediate cardiac output and peripheral vascular resistance. Increasing birthweight was associated with higher cerebroplacental ratio. Groups 3, 4, and 5 had stable cerebroplacental ratio across visits 3 and 4, whereas groups 1 and 2 demonstrated a significant decline (P<.001). In a general obstetrical population, maternal cardiac adaptation at 32 weeks' gestation parallels the pattern of fetal growth and oxygenation; babies with birthweight<20th percentile have progressive decline in fetal cerebroplacental ratio, decline in maternal cardiac output, and increase in peripheral vascular resistance.

Diabetes during pregnancy and birthweight trends among Aboriginal and non-Aboriginal people in the Northern Territory of Australia over 30 years

BackgroundEarly-life risk factors, including maternal hyperglycaemia and birthweight, are thought to contribute to the high burden of cardiometabolic disease experienced by Indigenous populations. We examined rates of pre-existing diabetes in pregnancy, gestational diabetes mellitus (GDM) and extremes of birthweight over three decades in the Northern Territory (NT) of Australia. MethodsWe performed a retrospective cohort analysis of the NT Perinatal Data Collection from 1987 to 2016, including all births >20 weeks gestation, stratified by maternal Aboriginal identification. Key outcomes were annual rates of pre-existing diabetes, GDM, small-for-gestational-age, large-for-gestational-age, low birthweight (<2500 g), and high birthweight (>4000 g). Logistic regression was used to assess trends and interactions. Findings109 349 babies were born to 64 877 mothers, 36% of whom identified as Aboriginal ethnicity. Among Aboriginal women, rates of GDM and pre-existing diabetes, respectively, were 3 · 4% and 0 · 6% in 1987 and rose to 13% and 5 · 7% in 2016 (both trends p<0 · 001). Among non-Aboriginal women, rates of GDM increased from 1 · 9% in 1987 to 11% in 2016 (p<0 · 001), while pre-existing diabetes was uncommon (≤0 · 7% throughout). Rates of small-for-gestational-age decreased, while rates of large-for-gestational-age and high birthweight increased in both groups (all trends p<0 · 001). Multivariable modelling suggests that hyperglycaemia was largely responsible for the growing rate of large-for-gestational-age births among Aboriginal women. InterpretationThe burden of hyperglycaemia in pregnancy has grown substantially in the NT over three decades and is impacting birthweight trends. The prevalence of pre-gestational diabetes in Aboriginal women is among the highest in the world. FundingDiabetes Australia Research Program.

Association of maternal and social characteristics with age-standardised birthweight

Objectives: To identify the maternal and social characteristics associated with age standardised birthweight in a modern developed setting. Methods: Birth records (n = 414,478) were obtained for live, singleton births in the period 2007–2015 in Queensland, Australia. Age-standardised birth weights were calculated and a multinomial logistic regression was performed to obtain odds ratios and 95% confidence intervals for a range of maternal and social characteristics. Results: Mothers who smoke (OR 2.82, 95% CI 2.72–2.93), and mothers from Southern and Central Asia (OR 3.30, 95% CI 3.08–3.53) had the highest odds of delivering small for gestational age babies. Smoking alone accounted for 21% of low birthweight. Pre-existing diabetes (OR 5.98, 95% CI 5.12–6.99) had the highest odds ratio for large for gestational age births; however, maternal overweight and obesity accounted for 24% of all cases due to its greater prevalence in the population. Conclusion for practice: Smoking continues to be an important modifiable predictor of low birthweight. The predictors associated with large for gestational age are modifiable, with maternal overweight and obesity the largest contributor to high birthweight. Significance: Maternal characteristics are changing alongside broader population change, with mothers often older and heavier than in previous decades. This study provides an update to the role of maternal and social characteristics in optimal birthweight within a large developed population. The present study finds a range of traditional and emerging risk factors remain important. Population attributable risk fractions show that maternal overweight and smoking are the most important modifiable risk factors for birthweight extremes (foetal macrosomia and small for gestational age, respectively). Public health efforts to address these risk factors could reduce up to 20% of birth weight extremes.

Developmental Programming of Body Composition: Update on Evidence and Mechanisms.

A growing body of epidemiological and experimental data indicate that nutritional or environmental stressors during early development can induce long-term adaptations that increase risk of obesity, diabetes, cardiovascular disease, and other chronic conditions-a phenomenon termed "developmental programming." A common phenotype in humans and animal models is altered body composition, with reduced muscle and bone mass, and increased fat mass. In this review, we summarize the recent literature linking prenatal factors to future body composition and explore contributing mechanisms. Many prenatal exposures, including intrauterine growth restriction, extremes of birth weight, maternal obesity, and maternal diabetes, are associated with increased fat mass, reduced muscle mass, and decreased bone density, with effects reported throughout infancy and childhood, and persisting into middle age. Mechanisms and mediators include maternal diet, breastmilk composition, metabolites, appetite regulation, genetic and epigenetic influences, stem cell commitment and function, and mitochondrial metabolism. Differences in body composition are a common phenotype following disruptions to the prenatal environment, and may contribute to developmental programming of obesity and diabetes risk.

