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

Sponsors asked the IOM's Food and Nutrition Board and the Division of Behavioral and Social Sciences and Education Board on Children, Youth, and Families to review and update the IOM (1990) recommendations for weight gain during pregnancy and recommend ways to encourage their adoption through consumer education, strategies to assist practitioners, and public health strategies.The committee was asked to address the following tasks: 1. Review evidence on the relationship between weight gain patterns before, during, and after pregnancy and maternal and child health outcomes, with particular attention to the prevalence of maternal obesity racial/ethnic and age differences, components of GWG, and implications of weight during pregnancy on postpartum weight retention, maternal and child obesity, and later child health. 2. Within a life-stage framework consider factors in relation to GWG that are associated with maternal health outcomes such as lactation performance, postpartum weight retention, cardiovascular disease, metabolic processes including glucose and insulin-related issues, and risk of other chronic diseases; for infants and children, in addition to low birth weight, consider early developmental impacts and obesity-related consequences (e.g., mental health, diabetes). 3. Recommend revisions to the existing guidelines, where necessary, including the need for specific pregnancy weight guidelines for underweight, normal weight, and overweight and obese women and adolescents and women carrying twins or higher-order multiples. 4. Consider a range of approaches to promote appropriate weight gain, including: individual (behavior), psychosocial, community, health care, and health systems; timing and components of interventions; and ways to enhance awareness and adoption of the guidelines, including interdisciplinary approaches, consumer education to men and women, strategies to assist practitioners to use the guidelines, and public health strategies. 5. Identify gaps in knowledge and recommend research priorities.

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Weight Gain During Pregnancy: Reexamining the Guidelines

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.

Inadequate maternal vascular response to placentation in pregnancies complicated by pre-eclampsia and by small-for-gestational age infants.

The assessment of fetal growth.

1. Skinfold thicknesses at seven sites were measured during and after pregnancy in eighty- four women; in forty-eight of these, total body water was measured concurrently.2. Early in pregnancy (10 weeks) the skinfold measurements were highly correlated with each other and with maternal weight, ratio of observed weight to standard weight-for-height,‘dry’ (water-free) weight, and with calculated estimates of body fat.3. At nearly all sites, skinfold thicknesses increased up to about 30 weeks of pregnancy. Increases were greater at ‘central’ and least at ‘peripheral’ sites, and were not proportional to the initial skinfold thickness.4. From 30 to 38 weeks of pregnancy, the patterns were variable: the mid-thigh skinfold continued to increase and at the other sites there was little change or a decrease.5. All sites decreased by a surprisingly large amount between 38 weeks of pregnancy and the end of the first post-partum week. The evidence suggests that this change, which was not related to the presence or absence of oedema, occurred about the time of parturition.6. From the end of the first post-partum week to 6–8 weeks post partum, the changes were again variable.7. The increase of skinfolds during pregnancy was greater in underweight than in overweight women, and in primiparae than in multiparae. The pattern of change was not affected in any consistent manner by oedema.8. The changes in skinfold thicknesses during pregnancy, especially up to about 30 weeks, showed patterns similar to those of total body-weight and ‘dry’ body-weight. A formula is given by means of which ‘dry’ weight can be predicted from five skinfolds, height and duration of gestation.

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W. Z. Billewicz

Papers

The assessment of fetal growth.

Changes in skinfolds during pregnancy

The weight of the placenta in relation to birthweight

Sources of variation in menstrual blood loss

A serial study of changes occurring in the oral glucose tolerance test during pregnancy