Risk factors for small for gestational age

BACKGROUND: The purpose of the paper was to determine the risk factors for small-for-gestational-age (SGA) infants at full term, in Japan. METHODS: The study was conducted at four hospitals and clinics in the Tokyo metropolitan area. A retrospective review of 2972 mothers and their infants born from singleton pregnancies at any time during the years 2002 and 2003 was conducted. RESULTS: Of these women, 8.4% gave birth to SGA infants. The proportion of SGA infants was significantly higher among heavy smokers (>10 cigarettes/day; 13.7%, P < 0.01). The odds ratio (OR) for SGA decreased significantly in proportion to the pregnancy body mass index (OR, 0.89; 95% confidence interval [CI]: 0.84-0.94, P < 0.001). The OR of SGA for stratified maternal weight gain was 1.79 (95%CI: 1.24-2.58, P 12 kg. CONCLUSION: The present study clearly confirms the detrimental effect of a low prepregnancy body mass index, low maternal weight gain and maternal smoking during pregnancy on the incidence of SGA infants.     

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??As a special group of neonates??small-for-gestational-age infants have a higher rate of morbidity and mortality during perinatal period. Even those who have survived also have increased risk of growth and developmental disorders in later life.Recent studies have showed a strong association between being born small for gestational age and increased risk of diabetes mellitus??metabolic syndrome and heart diseases in adulthood. Hence??rational nutritional support is needed for improving the survival rate??promoting growth and reducing the long-term risk of intellectual impairment and metabolic risks.     

Risk factors for obesity in 7-year-old European children: the Auckland Birthweight Collaborative Study.

OBJECTIVE: To identify risk factors associated with obesity in primary school children, with a particular focus on those which can be modified. To identify critical periods and growth patterns in the development of childhood obesity. METHODS: 871 New Zealand European children were enrolled in a longitudinal study at birth and data were collected at birth, 1, 3.5 and 7 years of age. Data collected at 7 years included weight, height, bioelectrical impedance analysis (BIA), television viewing time and a 24 h body movement record (actigraphy). The outcome measure was percentage body fat (PBF), which was calculated at 3.5 and 7 years using BIA. Univariate and multiple regression analyses were carried out using PBF as a continuous variable. RESULTS: Multivariable analysis found maternal overweight/obesity, maternal age, female gender, sedentary activity time and hours of television viewing to be independently associated with PBF at 7 years. Growth variables (birth weight, rapid weight gain in infancy, early (1-3.5 years) and middle childhood (3.5-7 years)) were also independently associated with adiposity at 7 years. There was a strong correlation between PBF at 3.5 years and PBF at 7 years. CONCLUSIONS: Many primary school aged children start on the trajectory of obesity in the preschool years, which suggests interventions need to start early. Maternal overweight/obesity, television watching, sedentary activity time and rapid weight gain in infancy, early and middle childhood are risk factors for childhood obesity, and are all potentially modifiable.     

早产儿和小于胎龄儿发生的危险因素的比较分析

目的 比较早产儿和小于胎龄儿发生的危险因素.方法 选择1 270例排除明确孕母疾病和产科危险因素的新生儿,自制调查问卷调查母亲身高、体重、被动吸烟和不良孕产史等因素,将研究对象分类为早产儿和足月儿、小于胎龄儿和适于胎龄儿,采用多因素logistic 回归分析比较早产儿和小于胎龄儿发生的危险因素.结果 孕期增重<9 kg使早产(OR=1.63,95%CI:1.12~2.07)和小于胎龄儿(OR=1.92,95%CI:1.56~2.58)发生的危险性均增高;母亲既往流产史(OR=1.46,95%CI:1.09~1.93)和早产史(OR=2.63,95%CI:1.81~3.92)是早产儿发生的的独立危险因素;孕母身高<1.55 m(OR=2.46,95%CI:1.78~3.48)、孕前BMI<18.5(OR=2.16,95%CI:1.53~3.16)、被动吸烟(OR=2.24,95%CI:1.65~2.98)是小于胎龄儿发生的的独立危险因素.结论 早产儿和小于胎龄儿的危险因素不同,针对两类特征孕妇应采取不同的预防措施,有针对性地减少两类不良妊娠结局的发生.     

