Morbidity and mortality patterns in small-for-gestational age infants born preterm

Necrotizing enterocolitis in monochorionic twins: Insights from an identical twin model

Necrotizing enterocolitis (NEC) is a major cause of neonatal morbidity and mortality in preterm neonates, yet its pathophysiology remains unclear. The aim of this study is to evaluate risk factors for NEC using an identical twin model. In this case-control study, all monochorionic twin pairs born in our center in 2002-2020 were retrospectively reviewed for NEC. Potential risk factors for NEC were studied. For within-pair comparison, outcomes were compared between affected and unaffected twins. Within-pair analyses showed that the twin with NEC had a lower birth weight compared to its unaffected co-twin (1100 (913-1364) vs. 1339 (1093-1755) grams). Median gestational age at birth and birth weight were lower in twin pairs in the NEC-group compared to the no-NEC group, 29.1 weeks (27.8-30.8) versus 33.6 (30.7-36.0) and 1221 g (1010-1488) versus 1865 (1356-2355) respectively. Twin pregnancies in the NEC-group were more often complicated by twin-to-twin transfusion syndrome compared to the no-NEC-group (70 % (14/20) vs. 49 % (472/962)), particularly when treated with amnioreduction. This unique population of identical twins confirms that preterm neonates with a relatively lower birth weight are more prone to develop NEC compared to their co-twin, regardless of other genetic, maternal and obstetrical factors.

Association of small-for-gestational-age status with mortality and morbidity in very preterm Chinese infants

BACKGROUND

Very preterm infants born small for gestational age (SGA) are at risk for short- and long-term excess mortality and morbidity resulting from immaturity and deficient intrauterine growth. However, previous findings are inconclusive, and there is a paucity of contemporary data in Chinese population.

OBJECTIVES

To evaluate the excess risks of mortality and morbidity independently associated with SGA birth in very preterm (before 32 weeks of gestation) Chinese infants.

MATERIALS AND METHODS

The study population included all very preterm infants admitted to the neonatal intensive care units (NICUs) in our hospital and our medical treatment partner hospitals during a 6-year period. The SGA group consisted of 615 SGA infants, and 1230 appropriate-for-gestation-age (AGA) infants were matched with GA and sex as controls at a ratio of 2:1. The associations between SGA birth and outcomes (in-hospital mortality and morbidity) were evaluated by using multivariate logistic regression analysis after adjustment for potential confounders. The CRIBII score was used to indicate admission illness severity, acting as a covariate in the multivariate analysis.

RESULTS

The SGA group was associated with increased risks of mortality [odds ratio (OR) 2.12; 95% CI: 1.27-3.54] and BPD [OR 1.95; 95% CI: 1.58-2.41] compared to the AGA group. No significant incidences of respiratory distress syndrome (RDS), severe retinopathy of prematurity (sROP), severe intraventricular hemorrhage (sIVH), and necrotizing enterocolitis (NEC) were observed in the SGA group. Further GA-stratified subgroup analysis showed SGA status exhibited certain patterns of effects on mortality and morbidity in different GA ranges.

CONCLUSIONS

SGA status is associated with excess risks of neonatal mortality and BPD in very preterm infants, but the increased risks of mortality and morbidity are not homogeneous in different GA ranges. The contemporary data can help inform perinatal care decision-making and family counseling, particularly for very preterm SGA neonates.

Fitness of INTERGROWTH-21st birth weight standards for Chinese-ethnicity babies

OBJECTIVE

To determine the fitness of the INTERGROWTH-21st birth weight standards (INTERGROWTH21) for ethnic Chinese babies compared with a local reference (FOK2003).

DESIGN

Population-based analysis of territory-wide birth data.

SETTING

All public hospitals in Hong Kong.

PARTICIPANTS

Live births between 24 and 42 complete weeks' gestation during 2006-2017.

MAIN OUTCOME MEASURES

Babies' birth weight Z-scores were calculated using published methods. The two references were compared in three aspects: (1) the proportions of large-for-gestational-age (LGA) or small-for-gestational-age (SGA) infants, (2) the gestation-specific and sex-specific mean birth weight Z-scores and (3) the predictive power for SGA-related complications.

RESULTS

488 896 infants were included. Using INTERGROWTH21, among neonates born <33 weeks' gestation, the mean birth weight Z-scores per week were closer to zero (-0.2 to 0.05), while most of them were further from zero (0.06 to 0.34) after excluding infants with a high risk of abnormal intrauterine growth. Compared with FOK2003, INTERGROWTH21 classified smaller proportions of infants as SGA (8.3% vs 9.6%) and LGA (6.6% vs 7.9%), especially SGA among preterm infants (13.1% vs 17.0%). The area under the receiver operating characteristic curve for predicting SGA-related complications was greater with FOK2003 (0.674, 95% CI 0.670 to 0.677) than INTERGROWTH21 (0.658, 95% CI 0.655 to 0.661) (p<0.001).

CONCLUSIONS

INTERGROWTH21 performed less well than FOK2003, a local reference for ethnic Chinese babies, especially in infants born <33 weeks' gestation. Although the differences are clinically small, both these references performed poorly for extremely preterm infants, and thus a more robust chart based on a larger sample of appropriately selected infants is needed.

Preterm pigs for preterm birth research: reasonably feasible

Preterm birth will disrupt the pattern and course of organ development, which may result in morbidity and mortality of newborn infants. Large animal models are crucial resources for developing novel, credible, and effective treatments for preterm infants. This review summarizes the classification, definition, and prevalence of preterm birth, and analyzes the relationship between the predicted animal days and one human year in the most widely used animal models (mice, rats, rabbits, sheep, and pigs) for preterm birth studies. After that, the physiological characteristics of preterm pig models at different gestational ages are described in more detail, including birth weight, body temperature, brain development, cardiovascular system development, respiratory, digestive, and immune system development, kidney development, and blood constituents. Studies on postnatal development and adaptation of preterm pig models of different gestational ages will help to determine the physiological basis for survival and development of very preterm, middle preterm, and late preterm newborns, and will also aid in the study and accurate optimization of feeding conditions, diet- or drug-related interventions for preterm neonates. Finally, this review summarizes several accepted pediatric applications of preterm pig models in nutritional fortification, necrotizing enterocolitis, neonatal encephalopathy and hypothermia intervention, mechanical ventilation, and oxygen therapy for preterm infants.

Neonatal mortality in small for gestational age infants based on reference local newborn curve at secondary and tertiary hospitals in Indonesia

BACKGROUND

Small for gestational (SGA) infants during the neonatal period have risks of mortality and sequelae for survival. Two - third of neonatal mortality occurs in the first weeks of life. Prevalence of SGA depends on the newbon curve used. Objectives of the study were to know the conditions that posed the risk of early neonatal and neonatal mortality, to identify preterm/full-term and SGA/appropriate gestational age (AGA) infants with cumulative mortality incident (CMI), to compare 5- year-period of early and neonatal mortality, and to investigate CMI on neonatal mortality of four categories during 5-year-period.

METHODS

A retrospective cohort study on all live births, during 1998-2017, was conducted in Sleman and Sardjito hospitals, Yogyakarta, Indonesia. Based on the reference local curve, the eligible subjects were categorized into SGA and AGA infants. The analyses were based on preterm/full-term and SGA/AGA, thus resulting in 4 categories: preterm-SGA, preterm-AGA, full-term-SGA and full-term-AGA. Analysis was made with Unadjusted Hazard Ratio (HR) by Simple Cox Regression and Adjusted HR was calculated by Multiple Cox Regression, survival analysis to calculate CMI, and analysis mortality for 5-year period ( 1998-2002, 2003-2007, 2008-2012, 2013-2017).

RESULT

There were 35,649 live births eligible for the study. Respiratory distress was the highest risk with HR 9,46, followed by asphyxia with HR 5,08, mother's death with HR 227, extra-health facility with HR 1,97, symmetrical SGA with HR 1,97, preterm-AGA with HR 1,75, low birth weight (LBW) with HR 1,64, primary health facility with HR 1,33, and boys with HR 1,16 consecutively. Early neonatal mortality in 4 categories by survival analysis revealed the highest CMI in preterm SGA. Similar result was found in neonatal mortality. Analysis of 5-year period unveiled the highest CMI during 1998-2002. The highest CMI based on the four categories, however, was found in preterm-SGA.

CONCLUSION

Respiratory distress posed the highest HR in early and neonatal mortality. Survival analysis showing the highest CMI on early and neonatal mortality was identified in preterm-SGA. The 5 - year - period of neonatal mortality showed the highest CMI during 1998-2002 period, whereas based on 4 SGA categories, preterm-SGA demonstrated the highest CMI.

