Weight in infancy and prevalence of coronary heart disease in adult life.

OBJECTIVE--To determine whether low birth weight and low weight at 1 year are followed by an increased prevalence of coronary heart disease in adult life. DESIGN--A follow up study of men born during 1920-30 whose birth weights and weights at 1 year were recorded. SETTING--Hertfordshire, England. SUBJECTS--290 men born and still living in East Hertfordshire. MAIN OUTCOME MEASURE--The prevalence of coronary heart disease, defined by the Rose/WHO chest pain questionnaire, standard electrocardiographic criteria, or history of coronary artery angioplasty or graft surgery. RESULTS--42 (14%) men had coronary heart disease. Their mean birth weight, 7.9 lb (3600 g), was the same as that of the other men. Their mean weight at 1 year, 21.8 lb (9.9 kg), was 1 lb (454 g) lower (95% confidence interval 0.1 to 1.8, P = 0.02). Percentages of men with coronary heart disease fell from 27% in those who weighed 18 lb (8.2 kg) or less at 1 year to 9% in those who weighed more than 26 lb (11.8 kg) (P value for trend = 0.03). This trend occurred in both smokers and non-smokers and within each social class. CONCLUSION--These findings add to the evidence that coronary heart disease is "programmed" during early growth.     

Mothers' birth weight and survival of their offspring: population based study.

OBJECTIVE: To test the hypothesis that a baby''s survival is related to the mother''s birth weight. DESIGN: Population based dataset for two generations. SETTING: Population registry in Norway. SUBJECTS: All birth records for women born in Norway since 1967 were linked to births during 1981-94, thereby forming 105104 mother-offspring units. MAIN OUTCOME MEASURES: Perinatal mortality specific for weight for offspring in groups of maternal birth weight (with 500 g categories in both). RESULTS: A mother''s birth weight was strongly associated with the weight of her baby. Maternal birth weight was associated with perinatal survival of her baby only for mothers with birth weights under 2000 g. These mothers were more likely to lose a baby in the perinatal period (odds ratio 2.3, 95% confidence interval 1.4 to 3.7). Among mothers with a birth weight over 2000 g there was no overall association between mother''s weight and infant survival. There was, however, a strong interaction between mother''s birth weight, infant birth weight, and infant survival. Mortality among small babies was much higher for those whose mothers had been large at birth. For example, babies weighing 2500-2999 g had a threefold higher mortality if their mother''s birth weight had been high (> or = 4000 g) than if the mother had been small (2500-2999 g). CONCLUSION: Mothers who weighed less than 2000 g at birth have a higher risk of losing their own babies. For mothers who weighed > or = 2000 g their birth weight provides a benchmark for judging the growth of their offspring. Babies who are small relative to their mother''s birth weight are at increased risk of mortality.     

Birth weight of offspring and mortality in the Renfrew and Paisley study: prospective observational study.

OBJECTIVE: To investigate the association between birth weight of offspring and mortality among fathers and mothers in the west of Scotland. DESIGN: Prospective observational study. PARTICIPANTS: 794 married couples in Renfrew district of the west of Scotland. MAIN OUTCOME MEASURES: Mortality from all causes and from cardiovascular disease over 15 year follow up. RESULTS: Women who had heavier babies were taller, had higher body mass index and better lung function, and were less likely to be smokers than mothers of lighter babies. Fathers of heavier babies were taller and less likely to be smokers than fathers of lighter babies. Mortality was inversely related to offspring''s birth weight for both mothers (relative rate for a 1 kg lower birth weight 1.82 (95% confidence interval 1.23 to 2.70)) and fathers (relative rate 1.35 (1.03 to 1.79)). For mortality from cardiovascular disease, inverse associations were seen for mothers (2.00 (1.18 to 3.33)) and fathers (1.52 (1.03 to 2.17)). Adjustment for blood pressure, plasma cholesterol, body mass index, height, social class, area based deprivation category, smoking, lung function, angina, bronchitis, and electrocardiographic evidence of ischaemia had little effect on these risk estimates, although levels of statistical significance were reduced. CONCLUSIONS: Birth weight of offspring was related inversely to mortality, from all causes and cardiovascular disease, in this cohort. The strength of this association was greater than would have been expected by the degree of concordance of birth weights across generations, but an extensive range of potential confounding factors could not account for the association. Mortality is therefore influenced by a factor related to birth weight that is transmissible across generations.     

Population genetics of polymorphisms in Cardiff newborn. Relationship between blood group and allozyme heterozygosity and birth weight

A newborn population of Cardiff, Wales, was screened for variation at three blood group loci (ABO, Rhesus and MN) and four enzyme loci (ACP-1, PGM-1, ADA and EST-D). Birth weights were measured. There were no significant differences between mean birth weights or birth weight variances for individuals homozygous or heterozygous at the MN and the four enzyme loci. (ABO and Rhesus loci cannot be used in these tests.) There was no significant heterogeneity in contingency tables relating phenotypes at the seven loci to birth weight. There were no significant differences in mean heterozygosity per locus between babies placed in different birth weight categories, ranging from 2.5 to 4.2 kg. The genetic variation screened appears therefore to be neutral with respect to this character.     

