Neonatal management of the growth-restricted infant

Fetal weight change close to term is proportional to the birthweight percentile

OBJECTIVE

To investigate the relationship between the difference in estimated fetal weight and birthweight at or close to term, and in relation to Doppler parameters.

STUDY DESIGN

A cohort study of all term singleton pregnancies who underwent an ultrasound within two weeks of delivery after 36 weeks at one institution in one calendar year. When available, Doppler measurements of umbilical and middle cerebral artery pulsatility index were recorded. Data were analysed by Pearson rank correlation.

RESULTS

Of 8517 eligible deliveries, 885 women had an ultrasound scan within 2 weeks of delivery. Mean daily differences between estimated fetal weight and birth weight were: those born <10th percentile lost 26 g per day (95 % CI -36 to -16), 10-50th percentile gained 7 g per day (95 % CI -2 to 15), 50th-90th percentile gained 27 g per day (95 % CI 19-35) and >90th percentile gained 48 g per day (95 % CI 32-64). There was a negative correlation between umbilical: middle cerebral artery pulsatility index and the change in weight per day (n = 348, p = 0.001, r = 0.17).

CONCLUSIONS

Difference in the estimated fetal weight and birthweight, expressed as grams growth per day, is proportional to the birthweight percentile. Fetuses with a birthweight >10th percentile gain weight, while those with a birthweight <10th percentile apparently decline in weight between their final ultrasound estimated fetal weight and delivery. In babies with the smallest or apparent negative weight gain there was an association with Doppler parameters that signified hypoxia indicating fetal growth at term may be restricted by impaired placental function. Estimated fetal weight may be a poor predictor of birthweight for reasons other than ultrasound or algorithmic error.

Kidney impairment in fetal growth restriction: three-dimensional evaluation of volume and vascularization

OBJECTIVES

Renal development is impaired in fetal growth restriction (FGR). Renal size can be considered a surrogate of renal function in childhood, and could be impaired in that condition. Our aim was to evaluate the ratio of total renal volume, measured by three-dimensional ultrasound, to estimated fetal weight (TRV/EFW) among fetuses with and without growth restriction. Furthermore, we correlated TRV/EFW with fetal Doppler velocimetry and renal vascularization indexes and evaluated the association of renal volume and vascular parameters with adverse neonatal events in growth-restricted fetuses.

METHODS

In a retrospective cohort, TRV and renal vascularization of growth-restricted and normal fetuses were evaluated by three-dimensional ultrasonography and VOCAL technique. Independent samples t-tests and Mann-Whitney test were used for comparisons between groups. Logistic regression model was applied to evaluate the association between renal characteristics and adverse neonatal events.

RESULTS

Seventy-one growth-restricted fetuses were compared to 194 controls. The TRV/EFW was lower in the growth-restricted group (P < .001). In our sample, this ratio did not correlate with Doppler velocimetry parameters, renal vascular indexes or any adverse neonatal events.

CONCLUSION

The TRV/EFW ratio is decreased in FGR. Further studies are needed to investigate the association of this ratio with long-term renal outcomes.

The frequency of pulmonary hypertension in newborn with intrauterine growth restriction

Intrauterine growth restriction (IUGR) is a clinical definition applied to neonates born with clinical features of malnutrition and in-utero growth retardation irrespective of their birth weight percentile. This study was aimed to determine the frequency of pulmonary hypertension (PH) in neonates with IUGR. In this descriptive cross-sectional study, we followed 96 neonates with IUGR (≤28 days) and 38 neonates without IUGR born in the department of the neonatal intensive care unit children hospital complex Multan, Pakistan. We analyzed certain factors such as gender, gestational age (GA) (weeks), birth weight (BW in kg), weight percentile (WP) for GA, meconium aspiration syndrome (MAS), birth asphyxia (BA) and respiratory distress syndrome (RDS) for pulmonary hypertension (PH) in IUGR and non-IUGR group. GA was measured by the Ballard scoring system. Echocardiography was performed for all patients by the pediatric cardiologist to measure pulmonary arterial (PA) pressure using Bernoulli’s equation. Out of total 96 IUGR neonates, 33.3% (n = 32) suffered from PH, of which 65.3% (n = 18) were male and 43.7% (n = 14) were female. The percentages of IUGR neonates with BA, MAS and RDS were 34.4%, 18.8% and 22.9% respectively. The data were analyzed using the SPSS-16 software to test the statistical significance of the results. A p-value less than 0.05 was considered significant. When the chi-square test was applied, it depicted that MAS was significantly associated with PH in IUGR neonates (p = 0.0001) compared to non-IUGR neonates. Our findings suggested an increased chance of PH in IUGR neonates and MAS may be a strong factor.