Increased Risk of Retinopathy of Prematurity in Donors with Twin-to-Twin Transfusion Syndrome: A Cohort Study

INTRODUCTION

The purpose of this study was to evaluate the within-pair difference in retinopathy of prematurity (ROP) between donors and recipients with twin-to-twin transfusion syndrome (TTTS) and to identify risk factors for ROP development.

METHODS

This retrospective cohort study included 147 TTTS twin pairs managed between 2002 and 2022 and eligible for ROP screening. Primary outcomes were any stage ROP and severe ROP. Secondary outcomes were hemoglobin at birth, red blood cell transfusions, mechanical ventilation days, postnatal steroids, and neonatal morbidity. Donor status was defined as having polyhydramnios pre-laser.

RESULTS

Rates of any stage ROP (23% vs. 14%) and severe ROP (8% vs. 3%) were significantly higher in donors compared to recipients. Donors received a higher number of blood transfusions (1 [±1.9] versus 0.7 [±1.5]). Five factors were univariately associated with any stage ROP: donor status (odds ratio [OR] 1.9; 95% CI 1.3-2.9), lower gestational age (GA) at birth (OR 1.7; 95% CI 1.4-2.1), small for GA (OR 2.1; 95% CI 1.3-3.5), mechanical ventilation days (OR 1.1; 95% CI 1.1-1.2), and blood transfusions in phase 1 (OR 2.3; 95% CI 1.2-4.3). Three factors were independently associated with any stage ROP: donor status (OR 1.8; 95% CI 1.1-2.9), lower GA at birth (OR 1.6; 95% CI 1.2-2.1), and mechanical ventilation days (OR 1.1, 95% CI 1.0-1.1). Donor status was univariately associated with severe ROP (OR 2.3, 95% CI 1.1-5.0).

CONCLUSION

Any stage ROP and severe ROP are detected twice as frequently in donors compared to recipients. Increased awareness for ROP is needed in donors, especially those with lower GA at birth and longer duration of mechanical ventilation.

A new method for customized fetal growth reference percentiles

BACKGROUND

Customized fetal growth charts assume birthweight at term to be normally distributed across the population with a constant coefficient of variation at earlier gestational ages. Thus, standard deviation used for computing percentiles (e.g., 10th, 90th) is assumed to be proportional to the customized mean, although this assumption has never been formally tested.

METHODS

In a secondary analysis of NICHD Fetal Growth Studies-Singletons (12 U.S. sites, 2009-2013) using longitudinal sonographic biometric data (n = 2288 pregnancies), we investigated the assumptions of normality and constant coefficient of variation by examining behavior of the mean and standard deviation, computed following the Gardosi method. We then created a more flexible model that customizes both mean and standard deviation using heteroscedastic regression and calculated customized percentiles directly using quantile regression, with an application in a separate study of 102, 012 deliveries, 37-41 weeks.

RESULTS

Analysis of term optimal birthweight challenged assumptions of proportionality and that values were normally distributed: at different mean birthweight values, standard deviation did not change linearly with mean birthweight and the percentile computed with the normality assumption deviated from empirical percentiles. Composite neonatal morbidity and mortality rates in relation to birthweight < 10th were higher for heteroscedastic and quantile models (10.3% and 10.0%, respectively) than the Gardosi model (7.2%), although prediction performance was similar among all three (c-statistic 0.52-0.53).

CONCLUSIONS

Our findings question normality and constant coefficient of variation assumptions of the Gardosi customization method. A heteroscedastic model captures unstable variance in customization characteristics which may improve detection of abnormal growth percentiles.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00912132.

MIR146A and ADIPOQ genetic variants are associated with birth weight in relation to gestational age: a cohort study

PURPOSE

To evaluate the genetic variants related to polycystic ovary syndrome (PCOS) and its metabolic complications in girls born small for gestational age (SGA).

DESIGN

Retrospective birth cohort study.

MATERIALS AND METHODS

We evaluated 66 women of reproductive age born at term (37-42 weeks of gestational age) according to the birth weight in relation to gestational age: 26 SGA and 40 AGA (Adequate for gestational age). Anthropometric and biochemical characteristics were measured, as well as the PCOS prevalence. We analyzed 48 single nucleotide polymorphisms (SNPs) previously associated with PCOS and its comorbidities using TaqMan Low-Density Array (TLDA). miRNet and STRING databases were used to predict target and disease networks.

RESULTS

Anthropometric and biochemical characteristics did not differ between the SGA and AGA groups, as well as insulin resistance and PCOS prevalence. Two SNPs were not in Hardy-Weinberg equilibrium, the rs2910164 (MIR146A C > G) and rs182052 (ADIPOQ G > A). The rs2910164 minor allele frequency (MAF) was increased in SGA (OR, 2.77; 95%; CI, 1.22-6.29), while the rs182052 was increased AGA (OR, 0.34; 95%; CI, 0.13 - 0.88). The alleles related to reduced miRNA-146a (C) and ADIPOQ (A) activity showed increased frequency in SGA. The mature miR-146a targets 319 genes, been the CXCR4, TMEM167A and IF144L common targets and contributes to PCOS. The ADIPOQ main protein interactions were ERP44, PPARGCIA and CDH13.

CONCLUSIONS

The miR-146a (rs2910164) and ADIPOQ (rs182052) allelic variants are related to birth weight in SGA and may predict health-related outcomes, such as PCOS and obesity risk.

Propensity-Matched Comparison of Very Preterm Small- and Appropriate-for-Gestational-Age Neonates

OBJECTIVE

Comparison of mortality and major morbidities between very preterm (< 32 wk gestational age) small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) neonates.

METHODS

A retrospective observational study of neonates born between 26-31 wk gestational age from January 2015 to December 2019 was done in level-3 neonatal intensive care unit of a high-risk perinatal center in South India.

RESULTS

Of the 1,178 very preterm neonates born in the study period, 909 were eligible for inclusion. After propensity score matching for gestational age, gender, and antenatal steroid use, 592 (444 AGA and 148 SGA) were included in the final analysis. SGA neonates had increased odds of necrotizing enterocolitis (NEC) ≥ stage 2A [adjusted odds ratio (aOR): 2.2; 95% CI: 1.15-4.21], abnormal composite outcome, i.e., any one of the mortality or major morbidities (aOR: 2.99; 95% CI: 1.96-4.57), hypoglycemia requiring intravenous fluids (aOR: 2.11; 95% CI: 1.05-4.23), and anemia requiring blood transfusions (aOR: 3.13; 95% CI: 1.98-4.93); and a trend towards increased odds of bronchopulmonary dysplasia (aOR: 1.9, 95% CI: 0.92-3.91). Mortality, intraventricular hemorrhage ≥ grade 2, periventricular leukomalacia ≥ grade 2, and retinopathy of prematurity requiring treatment were not different.

CONCLUSIONS

SGA neonates have higher odds of having NEC ≥ stage 2A, abnormal composite outcome, hypoglycemia, and anemia compared to appropriately grown neonates.

Association of high maternal blood alpha-fetoprotein level with risk of delivering small for gestational age: a meta-analysis

BACKGROUND

Early identification of pregnant women at risk of delivering small-for-gestational-age (SGA) infants is required to reduce the rates of mortality and morbidity in their whole life. This meta-analysis was performed to determine whether women with higher blood alpha-fetoprotein (AFP) levels are at increased risk of SGA.

METHODS

Studies identified by searching 11 databases, including PubMed, were assessed using the Newcastle-Ottawa Scale. Subgroup and meta-regression analyses and sensitivity analysis removing a potential outlier were performed. Publication bias was assessed using Egger's test.

RESULTS

A total of 39 good-quality cohort studies involving 93,968 women and their newborn infants or fetuses ensured both internal and external validity. Relative risk of SGA among women with higher in comparison to lower blood AFP levels was 2.021 (95% CI: 1.751-2.334). Maternal blood AFP levels showed a dose-response relationship with risk of SGA. Relative risk was higher with diagnosis of SGA by ultrasound than actual birth weight (P = 0.004). Sources of heterogeneity, subgroups, confounding factors, or potential outliers did not alter the interpretations without publication bias (P = 0.320).

CONCLUSIONS

Pregnant women with higher blood AFP levels are at increased risk of SGA compared to those with lower blood AFP levels.

IMPACT

Pregnant women with higher blood alpha-fetoprotein levels (AFP) levels are at increased risk of small for gestational age (SGA) compared to those with lower blood AFP levels. High-quality evidence showed a dose-response relationship of maternal blood AFP levels with risk of delivering SGA and was robust to sources of heterogeneity, subgroups, confounding factors, potential outliers, or publication bias. Politically and practically, monitoring of maternal blood AFP level is strongly recommended to identify women at risk of delivering SGA.