Comparison of the accuracy of INTERGROWTH-21 formula with other ultrasound formulae in fetal weight estimation

ObjectiveA new ultrasound formula for fetal weight estimation was proposed from the INTERGROWTH-21 project in 2017. There is no comparison of its accuracy with other ultrasound formulae. This study aims to compare the accuracy of INTERGROWTH-21 formula in fetal weight estimation with the traditional Hadlock1 and Shepard formula. Materials and methodsAll pregnant patients who had delivery in United Christian Hospital between January to December 2016 were retrospectively reviewed. Those who had prenatal ultrasound scan performed within 7 days of delivery were recruited. Hadlock1, Shepard and INTERGROWTH-21 formula were used to estimate the fetal weight and their accuracies were compared with the actual birthweight of neonates. ResultsA total of 403 patients were recruited. Hadlock1 was the most accurate with the lowest mean absolute percentage error (MAPE) 7.34 when compared with Shepard (9.00; p < 0.001) and INTERGROWTH-21 (9.07; p < 0.001). INTERGROWTH-21 had the lowest proportion of patients having estimated fetal weight within 10% discrepancy from the actual birthweight (57.6%) compared with Hadlock1 (71.2%; p < 0.001) and Shepard (66.3; p = 0.011). Presence of intrauterine growth restriction (IUGR) or fetal macrosomia (>=4000 g) were both associated with significantly higher MAPE in Hadlock1 and INTERGROWTH-21. IUGR (p = 0.005) and macrosomia (p = 0.004) remained significant in the final equation of logistic regression model that affect the precision of fetal weight estimation in Hadlock1, while only IUGR was significant in INTERGROWTH-21 (p < 0.001). ConclusionINTERGROWTH-21 formula was not shown to be better than the traditional Hadlock1 or Shepard formulae. Future prospective studies would be required to evaluate the accuracy of INTERGROWTH-21 formula especially at the extremes of birthweight.

Multi-behavioral obesogenic phenotypes among school-aged boys and girls along the birth weight continuum.

Evidence shows that extremes of birth weight (BW) carry a common increased risk for the development of adiposity and related cardiovascular diseases, but little is known about the role of obesogenic behaviors in this process. Moreover, no one has empirically examined whether the relationship between BW, obesogenic behaviors and BMI along the full low-to-high birthweight continuum reflects the U-shape pattern expected from common risk at both BW extremes. Our objective was to characterize physical activity, screen time, and eating behavior and their relationship to BMI as a function of BW among school-aged boys and girls. In this cross-sectional study, 460 children aged 6 to 12 years (50% boys) from Montreal, Canada provided information on sleeping time, screen time, physical activity levels, eating behavior (emotional, external and restrained eating) and anthropometrics (height, weight, BW) through parent reported questionnaires. BMI was normalized using WHO Standards (zBMI), and BW expressed as ratio using Canadian population standards (BW for gestational age and sex). Analyses were conducted using generalized linear models with linear and quadratic terms for BW, stratified by sex and adjusted for age, ethnicity and household income. In boys, physical activity and screen time showed U-shaped associations with BW, while physical activity had an inverted U-shaped in girls. Emotional and restrained eating had positive linear relations with BW in boys and girls. Sleep time and external eating were not associated with BW. A U-shaped relationship between BW and zBMI was found in boys but no association was found in girls. Only sleep (in boys and girls), and emotional eating (girls only) were related to zBMI and mediation of the BW-zBMI relationship was only supported for emotional eating. In conclusion, BW relates to obesogenic behaviors and BMI in both non-linear and linear ways, and these associations differed by sex.

Impact of in-hospital birth weight loss on short and medium term breastfeeding outcomes

BackgroundThe definition for lower limit of safe birthweight loss among exclusively breastfed neonates is arbitrary. Despite this, in cases of great in-hospital weight loss, breastfeeding adequacy is immediately questioned. The aim of this study was to examine the relationship between weight loss at discharge from hospital, when babies are ready to go home, and eventual cessation of exclusive breastfeeding since birth.MethodsThis is a secondary analysis of a cohort study. Study participants were 788 full term, breastfed and stable babies, born in 2007–2012 consecutively enrolled to primary care pediatric clinics in Majorca, Spain. Data were collected by chart review. The main predictor was birthweight loss at discharge. Extreme weight loss was defined as the 90th and 95th centiles of birthweight loss for babies who were delivered by vaginal delivery and by cesarean section. Main outcomes were cessation of exclusive breastfeeding by 7, 15, 30 and 100 days of life. Multivariate regression analysis was performed to study the relationship of selected variables with exclusive breastfeeding cessation since birth.ResultsWe observed a median weight loss of 6%. In bivariate analysis, quartiles of birthweight loss at discharge were predictive of exclusive breastfeeding cessation at 15, 30 and 100 days postpartum. In multivariate analysis: in-hospital weight loss above the median did predict exclusive breastfeeding cessation by 15, 30 and 100 days of life, Adjusted Odds Ratios (AORs) (95% Confidence Intervals [CIs]): 1.57 (1.12, 2.19), 1.73 (1.26, 2.38) and 1.69 (1.25, 2.29), respectively. In contrast, we did not find that newborn extreme weight losses were associated with exclusive breastfeeding cessation.ConclusionsWe report that extreme birthweight loss does not trigger immediate formula supplementation. We do not identify any cut-off values to be used as predictors for the initiation of supplementary feeding, this research question remains unanswered.