Keep it in the family: comparing perinatal risks in small-for-gestational-age infants based on population vs within-sibling designs

BACKGROUND

Small-for-gestational-age (SGA) birth is commonly used as a proxy for fetal growth restriction, but also includes constitutionally small infants. Genetic factors account for almost half of the risk of SGA birth. We estimated perinatal risks of SGA birth using both population-based and within-sibling analyses, where the latter by design controls for shared genetic factors and maternal environmental factors that are constant across pregnancies.

METHODS

This was a prospective nationwide cohort study of 2 616 974 singleton infants born in Sweden between January 1987 and December 2012, of whom 1 885 924 were full siblings. We estimated associations between severe or moderate SGA (<3rd percentile and 3rd to <10th percentiles, respectively) and risks of stillbirth, neonatal mortality and morbidity, using both population-based and within-sibling analyses. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated in stillbirth analyses, whereas relative risks (RRs) were used for analyses of neonatal outcomes.

RESULTS

Compared with non-SGA births (>10th percentile), the HR (95% CI) of stillbirth was 18.5 (95% CI 17.4-19.5) among severe SGA births in the population analysis and 22.5 (95% CI 18.7-27.1) in the within-sibling analysis. In non-malformed infants, RRs for neonatal mortality in moderate and severe SGA infants were similarly increased in both population and within-sibling analyses. In term non-malformed infants (≥37 weeks), SGA-related RRs of several neonatal morbidities were higher in within-sibling than in population analyses.

CONCLUSIONS

Perinatal risks associated with fetal growth restriction are more accurately estimated from analyses of SGA in which genetic factors are accounted for.

SWATH-MS quantitative proteomic investigation of intrauterine growth restriction in a porcine model reveals sex differences in hippocampus development

Intrauterine growth restriction (IUGR) is characterized by reduced growth and weight of the foetus, mainly due to the lack of nutrients and oxygen. Animals affected by IUGR show changes in specific brain areas and several neuronal processes. Female offspring affected by IUGR show increased survival and development compared to males. The objective of this study was to analyse changes in the hippocampus proteome in male and female piglets affected by IUGR. Seven pregnant Iberian sows were fed from Day 35 of pregnancy onwards at 50% of their requirements. At Day 100 of pregnancy, foetuses were obtained and classified by sex and weight, as mild IUGR (Normal Body Weight) versus severe IUGR (Low Body Weight). Hippocampi were dissected and the proteomes analysed by SWATH-MS DIA. In this study, 1497 proteins were identified of which 260 were quantitatively analysed. All differential proteins were more abundant in females versus males and were involved in protein synthesis, neuronal development, metabolism, antiapoptotic signalling and vesicular transport. Our findings support that female foetuses tolerate nutrient limitation better than males, especially under mild IUGR. Under severe IUGR, females still seems to maintain normal lipid metabolism and antiapoptotic signalling, which may be related to the increased female survival. SIGNIFICANCE: In the last years, proteomics have been used to evidence differences related to sex in non-reproductive organs. Intrauterine Growth Restriction (IUGR) can affect female and male offspring differently. Female offspring has stronger protective strategies compared to males, enhancing growth and postnatal survival. Most studies regarding this issue have focused on metabolic organs (i.e. liver). However, the predominance of neurodevelopmental disorders in males suggests that the central nervous system in female offspring adapt better to nutritional stress conditions than that of males. Based on the differential protein expression in hippocampal samples, our work demonstrates that female foetuses indeed adapt better to IUGR than males, especially under mild IUGR conditions. In severe IUGR conditions, differences between males and females were not so evident, but even in this case, the remaining differences suggest increased survival in females than in males.