Vegetarian diets during pregnancy, and maternal and neonatal outcomes

BACKGROUND

Vegetarian diets are becoming increasingly popular in the USA. Limited research has examined the health consequences of vegetarian diets during pregnancy. We comprehensively examined associations of vegetarianism during pregnancy with maternal and neonatal outcomes.

METHODS

We used data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development's Fetal Growth Studies-Singletons, a prospective multi-site cohort of 1948 low-risk pregnant women of four races/ethnicities (White, Black, Hispanic, Asian/Pacific Islander) in the USA (2009-2013). Vegetarianism was self-reported and also defined based on dietary patterns measured using a self-administered first-trimester food-frequency questionnaire (full [lacto-ovo and vegan], pesco-, semi- and non-vegetarians). Neonatal outcomes included birthweight and neonatal anthropometric measures, small for gestational age, small for gestational age with neonatal morbidity and preterm delivery. Maternal outcomes included gestational weight gain, gestational diabetes, hypertensive disorders of pregnancy and gestational anaemia.

RESULTS

Ninety-nine (6.2%) women self-reported being vegetarian. The diet-based definition identified 32 (2.0%) full vegetarians, 7 (0.6%) pesco-vegetarians and 301 (17.6%) semi-vegetarians. Neonates of diet-based full vegetarians had higher odds of being small for gestational age [adjusted odds ratio (ORadj) = 2.51, 95% confidence interval: 1.01, 6.21], but not of being small for gestational age with a postnatal morbidity. Full vegetarians had marginally increased the odds of inadequate second-trimester gestational weight gain (ORadj = 2.24, 95% confidence interval: 0.95, 5.27).

CONCLUSION

Vegetarian diets during pregnancy were associated with constitutionally smaller neonatal size, potentially via the mothers' reduced gestational weight gain. Notably, vegetarianism was not associated with small-for-gestational-age-related morbidities or other adverse maternal outcomes.

[A comparative study of cerebellar development between appropriate-for-gestational age infants and small-for-gestational-age infants]

OBJECTIVE

To investigate whether there is a difference in cerebellar development between appropriate -for-gestational-age (AGA) infants and small-for-gestational-age (SGA) infants.

METHODS

A total of 165 AGA infants and 105 SGA infants, with a gestational age of 26-40⁺⁶ weeks, were enrolled in this study. Within 24-48 hours after birth, ultrasound examination was performed to measure the transverse diameter of the cerebellum, the height of the vermis, the area of the vermis, the perimeter of the vermis, and the area and perimeter of the cerebellum on transverse section. A Pearson correlation analysis was used to investigate the correlation between cerebellar measurements and gestational age.

RESULTS

In both AGA and SGA infants, all cerebellar measurements were positively correlated with gestational age (r=0.50-0.81, P<0.05). In AGA and SGA infants, there were no significant differences in the measurements between the 25-27⁺⁶ weeks, 28-30⁺⁶ weeks, and 31-33⁺⁶ weeks of gestational age subgroups (P>0.05), while in the 34-36⁺⁶ weeks and 37-40⁺⁶ weeks subgroups, the SGA infants had significantly lower measurements than the AGA infants (P<0.05).

CONCLUSIONS

The SGA infants with a gestational age of <34 weeks have intrauterine cerebellar development similar to AGA infants, but those with a gestational age of ≥34 weeks have poorer intrauterine cerebellar development than AGA infants.

Outcome of extremely low birth weight (ELBW) infants from a birth cohort (2013-2018) in a tertiary care unit in North India

OBJECTIVE

To evaluate mortality and short-term morbidities in extremely low birth weight (ELBW) infants (<1000 g) in a birth cohort in North India.

METHODS

In-hospital data of 231 ELBW infants (Jan 2013 to Sept 2018) were collected from a prospectively maintained electronic database by using standard definitions.

RESULTS

The mean (SD) gestation and birth weight were 27.9 (2.2) weeks and 783 (133) g, respectively. Major morbidities included respiratory distress syndrome (n = 132, 57%), moderate-to-severe bronchopulmonary dysplasia (n = 62, 26.8%), hemodynamically significant patent ductus arteriosus (n = 65, 28%), intracranial hemorrhage ≥ grade II (n = 38, 16%), and culture-positive sepsis (n = 44, 19%). Median (IQR) duration of hospital stay (survivors) was 50 (17-79) days. The overall survival was 62%. On logistic regression, severe birth asphyxia, gestation ≤26 weeks, and respiratory distress syndrome were major predictors of mortality.

CONCLUSION

In the current ELBW cohort, nearly two-thirds survived until discharge, who had considerable morbidities needing prolonged hospital stay. This study can be utilized for counseling and planning of care of ELBW infants in similar settings.

Association of small for gestational age with retinopathy of prematurity: a systematic review and meta-analysis

CONTEXT

The association between small for gestational age (SGA) and retinopathy of prematurity (ROP) is unclear.

OBJECTIVE

A systematic review and meta-analysis was conducted to evaluate the association between ROP and SGA in preterm infants <37 weeks' gestational age (GA) admitted to neonatal intensive care unit.

METHODS

Medline, PubMed, Web of Science and Cochrane Central databases were searched from inception through 15 January 2019. Studies reporting outcomes based on SGA as the primary exposure variable were included. Data were extracted independently by two coauthors. Modified Newcastle-Ottawa scale was used for risk of bias assessment.

RESULTS

Database search yielded 536 records (Medline=152, PubMed=171, Web of Science=144 and Cochrane Central=69). Twenty-one studies evaluating 190 946 infants were included. SGA was associated with significantly higher odds of any stage of ROP on unadjusted analysis (unadjusted OR (uOR) 1.55; 95% CI 1.22 to 1.98; 10 studies) but not on adjusted analysis (adjusted OR (aOR) 2.16; 95% CI 0.66 to 7.11; 3 studies). SGA was associated with significantly higher odds of severe ROP (aOR 1.92; 95% CI 1.57 to 2.34; nine studies). SGA was also significantly associated with higher odds of treated ROP (aOR 1.39; 95% CI 1.18 to 1.65; three studies). In subgroup analysis of infants <29 weeks' GA, SGA was significantly associated with increased odds of ROP (uOR 1.64; 95% CI 1.19 to 2.26; two studies), severe ROP (aOR 1.61; 95% CI 1.23 to 2.10; four studies) and treated ROP (aOR 1.37; 95% CI 1.16 to 1.62; two studies).

CONCLUSION

SGA was associated with increased odds of any stage of ROP, severe ROP and treated ROP in preterm infants. Neonatologists should incorporate SGA into the risk assessment during ROP evaluation and while providing counselling to the families of preterm SGA infants. ROP screening guidelines should look into the frequency of follow-up examination in SGA infants in aim to offer early detection and treatment.

A need for an update of Polish birth weight reference norms

The indicators of perinatal outcome are birth weight and gestational age. The standard method of assessing the outcome is comparing the newborn’s birth weight with the reference system, presented in the form of percentile charts. Acceleration or delay in prenatal development, which are associated with environmental changes, stress the need to validate the developmental norms. The goal of this study is to evaluate the need to construct new and accurate reference standards. The study includes data of newborns from singleton pregnancies: 4919 born in 2000 and 3683 born in 2015. Study variables included gestational age, sex, and birth weight. Percentile values estimated for two groups of infants born in years separated by a 15-year period, born in 2000 and in 2015, were compared. Birth weight percentiles, from the 28th to the 42nd week of gestation, were calculated using the Lambda Mu Sigma method. Estimated values revealed the birth weight standards in different weeks of gestational age for both years: 2000 and 2015. Comparison among medians estimated for infants born in these years showed the existence of significant differences among boys in the 28th, 36th, and 39th weeks and among girls in the 34th and 41st weeks of gestational age. As the period between the two measurements involves several years, environmental changes during this time period might have significantly affected the course of pregnancy and thus the birth weight. Hence, there is a need to validate the developmental norms. The reference standards should be renewed, and must be done on a periodical basis.

Comparison of neonatal outcomes of small for gestational age and appropriate for gestational age preterm infants born at 28-36 weeks of gestation: a multicentre study in Ethiopia

PURPOSE

The aim of this study was to assess morbidity and mortality pattern of small for gestational age (SGA) preterm infants in comparison to appropriate for gestational age (AGA) preterm infants of similar gestational age.

