A long-term follow-up study of men born with very low birth weight and their reproductive hormone profile

Environmental factors during the fetal period may adversely affect reproductive functions in men being born with very low birth weight (VLBW, <1500 g). The objective of this prospective, controlled cohort study was to investigate if VLBW men have an altered reproductive hormone profile compared with men born at term. The study group initially consisted of all VLBW boys live-born between 1 February 1987 and 30 April 1988 in the south-east region of Sweden (n = 47). A control child was chosen born at term, at the same hospital, with the same parity, without malformations, and next in order after each VLBW child who survived the first four weeks (n = 45). The present follow-up was performed when the men were 26–28 years of age and included measurements of serum hormone levels, hair testosterone concentration, and anthropometric data. Also life-style questionnaires were collected from 26 VLBW men and 19 controls.

The VLBW group (n = 26) had higher median levels of serum estradiol, 84.5 pmol/L than controls (n = 19), 57.5 pmol/L (p = 0.008). There was no significant correlation between serum estradiol and BMI (r = 0.06, p = 0.74). There were no differences in other hormone levels or the reproductive pattern between the groups. In conclusion, even though there was a statistically significant difference in estradiol levels between the groups, both groups had low normal mean levels of questionable clinical significance. The reproductive pattern was similar in the two groups and in this study being born VLBW does not seem to affect these measured aspects of reproduction.

Abbreviations: ADHD: attention deficit hyperactive disorder; AGA: average for gestational age; BMI: body mass index; CP: cerebral palsy; DHT: dihydrotestosterone; FSH: follicle stimulating hormone; LBW: low birth weight; LH: luteinizing hormone; SAD: sagittal abdominal diameter; SGA: small for gestational age; SHBG: sex hormone binding globulin; TSH: thyroid stimulating hormone; T3: triiodothyronine; T4: thyroxin; VLBW: very low birth weight     

Factors associated with low birth weight: a multivariate analysis

The low birth weight of infants is a major public health problem of unknown cause in Benin. We recruited 4,213 pregnant women from a maternity ward in Cotonou for a prospective study. The women were interviewed and further information was obtained from their maternity records. The women were followed until delivery. We found that 6.9% of the births occurred pre-term and there was intrauterine growth retardation in 10.9% of cases. Multiple regression analysis showed that the risks of giving birth to underweight infants were highest for women who were themselves underweight, who had complications due to bleeding or malaria or had social and psychological risk factors. For these particular women, unwanted pregnancy (ORa = 1.60; CI = 1.30-2.00) and lifting heavy loads (ORa = 1.30; CI = 1.10-1.60) were high risk factors. However, adequate prenatal care (ORa = 0.85; CI = 0.69-0.99) and having given birth before were protective factors, reducing the likelihood of a low birth weight. These results have implications for preventive care, in terms of nutrition during pregnancy and psychosociological factors.     

Triglycerides and blood glucose are the major coronary risk factors in elderly Swedish men. The study of men born in 1913.

In 1980 we examined 707 67-year-old men, 656 of whom had no previous myocardial infarction. During 8 years of follow-up, 70 (10.7%) of the 656 men developed a first myocardial infarction or died from coronary heart disease (CHD). The incidence of CHD increased 1.6-fold from the lowest to the highest quintile of cholesterol levels, 2.7-fold from the lowest to the highest quintile of triglyceride levels, and 2.2-fold among those with diabetes. Blood pressure, smoking habits, and two measurements of obesity (body mass index and waist circumference) were not significantly related to the incidence of CHD. In multivariate analysis, serum triglyceride levels and blood glucose concentration remained as significant risk factors for CHD. This may reflect that disturbances in glucose and triglyceride metabolism (as part of a metabolic syndrome?) are more important CHD risk factors in older than in younger men.     