Effects of fetal genotype and sex on developmental response to maternal malnutrition

The present study aimed to determine whether developmental patterns, adiposity level and fatty-acid composition of fetuses exposed to maternal malnutrition are driven by their sex or their genotype, or both, as these may modulate the adaptive response to the intrauterine environment independently of the maternal genotype. We used a single maternal genotype (purebred Iberian (IB) sows), which was inseminated with heterospermic semen (obtained by mixing semen from Iberian and Large White (LW) boars), to obtain four different subsets of fetuses (male and female, purebred (IB×IB) and crossbred (IB×LW)) in Iberian purebred sows. Analysis of fetal phenotypes indicated a better adaptive response of the female offspring, which was modulated by their genotype. When faced with prenatal undernutrition, females prioritised the growth of vital organs (brain, liver, lungs, kidneys and intestine) at the expense of bone and muscle. Moreover, the analysis of fat composition showed a higher availability of essential fatty acids in the female sex than in their male counterparts and also in the Iberian genotype than in crossbred fetuses. These results are of high translational value for understanding ethnic differences in prenatal programming of postnatal health and disease status, and show evidence that prenatal development and metabolic traits are primarily determined by fetal sex and strongly modulated by fetal genotype.

Prevalence and risk factors of retinopathy of prematurity in Iran: a systematic review and meta-analysis

Background

Retinopathy of prematurity (ROP) refers to the developmental disorder of the retina in premature infants and is one of the most serious and most dangerous complications in premature infants. The prevalence of ROP in Iran is different in various parts of Iran and its prevalence is reported to be 1–70% in different regions. This study aims to determine the prevalence and risk factors of ROP in Iran.

Methods

This review article was conducted based on the preferred reporting items for systematic review and meta-analysis (PRISMA) protocols. To find literature about ROP in Iran, a comprehensive search was done using MeSH keywords in several online databases such as PubMed, Ovid, Science Direct, EMBASE, Web of Science, CINAHL, EBSCO, Magiran, Iranmedex, SID, Medlib, IranDoc, as well as the Google Scholar search engine until May 2017. Comprehensive Meta-analysis Software (CMA) Version 2 was used for data analysis.

Results

According to 42 studies including 18,000 premature infants, the prevalence of ROP was reported to be 23.5% (95% CI: 20.4–26.8) in Iran. The prevalence of ROP stages 1, 2, 3, 4 and 5 was 7.9% (95% CI: 5.3–11.5), 9.7% (95% CI: 6.1–15.3), 2.8% (95% CI: 1.6–4.9), 2.9% (95% CI: 1.9–4.5) and 3.6% (95% CI: 2.4–5.2), respectively. The prevalence of ROP in Iranian girls and boys premature infants was 18.3% (95% CI: 12.8–25.4) and 18.9% (95% CI: 11.9–28.5), respectively. The lowest prevalence of ROP was in the West of Iran (12.3% [95% CI: 7.6–19.1]), while the highest prevalence was associated with the Center of Iran (24.9% [95% CI: 21.8–28.4]). The prevalence of ROP is increasing according to the year of study, and this relationship is not significant (p = 0.181). The significant risk factors for ROP were small gestational age (p < 0.001), low birth weight (p < 0.001), septicemia (p = 0.021), respiratory distress syndrome (p = 0.036), intraventricular hemorrhage (p = 0.005), continuous positive pressure ventilation (p = 0.023), saturation above 50% (p = 0.023), apnea (p = 0.002), frequency and duration of blood transfusion, oxygen therapy and phototherapy (p < 0.05), whereas pre-eclampsia decreased the prevalence of ROP (p = 0.014).

