Small birth weight and later body composition and fat distribution in adolescents: the Avena study

Objective: To assess the association between birth weight and body composition and fat distribution in adolescents, and to test the possible sex‐specific effect in these relationships. Methods and Procedures: A total of 1,223 adolescents 13–18.5 years old (553 male adolescents and 670 female adolescents) born at >35 weeks, were selected from a cross‐sectional multicenter study conducted in five Spanish cities in 2000–2002. BMI was calculated from weight and height. Triceps and subscapular skinfold thickness (ST) were measured on the left side, and fat mass (FM) and fat‐free mass (FFM) were estimated according to the equations of Slaughter et al. Subscapular skinfold adjusted by tricipital (ST) and waist circumference were used as markers of central adiposity. Results: Birth weight Z‐score was positively associated with FFM in female adolescents (P < 0.001), but not in male adolescents, after controlling for age, pubertal stage, gestational age, socioeconomic status, physical activity, and current height (P < 0.001 for interaction between adjusted birth weight Z‐score and sex). Adjusted birth weight Z‐score was inversely associated with central adiposity in male and female adolescents as measured by ST (P = 0.026). Discussion: These results provide further evidence that gender has an important influence on the programming effect of birth weight on later FFM in adolescents because the effect was only observed in female adolescents. Our results suggest that small size for gestational age at birth could program more central subcutaneous fat deposition in adolescents of both sexes, but further research is needed on this issue.     

Effects of aminoglutethimide phosphate on litter size and birth weight in superovulated rats

In this study, litter sizes, birth weights and survival rates of neonates in superovulated rats treated with aminoglutethimide phosphate (AGP) were studied. Young (8- to 9-week old) and adult (14- to 16-week old) rats were treated with 20 or 40 IU PMSG between 1100 and 1300 hours on the day of early diestrus, followed by identical doses of hCG 52 to 54 hours later. These rats received 10 mg AGP on Days 0 to 2 of pregnancy (AGP rats). The duration of pregnancy in the AGP-treated and control rats was about the same. Mean live litter sizes in young and in adult AGP rats treated with 20 IU PMSG and 20 IU hCG were significantly higher (15.5 and 15.4; P<0.01) than in the control rats (11.5 and 12.6). When AGP was given to young and adult rats pretreated with 40 IU PMSG and 40 IU hCG, they produced means of 17.7 and 17.3 live neonates, respectively. The birth weights for young (5.55 to 5.88 g) and adult (5.89 to 5.96 g) AGP rats were smaller than those of respective control rats (6.44 and 6.40 g; P < 0.05-0.01). When the number of neonates was adjusted to 8 per dam for nursing and rearing, all of them were alive at 5 weeks after birth and showed normal growth. However, body weight gains of the progeny of AGP dams were lower than those of controls. These results indicate that rats treated with large doses of gonadotropins and AGP produce larger litter sizes than nontreated controls.     

Effects of grandmothers' smoking in pregnancy on birth weight: intergenerational cohort study

Objective To investigate the influences on birth weight of maternal smoking during pregnancy across generations.Design Intergenerational cohort study.Participants Members of the 1958 birth cohort and their offspring and mothers.Setting England, Scotland, and Wales.Main outcome measure Birth weight.Results Information on grandmothers'' smoking during pregnancy was available for 9028 singleton offspring of 4302 female cohort members. Assuming heritable transmission through the intergenerational association, grandmothers'' smoking was predicted to result in a 34 g reduction (95% confidence interval -41 g to -28 g) in the birth weight of grandchildren. Random effects models showed a negative association between grandmothers'' smoking and birth weight of grandchildren (β regression coefficient -24 g, -50 g to 3 g), but this effect was eliminated after adjustment for maternal smoking (0 g, -26 g to 26 g).No association was evident among the offspring of non-smoking mothers (n = 6105; 14 g, -17 g to 46 g), and after adjustment for maternal birth weight, adult height and body mass index, grandmothers'' smoking was positively associated with the birth weight of grandchildren (45 g, 10 g to 80 g).Conclusion Deficits in mothers'' birth weight attributable to their mother smoking was not evident in the grandchildren.     