Smoking,nicotine and tar and risk of small for gestational age babies

AIMS: To assess the effect of maternal smoking and environmental tobacco smoke (ETS) on risk of small for gestational age infants (SGA). METHODS: Case-control study of 844 cases and 870 controls. RESULTS: Maternal smoking in pregnancy was associated with an increased risk of SGA (adjusted odds ratio (OR)= 2.41; 95% confidence interval (CI) = 1.78, 3.28). We could not detect an increased risk of SGA with paternal smoking, or with other household smokers when the mother was a non-smoker, but did find an increased risk with exposure to ETS in the workplace or while socializing. Infants of mothers who ceased smoking during pregnancy were not at increased risk of SGA, but those who decreased but did not stop remained at risk of SGA. There was no evidence that the concentration of nicotine and tar in the cigarettes influenced the risk of SGA. CONCLUSIONS: Maternal smoking in pregnancy is a major risk factor for SGA. This study suggests that mothers should be advised to cease smoking completely during pregnancy, and that a reduction in the number of cigarettes smoked or smoking low tar or nicotine concentration cigarettes does not reduce the risk of SGA.     

Risk factors for preterm and small-for-gestational-age babies: a cohort from the Pacific Islands Families Study

AIM: To explore risk factors that are associated with preterm birth and full-term small-for-gestational-age (SGA) birth for a Pacific population. METHODS: Data were gathered from the Pacific Islands Families Study. Mothers of a cohort of 1398 Pacific infants born in South Auckland, New Zealand during 2000 were interviewed when their infants were 6 weeks old. Mothers were questioned regarding maternal health, antenatal care and life-style behaviours. Data regarding birth outcomes were obtained from hospital records. Analyses focused on 1324 biological mothers who gave birth to a singleton and had valid data for birth outcomes. RESULTS: Of 1324 singleton infants, the mean birthweight was 3.60 kg with standard deviation of 0.60 kg. Fifty-two (3.9%) had birthweight less than 2500 g. Ninety-four (7.1%) were born at less than 37 weeks of gestation. Most socio-demographic factors were not associated with poor birth outcomes. Primiparous birth, less frequent attendance of antenatal care and mother's history of high blood pressure were associated with preterm birth and SGA. Smoking during pregnancy increased the odds of having an SGA but not preterm birth. On the other hand, unplanned/unsure pregnancy and prior early pregnancy loss were associated with preterm birth but not SGA. CONCLUSION: Corroborating research conducted with other populations, most of the internationally and nationally recognised risk factors for preterm birth and SGA are also important for Pacific people. Smoking seems to explain more poor birth outcomes in Pacific Islands than in the New Zealand population as a whole.     

Small for gestational age babies: Indian scene

Intrauterine growth retardation (IUGR) is an important determinant of neonatal mortality, morbidity and poor neurologic outcome. The study was aimed to evaluate the magnitude of perinatal risk factors in causation and the neonatal outcome of small for gestational age (SGA) babies. One hundred and three SGA babies born over a period of one year were retrospectively analysed during their hospital stay. 3.53 per cent of the babies were SGA with mean birth weight of 1657±SD 354 gm (range 600–2200 gm). 68.9 per cent were term babies and 51.5 per cent were females. Toxemia of pregnancy (30.09%), hypertensive diseases of pregnancy (HDP) excluding toxemia (5.8%), diabetes mellitus (1.94%), medical disorders including renal and cardiac (3.88%), anemia (Hb<8 gm%) and IU infection (0.97%) were the main conditions responsible for SGA. In 56.3% pregnancies, no cause could be ascertained. The common perinatal problems were infections in 27 (26.2%), birth asphyxia in 22 (21.36%), polycythemia in 25 (24.3%), jaundice in 22 (21.36%) and hypoglycemia in 7 (6.8%). Congenital malformations in 2 (1.94%) and Hyaline membrane disease in 1 (0.97%) were uncommon problems. 5.8 per cent babies died due to various perinatal problems. Based on these findings it was concluded that idiopathic (? Constitutional) intrauterine growth retardation was the commonest cause of SGA in Indian babies. 58.3 per cent babies had neonatal problems and they had a better survival compared to their western counterparts.     