Conclusion

Considering the high prevalence of ROP in Iran, screening and close supervision by experienced ophthalmologists to diagnose and treat the common complications of pre-maturity and prevent visual impairment or blindness is necessary.

Fetal growth-retardation and brain-sparing by malnutrition are associated to changes in neurotransmitters profile

The present study assesses possible changes in the levels of different neurotransmitters (catecholamines and indoleamines) in fetuses affected by nutrient shortage. Hence, we determined the concentration of catecholamines and indoleamines at the hypothalamus of 56 swine fetuses obtained at both 70 and 90days of pregnancy (n=33 and 23 fetuses, respectively). The degree of fetal development and the fetal sex affected the neurotransmitters profile at both stages. At Day 70, there were found higher mean concentrations of l-DOPA in both female and male fetuses with severe IUGR; male fetuses with severe IUGR also showed higher concentrations of TRP than normal male littermates. At Day 90 of pregnancy, the differences between sexes were more evident. There were no significant effects from either severe IUGR on the neurotransmitter profile in male fetuses. However, in the females, a lower body-weight was related to lower concentrations of l-DOPA and TRP and those female fetuses affected by severe IUGR evidenced lower HVA concentration. In conclusion, the fetal synthesis and use of neurotransmitters increase with time of pregnancy but, in case of IUGR, both catecholamines and indoleamines pathways are affected by sex-related effects.

Retinopathy of prematurity: Revisiting incidence and risk factors from Oman compared to other countries

Purpose:

The purpose of this study is to determine the incidence of retinopathy of prematurity (ROP) and the maternal/neonatal risk factors at a tertiary care hospital in Oman, compared to other countries.

Patients and Methods:

A retrospective analysis of premature neonates born with gestational age (GA) 24–32 weeks at Sultan Qaboos University Hospital, Oman, from January 2007 to December 2010. Maternal and neonatal in-hospital course was retrieved. The incidence of ROP was reported. Risk factors analyses were performed using univariate and multivariate statistics.

Results:

A total of 171 neonates (57% males, 43% females) were included for analysis. The incidence of ROP (any stage) was 69/171 (40.4%). Infants with ROP had significantly lower GA (27.7±2 weeks) compared to non-ROP group (30.2±1.7 weeks), P < 0.001),P < 0.001) and significantly lower birth weight (BW) (948 ± 242 g in ROP group vs. 1348 ± 283 g in non-ROP group;P < 0.001). Other significant risk factors associated with ROP were: small for GA, respiratory distress syndrome, requirement for ventilation, duration of ventilation or oxygen therapy, bronchopulmonary dysplasia, hyperglycemia, late onset sepsis (clinical or proven), necrotizing enterocolitis, patent ductus arteriosus, seizures, and number of blood transfusions. There was no significant difference in maternal characteristics between the ROP and non-ROP groups except that mothers of infants with ROP were found to be significantly younger. Logistic regression analysis revealed early GA, low BW, duration of Oxygen therapy, and late-onset clinical or proven sepsis as independent risk factors.

Conclusion:

ROP is still commonly encountered in neonatal practice in Oman and other countries. Early GA, low BW, and prolonged oxygen therapy continue to be the main risk factors associated with the occurrence of ROP in our setting. In addition, an important preventable risk factor identified in our cohort includes clinical or proven late-onset sepsis.

Sex and intrauterine growth restriction modify brain neurotransmitters profile of newborn piglets