METHOD

We compared neonatal outcomes of 1336, 1:1 matched, singleton SGA and AGA preterm infants based on their gestational age using data from the study 'Causes of Illness and Death of Preterm Infants in Ethiopia (SIP)'. Data were analysed using SPSS V.23. ORs and 95% CIs and χ² tests were done, p value of <0.05 was considered statistically significant.

RESULT

The majority of the infants (1194, 89%) were moderate to late preterm (32-36 weeks of gestation), 763 (57%) were females. Male preterm infants had higher risk of being SGA than female infants (p<0.001). SGA infants had increased risk of hypoglycaemic (OR and 95% CI 1.6 (1.2 to 2.0), necrotising enterocolitis (NEC) 2.3 (1.2 to 4.1), polycythaemia 3.0 (1.6 to 5.4), late-onset neonatal sepsis (LOS) 3.6 (1.1 to 10.9)) and prolonged hospitalisation 2.9 (2.0 to 4.2). The rates of respiratory distress syndrome (RDS), apnoea and mortality were similar in the SGA and AGA groups.

CONCLUSION

Neonatal complications such as hypoglycaemic, NEC, LOS, polycythaemia and prolonged hospitalisation are more common in SGA infants, while rates of RDS and mortality are similar in SGA and AGA groups. Early recognition of SGA status, high index of suspicion and screening for complications associated and timely intervention to prevent complications need due consideration.

Perinatal Undernutrition, Metabolic Hormones, and Lung Development

Maternal and perinatal undernutrition affects the lung development of litters and it may produce long-lasting alterations in respiratory health. This can be demonstrated using animal models and epidemiological studies. During pregnancy, maternal diet controls lung development by direct and indirect mechanisms. For sure, food intake and caloric restriction directly influence the whole body maturation and the lung. In addition, the maternal food intake during pregnancy controls mother, placenta, and fetal endocrine systems that regulate nutrient uptake and distribution to the fetus and pulmonary tissue development. There are several hormones involved in metabolic regulations, which may play an essential role in lung development during pregnancy. This review focuses on the effect of metabolic hormones in lung development and in how undernutrition alters the hormonal environment during pregnancy to disrupt normal lung maturation. We explore the role of GLP-1, ghrelin, and leptin, and also retinoids and cholecalciferol as hormones synthetized from diet precursors. Finally, we also address how metabolic hormones altered during pregnancy may affect lung pathophysiology in the adulthood.

Neonatal morbidity in late preterm small for gestational age neonates

INTRODUCTION

To compare neonatal respiratory morbidity among small for gestational age (SGA; birth weight less than 10th percentile for gestational age) versus appropriate for gestational age (AGA; BW at 10-90th percentile) neonates born in the late preterm period.

METHODS

A secondary analysis of a multicenter randomized trial of antenatal corticosteroids for women at risk for late preterm birth. Singleton, nonanomalous, AGA or SGA births that delivered at 34-36 weeks were included. Women were excluded if they delivered after 37 weeks or had a large for gestational age baby (LGA; weight over 90th for gestational age). The primary outcome was a composite of any of the following: respiratory support by 72 h (continuous positive airway pressure or high flow nasal cannula ≥2 h, oxygen with a fraction of inspired oxygen of ≥30% for ≥4 h, extra corporeal membrane oxygenation or mechanical ventilation) or neonatal death. The secondary outcomes included several neonatal and maternal morbidities. Multivariable Poisson regression models were used to examine the association between neonatal weight and outcomes (using adjusted relative risk [aRR] and 95% confidence intervals [CI]).

RESULTS

Of the 2831 women in the parent trial, 2315 (82%) women met inclusion criteria; among them, 426 (18%) of the neonates were SGA. There was no significant difference in the risk of the primary outcome between SGA and AGA (13.1 versus 15.1%, aRR 0.85, 95% CI 0.66-1.10). SGA, however, was associated with an increased risk for neonatal intensive care unit admission (68 versus 45%, aRR 1.60, 95% CI 1.47-1.74), hypothermia (12.2 versus 8.8%, aRR 1.36, 95% CI 1.01-1.83), feeding problems (47.2 versus 36.9%, aRR 1.24, 95% CI 1.07-1.45) and a decreased risk of neonatal hyperbilirubinemia (7.5 versus 12.7%, aRR 0.59, 95% CI 0.41-0.84), when compared to AGA.

CONCLUSION

In this cohort of late preterm birth, there was no significant difference in the rate of composite respiratory morbidity between SGA and AGA newborns.

Maternal blood leptin concentration in small for gestational age: a meta-analysis

Monitoring leptin concentration in maternal blood would be useful for earlier identification of mothers at risk of delivering small for gestational age (SGA) neonates. This study was performed to examine whether maternal blood leptin concentrations are different between SGA neonates and healthy controls. Meta-analysis was performed to summarize the data of all English-language studies providing the numbers of SGA neonates, the numbers of healthy controls, and the means and standard deviations of maternal blood leptin concentrations in these two groups. The studies were collected by searching ten databases including PubMed (MEDLINE) and investigating the PubMed Related Citations and bibliographic references. The Newcastle-Ottawa Scale was used to assess study quality. Publication bias was assessed using Egger's test. The primary outcome of this study was the standardized mean difference (SMD) in maternal blood leptin concentration between SGA neonates and healthy controls. Thirty-two overall good-quality studies involving 1734 women and their neonates were extracted from 17 articles. Synthetic evidence did not indicate statistically significant SMD in maternal blood leptin concentration between SGA neonates and healthy controls (P = 0.172). Egger's test showed no publication bias (P = 0.309).Conclusion: Maternal blood leptin concentration is not significantly different between SGA neonates and healthy controls. What is Known: • Monitoring leptin concentration in maternal blood would be useful for earlier identification of mothers at risk of delivering small for gestational age (SGA) neonates. What is New: • The results of this meta-analysis including 1734 women and their neonates in 32 overall good-quality studies showed that maternal blood leptin concentration is not significantly different between SGA neonates and healthy controls.

From population reference to national standard: new and improved birthweight charts

BACKGROUND

Antenatal detection of intrauterine growth restriction remains a major obstetrical challenge, with the majority of cases not detected before birth. In these infants with undetected intrauterine growth restriction, the diagnosis must be made after birth. Clinicians use birthweight charts to identify infants as small-for-gestational-age if their birthweights are below a predefined threshold for gestational age. The choice of birthweight chart strongly affects the classification of small-for-gestational-age infants and has an impact on both research findings and clinical practice. Despite extensive literature on pathological risk factors associated with small-for-gestational-age, controversy exists regarding the exclusion of affected infants from a reference population.

OBJECTIVE

This study aims to identify pathological risk factors for abnormal fetal growth, to quantify their effects, and to use these findings to calculate prescriptive birthweight charts for the Dutch population.

MATERIALS AND METHODS

We performed a retrospective cross-sectional study, using routinely collected data of 2,712,301 infants born in The Netherlands between 2000 and 2014. Risk factors for abnormal fetal growth were identified and categorized in 7 groups: multiple gestation, hypertensive disorders, diabetes, other pre-existing maternal medical conditions, maternal substance (ab)use, medical conditions related to the pregnancy, and congenital malformations. The effects of these risk factors on mean birthweight were assessed using linear regression. Prescriptive birthweight charts were derived from live-born singleton infants, born to ostensibly healthy mothers after uncomplicated pregnancies and spontaneous onset of labor. The Box-Cox-t distribution was used to model birthweight and to calculate sex-specific percentiles. The new charts were compared to various existing birthweight and fetal-weight charts.

RESULTS

We excluded 111,621 infants because of missing data on birthweight, gestational age or sex, stillbirth, or a gestational age not between 23 and 42 weeks. Of the 2,599,640 potentially eligible infants, 969,552 (37.3%) had 1 or more risk factors for abnormal fetal growth and were subsequently excluded. Large absolute differences were observed between the mean birthweights of infants with and without these risk factors, with different patterns for term and preterm infants. The final low-risk population consisted of 1,629,776 live-born singleton infants (50.9% male), from which sex-specific percentiles were calculated. Median and 10th percentiles closely approximated fetal-weight charts but consistently exceeded existing birthweight charts.

CONCLUSION

Excluding risk factors that cause lower birthweights results in prescriptive birthweight charts that are more akin to fetal-weight charts, enabling proper discrimination between normal and abnormal birthweight. This proof of concept can be applied to other populations.

Adverse effects of small for gestational age differ by gestational week among very preterm infants

OBJECTIVE

To characterise the excess risk for death, grade 3-4 intraventricular haemorrhage (IVH), bronchopulmonary dysplasia (BPD) and stage 3-5 retinopathy of prematurity independently associated with birth small for gestational age (SGA) among very preterm infants, stratified by completed weeks of gestation.