Determinants of blood oxygenation during pregnancy in Andean and European residents of high altitude

High altitude decreases birth weight, but this effect is diminished in long vs. short-resident, high-altitude populations. We asked whether women from long vs. short-resident, high-altitude populations had higher arterial oxygenation levels by comparing 42 Andean and 26 European residents of La Paz, Bolivia (3,600 m), serially during pregnancy (weeks 20, 30, and 36) and again 4 mo postpartum. Pregnancy raised hypoxic ventilatory sensitivity threefold, resting ventilation (.Ve), and arterial O(2) saturation (Sa(O2)) in both groups. Ancestry, as identified using 81 genetic markers, correlated with respiratory pattern, such that greater Andean ancestry was associated with higher respiratory frequency and lower tidal volume. Pregnancy increased total blood and plasma volume approximately 40% in both groups without changing red blood cell mass relative to body weight; hence, hemoglobin fell. The hemoglobin decline was compensated for by the rise in .Ve and Sa(O2) with the result that arterial O2 content (Ca(O2)) was maintained near nonpregnant levels in both groups. Birth weights were similar for all Andean and European babies, but after adjusting for variation in gestational age, maternal height and parity, Andeans weighed 209 g more than Europeans. Babies with heavier birth weights and greater ponderal indices were born to Andean women with higher Ve during pregnancy. We concluded that while maternal .Ve and arterial oxygenation were important, some factor other than higher Ca(O2) was responsible for protecting Andeans from altitude-associated reductions in fetal growth.     

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.     

Early discharge of infants of low birth weight: a prospective study.

A total of 495 African infants of low birth weight were discharged from Harari Maternity Hospital, Salisbury, between October 1972 and September 1973. Criteria used for discharge were (a) no clinical evidence of disease, (b) satisfactory feeding by mouth (breast or bottle or both), and (c) stable temperature control under normal room conditions. Of the 495 babies 264 fulfilled these criteria when they weighed 1801-1900 g (group 1), 99 when they weighed 1901-2000 g (group 2), and 132 (group 3) when they weighed 2001-2500 g. The overall follow-up rate of those infants living in greater Salisbury was 85-5%, the health visitor playing an important contributory role in their progress, especially those in group 1. More than two clinic visits in the first four to five weeks after discharge were essential for continuing weight gain in groups 1 and 2 but not in group 3. The mean daily weight gain for all babies at the end of four to five weeks was 26 g. Readmission rates for babies in groups 1,2, and 3 were 9-5%, 1%, and 0-8%, respectively, the largest single cause for readmission being bronchopneumonia associated with hypothermia. Altogether 60% of the readmissions occurred during the two winter months (June and July). Hypothermia, associated with low environmental temperatures played a significant part in morbidity and mortality, and twins, particularly in group 1, had a mortality rate three times greater than singletons in the same group. In general, even in underdeveloped communities singleton babies born outside the winter months with reasonable clinic or home visiting facilities can be discharged at a weight of 1800 g or more.     

Sex of preceding sibling and anthropometrics of subsequent offspring at birth and in young adulthood: A population‐based study in Sweden

In many mammal species with sexual dimorphism producing sons is energetically more demanding to the mother than producing daughters. Although some studies in humans have suggested that offspring born after a brother have a smaller birth weight and adult height when compared with those born after a sister, little is known about this intergenerational cost of producing sons. We aimed to study whether the sex of preceding sibling is associated with anthropometrics of the subsequent child at birth and in young adulthood. This population‐based study was carried out on two data sets derived from the Swedish registers. Information on birth weight and length was obtained for 752,723 children of both sexes. Adult weight, height and muscle strength were available for 506,326 men. Multiple linear regression analyses showed that boys and girls born after a brother were, respectively, 18 and 9 g lighter and 0.08 and 0.03 cm (P < 0.001) shorter at birth than those born after a sister. Adjustment for gestational age decreased the magnitude of the associations [10 g and 0.04 cm (P < 0.001) in men and nonsignificant estimates in women], suggesting that part of the lower mean birth weight and length of individuals born after a brother was due to a shorter gestation. In young adulthood, men with a preceding brother showed 0.16 kg more in weight, 0.3% higher body mass index (P < 0.001) and a trend towards reduced height and muscle strength. Our results suggest that even though the sex of the previous child is associated with the anthropometrics of the subsequent child, the effect sizes are very small questioning whether this mechanism has adaptive value in contemporary humans. Am J Phys Anthropol 154:471–478, 2014. © 2014 Wiley Periodicals, Inc.     

Are birth defects among Hispanics related to maternal nativity or number of years lived in the United States?