The current study aimed to determine, using a swine model of intrauterine growth restriction (IUGR), whether short- and long-term neurological deficiencies and interactive dysfunctions of Low Birth-Weight (LBW) offspring might be related to altered pattern of neurotransmitters. Hence, we compared the quantities of different neurotransmitters (catecholamines and indoleamines), which were determined by HPLC, at brain structures related to the limbic system (hippocampus and amygdala) in 14 LBW and 10 Normal Body-Weight (NBW) newborn piglets. The results showed, firstly, significant effects of sex on the NBW newborns, with females having higher dopamine (DA) concentrations than males. The IUGR processes affected DA metabolism, with LBW piglets having lower concentrations of noradrenaline at the hippocampus and higher concentrations of the DA metabolites, homovanillic acid (HVA), at both the hippocampus and the amygdala than NBW neonates. The effects of IUGR were modulated by sex; there were no significant differences between LBW and NBW females, but LBW males had higher HVA concentration at the amygdala and higher concentration of 5-hydroxyindoleacetic acid, the serotonin metabolite, at the hippocampus than NBW males. In conclusion, the present study shows that IUGR is mainly related to changes, modulated by sex, in the concentrations of catecholamine neurotransmitters, which are related to adaptation to physical activity and to essential cognitive functions such as learning, memory, reward-motivated behavior and stress.

Defining small-for-gestational-age: prescriptive versus descriptive birthweight standards

Descriptive population-based birthweight standards possess low sensitivity in detecting infants with growth impairment. A prescriptive birthweight standard based on a 'healthy' subpopulation without risk factors for intrauterine growth restriction might be superior. We created two birthweight standards based on live born, singleton infants with gestational age 24-42 weeks and born in The Netherlands between 2000 and 2007. Inclusion criteria for the prescriptive birthweight standard were restricted to infants without congenital malformations, born to healthy mothers after uncomplicated pregnancies. We defined small-for-gestational-age (SGA) as birthweight <10th percentile and assessed the ability of both standards to predict adverse neonatal outcomes. The prescriptive birthweight standard identified significantly more infants as SGA, up to 38.0 % at 29 weeks gestation. SGA infants classified according to both standards as well as those classified according to the prescriptive birthweight standard only, were at increased risk of both major and minor adverse neonatal outcomes. The prescriptive birthweight standard was both more sensitive and less specific, with a maximum increase in sensitivity predicting bronchopulmonary dysplasia (+42.6 %) and a maximum decrease in specificity predicting intraventricular haemorrhage (-26.9 %) in infants aged 28-31 weeks.

CONCLUSION

Prescriptive birthweight standards could improve identification of infants born SGA and at risk of adverse neonatal outcomes.

WHAT IS KNOWN

• Descriptive birthweight standards possess low sensitivity in detecting growth restricted infants at risk of adverse neonatal outcomes. • Prescriptive standards could improve identification of very preterm small-for-gestational-age (SGA) infants at risk of intraventricular haemorrhage. What is New: • Prescriptive standards identify more preterm and term SGA infants at risk of major adverse neonatal outcomes. • Late preterm and term SGA infants classified according to the prescriptive standard are at increased risk of minor adverse neonatal outcomes with potentially harmful implications.

Choosing the Best Newborn Anthropometric Measure Associated With the Risks and Outcomes of Intrauterine Growth Restriction

Intrauterine growth restriction (IUGR) is associated with various prenatal risks and postnatal adverse outcomes. The aim of this study is to choose the most sensitive newborn anthropometric measure, which is closely associated with IUGR-related risks and outcomes, to substitute IUGR after delivery. Data were obtained from the Collaborative Perinatal Project, a multicenter prospective cohort study in the United States from 1959 to 1976. Maternal heavy smoking and severe hypertensive disorders during pregnancy, neonatal polycythemia and hypothermia, low intelligence quotient (<70) at age 7 years were chosen as IUGR-related risks and outcomes. Eight anthropometric measures at birth were tested by logistic regression model. Birth weight-to-head circumference (W/HC) had the largest odds ratio (OR) for neonatal polycythemia (OR = 1.8, 95% confidence interval [CI] = 1.5-2.0), severe hypertensive disorders (OR = 1.9, 95% CI = 1.5-2.2), and maternal heavy smoking (OR = 1.9, 95% CI = 1.7-2.1) during pregnancy. It also had the highest summary OR (9.3). Thus, W/HC may be a good measure for IUGR.

