PIP: 43 determinants of low birth weight were analyzed from 895 published papers in the English and French literature from 1970-1984 The assessment was limited to singleton births of women living at sea level with no chronic illness; rare factors and complications of pregnancy were excluded The 43 factors were categorized as genetic and constitutional, demographic and psychosocial, obstetric, nutritional, maternal morbidity during pregnancy, toxic exposure and antenatal care The existence and magnitude of a causal effect on birth weight, gestational age, prematurity and intrauterine growth retardation were determined by a set of methodological standards In developed countries, the most important factor was cigarette smoking, followed by nutrition and pre-pregnancy weight In developing countries the major determinants were racial origin, nutrition, low pre-pregnancy weight, short maternal stature, and malaria Pre-pregnancy weight, prior premature birth or miscarriage, diethylstilbestrol exposure and smoking were major determinants of gestational duration, but the majority of prematurity was unexplained in both developed and developing countries There is a need for future research on the effect of maternal work, prenatal care, and certain vitamin and mineral deficiencies on intrauterine growth, and the effect of genital tract infection, prenatal care, maternal employment, stress and anxiety on prematurity

Determinants of low birth weight: Methodological assessment and meta-analysis

A united states national reference for fetal growth

Objective. Childhood obesity has contributed to an increased incidence of type 2 diabetes mellitus and metabolic syndrome (MS) among children. Intrauterine exposure to diabetes and size at birth are risk factors for type 2 diabetes mellitus, but their association with MS in childhood has not been demonstrated. We examined the development of MS among large-for-gestational-age (LGA) and appropriate-for-gestational age (AGA) children. Study Design. The major components of MS (obesity, hypertension, dyslipidemia, and glucose intolerance) were evaluated in a longitudinal cohort study of children at age 6, 7, 9, and 11 years who were LGA ( n = 84) or AGA ( n = 95) offspring of mothers with or without gestational diabetes mellitus (GDM). The cohort consisted of 4 groups, ie, LGA offspring of control mothers, LGA offspring of mothers with GDM, AGA offspring of control mothers, and AGA offspring of mothers with GDM. Biometric and anthropometric measurements were obtained at 6, 7, 9, and 11 years. Biochemical testing included measurements of postprandial glucose and insulin levels and high-density lipoprotein (HDL) cholesterol levels at 6 and 7 years and of fasting glucose, insulin, triglyceride, and HDL cholesterol levels at 9 and 11 years. We defined the components of MS as (1) obesity (BMI >85th percentile for age), (2) diastolic or systolic blood pressure >95th percentile for age, (3) postprandial glucose level >140 mg/dL or fasting glucose level >110 mg/dL, (4) triglyceride level >95th percentile for age, and (5) HDL level Results. There were no differences in baseline characteristics (gender, race, socioeconomic status, and maternal weight gain during pregnancy) for the 4 groups except for birth weight, but there was a trend toward a higher prevalence of maternal obesity before pregnancy in the LGA/GDM group. Obesity (BMI >85th percentile) at 11 years was present in 25% to 35% of the children, but rates were not different between LGA and AGA offspring. There was a trend toward a higher incidence of insulin resistance, defined as a fasting glucose/insulin ratio of Conclusions. We showed that LGA offspring of diabetic mothers were at significant risk of developing MS in childhood. The prevalence of MS in the other groups was similar to the prevalence (4.8%) among white adolescents in the 1988–1994 National Health and Nutrition Examination Survey. This effect of LGA with maternal GDM on childhood MS was previously demonstrated for Pima Indian children but not the general population. We also found that children exposed to maternal obesity were at increased risk of developing MS, which suggests that obese mothers who do not fulfill the clinical criteria for GDM may still have metabolic factors that affect fetal growth and postnatal outcomes. Children who are LGA at birth and exposed to an intrauterine environment of either diabetes or maternal obesity are at increased risk of developing MS. Given the increased obesity prevalence, these findings have implications for perpetuating the cycle of obesity, insulin resistance, and their consequences in subsequent generations.

Metabolic Syndrome in Childhood: Association With Birth Weight, Maternal Obesity, and Gestational Diabetes Mellitus

Preface Abstract 1. Basis of ICRP Reference Values 2. Summary of Reference Values 3. Embryo and Fetus 4. Total Body 5. Respiratory System 6. Alimentary System 7. Circulatory and Lymphatic Systems 8. Urogenital System 9. Skeletal System 10. Integumentary System 11. Additional Organs and Tissues 12. Pregnant Woman: Anatomical and Physiological Changes 13. Elemental Composition of the Body Reference

Basic anatomical and physiological data for use in radiological protection : reference values

Available standard intrauterine growth curves based on birthweights underestimate foetal growth in preterm period. New growth curves are presented based on data from four Scandinavian centres for 759 ultrasonically estimated foetal weights in 86 uncomplicated pregnancies. Mean weight of boys exceeded that of girls by 2-3%. A uniform SD value of 12% of the mean weight was adopted for the standard curves as the true SD varied non-systematically between 9.1 and 12.4%. Applied to an unselected population of 8663 singleton births, before 210 days of gestation, 32% of birthweights were classified as small-for-gestational age (SGA; i.e. below mean - 2 SD); the corresponding figures were 11.1% for gestational ages between 210 and 258 days, and 2.6% for ages of 259 days or longer. The new growth curves reveal better the true distribution of SGA foetuses and neonates, and are suggested for use in perinatological practice.

Intrauterine growth curves based on ultrasonically estimated foetal weights.

Percentile curves representing intrauterine growth of Caucasian infants in Colorado are constructed from the birthweights of liveborn infants at gestational ages ranging from 24 to 42 weeks. The median weights of Colorado babies were found to be lower at 40 weeks of gestation than the national median, and mean weights at 40 and 42 weeks were lower than those given by other authors. The use of the intrauterine growth chart in studying the nutrition of babies at birth and during their postnatal growth period has been described.

Intrauterine growth as estimated from liveborn birth-weight data at 24 to 42 weeks of gestation.

A practical classification of newborn infants by weight and gestational age.

Charts of intrauterine growth in length, weight-length ratio and head circumference as estimated from liveborn measurements are presented. These, in conjunction with intrauterine weight charts, permit the identification of infants with unusual intrauterine growth patterns.

Intrauterine growth in length and head circumference as estimated from live births at gestational ages from 26 to 42 weeks.

Neonatal mortality rate: relationship to birth weight and gestational age.

The incidence of hypoglycemia was determined in newborn infants in a general obstetric service. A random sample of patients was studied from nine birth weight-gestational age groups before the first feeding at 3 to 6 hours after birth. The highest incidence of hypoglycemia, 67% (serum glucose level Except for IDM9s, evidence of intra-uterine growth retardation from the physical examination and confirmed by the weight/length ratio was demonstrated in infants who became hypoglycemic. An added stress in the form of birth hypoxia was present in the majority of the infants who became hypoglycemic. The combination of reduced energy reserves in newborn infants with intra-uterine growth retardation, plus the increased utilization of carbohydrates during birth hypoxia, resulted in a high incidence of neonatal hypoglycemia in the first few hours after birth.

Lula O. Lubchenco

Papers

Intrauterine growth as estimated from liveborn birth-weight data at 24 to 42 weeks of gestation.

A practical classification of newborn infants by weight and gestational age.

Intrauterine growth in length and head circumference as estimated from live births at gestational ages from 26 to 42 weeks.

Neonatal mortality rate: relationship to birth weight and gestational age.

Incidence of hypoglycemia in newborn infants classified by birth weight and gestational age.