METHODS

Retrospective cohort study using the Optum Neonatal Database. Study infants were born <32 weeks gestation without severe congenital anomalies. SGA was defined as a birth weight <10th percentile. The excess outcome risk independently associated with SGA birth among SGA babies was assessed using adjusted risk differences (aRDs).

RESULTS

Of 6708 infants sampled from 717 US hospitals, 743 (11.1%) were SGA. SGA compared with non-SGA infants experienced higher unadjusted rates of each study outcome except grade 3-4 IVH among survivors. The excess risk independently associated with SGA birth varied by outcome and gestational age. The highest aRD for death (0.27; 95% CI 0.13 to 0.40) occurred among infants born at 24 weeks gestation and declined as gestational age increased. In contrast, the peak aRDs for BPD among survivors (0.32; 95% CI 0.20 to 0.44) and the composites of death or BPD (0.35; 95% CI 0.24 to 0.46) and death or major morbidity (0.35; 95% CI 0.24 to 0.45) occurred at 27 weeks gestation. The risk-adjusted probability of dying or developing one or more of the evaluated morbidities among SGA infants was similar to that of non-SGA infants born approximately 2-3 weeks less mature.

CONCLUSION

The excess risk for neonatal morbidity and mortality associated with being born SGA varies by adverse outcome and gestational age.

Intrauterine Growth Restriction and Patent Ductus Arteriosus in Very and Extremely Preterm Infants: A Systematic Review and Meta-Analysis

It is generally accepted that intrauterine growth restriction (IUGR) increases morbidity and mortality among very preterm neonates. However, evidence is hampered by the widespread practice of using the terms small for gestational age (SGA) and IUGR as synonyms. We conducted a systematic review of studies reporting on the association between IUGR/SGA and patent ductus arteriosus (PDA). PubMed/MEDLINE and EMBASE databases were searched. Of 993 studies reviewed, 47 (50,790 infants) were included. Studies were combined using a random effects model and sources of heterogeneity were determined by subgroup and meta-regression analyses. Meta-analysis of all included studies showed a significantly reduced risk of PDA in the SGA/IUGR group with an odds ratio (OR) of 0.82, and a 95% confidence interval (CI) of 0.70 to 0.96 (p = 0.015). Of the 47 studies, only 7 used a definition for growth restriction that went beyond birth weight (BW) for gestational age (GA). When pooled, meta-analysis could not demonstrate a significant effect size (OR 1.31, 95% CI 0.75 to 2.27, p = 0.343). Moreover, the significantly reduced risk of PDA was found in the 25 studies defining SGA as BW <10th percentile (OR 0.81, 95% CI 0.66 to 0.98, p = 0.032), but not in the 6 studies defining SGA as BW <3rd (OR 1.09, 95% CI 0.70 to 1.71, p = 0.694), or in the 27 studies using a more refined definition of PDA (i.e., hemodynamically significant PDA or PDA requiring treatment, OR 0.87, 95% CI 0.72 to 1.04, p = 0.133). In addition, we found that GA was significantly higher in the SGA/IUGR group (18 studies, mean difference 0.63 weeks, 95% CI 0.24 to 1.03, p = 0.002). Meta-regression analysis confirmed the correlation between this difference in GA and PDA risk. In summary, we observed marked heterogeneity across studies in the definition of growth restriction and PDA, and we found differences between the control and growth-restricted groups in relevant baseline characteristics, such as GA. Therefore, our meta-analysis could not provide conclusive evidence on the association between growth restriction and PDA.

Blood adiponectin concentration at birth in small for gestational age neonates: A meta-analysis

AIMS

Small for gestational age (SGA) is associated with increased rates of neonatal mortality and morbidity. Adiponectin secreted from adipose tissue is implicated in the etiology of death and illness during infancy. SGA is also a likely risk factor for the development of metabolic and clinical complications in adulthood. The present study was performed to determine whether SGA neonates and healthy controls show differences in blood adiponectin concentration at birth.

METHODS

Databases were searched to identify English-language studies providing the numbers of SGA neonates, the numbers of healthy controls, and the means and standard deviations (SDs) of blood adiponectin concentrations at birth in both groups. Study quality was assessed using the Newcastle-Ottawa Scale (NOS). A meta-analysis was performed to summarize the standardized mean differences (SMDs) in blood adiponectin concentration between SGA neonates and healthy controls.

RESULTS

The results summarized from five good quality (i.e., NOS score ≥ 5) studies involving 253 neonates showed that blood adiponectin concentration was significantly lower in SGA neonates than in healthy controls (P = 0.016), and the effect was moderate (i.e., SMD = 0.4-0.7).

CONCLUSIONS

Synthetic evidence indicated that blood adiponectin concentration at birth is lower in SGA neonates than in healthy controls.

Mortality after emergency abdominal operations in premature infants

CONTEXT/BACKGROUND

To determine risk of 30-day mortality for premature infants undergoing abdominal operations during the first 2 months of life and to identify risk factors for perioperative mortality using available demographic and clinical variables of interest.

BASIC PROCEDURES

Retrospective descriptive analysis of premature infants (gestational age less than or equal to 36weeks) undergoing abdominal operations during the first 2 months of life using the American College of Surgeon's National Surgical Quality Improvement Project Pediatric (NSQIP-P, 2012-2015) database. A stepwise logistic regression model incorporating multiple demographic and clinical factors was constructed to identify independent predictors of 30-day mortality.

FINDINGS

A total of 1554 premature infants were identified who underwent abdominal operations during the first 2 months of life. Unadjusted 30-day mortality ranged from 31% for infants born <24weeks gestational age to 4.9% for those born at 35-36weeks. Increased gestational age corresponded to decreased risk of mortality but week-by-week was not independently predictive of mortality in multivariate modeling. Female sex (aOR 1.51, 95% C.I. 1.08-2.10, p=0.014), inotrope support (aOR 3.46, 95% C.I. 2.43-4.92, p<0.001), ventilator use (aOR 2.86, 95% C.I. 1.56-5.25, p<0.001) and American Society of Anesthesiologists (ASA) class 3 (aOR 4.14, 95% C.I. 1.58-10.81, p=0.004) at time of operation were all associated with significantly increased risk of 30-day mortality. On stepwise logistic regression incorporating only those variables with statistical significance, female sex, inotrope, and ventilator support retained statistical significance.

CONCLUSIONS

Premature infants undergoing abdominal operations during the first 2 months of life have expectedly high risk of 30-day mortality. Female sex, inotrope, and ventilator support are independently associated with increased risk of mortality and can be incorporated into a model where, if present, risk of mortality is greater than 14.2%.

LEVEL OF EVIDENCE

Level III.

Prevalence and factors associated with surfactant use in Brazilian Neonatal Intensive Care Units: A multilevel analysis

The treatment with exogenous surfactant reduces mortality and the risk of complications in preterm newborns with Respiratory Distress Syndrome. Higher usage levels have been associated with individual and institutional factors. The study aimed to identify these factors associated with use of this technology in 16 public Brazilian Neonatal Units using logistic multilevel analysis. In a sample of 630 newborns the use at some time was 82.6%. Only 24.7% made use of this technology up to two hours after birth. An intraclass correlation of 0.30 showed that 30% of the variance in the use of exogenous surfactant could be assigned to the contextual level. In the final model, a greater severity score (SNAPPE-II) was associated with increased surfactant use (OR = 2.64), whereas being small for gestational age (SGA) (OR = 0.59) was associated with lower use of this technology. At the contextual level the number of beds in the unit >15 (OR = 5.86), units with higher complexity (OR = 1.73) or units with implemented Kangaroo Mother Care (OR = 2.91), especially units in Rio de Janeiro state (OR = 16.17) were associated with greater surfactant use. Although individual clinical features explained most of the variation in the use of this technology, factors linked to the institution were also of utmost importance.

Fetal growth velocity: the NICHD fetal growth studies

BACKGROUND

Accurately identifying pregnancies with accelerated or diminished fetal growth is challenging and generally based on cross-sectional percentile estimates of fetal weight. Longitudinal growth velocity might improve identification of abnormally grown fetuses.

OBJECTIVE

We sought to complement fetal size standards with fetal growth velocity, develop a model to compute fetal growth velocity percentiles for any given set of gestational week intervals, and determine association between fetal growth velocity and birthweight.

