Bone Maturation as a Predictive Factor of Catch-Up Growth During the First Year of Life in Born Small for Gestational Age Infants: A Prospective Study

This was a nationwide prospective study carried out in Italy between 2005 and 2007, involving 34 centers with a neonatal intensive care unit. The study reports the Italian Neonatal Study charts for weight, length, and head circumference of singletons born between 23 and 42 gestational weeks, comparing them with previous Italian data and with the most recent data from European countries. Single live born babies with ultrasound assessment of gestational age within the first trimester, and with both parents of Italian origin. Only fetal hydrops and major congenital anomalies diagnosed at birth were excluded. The reference set consists of 22,087 girls and 23,375 boys. At each gestational age, boys are heavier than girls by about 4%. Later-born neonates are heavier than firstborn neonates by about 3%. The effects of sex and birth order on length and head circumference are milder. No differences were observed between babies born in central-north Italy and southern Italy. A large variability emerged among European neonatal charts, resulting in huge differences in the percentage of Italian Neonatal Study neonates below the 10th centile, which is traditionally used to define small-for-gestational-age babies. In the last 2 decades prominent changes in the distribution of birth weight emerged in Italy and in the rest of Europe, in both term and preterm neonates. The existing European neonatal charts, based on more or less recent data, were found to be inappropriate for Italy. Until an international standard is developed, the use of national updated reference charts is recommended.

Small for gestational age is usually defined as an infant with a birthweight <10th centile for a population or customized standard. Fetal growth restriction refers to a fetus that has failed to reach its biological growth potential because of placental dysfunction. Small-for-gestational-age babies make up 28-45% of nonanomalous stillbirths, and have a higher chance of neurodevelopmental delay, childhood and adult obesity, and metabolic disease. The majority of small-for-gestational-age babies are not recognized before birth. Improved identification, accompanied by surveillance and timely delivery, is associated with reduction in small-for-gestational-age stillbirths. Internationally and regionally, detection of small for gestational age and management of fetal growth problems vary considerably. The aim of this review is to: summarize areas of consensus and controversy between recently published national guidelines on small for gestational age or fetal growth restriction; highlight any recent evidence that should be incorporated into existing guidelines; and identify future research priorities in this field. A search of MEDLINE, Google, and the International Guideline Library identified 6 national guidelines on management of pregnancies complicated by fetal growth restriction/small for gestational age published from 2010 onwards. There is general consensus between guidelines (at least 4 of 6 guidelines in agreement) in early pregnancy risk selection, and use of low-dose aspirin for women with major risk factors for placental insufficiency. All highlight the importance of smoking cessation to prevent small for gestational age. While there is consensus in recommending fundal height measurement in the third trimester, 3 specify the use of a customized growth chart, while 2 recommend McDonald rule. Routine third-trimester scanning is not recommended for small-for-gestational-age screening, while women with major risk factors should have serial scanning in the third trimester. Umbilical artery Doppler studies in suspected small-for-gestational-age pregnancies are universally advised, however there is inconsistency in the recommended frequency for growth scans after diagnosis of small for gestational age/fetal growth restriction (2-4 weekly). In late-onset fetal growth restriction (≥32 weeks) general consensus is to use cerebral Doppler studies to influence surveillance and/or delivery timing. Fetal surveillance methods (most recommend cardiotocography) and recommended timing of delivery vary. There is universal agreement on the use of corticosteroids before birth at <34 weeks, and general consensus on the use of magnesium sulfate for neuroprotection in early-onset fetal growth restriction (<32 weeks). Most guidelines advise using cardiotocography surveillance to plan delivery in fetal growth restriction <32 weeks. The recommended gestation at delivery for fetal growth restriction with absent and reversed end-diastolic velocity varies from 32 to ≥34 weeks and 30 to ≥34 weeks, respectively. Overall, where there is high-quality evidence from randomized controlled trials and meta-analyses, eg, use of umbilical artery Doppler and corticosteroids for delivery <34 weeks, there is a high degree of consistency between national small-for-gestational-age guidelines. This review discusses areas where there is potential for convergence between small-for-gestational-age guidelines based on existing randomized controlled trials of management of small-for-gestational-age pregnancies, and areas of controversy. Research priorities include assessing the utility of late third-trimester scanning to prevent major morbidity and mortality and to investigate the optimum timing of delivery in fetuses with late-onset fetal growth restriction and abnormal Doppler parameters. Prospective studies are needed to compare new international population ultrasound standards with those in current use.

The aim of this study was to identify factors predictive of individual final height (FH) in subjects born small for gestational age (SGA). All full-term singleton subjects born SGA (birth weight and/or length <3rd percentile) during the period 1971-1978, matched with appropriate birth weight for gestational age (AGA) subjects (birth weight between 25th and 75th percentile) were followed from birth to FH and evaluated before puberty at a mean age +/- SD of 6.1 +/- 0.7 y and after puberty at a mean age of 20.8 +/- 2.0 y (subjects born SGA, n = 213; born AGA, n = 272). When adjusted for target height, a significant deficit in final height (p < 0.0001) was found in SGA as compared with AGA subjects for both male subjects (-3.99 cm with 95% confidence interval from -5.6 to -2.4) and female subjects (-3.64 cm with 95% confidence interval from -5.0 to -2.3), with 13.6% of subjects in the SGA population presenting short final stature. In a multiple regression analysis, target height and studied group (SGA or AGA) were found to be the strongest predictors of individual FH (p < 0.0001, r2 = 0.35 for male subjects, p < 0.0001, r = 0.40 for female subjects). For SGA subjects and according to a multiple stepwise linear regression model, 31% of the variability of individual FH [SD score (SDS)] and 58% of the variability of individual height gain SDS could be explained at birth from mother's height, father's height, and birth length SDS. No other variables were found to be predictive such as sex, gestational age (from 37 to 42 wk), birth weight SDS, ponderal index at birth, or risk factors during pregnancy associated with intrauterine growth retardation such as pregnancy-induced hypertension, smoking, or a history of SGA in offspring. Although a significant increase of body mass index SDS was documented before and after puberty in SGA subjects, puberty was not found to have any influence on growth outcome.