Obesity, adipose tissue distribution and health in men--the study of men born in 1913

Recent studies suggest that cardiovascular disease is associated with abdominal distribution of adipose tissue rather than obesity in terms of total body fat. A number of other variables, known to be associated with obesity, were therefore examined in a cohort of randomly selected middle-aged men in relation to abdominal distribution of adipose tissue, measured as the ratio of the circumferences of the waist and hips (WHR), as well as to degree of obesity, measured as body mass index (BMI). These variables included anthropometric variables, cardiovascular risk factors as well as socioeconomic factors and physical health. Increased WHR, independent of BMI, was negatively associated with height, and hip circumference. Positive associations were found with blood pressure, cholesterol, triglycerides, fibrinogen and smoking. In addition positive associations were found with low social class and social group, illness in terms of sick leave, frequent use of health facilities such as X-rays, as well as diseases such as peptic ulcer. In sharp contrast to this, BMI, independent of WHR, was not associated with physical health variables or social class. Generalized obesity seemed to be associated with good health in the variables measured. There were positive associations to various anthropometric variables, including lean body mass. High BMI was also associated with elevated blood pressure and triglycerides. Several of the indicators of poor health traditionally associated with obesity thus do not seem to be characteristic for obesity in middle-aged men selected at random from the population but rather for an abdominal fat distribution, independent of obesity.     

Comparison of participants and non-participants in a population study of injuries. The study of men born in 1913 and 1923

In a population study of injuries in two samples from the general population of G?teborg, Sweden, of altogether about 1200 50- and 60-year-old men, the non-participation rates were 25% and 19% respectively. The aim of this report was to estimate the size of the bias caused by non-participation. Besides comparing official register data, e.g., marital status, dwelling conditions and mortality between non-participants and participants, it was also possible to measure certain morbidity variables by using the register of an emergency department over a 7-year period. The non-participants had less stable dwelling conditions and were more often unmarried, divorced or widowed than the participants. They also had more accidents per person and more head injuries, were more often transported to the emergency department by ambulance, tended to have more serious injuries and had a higher mortality rate during follow-up. The non-participants were about six times more often inebriated at the attendance and the differences seemed to be associated mainly with the alcohol factor and less with the participation factor. In conclusion, the bias in incidence estimates caused by non-participation appears to be small to moderate in this type of study as long as the non-participation rate can be kept on the same level as in this study or lower.     

Low birth weight in Spain associated with sociodemographic factors.

STUDY OBJECTIVE--To describe the effect of different social and demographic characteristics on low birth weight (LBW) (less than 2500 g) in Spain, in both preterm (less than 37 weeks' gestation) and term infants (between 37 and 42 weeks' gestation). DESIGN--The study used data obtained from the Spanish birth registry. SETTING--The study was based on those live born infants registered in 1988 from provinces where the birthweight details were completed in at least 99.5% of the birth registration records. PARTICIPANTS--A total of 1332 preterm LBW infants, 1292 term LBW infants, and 38,967 controls were included in the study. MEASUREMENTS AND MAIN RESULTS--The odds ratio (OR) calculated by logistic regression was used as the measure of association between LBW and the sociodemographic variables. The highest ORs of preterm LBW were found in mothers younger than 20 years (1.32; 95% CI 0.98, 1.77) and older than 34 years (1.28; 95% CI 1.04, 1.59), in unmarried mothers (1.68; 95% CI 1.36, 2.07), and in fathers with manual occupations (1.26; 95% CI 1.08, 1.46). In term, live born infants the highest ORs were found in adolescent mothers (1.63; 95% CI 1.25, 2.14), in first born live born infants (1.38; 95% CI 1.09, 1.74) or the fourth born or more (1.28; 95% CI 0.91, 1.80), in unmarried mothers (1.55; 95% CI 1.27, 1.90), in housewives (1.13; 95% CI 0.99, 1.29), and in fathers with manual occupations (1.21; 95% CI 1.04, 1.42). CONCLUSIONS--The results have allowed documentation of the risk of preterm and term LBW in various age and social groups in Spain.     