Hyperphenylalaninemia and birth weight

Hyperphenylalaninemias (HPAs) are due to autosomal recessive inherited deficiency of phenylalanine hydroxylase and include three different biochemical and clinical phenotypes: classic phenylketonuria, mild phenylketonuria and persistent HPA. Recently the relationship between birth weight and HPA has been investigated. We performed an evaluation of birth weight in our 260 HPA patients. Our results do not support the view that birth weight is reduced in HPA patients and we found no correlation between birth weight and severity of the disease. Only a better knowledge of genetic mechanisms involved in HPA can clarify the interaction between HPA and fetal development.     

Effects of parenteral lipid infusion on DNA damage in very low birth weight infants

Very low birth weight (VLBW) infants are known to have poorly developed antioxidant system and may be at increased risk for radical damage. Previous studies have reported higher levels of lipid peroxide products in lipid emulsion used for parenteral nutrition. To examine the direct effects of parenteral lipid infusion on DNA damage in VLBW infants, we measured urinary 8-hydroxydeoxyguanosine (8-OHdG) levels in VLBW infants before, during, and after the parenteral lipid infusion. In both the lipid-infused and lipid-free groups, urinary 8-OHdG excretion levels at 14 days old were significantly (p < 0.01) lower than those at 2 and 7 days old. However, there were no significant differences in urinary 8-OHdG excretion levels between the lipid-infused and lipid-free groups at 2, 7, and 14 days old. Our results suggest that parenteral lipid infusion does not cause oxidative DNA damage, but irrespective of the infusion DNA damage during the first week of life is enhanced when compared with 14 days after birth in VLBW infants.     

Effects of sow nutrition during gestation on within-litter birth weight variation: a review

The increasing demand for efficiency in pork production requires great specialization of all sectors involved in this activity. In this context, the development of strategies that could reduce undesirable traits related with negative effects on piglet survival and postnatal growth and development are essential for the pig industry. Currently, special attention is given to variation in birth weight, as some evidences suggest an increased within-litter birth weight variation in modern sows. This variation has been shown to be associated with preweaning mortality, variable weights at weaning and deteriorated growth performance, which results in economic losses and lower efficiency. Therefore, understanding the factors that can influence the events that occur during gestation and that have an impact on the fetal growth and development are important to achieve better efficiency and also to develop strategies that can be used to achieve increased within-litter uniformity of piglet birth weight. This study concludes that even at a given placental size, fetal growth may vary because of differences in placental vascularization and efficiency. Feeding extra feed or energy during late gestation only marginally improves birth weight, and positive effects are not consistent between different studies. The detrimental effects of protein restriction on fetal growth during early gestation may be due to altered placental and endometrial angiogenesis and growth, which leads to a reduction in placental-fetal blood flow, nutrient supply from mother to the fetuses and ultimately to fetal growth retardation. The number of studies that attempted to influence within-litter birth weight variation by means of sow nutrition during gestation is limited. Therefore, more research concerning sow nutrition during gestation associated with the provision of balanced diets to meet requirements of the sows and fetuses are still required. This knowledge may subsequently provide starting points for the design of nutritional strategies that can influence within-litter birth variation.     

Effect of parental anthropometric parameters on neonatal birth weight and birth length

Data on 550 healthy pregnant women, 550 healthy fathers and their healthy term neonates born from singleton pregnancies (37(+0) through 41(+6) week) during a one-year period were reviewed. Maternal mean age was 27.7 +/- 9.37 years, mean pregestational weight 64.0 +/- 9.50 kg, mean gestational weight gain 15.4 +/- 4.33 kg, mean height 169.7 +/- 5.81 cm, and mean gestational age 40.1 +/- 0.95 weeks. Paternal mean age was 31.4 +/- 6.22 years, mean weight 84.6 +/- 10.35 kg, and mean height 182.8 +/- 6.84 cm. Mean birth weight was 3,709.8 +/- 500.48 g and 3,562.5 +/- 443.02 g, and mean birth length 51.5 +/- 1.91 cm and 50.7 +/- 1.62 cm in male and female newborns, respectively, yielding a birth weight greater by 147.3 g and birth length by 0.8 cm in the former. Study variables showed statistically significant correlations: maternal age contributed to the significant correlation between maternal weight and parity, maternal pregestational weight, weight at delivery, gestational weight gain and body height correlated significantly with neonatal birth weight and birth length, gestational age correlated significantly with neonatal weight and length (p = 0.01 all), parity had no major impact (p > 0.05). Paternal height and weight correlated significantly with neonatal birth weight and birth length (p = 0.01). Study results pointed to a significant correlation of maternal pregestational weight, gestational weight gain and body height, and of paternal weight and height with the neonate birth weight and birth length.     