STUDY DESIGN

This was a prospective cohort study with data collected at 12 US sites (2009 through 2013) from 1733 nonobese, low-risk pregnancies included in the singleton standard. Following a standardized sonogram at 10w0d-13w6d, each woman was randomized to 1 of 4 follow-up visit schedules with 5 additional study sonograms (targeted ranges: 16-22, 24-29, 30-33, 34-37, and 38-41 weeks). Study visits could occur ± 1 week from the targeted GA. Ultrasound biometric measurements included biparietal diameter, head circumference, abdominal circumference, and femur length, and estimated fetal weight was calculated. We used linear mixed models with cubic splines for the fixed effects and random effects to flexibly model ultrasound trajectories. We computed velocity percentiles in 2 ways: (1) difference between 2 consecutive weekly measurements (ie, weekly velocity), and (2) difference between any 2 ultrasounds at a clinically reasonable difference between 2 gestational ages (ie, velocity calculator). We compared correlation between fetal growth velocity percentiles and estimated fetal weight percentiles at 4-week intervals, with 32 (±1) weeks' gestation for illustration. Growth velocity was computed as estimated fetal growth rate (g/wk) between ultrasound at that gestational age and from prior visit [ie, for 28-32 weeks' gestational age: velocity = (estimated fetal weight 32-28)/(gestational age 32-28)]. We examined differences in birthweight by whether or not estimated fetal weight and estimated fetal weight velocity were <5th or ≥5th percentiles using χ².

RESULTS

Fetal growth velocity was nonmonotonic, with acceleration early in pregnancy, peaking at 13, 14, 15, and 16 weeks for biparietal diameter, head circumference, femur length, and abdominal circumference, respectively. Biparietal diameter, head circumference, and abdominal circumference had a second acceleration at 19-22, 19-21, and 27-31 weeks, respectively. Estimated fetal weight velocity peaked around 35 weeks. Fetal growth velocity varied slightly by race/ethnicity although comparisons reflected differences for parameters at various gestational ages. Estimated fetal weight velocity percentiles were not highly correlated with fetal size percentiles (Pearson r = 0.40-0.41, P < .001), suggesting that these measurements reflect different aspects of fetal growth and velocity may add additional information to a single measure of estimated fetal weight. At 32 (SD ± 1) weeks, if both estimated fetal weight velocity and size were <5th percentile, mean birthweight was 2550 g; however, even when size remained <5th percentile but velocity was ≥5th percentile, birthweight increased to 2867 g, reflecting the important contribution of higher growth velocities. For estimated fetal weight ≥5th percentile, but growth velocity <5th, birthweight was smaller (3208 vs 3357 g, respectively, P < .001).

CONCLUSION

We provide fetal growth velocity data to complement our previous work on fetal growth size standards, and have developed a calculator to compute fetal growth velocity. Preliminary findings suggest that growth velocity adds additional information over knowing fetal size alone.

Infant mortality and causes of death by birth weight for gestational age in non-malformed singleton infants: a 2002-2012 population-based study

OBJECTIVE

To explore the associations between birth weight for gestational age (GA) and infant mortality as well as causes of infant death.

STUDY DESIGN

A population-based observational study conducted between 2002 and 2012 included 203,620 non-malformed singleton live births from Slovenia. Poisson regression analyses were performed to estimate the crude relative risk (RR) and adjusted RR (aRR) for infant mortality by birth weight percentiles stratified by the GA subgroups term, moderate-to-late preterm, very preterm and extremely preterm.

RESULTS

Compared with appropriate for GA (AGA) term infants (referent-AGA), infant mortality was significantly higher in small for GA (SGA) term infants [aRR=2.79 (1.41-5.50)], with significant cause-specific infant mortality risk for neuromuscular disorders [RR=10.48 (2.62-41.91)]. The differences in infant mortality and cause-specific infant mortality in preterm subgroups between referent-AGA and SGA were insignificant.

CONCLUSIONS

In the Slovenian population, birth weight for GA is significantly associated with infant mortality only in infants born at term.

Nutrition and Lung Growth

Experimental evidence from animal models and epidemiology studies has demonstrated that nutrition affects lung development and may have a lifelong impact on respiratory health. Chronic restriction of nutrients and/or oxygen during pregnancy causes structural changes in the airways and parenchyma that may result in abnormal lung function, which is tracked throughout life. Inadequate nutritional management in very premature infants hampers lung growth and may be a contributing factor in the pathogenesis of bronchopulmonary dysplasia. Recent evidence seems to indicate that infant and childhood malnutrition does not determine lung function impairment even in the presence of reduced lung size due to delayed body growth. This review will focus on the effects of malnutrition occurring at critical time periods such as pregnancy, early life, and childhood, on lung growth and long-term lung function.

Postnatal Growth Disadvantage of the Small for Gestational Age Preterm Twins

In this study, we examined early growth characteristics among small-for-gestational-age (SGA) preterm twins compared to their appropriate-for-gestational-age (AGA) counterparts. A retrospective study evaluated all consecutive twins born between 2008 and 2015 at a tertiary referral center whose gestational age ranged from 30.0 to 34.86 weeks. Included were twins in which one twin was AGA and the other SGA at birth. Changes of ≥2, 1–1.99, and 0–0.99 in z-score between births and 36 weeks post menstrual age (PMA) were respectively defined as severe, moderate, and mild postnatal growth failure (PNGF) in weight or head circumference (HC). Early neonatal morbidities were documented. Multiple logistic regression analysis was applied to determine conditions associated with PNGF and its severity. Out of 666 sets of twins, 83 met the inclusion criteria. Weight PNGF was similar and mild among the SGA and the AGA groups (0.9 ± 0.46 vs. 0.96 ± 0.44 z-score, respectively, p = 0.24). At 36 weeks PMA, a significantly larger proportion of SGAs were below −2 z-scores in weight (84.3%) compared to birth (31.3%) or to the AGAs (8.4%). In both groups, weight PNGF correlated with the time needed to regain birth weight. HC PNGF was mild among both groups, yet significantly more prominent among the AGAs (0.39 ± 0.72 z-score) vs. SGAs (0.75 ± 0.65 z-score, p = 0.001). We suggest that among preterm SGA infants, the absolute z-score should be used to assess the severity of weight PNGF. Individual nutritional strategies to decrease time to regain birth weight may mitigate severe malnutrition among SGAs.

Neonatal and Infant Mortality Risk Associated with Preterm and Small for Gestational Age Births in Tanzania: Individual Level Pooled Analysis Using the Intergrowth Standard

OBJECTIVES

To evaluate the risk of newborn and infant mortality associated with preterm, small for gestational age (SGA), and low birth weight (LBW) stratified by maternal HIV status and the location of birth.

STUDY DESIGN

We created a prospective cohort by pooling 5 individually randomized trials. We used Cox proportional hazard models to estimate the risk of mortality for SGA defined using the recently published Intergrowth standard, preterm, LBW, and gestational age and size for gestational age categories (preterm- appropriate for gestational age [AGA], term-SGA, and preterm-SGA). Effect modification by maternal HIV status and place of residence was assessed using the likelihood ratio test.

RESULTS

Of the 31 988 infants, 15.3% were preterm, 16.6% were SGA, and 7.3% were LBW. The proportion of preterm and SGA births was higher among the HIV-infected cohort than in the uninfected cohort. Compared with term-AGA groups, infants born both preterm and SGA had a greater risk of neonatal mortality (hazard ratio [HR] 5.43, 95% CI 2.01-14.63) than preterm-AGA infants (HR 2.40, 95% CI 1.89-3.05) and term-SGA infants (HR 2.56, 95% CI 1.96-3.34). Maternal HIV infection modified the risk of infant mortality associated with being born preterm or LBW, with a higher relative risk among those born to HIV-uninfected women. Rural residence significantly modified the risk of neonatal mortality associated with being LBW (P for interaction = .005).

CONCLUSIONS

Preterm and SGA newborns had an increased risk of mortality during the first year of life. Interventions targeting these conditions, especially in HIV-exposed and rural populations, should be integrated into existing maternal and child health programs.

Maternal and Cord Blood Adiponectin Concentrations in Small for Gestational Age: A Meta-Analysis

Background: Adiponectin, which may have a growth-promoting effect through its insulin-sensitizing action, is thought to play a key role in fetal growth. This study was performed to determine whether maternal and/or cord blood adiponectin concentrations differ between small for gestational age (SGA) and healthy controls. Methods: Databases were searched to identify good quality English language studies providing the number of SGA and healthy controls, and the means and standard deviations of maternal or cord blood adiponectin concentration in both groups. A meta-analysis was performed to summarize the standardized mean differences (SMDs) in maternal and cord blood adiponectin concentrations between SGA and healthy controls. Results: There was no statistically significant difference in maternal blood adiponectin concentration between SGA and healthy controls (n = 8, p = 0.951). However, cord blood adiponectin concentration was significantly lower in SGA than in healthy controls (n = 6, p = 0.028), and the effect was large (i.e., SMD >0.7). Conclusions: Maternal blood adiponectin concentration is not low in SGA compared with healthy controls. However, SGA shows lower cord blood adiponectin concentration than healthy controls.