Factors associated with preterm births in southeast Brazil: a comparison of two birth cohorts born 15 years apart

An increase in preterm deliveries in Ribeirão Preto stimulated an analysis of possible explanatory factors. Two cohorts of singleton livebirths were studied, the first based on 6746 births in 1978–9 and the second based on 2846 births in 1994. A logistic regression was carried out to assess the association of preterm birth with several socio‐demographic, behavioural and clinical variables, including year of survey. Delivery in private settings compared with a public setting, maternal age of 17 compared with any other age group, and mothers who had had previous abortions and previous stillbirths were associated with greater rates of preterm birth. Although there was an increase in preterm birth rates regardless of mode of delivery, the increase was greater in the caesarean section group than in the vaginal delivery group. Over the study period, deliveries in private hospitals and caesarean section operations increased markedly (from 4% to 36% and from 30% to 51% respectively). Caesarean section may be the main contributor to the increase of preterm birth rate in this study. It is essential to ensure that health‐care staff, especially those in private facilities, are properly educated and audited.     

Low birth weight is associated with altered immune function in rural Bangladeshi children: a birth cohort study

BACKGROUND: Low birth weight is generally an outcome of a fetal insult or nutritional insufficiency. Recent studies have shown that such exposure early in life may have long-term implications for later immunocompetence and susceptibility to infectious diseases. OBJECTIVE: We aimed to investigate the effect of birth weight on immune function in preschool-age children. DESIGN: A birth cohort cross-sectional study was conducted in children (n = 132) aged 60.8 +/- 0.32 mo who were born in Matlab, a rural area of Bangladesh, and whose weight and length were measured within 72 h of birth. The outcome measures were thymopoiesis, T cell turnover, acute phase response, and percentage of lymphocytes. RESULTS: Children born with low birth weight (<2500 g; LBW group, n = 66) had significantly higher concentrations of T cell receptor excision circles in peripheral blood mononuclear cells-a biomarker for thymopoiesis-and significantly higher serum bactericidal activity and C-reactive protein concentrations than did children born with normal birth weight (>or=2500 g; NBW group, n = 66) (P < 0.05 for both). The LBW group children had significantly lower concentrations of interleukin 7 in plasma (P = 0.02), shorter telomere length in peripheral blood mononuclear cells (P = 0.02), and a lower percentage of CD3 T cells (P = 0.06) than did the NBW group children. CONCLUSIONS: Greater peripheral T cell turnover (shorter telomeres and lower CD3 concentrations) due to immune activation (elevated C-reactive protein concentrations and bactericidal activity) may have resulted in a greater need for replenishment from the thymus (higher T cell receptor excision circles); these events may cause lower immune functional reserve in preschool-age children born with LBW. Thus, LBW has implications for immunocompetence and increased vulnerability to infectious diseases in later life.     

Factors associated with the quality of life of mothers of preterm infants with very low birth weight: a 3-year follow-up study

Quality of Life Research - To analyze possible factors associated with the quality of life (QoL) of mothers of preterm infants with very low birth weight (VLBW) during the first 3&nbsp;years...     

Massage interventions and developmental skills in infants born with low birth weight

This study aimed at evaluating possible effects of massage interventions on developmental progress in the infants born with low birth weight (LBW). Forty infants (17 boys, 23 girls) who were born in St. Petersburg in 2000 through 2002 and met a conventional definition of LBW (<2500 g at birth) entered the study. Of these, 36 (17 boys, 19 girls) were born both light and pre‐term (gestational age ≤36 weeks), and 4 (2 boys, 2 girls) were born light but at term. The control group consisted of an equal number of infants matched to cases for gender, gestational age, weight at birth, date of birth and geographical distribution. The infants from the case group were assigned to the massage intervention therapy at the age of two months. Infant Development Inventory (IDI) was used to check infant’s developmental progress in five areas: social, self‐help, gross motor, fine motor and language skills. The findings were that LBW infants who received massage intervention had advanced skills in all five areas at the age three through eight months. Revealed associations between massage and certain features of advanced behavioural outcomes remained significant after adjustment was made for major potential confounders. Massage can be undertaken to stimulate development in the infants born with LBW.     