Adverse fetal and neonatal outcomes associated with a life-long high fat diet: role of altered development of the placental vasculature

Maternal obesity results in a number of obstetrical and fetal complications with both immediate and long-term consequences. The increased prevalence of obesity has resulted in increasing numbers of women of reproductive age in this high-risk group. Since many of these obese women have been subjected to hypercaloric diets from early childhood we have developed a rodent model of life-long maternal obesity to more clearly understand the mechanisms that contribute to adverse pregnancy outcomes in obese women. Female Sprague Dawley rats were fed a control diet (CON--16% of calories from fat) or high fat diet (HF--45% of calories from fat) from 3 to 19 weeks of age. Prior to pregnancy HF-fed dams exhibited significant increases in body fat, serum leptin and triglycerides. A subset of dams was sacrificed at gestational day 15 to evaluate fetal and placental development. The remaining animals were allowed to deliver normally. HF-fed dams exhibited a more than 3-fold increase in fetal death and decreased neonatal survival. These outcomes were associated with altered vascular development in the placenta, as well as increased hypoxia in the labyrinth. We propose that the altered placental vasculature may result in reduced oxygenation of the fetal tissues contributing to premature demise and poor neonatal survival.

Parenteral nutrition-associated cholestasis in small for gestational age infants

OBJECTIVE

To identify small for gestational age (SGA) as an independent risk factor for parenteral nutrition-associated cholestasis (PNAC).

STUDY DESIGN

In a case-control study, records of infants treated in the neonatal intensive care unit from 1994 through 2003 with gestational ages (GA) < 34 weeks and exposure to parenteral nutrition (PN) > or = 7 days were reviewed. The primary outcome was the incidence of cholestasis in infants who were SGA. Secondary outcomes included PN duration, age at full enteral nutrition (FEN) and incidence of late-onset sepsis, necrotizing enterocolitis (NEC) and bronchopulmonary dysplasia (BPD). Analysis was by t test, logistic regression, and chi2 analysis.

RESULTS

Cases (n = 79) and control subjects (n = 152) had similar birth weights and GA (963 +/- 465 g versus 1090 +/- 463 g; 27 +/- 2 weeks versus 27 +/- 2 weeks; [mean +/- SD]). Of the infants who were SGA, 58% developed cholestasis (OR = 3.3, P < .01). Infants with cholestasis achieved FEN later (43 +/- 25 days versus 23 +/- 11 days) and had higher rates of sepsis (80% versus 34%), NEC (51% versus 7%), and BPD (65% versus 25%; P < .01). Of infants with cholestasis, infants who were SGA received fewer days of PN than infants who were appropriate for GA (49 +/- 24 days versus 68 +/- 36 days, P = .024).

CONCLUSION

Being SGA is an independent risk factor for PNAC. Infants who are SGA require less PN for cholestasis to develop.

Severe hypoinsulinaemic hypoglycaemia in a premature infant associated with poor weight gain and reduced adipose tissue

BACKGROUND

Hypoglycaemia is common in preterm and intrauterine growth retarded (IUGR) newborns. Although preterm and IUGR infants have limited adipose tissue stores, the role of adipose tissue and the associated adipocytokines in glucose physiology is not known.

AIM

We report the case of a premature intrauterine growth retarded infant who had poor weight gain for the first 6 weeks of life and then developed severe hypoinsulinaemic hypoketotic hypoglycaemia.

RESULTS

There was markedly reduced adiposity with low serum leptin and adiponectin levels. Total energy expenditure and body composition measurements showed that body fat as a percentage of weight averaged 7% at 20 weeks and 28% at 28 weeks. At 20 weeks of age, the patient was equivalent to a deficit of >2 SD scores of body fat, but average fatness by 28 weeks. The hypoglycaemia completely resolved when the patient started gaining weight with an increase in fat mass and a concomitant increase in serum leptin and adiponectin level.

CONCLUSIONS

Although the precise mechanism of this patient's severe hypoglycaemia is unclear, further studies are required to understand the role of adipose tissue and adipocytokines in glucose homeostasis in preterm and IUGR infants.