Prediction of early tolerance to enteral feeding by measurement of superior mesenteric artery blood flow velocity: appropriate- versus small-for-gestational-age preterm infants

AIM: To evaluate whether serial Doppler measurements of superior mesenteric artery blood flow velocity could predict early tolerance to enteral feeding in preterm infants. METHODS: In a prospective study, 54 healthy preterm neonates were assigned to one of the following groups: neonates with birthweight appropriate for gestational age (group 1), neonates small for gestational age without (group 2) and with prenatal haemodynamic disturbances (group 3). We studied Doppler blood flow velocity and resistance index before and after the first feed. RESULTS: Contrary to patients of group 3, infants in groups 1 and 2 showed a significant increase in blood flow velocity and a significant decrease in resistance index from the preprandial values after the first feed. At each postprandial time, we found significant differences in all velocity and resistance measurements between patients of group 3 and patients of both groups 1 and 2. In all patients, we found that the value of mean velocity measured 30 min after the first feed was the most predictive of early feed tolerance, with 95% sensitivity and 94% specificity when mean velocity >0.38 m/s. CONCLUSION: Small-for-gestational-age preterm infants with prenatal haemodynamic disturbances have an unusual intestinal haemodynamic response to the first feed. In the whole group of preterm infants, the value of mean velocity measured 30 min after the first feed is a good tool for the clinician in predicting early enteral feeding.     

Small and growth-restricted babies: drawing the distinction

The terms “small for gestational age” and “intrauterine growth restriction” have been used interchangeably to denote an in utero growth-restricted neonate. However, the two terms are not synonymous; not all small babies are growth restricted and not all growth-restricted ones are small. Research evidence, extending back to the middle of the last century, reveals that the number of growth-restricted babies who escape attention is not negligible and that the postnatal outcome of these babies is not uneventful. This paper highlights this issue and further discusses the available diagnostic tools for the identification of in utero-restricted neonates, that is, clinical assessment, anthropometric indices and obstetric ultrasound. Each of these tools has strengths and limitations, but, if combined, each could complement the other and help differentiate well-grown babies from those who are growth restricted.

Conclusion: Identification of growth-restricted neonates is feasible through the integrated use of diagnostic tools.     

Risk factors for low birthweight in Japanese infants

The purpose of our study was to identify risk factors for low birthweight (LBW; birthweight < 2500 g) in Japanese infants. The data was collected from questionnaires completed by the parents of 23 132 infants who underwent a standardized well baby check-up for 1-month-old infants, conducted by the Fukuoka City Medical Association from 1987 to 1995. The following eight factors and their second-order interaction terms were examined as potential risk factors for LBW: maternal age at delivery, history of live-born LBW infant, history of abortion in previous pregnancies, maternal smoking, coffee and alcohol consumption during pregnancy, prenatal training and live birth order. The results of multiple logistic regression analysis showed that the following three factors and one interaction term significantly contributed to LBW: history of live born LBW infant, maternal smoking, live birth order and the interaction between maternal smoking and live birth order. The smoker-related risk for LBW was quite different in each of the three groups stratified by live birth order. Efforts should be made, for example, to increase the accessibility of early, high-quality prenatal care for the high-risk groups with previous LBW babies and to implement smoking intervention, ranging from specific medical procedures to broad-scale public health and health-related educational programs in schools.     

匀称型和非匀称型婴儿智能发育观察

目的根据中华儿科杂志小于胎龄儿(SGA)的临床分型对43例SGA进行临床分型并观察其智能发育情况。 方法应用Bayley婴儿发育量表对不同临床分型的SGA婴儿的智能发育进行评价。 结果匀称型SGA其两种临床分型方法的符合率达到72．09％,而体重、头围和身高均在该胎龄值的第10百分位以下婴儿仅占32．56％,其精神发育指数(MDI)和心理运动发育指数(PDI)均较低。匀称型SGA的MDI和PDI高于非匀称型。 结论对目前SGA的临床分型方法尚需商榷。     

Macromolecular absorption in small-for-gestational-age infants

Using human alpha-lactalbumin as a marker protein, macromolecular absorption was studied in 40 preterm infants, appropriate for gestational age (AGA), in 12 AGA term infants and in 18 preterm infants, small for gestational age (SGA). The absorption of alpha-lactalbumin was measured as concentration in serum after a human milk feed and expressed as micrograms alpha-lactalbumin/l serum/l human milk/kg body weight on day 7, 14, 21 and 42 after delivery. The serum concentration of alpha-lactalbumin was correlated negatively with maturity and postnatal age. In the SGA infants, the concentration of alpha-lactalbumin was significantly higher than in the AGA infants of similar gestational age. The data show that intrauterine growth retardation causes a delayed postnatal decrease in macromolecular absorption. This may indicate delayed intestinal maturation.     