Abdominal fat distribution measured by ultrasound and aerobic fitness in young Danish men born with low and normal birth weight

Abdominal subcutaneous and visceral adipose tissue thickness was examined by ultrasound in 17 men with low birth weight (LBW) and 26 with normal BW control individuals to determine if abdominal obesity in LBW individuals is due to increased visceral or subcutaneous fat mass/thickness, or both. Men born with LBW had an increased waist-to-hip ratio (P = 0.04), greater abdominal fat thickness (P = 0.05) and increased visceral (VAT) and subcutaneous adipose tissue (SAT) thickness compared with controls, however the latter not statistically significant (P = 0.08, P = 0.10). A significant difference between birth weight groups in both SAT (P = 0.04) and VAT (P = 0.03) was found after adjustment for weight, whereas no significant difference in either SAT (P = 0.93) or VAT (P = 0.30) was found after adjustment for BMI. Increased waist-to-hip ratio in LBW individuals is due to increased total abdominal fat including both subcutaneous and visceral fat.     

Socioeconomic position in early life,birth weight,childhood cognitive function,and adult mortality. A longitudinal study of Danish men born in 1953

OBJECTIVE: To examine the relation between socioeconomic position in early life and mortality in young adulthood, taking birth weight and childhood cognitive function into account. DESIGN: A longitudinal study with record linkage to the Civil Registration System and Cause of Death Registry. The data were analysed using Cox regression. SETTING: The metropolitan area of Copenhagen, Denmark. SUBJECTS: 7493 male singletons born in 1953, who completed a questionnaire with various cognitive measures, in school at age 12 years, and for whom birth certificates with data on birth and parental characteristics had been traced manually in 1965. This population was followed up from April 1968 to January 2002 for information on mortality. MAIN OUTCOME MEASURES: Mortality from all causes, cardiovascular diseases, and violent deaths. RESULTS: Men whose fathers were working class or of unknown social class at time of birth had higher mortality rates compared with those whose fathers were high/middle class: hazard ratio 1.39 (95% CI 1.15 to 1.67) and 2.04 (95% CI 1.48 to 2.83) respectively. Birth weight and childhood cognitive function were both related to father's social class and inversely associated with all cause mortality. The association between father's social class and mortality attenuated (HR(working class)1.30 (1.08 to 1.56); HR(unknown class)1.81 (1.30 to 2.52)) after control for birth weight and cognitive function. Mortality from cardiovascular diseases and violent deaths was also significantly higher among men with fathers from the lower social classes. CONCLUSION: The inverse association between father's social class at time of birth and early adult mortality remains, however somewhat attenuated, after adjustment for birth weight and cognitive function.     

Is abdominal body fat distribution a major explanation for the sex difference in the incidence of myocardial infarction? The study of men born in 1913 and the study of women, G?teborg, Sweden.

The authors considered whether the difference in body fat distribution between men and women, measured as waist:hip ratio, might explain part of the sex difference in coronary heart disease incidence in prospective population studies of 1,462 women and 792 men. In these studies, conducted in Sweden, men were found to have about four times higher odds for coronary heart disease than women during a 12-year follow-up period (men, 1967 to 1979; women, 1968-1969 to 1980-1981). Controlling for differences in blood pressure, serum cholesterol, smoking, and body mass index only marginally altered the magnitude of the male-female difference. When waist:hip ratio, which predicted coronary heart disease rates in both sexes, was also considered, the sex difference in coronary heart disease risk was significantly reduced and virtually disappeared (odds ratios = 1.0-1.1; nonsignificant). The findings suggest that body fat distribution or a factor highly correlated with waist:hip ratio (genetic, hormonal, or behavioral) may help to explain the sex differences in coronary heart disease.     

Factors associated with interruption of exclusive breastfeeding in low birth weight infants receiving primary care

This study aimed to identify factors associated with interruption of exclusive breastfeeding (EBF) in low birth weight infants receiving primary care. This was a cross-sectional study of 170 infants treated at primary care units on the urban periphery of S?o Paulo, Brazil. The sample included infants with birth weight ≤ 2,500g (including twins) and 5-minute Apgar ≥ 7, followed until the third month of life, and excluded infants/mothers with complications that would impede EBF, besides infant/maternal deaths. Data were collected from forms completed during consultations and patient records. Prevalence ratios were obtained by Poisson regression. The following factors were associated with interruption of EBF in the first three months of life: maternal age ≤ 18 years; informal employment (protective factor); alcohol intake during pregnancy; < 6 prenatal visits; multiple gestations; birth weight ≤ 2,000g; difficulty breastfeeding in the first month; complaints in breastfeeding during the first month; and use of pacifiers in the first two months. Prior knowledge of these factors can help plan measures and policies to increase EBF rates among low birth weight infants.     