Patterns of gestational weight gain and birthweight outcomes in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies-Singletons: a prospective study

BACKGROUND

Inadequate or excessive total gestational weight gain is associated with increased risks of small- and large-for-gestational-age births, respectively, but evidence is sparse regarding overall and trimester-specific patterns of gestational weight gain in relation to these risks. Characterizing the interrelationship between patterns of gestational weight gain across trimesters can reveal whether the trajectory of gestational weight gain in the first trimester sets the path for gestational weight gain in subsequent trimesters, thereby serving as an early marker for at-risk pregnancies.

OBJECTIVE

We sought to describe overall trajectories of gestational weight gain across gestation and assess the risk of adverse birthweight outcomes associated with the overall trajectory and whether the timing of gestational weight gain (first vs second/third trimester) is differentially associated with adverse outcomes.

STUDY DESIGN

We conducted a secondary analysis of a prospective cohort of 2802 singleton pregnancies from 12 US prenatal centers (2009 through 2013). Small and large for gestational age were calculated using sex-specific birthweight references <5th, <10th, or ≥90th percentiles, respectively. At each of the research visits, women's weight was measured following a standardized anthropometric protocol. Maternal weight at antenatal clinical visits was also abstracted from the prenatal records. Semiparametric, group-based, latent class, trajectory models estimated overall gestational weight gain and separate first- and second-/third-trimester trajectories to assess tracking. Robust Poisson regression was used to estimate the relative risk of small- and large-for-gestational-age outcomes by the probability of trajectory membership. We tested whether relationships were modified by prepregnancy body mass index.

RESULTS

There were 2779 women with a mean of 15 (SD 5) weights measured across gestation. Four distinct gestational weight gain trajectories were identified based on the lowest Bayesian information criterion value, classifying 10.0%, 41.8%, 39.2%, and 9.0% of the population from lowest to highest weight gain trajectories, with an inflection at 14 weeks. The average rate in each trajectory group from lowest to highest for 0-<14 weeks was -0.20, 0.04, 0.21, and 0.52 kg/wk and for 14-39 weeks was 0.29, 0.48, 0.63, and 0.79 kg/wk, respectively; the second lowest gaining trajectory resembled the Institute of Medicine recommendations and was designated as the reference with the other trajectories classified as low, moderate-high, or high. Accuracy of assignment was assessed and found to be high (median posterior probability 0.99, interquartile range 0.99-1.00). Compared with the referent trajectory, a low overall trajectory, but not other trajectories, was associated with a 1.55-fold (95% confidence interval, 1.06-2.25) and 1.58-fold (95% confidence interval, 0.88-2.82) increased risk of small-for-gestational-age <10th and <5th, respectively, while a moderate-high and high trajectory were associated with a 1.78-fold (95% confidence interval, 1.31-2.41) and 2.45-fold (95% confidence interval, 1.66-3.61) increased risk of large for gestational age, respectively. In a separate analysis investigating whether early (<14 weeks) gestational weight gain tracked with later (≥14 weeks) gestational weight gain, only 49% (n = 127) of women in the low first-trimester trajectory group continued as low in the second/third trimester, and had a 1.59-fold increased risk of small for gestational age; for the other 51% (n = 129) of women without a subsequently low second-/third-trimester gestational weight gain trajectory, there was no increased risk of small for gestational age (relative risk, 0.75; 95% confidence interval, 0.47-1.38). Prepregnancy body mass index did not modify the association between gestational weight gain trajectory and small for gestational age (P = 0.52) or large for gestational age (P = .69).

CONCLUSION

Our findings are reassuring for women who experience weight loss or excessive weight gain in the first trimester; however, the risk of small or large for gestational age is significantly increased if women gain weight below or above the reference trajectory in the second/third trimester.

The use of angiogenic biomarkers in maternal blood to identify which SGA fetuses will require a preterm delivery and mothers who will develop pre-eclampsia

OBJECTIVE

To determine (1) whether maternal plasma concentrations of angiogenic and anti-angiogenic factors can predict which mothers diagnosed with "suspected small for gestational age fetuses (sSGA)" will develop pre-eclampsia (PE) or require an indicated early preterm delivery (≤ 34 weeks of gestation); and (2) whether risk assessment performance is improved using these proteins in addition to clinical factors and Doppler parameters.

METHODS

This prospective cohort study included women with singleton pregnancies diagnosed with sSGA (estimated fetal weight <10th percentile) between 24 and 34 weeks of gestation (n = 314). Plasma concentrations of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1), soluble endoglin (sEng) and placental growth factor (PlGF) were determined in maternal blood obtained at the time of diagnosis. Doppler velocimetry of the umbilical (Umb) and uterine (UT) arteries was performed. The outcomes were (1) subsequent development of PE; and (2) indicated preterm delivery at ≤ 34 weeks of gestation (excluding deliveries as a result of spontaneous preterm labor, preterm pre-labor rupture of membranes or chorioamnionitis).

RESULTS

(1) The prevalence of PE and indicated preterm delivery was 9.2% (n = 29/314) and 7.3% (n = 23/314), respectively; (2) the area under the receiver operating characteristic curve (AUC) for the identification of patients who developed PE and/or required indicated preterm delivery was greater than 80% for the UT artery pulsatility index (PI) z-score and each biochemical marker (including their ratios) except sVEGFR-1 MoM; (3) using cutoffs at a false positive rate of 15%, women with abnormal plasma concentrations of angiogenic/anti-angiogenic factors were 7-13 times more likely to develop PE, and 12-22 times more likely to require preterm delivery than those with normal plasma MoM concentrations of these factors; (4) sEng, PlGF, PIGF/sEng and PIGF/sVEGFR-1 ratios MoM, each contributed significant information about the risk of PE beyond that provided by clinical factors and/or Doppler parameters: women who had low MoM values for these biomarkers were at 5-9 times greater risk of developing PE than women who had normal values, adjusting for clinical factors and Doppler parameters (adjusted odds ratio for PlGF: 9.1, PlGF/sEng: 5.6); (5) the concentrations of sVEGFR-1 and PlGF/sVEGFR-1 ratio MoM, each contributed significant information about the risk of indicated preterm delivery beyond that provided by clinical factors and/or Doppler parameters: women who had abnormal values were at 8-9 times greater risk for indicated preterm delivery, adjusting for clinical factors and Doppler parameters; and (6) for a two-stage risk assessment (Umb artery Doppler followed by Ut artery Doppler plus biochemical markers), among women who had normal Umb artery Doppler velocimetry (n = 279), 21 (7.5%) developed PE and 11 (52%) of these women were identified by an abnormal UT artery Doppler mean PI z-score (>2SD): a combination of PlGF/sEng ratio MoM concentration and abnormal UT artery Doppler velocimetry increased the sensitivity of abnormal UT artery Doppler velocimetry to 76% (16/21) at a fixed false-positive rate of 10% (p = 0.06).

CONCLUSION

Angiogenic and anti-angiogenic factors measured in maternal blood between 24 and 34 weeks of gestation can identify the majority of mothers diagnosed with "suspected SGA" who subsequently developed PE or those who later required preterm delivery ≤ 34 weeks of gestation. Moreover, incorporation of these biochemical markers significantly improves risk assessment performance for these outcomes beyond that of clinical factors and uterine and umbilical artery Doppler velocimetry.

Predicting gestational age using neonatal metabolic markers

BACKGROUND

Accurate gestational age estimation is extremely important for clinical care decisions of the newborn as well as for perinatal health research. Although prenatal ultrasound dating is one of the most accurate methods for estimating gestational age, it is not feasible in all settings. Identifying novel and accurate methods for gestational age estimation at birth is important, particularly for surveillance of preterm birth rates in areas without routine ultrasound dating.

OBJECTIVE

We hypothesized that metabolic and endocrine markers captured by routine newborn screening could improve gestational age estimation in the absence of prenatal ultrasound technology.

STUDY DESIGN

This is a retrospective analysis of 230,013 newborn metabolic screening records collected by the Iowa Newborn Screening Program between 2004 and 2009. The data were randomly split into a model-building dataset (n = 153,342) and a model-testing dataset (n = 76,671). We performed multiple linear regression modeling with gestational age, in weeks, as the outcome measure. We examined 44 metabolites, including biomarkers of amino acid and fatty acid metabolism, thyroid-stimulating hormone, and 17-hydroxyprogesterone. The coefficient of determination (R(2)) and the root-mean-square error were used to evaluate models in the model-building dataset that were then tested in the model-testing dataset.