34 周以下适于胎龄及小于胎龄早产儿出生 2 周内 蛋白质、能量摄入及体质量变化

目的了解34周以下早产适于胎龄儿(AGA)和小于胎龄儿(SGA)生后蛋白质、能量摄入量以及体质量z评分的变化情况。方法回顾收集2012年1月至2014年12月入院的314例早产儿,比较268例AGA和46例SGA早产儿生后2周内蛋白质、能量摄入情况和体质量变化。结果 SGA组住院时间、肠外联合肠内营养时间、全肠内营养时间、达足量喂养时间均较AGA早产儿长,差异有统计学意义(P??0.05);SGA组生后第4、8、12天能量摄入量明显低于AGA组,SGA组生后第6、8天总蛋白质摄入量明显低于AGA组,差异均有统计学意义(P??0.05);SGA组日平均体质量增长量大于AGA组,差异有统计学意义(P??0.05);AGA组与SGA组生后2周内体质量z评分均逐渐远离中位水平,且SGA组2周时体质量z评分低于AGA组(P??0.05)。结论胎龄??34周的SGA早产儿恢复出生体质量后的生长速率快于AGA早产儿,存在一定的追赶生长;但SGA、AGA早产儿的生长均有待提高。     

Environmental risk factors for allergy and socioeconomic status in a birth cohort (BAMSE)

Associations between parental educational level and possible risk factors for atopic disease during the first months of life were explored in a cohort of 4089 neonate children born 1994–96 in Stockholm, Sweden. Reports concerning a number of life style factors during pregnancy and after the baby was born were obtained by questionnaire. There was a strong negative association between duration of education and maternal smoking during pregnancy, parental smoking after the baby was born and keeping of cat and dog (p‐trend < 0.001), respectively. For example, smoking during pregnancy was reported by 6.7% (95% CI 5.5–7.9) of mothers with college or university degree and by 22.2% (95% CI 20.1–24.5) of those with the shortest education. Indicators of dampness and poor ventilation were also more common in homes of those with the shortest education. The results show that the educational level has an influence on risk factors for development of atopic disease in childhood and indicates a need of deeper understanding of life style in different socioeconomic groups. The data also indicate that various possible confounding factors need to be thoroughly investigated when analysing studies of risk factors for allergic disease in childhood.     

Ventilatory requirements for respiratory distress syndrome in small-for-gestational-age infants

Neonatal ventilatory requirements and outcome were examined in 135 very preterm, small-for-gestational age (SGA) infants to determine whether fetal growth retardation protects against severe respiratory distress syndrome (RDS) in very immature infants. Their results were compared to those from gestational age-and gender-matched controls. Although there was no significant difference in the median duration of mechanical ventilation between the two groups, more SGA infants required ventilation and were ventilated because of RDS. In a subgroup also matched for mode of delivery, there was no significant difference between the proportion of SGA infants requiring mechanical ventilation for RDS compared to their matched controls. The mortality was greater in the SGA group. We conclude that fetal growth retardation does not protect against severe RDS.     

Hospital care techniques resulting in intact survival of a 380-g infant

Intact survival of infants delivered before completion of the 26th week of gestation or weighing less than 500 g is a well known phenomenon. We recently cared for an infant whose birth weight was 380 g, making her one of the smallest survivors in the United States. Her hospitalization (including expenses), the techniques of our minimal intervention protocol and her 20-month (corrected) follow-up are presented together with a discussion of the moral, economic and social implications involved in the care of such an infant.     

Does age potentiate the smoking-related risk of fetal growth retardation?

Whether smoking is more harmful in certain pregnancies than others is a matter of controversy. In a large prospective study, interactions between smoking and other risk factors for small-for-gestational-age (SGA) were studied. Practically all Swedish live births between 1983 and 1985 were included, 280 809 births in all. In single births, significant interaction between maternal age on one hand and moderate (1–9 cigarettes/day) or heavy (ten cigarettes or more per day) smoking on the other, were obtained. The relative risk of SGA for heavy smokers versus non-smokers was 1.9 in the lowest age group (15–19 years) and 3.4 among women aged 40–44. Although smoking was twice as common among teenagers as compared to women aged 40–44, the attributable risk of smoking for SGA was higher among the older women. No other significant interactions with regard to fetal growth were obtained.

In Sweden, there has been a shift towards delayed childbearing, and smoking during pregnancy is prevalent. These socio-demographic changes and the increased risk for SGA among older smokers must be considered when evaluating antenatal programs aimed at surveillance of fetal well-being.