极低出生体重儿童学龄期的行为适应分析

目的 评估极低出生体重(very low birth weight,VLBW)儿童学龄期行为适应状况并探讨相关的影响因素。方法 采用BASICS行为适应量表对235名就读主流学校的极低出生体重儿童和396名正常出生体重儿童的家长进行问卷调查。 结果 调查的631个家庭中570个家庭完成问卷,应答率90.3%。极低出生体重儿童组成就[(3.06±0.93)分]、自我关系[(3.62±0.88)分]、内在状态[(4.11±1.18)分]得分及行为适应总分[(3.19±0.71)分]高于正常出生体重儿童组,分别为[(2.29±0.85)分],[(2.27±0.78)分],[(2.45±0.86)分]和[(2.31±0.75)分],差异有统计学意义(P<0.05)。多元线性回归分析结果显示,家庭收入高、主要管教者受教育程度高的VLBW儿童行为适应较好,新生儿期患颅内出血及使用激素总量较多的VLBW儿童行为适应较差。 结论 极低出生体重儿童存在行为适应问题,应进行早期的行为评估和干预。     

Factors associated with weight loss dieting among adolescents: the 11-year follow-up of the 1993 Pelotas (Brazil) birth cohort study

Evidence has shown the negative effects of unsupervised diets and those with excessive calorie restriction. The aim of this study was to determine the proportion of adolescents engaging in weight loss dieting and associated factors. This was a cross-sectional study of 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil, in 1993. The outcome was defined as adolescents that reported having practiced some type of weight loss dieting in the previous 12 months. Prevalence of such dieting was 8.6% (95%CI: 7.7;9.4), and was higher in girls. Elevated maternal body mass index (BMI) was associated with dieting among girls. The adolescent's and parents' view of the adolescent's weight, excess weight, and consumption of diet or light soft drinks were associated with adolescent dieting. There was a positive association between dieting and socioeconomic status. The findings provide important backing for policies aimed at improving adolescents' diet, since they express a major concern over weight and thus a significant percentage of individuals with erroneous and unhealthy behaviors.     

Obstetric factors associated with low birth weight

An analysis was made of 18,804 of 19,446 consecutive births of the number analysed 15.93% presented low birth-rate. Significant statistical association was found in relation to maternal age, pre-natal care, previous pregnancies, smoking and gestational age at birth. Measures with a view to the attenuation of the problem are proposed, among them being: educational programs for teenagers on human reproduction, programs designed to create awareness of the harm done by smoking, amplification of antenatal assistance, medical programs for the limitation of premature labor, all of these and others, in association with programs of socio-economic support.     

Education, infant mortality, and low birth weight in Sweden 1973-1990: emergence of the low birth weight paradox

AIMS: Educational differences in infant mortality, birth weight, and birth weight-specific infant mortality in Sweden were analysed. The "low birth weight paradox", where low birth weight infants have a lower mortality risk if born to women of lower rather than higher social strata, was addressed. METHODS: The study includes about a million single births 1973-90 to women born 1946-60. There were 6,544 infant deaths and 35,334 low birth weight infants. Analysis conducted on six-year time periods was restricted to 652,859 births to women aged 25-32 at the time of delivery. Odds ratios and 95% CI were estimated by logistic regression. Birth weight-specific infant mortality rates were calculated by education. RESULTS: Infants of women with low/low intermediate education had significantly higher odds ratios than those of highly educated women of being of low birth weight or of dying. If one compares only the infants of women with low and high education, these differences were accentuated over time. The low birth weight paradox appears over time. CONCLUSION: The widening differences in infant mortality and low birth weight over time may be caused by the decrease in women with low education, signifying increased selection and growing social disadvantage in this group. The emergence of the low birth weight paradox suggests that the distribution of causes of low birth weight differs between educational groups, and further that these causes are differently related to infant mortality. To disentangle these two groups of causes and their effects on infant mortality seems highly relevant.