Regulation of birthweight by placenta-derived miRNAs: evidence from an arsenic-exposed birth cohort in Bangladesh

ABSTRACTAltered expression of microRNAs (miRNAs) is implicated in fetal growth. However, the mechanisms by which placenta-derived miRNAs regulate birthweight are not well understood. In Phase 1, we compared the expression of 754 miRNAs in the placenta from two extreme birthweight groups (0.8–2.2 kg vs. 3.3–3.9 kg, n = 77 each) selected from an arsenic-exposed Bangladeshi birth cohort (n = 1,141). We identified 49 miRNAs associated with the extreme birthweight groups and/or gestational age in Phase 1, which were further analyzed in Phase 2 among 364 randomly selected mother-infant pairs. Gestational age was determined by ultrasound. Causal mediation analysis was used to estimate the effect of miRNAs on birthweight considering gestational age a mediator, adjusting for cord blood arsenic and other risk factors. miR-1290, miR-195, and let-7g showed significant inverse associations with gestational age, while miR-328 showed significant positive association [false discovery rate (FDR) <0.05]. Via changing gestational age, miR-1290, miR-195, and miR-27a showed significant inverse associations with birthweight, while miR-328 and miR-324-5p showed significant positive associations (FDR <0.05). The effect of miRNAs on birthweight varied by gestational age (for miR-1290, miR-195, miR-328) and in utero arsenic exposure (for miR-1290): stronger effect was observed among infants delivered early in gestation or exposed to higher concentrations of arsenic in cord blood. Gene enrichment analysis with in silico predicted targets identified cell proliferation, inflammation, apoptosis, insulin, and IGF family signaling cascades associated with these miRNAs. Future studies are warranted to replicate these findings and assess these miRNAs as early biomarkers of fetal growth.

743: Maternal complications associated with low birthweight delivery

Delivery of an infant at the extremes of birthweight (bwg) is associated with high neonatal morbidity however there is a paucity of literature regarding maternal complications associated with delivery of an infant the cusp of viability. We sought to quantify the rate of maternal complications by neonatal bwg. Population-based retrospective cohort study of all live births in Ohio (2006-2015) using birth certificate data. Frequency of maternal complications were stratified by neonatal bwg in increments of 250g (0-249g to ≥ 5,550g). Obstetric characteristics were compared between women who delivered in the cumulative “highest risk” bwg group (<1500g) to the referent lowest risk bwg group (2500-4000g). Multivariate logistic regression estimated the relative influence of low bwg (<1500g) on the outcome of maternal complications at delivery. Of the 1,462,995 live births in Ohio during the 10-year study period, the highest rates of each complication per associated bwg group were; cesarean delivery (CD), (76.7%; 1250-1499g), blood transfusion (3.9%; <250g), unplanned operation (6.6%; <250g), unplanned hysterectomy (0.26%; 250-499g), uterine rupture (1.5%; 1000-1249g), maternal ICU admission (1.5%; 750-999g), maternal hospital transfer (17.5%; 500-749g), chorioamnionitis (12.3%; 250-499g), cerclage (6.1%; 250-499g), and higher-degree perineal laceration (2.4%; 4750-4999g). The cumulative complication rate for transfusion, unplanned operation, maternal ICU admission, and chorioamnionitis was highest in the <250g bwg group at 23.0%. Birth of an infant <1500g was associated with an increased risk of CD (aOR 2.5, 95% CI 2.4-2.6). Even after exclusion of women who had a CD, delivery of a singleton infant with bwg <1500g was associated with chorioamnionitis (aOR 10.2, 95% CI 9.1-11.5), ICU admission (aOR 4.7, 95% CI 2.2-9.9), and blood product transfusion (aOR 2.1, 95% CI 1.3-3.5). Birth of an infant < 1500g (low birthweight) is not only associated with complications of prematurity but also high rates of maternal morbidity secondary to CD and other operative complications. Counseling and discussions regarding maternal risks should be considered for a mother at risk of preterm birth. Additionally, these risks should be reflected when determining the societal cost of a preterm birth on the population and support further perinatal efforts on primary prevention.View Large Image Figure ViewerDownload Hi-res image Download (PPT)