早期应用微生态制剂对极低出生体重儿影响的临床观察

目的观察早期应用微生态制剂对极低出生体重儿黄疸、喂养、生长以及免疫功能的影响。方法我院NICU收治的生后24h内极低出生体重儿84例,随机分为观察组46例,对照组38例。观察组生后4h内开始口服或鼻饲胃管服用妈咪爱0.5g,2次/d,连用14d。观察两组达到高胆红素血症标准的人数,以及生后24h、5d总胆红素值;喂养不耐受人数;生后5d生理性体重下降及1个月体重增长情况;生后1个月免疫学指标。并加以对比。结果24h内血清胆红素比较无统计学意义(P0.05),治疗5d后观察组血清总胆红素明显低于对照组(P0.05),观察组出现高胆红素血症人数明显低于对照组(P0.05);观察组喂养不耐受出现例数明显低于对照组(P0.01);观察组生后5d体重下降的克数低于对照组(P0.05),1个月时体重增长克数高于对照组(P0.01);观察组IgA水平较对照组明显增加(P0.05),但IgG及IgM含量与对照组比较差异无统计学意义(P0.05)。结论早期应用微生态制剂能降低血清胆红素水平,对预防极低出生体重儿高胆红素血症有一定作用;能提高喂养的耐受性,有利于患儿生长发育;对极低出生体重儿的肠道功能及免疫功能有明显影响,能增加免疫球蛋白IgA水平,从而促进体液免疫的发展。     

Insulin resistance and birth weight

This review article describes the scientific evidence for the relationship between birth weight and insulin resistance. Most studies demonstrate that low birth weight is closely connected to insulin resistance and later development of diabetes type II in adulthood. For this reason it is important for clinicians to focus on the personal history of the patient's birth weight. In patients with low birth weight, primary measures should be taken to prevent the development or progress of insulin resistance, and late consequences like diabetes and atherosclerotic complications.     

Genetic and environmental influences on human birth weight

Path-analytic techniques were used to demonstrate a significant influence of both fetal genes and maternal environment on birth weight in a sample of infants born to primarily white, middle-class, nonsmoking mothers. If the mother smoked before conception, however, the expression of the fetal birth-weight genes in males was significantly reduced. Multiparity was associated with an increase in genetic variance. This is the first report that genetic influences on birth weight are dependent on the environmental conditions imposed on the fetus by the mother.     

Absence of selection on birth weight in modern Italy

The effect of stabilizing and directional selection on birth weight has been analyzed for Italian births from 1954 to 1994, a period of rapid improvement in environmental conditions. The population of newborns was subdivided according to gestational age, one of the main covariates of birth weight. In the last cohort of births, no selection at all (neither stabilizing nor directional) was found in full-term babies, which represent more than 95% of total deliveries. Preterm babies are still selected against, even if at lower rates than in the past. It can therefore be claimed that improved and widely available prenatal and neonatal care has dramatically changed the selection patterns previously associated with birth weight in the majority of the Italian population. The mortality rates associated with birth-weight variations lying in a wide interval (2.5 kg-4.5 kg) are nowadays very similar, and both stabilizing and directional selection have practically disappeared.     

New assessment of the effects of birth order and socioeconomic status on birth weight.

A survey of the 20 698 singleton births occurring in one year to women resident in the Greater Dublin area provided information on birth weight, birth order, and social class. Low (less than or equal to 2500 g), suboptimal (less than or equal to 3000 g), and optimal (3001-4499 g) birth weights all showed a linear relation with social class. The incidence of low and suboptimal birth weight was highest in first, fifth, and subsequent births, and conversely optimal weight was commonest in second, third, and fourth births. Analysis indicated that a major part of the birth-order effect was attributable to social class. Birthweight categories give information which may be distorted when using mean weight alone. The ue of suboptimal and optimal weight offers the possibility of more accurate assessment of trends in performance, particularly in small samples, than does the conventional sole use of low birth weight. Low and suboptimal birth weights are uncommon in Dublin.