RESULTS

The newborn metabolic regression model consisted of 88 parameters, including the intercept, 37 metabolite measures, 29 squared metabolite measures, and 21 cubed metabolite measures. This model explained 52.8% of the variation in gestational age in the model-testing dataset. Gestational age was predicted within 1 week for 78% of the individuals and within 2 weeks of gestation for 95% of the individuals. This model yielded an area under the curve of 0.899 (95% confidence interval 0.895-0.903) in differentiating those born preterm (<37 weeks) from those born term (≥37 weeks). In the subset of infants born small-for-gestational age, the average difference between gestational ages predicted by the newborn metabolic model and the recorded gestational age was 1.5 weeks. In contrast, the average difference between gestational ages predicted by the model including only newborn weight and the recorded gestational age was 1.9 weeks. The estimated prevalence of preterm birth <37 weeks' gestation in the subset of infants that were small for gestational age was 18.79% when the model including only newborn weight was used, over twice that of the actual prevalence of 9.20%. The newborn metabolic model underestimated the preterm birth prevalence at 6.94% but was closer to the prevalence based on the recorded gestational age than the model including only newborn weight.

CONCLUSIONS

The newborn metabolic profile, as derived from routine newborn screening markers, is an accurate method for estimating gestational age. In small-for-gestational age neonates, the newborn metabolic model predicts gestational age to a better degree than newborn weight alone. Newborn metabolic screening is a potentially effective method for population surveillance of preterm birth in the absence of prenatal ultrasound measurements or newborn weight.

An Influence of Birth Weight, Gestational Age, and Apgar Score on Pattern Visual Evoked Potentials in Children with History of Prematurity

Purpose. The objective of our study was to examine a possible influence of gestational age, birth weight, and Apgar score on amplitudes and latencies of P100 wave in preterm born school-age children. Materials and Methods. We examined the following group of school-age children: 28 with history of prematurity (mean age 10.56 ± 1.66 years) and 25 born at term (mean age 11.2 ± 1.94 years). The monocular PVEP was performed in all children. Results. The P100 wave amplitudes and latencies significantly differ between preterm born school-age children and those born at term. There was an essential positive linear correlation of the P100 wave amplitudes with birth weight, gestational age, and Apgar score. There were the negative linear correlations of P100 latencies in 15-minute stimulation from O1 and Oz electrode with Apgar score and O1 and O2 electrode with gestational age. Conclusions. PVEP responses vary in preterm born children in comparison to term. Low birth weight, early gestational age, and poor baseline output seem to be the predicting factors for the developmental rate of a brain function in children with history of prematurity. Further investigations are necessary to determine perinatal factors that can affect the modified visual system function in preterm born children.

Necrotizing enterocolitis in small-for-gestational-age neonates: a matched case-control study

BACKGROUND

Small for gestational age (SGA) neonates are at increased risk of mortality and morbidity, including necrotizing enterocolitis (NEC), but detailed information on the incidence and risk factors of NEC in SGA neonates is lacking.

OBJECTIVE

This study aims to estimate the incidence of NEC in a large cohort of SGA neonates, compared to appropriate for gestational age (AGA) neonates.

METHODS

We included all SGA neonates without congenital malformations admitted to our neonatal nursery between 2004 and 2013. Neonates in the SGA group were matched for gestational age with a control group of AGA neonates admitted during the same study period. We recorded the occurrence of NEC and studied the association with SGA and other potential risk factors.

RESULTS

A total of 475 SGA neonates were matched for gestational age at birth to 475 control AGA neonates. The incidence of NEC in the SGA group was 3.2% (15/475) versus 1.3% (6/475) in the AGA group (OR 2.55, 95% CI 0.98-6.63, p = 0.047). The incidence of NEC in the subgroups with mild, moderate and severe SGA was 2.3% (5/215), 4.7% (5/1.07) and 3.2% (5/153), respectively (p = 0.531).

CONCLUSIONS

The risk of development of NEC is more than twofold increased in SGA neonates compared to AGA neonates. We found no association between the severity of SGA and NEC.

The anti-aging factor α-klotho during human pregnancy and its expression in pregnancies complicated by small-for-gestational-age neonates and/or preeclampsia

OBJECTIVE

α-klotho, a protein with anti-aging properties, has been involved in important biological processes, such as calcium/phosphate metabolism, resistance to oxidative stress, and nitric oxide production in the endothelium. Recent studies have suggested a role of α-klotho in endocrine regulation of mineral metabolism and postnatal growth in infants. Yet, the role of α-klotho during pregnancy remains largely unknown. The aim of this study was to determine whether maternal plasma concentration of α-klotho changes during pregnancy and evaluate its expression in pregnancies complicated by small for gestational age (SGA) and/or preeclampsia (PE).

STUDY DESIGN

This cross-sectional study included patients in the following groups: (1) non pregnant women (n = 37); (2) uncomplicated pregnancy (n = 130); (3) PE without an SGA neonate (PE; n = 58); (4) PE with an SGA neonate (PE and SGA; n = 52); and (5) SGA neonate without PE (SGA; n = 52). Plasma concentrations of α-klotho were determined by ELISA.

RESULTS

The median plasma α-klotho concentration was higher in pregnant than in non-pregnant women. Among women with an uncomplicated pregnancy, the median plasma concentration of α-klotho increased as a function of gestational age (Spearman Rho = 0.2; p = 0.006). The median (interquartile range) plasma concentration of α-klotho in women with PE and SGA [947.6 (762-2013) pg/mL] and SGA without PE [1000 (585-1567) pg/mL] were 21% and 17% lower than that observed in women with an uncomplicated pregnancy [1206.6 (894-2012) pg/mL], (p = 0.005 and p = 0.02), respectively. Additionally, there were no significant differences in the median plasma concentration of α-klotho between uncomplicated pregnancies and women with PE without an SGA neonate (p = 0.5).

CONCLUSION

Maternal plasma concentration of α-klotho was higher during pregnancy than in a non-pregnant state. Moreover, the median maternal plasma concentration of α-klotho was lower in mothers who delivered an SGA neonate than in those with an uncomplicated pregnancy regardless of the presence or absence of PE.

Socioeconomic status accounts for rapidly increasing geographic variation in the incidence of poor fetal growth

Fetal growth is an important risk factor for infant morbidity and mortality. In turn, socioeconomic status is a key predictor of fetal growth; however, other sociodemographic factors and environmental effects may also be important. This study modelled geographic variation in poor fetal growth after accounting for socioeconomic status, with a fixed effect for socioeconomic status and a combination of spatially-correlated and spatially-uncorrelated random effects. The dataset comprised 88,246 liveborn singletons, aggregated within suburbs in Perth, Western Australia. Low socioeconomic status was strongly associated with an increased risk of poor fetal growth. An increase in geographic variation of poor fetal growth from 1999–2001 (interquartile odds ratio among suburbs = 1.20) to 2004–2006 (interquartile odds ratio = 1.40) indicated a widening risk disparity by socioeconomic status. Low levels of residual spatial patterns strengthen the case for targeting policies and practices in areas of low socioeconomic status for improved outcomes. This study indicates an alarming increase in geographic inequalities in poor fetal growth in Perth which warrants further research into the specific aspects of socioeconomic status that act as risk factors.

Comparison of the fatty acid composition of maternal blood and cord blood of mothers who delivered healthy full-term babies, preterm babies, and full-term small for gestational age infants

OBJECTIVE

The aim of this study was to determine and compare the fatty acid (FA) profile of maternal blood and cord blood of children born at term (group A); those born prematurely (group B); and children born with hypotrophic features (group C).

METHODS

The study consisted of 109 women. FA composition was determined by gas chromatography-mass spectrometry.

RESULTS

Twenty-two FAs were identified in the maternal blood and 33 FAs were identified in the cord blood. Significant differences in the levels of C18:3n-6 and C20:5n-3 were noted when comparing the FA composition of maternal blood samples from the three different groups (A, B, and C). Seven statistical differences were detected in the cord blood. They concerned C12:0, C18:0, C18:1c, C18:3n-6, C20:0, C20:3n-6, and C20:4n-6.

CONCLUSION

Our research has shown that the FA profile of both the maternal blood and the cord blood undergoes changes in response to pregnancy duration and the presence of reduced fetal growth. Statistical differences between groups B and C compared with group A, show that the placental-fetal transport of FA in group B and C infants may differ from that of group A children.