BACKGROUND: Literature on the risk of birth defects among foreign‐ versus U.S.–born Hispanics is limited or inconsistent. We examined the association between country of birth, immigration patterns, and birth defects among Hispanic mothers. METHODS: We used data from the National Birth Defects Prevention Study and calculated odds ratios (ORs) and 95% confidence intervals and assessed the relationship between mothers' country of birth, years lived in the United States, and birth defects among 575 foreign‐born compared to 539 U.S.–born Hispanic mothers. RESULTS: Hispanic mothers born in Mexico/Central America were more likely to deliver babies with spina bifida (OR = 1.53) than their U.S.–born counterparts. Also, mothers born in Mexico/Central America or who were recent United States immigrants (≤5 years) were less likely to deliver babies with all atrial septal defects combined, all septal defects combined, or atrial septal defect, secundum type. However, Hispanic foreign‐born mothers who lived in the United States for >5 years were more likely to deliver babies with all neural tube defects combined (OR = 1.42), spina bifida (OR = 1.89), and longitudinal limb defects (OR = 2.34). Foreign‐born mothers, regardless of their number of years lived in the United States, were more likely to deliver babies with anotia or microtia. CONCLUSIONS: Depending on the type of birth defect, foreign‐born Hispanic mothers might be at higher or lower risk of delivering babies with the defects. The differences might reflect variations in predisposition, cultural norms, behavioral characteristics, and/or ascertainment of the birth defects. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.     

Variation in early neonatal mortality for different types of fetal growth retardation

Birth and first-48-hr death records were analyzed for 10,024 liveborn infants in Mexico City and 12,786 liveborn infants in Santa Cruz, Bolivia. The objective of the analysis was to characterize the early postnatal mortality rates for different types of fetal growth retardation and prematurity. Infants who were delivered prior to 37 weeks of gestation had 23-100 times the mortality risk of infants born at full term and normal weight. Light-for-gestational-age infants (birth weight less than 2,900 g) were further divided into proportionately growth-retarded with normal Rohrer's index (weight/height) and disproportionately growth-retarded with low Rohrer's index. The proportionately growth-retarded infant had nearly twice the mortality of the full-term, appropriate-weight infants, whereas the disproportionately growth-retarded infants had 2.9-5.7 times the mortality rate of the full-term, appropriate-weight infants. There were some differences between samples in mortality rates and prevalence of the different classes of small infants, but the pattern of mortality within samples was consistent between samples.     

Admixture in a biologically African caste of black Americans

Social and historical factors account for much of the variation in European ancestry among different Black American populations, including that of McNary, Arizona. The Black population of McNary is socioculturally and geographically isolated. Admixture estimates based upon reflectometry and serological data suggest that this population has less than 5% European ancestry. Anthropometric and hemoglobin data also suggest that this population is more African in ancestry than other Black American populations. Admixture estimates for the population are complicated by several factors. Genetic drift has probably affected Black McNary; estimated effective population size (Ne) is 52.11 and the coefficient of breeding isolation is less than 50. Frequencies of the alleles B, O, and r support this hypothesis; they are quite atypical for a Black American group. Selective migration and occupational selection may also have influenced the current genetic composition of Black McNary. Over 80% of the Black residents of McNary were born in backwoods lumbering towns in the American South. Most Black families in McNary trace their economic reliance on lumbering back several generations. Historical sources and demographic data from Black McNary suggest that Southern Black millworking families formed an endogamous unit that produced this caste, which has a relatively small amount of European ancestry.     

Life-history characteristics of a wild population of vervets (Cercopithecus aethiops sabaeus) in Barbados,West Indies

Life history data are presented for a population of vervets, Cercopithecusaethiops sabaeus, in Barbados, West Indies. The data were obtained from two habituated troops and from vervets captured during a large-scale trapping program. Individuals of known age from one troop were weighed periodically, and separate growth curves generated for males and females. The mean weight of captured adult females was 3.3 kg; that of adult males, 5.3 kg. The average age at sexual maturity is estimated at 34 months for females and 60 months for males. Vervets give birth throughout the year, but most infants are born between April and July. The average interbirth interval following a surviving infant is 11.8 months. The mortality of juveniles is heaviest between birth and 2 years of age and decreases thereafter. Males emigrate from their natal troops at sexual maturity and one incident of a juvenile female emigrating is reported.     

Influence of season on birth weight and weaning age of indigenous Balami and imported Sudan Desert sheep in the Sahel region of Northeastern Nigeria

Data on birth weight and age at weaning for 1,092 (609 indigenous Balami and 483 imported Sudan Desert) sheep born from 1975 to 1979 in a Government farm near Maiduguri were analysed to study the influence of season on birth weight and age at weaning in sheep reared in the sahel region of Northeastern Nigeria. The suitability of the Sudan Desert for replacing or upgrading the indigenous Balami was considered.Season, breed, sex and type of birth significantly (P<0.001) influenced birth weight, age at weaning and the average daily gain from birth to weaning of lambs. Heaviest lambs were born during the rainy season-June–August. Birth weight was lowest during the dry hot season. Balami lambs were heavier at birth and were weaned earlier with greater average daily gain than the Sudan Desert (P<0.001). Ram lambs were heavier at birth and had greater daily gain than the ewes (P<0.001). Also single-born lambs were heavier at birth and were weaned earlier (P<0.001) than twins. Twining rate in Balami was almost double that in the Sudanese. Survival tended to be greater in Sudanese than in Balami. Birth, twining and survival rates were highest for the dry cold season-born lambs. The dry cold season seems the best lambing season here. In all, the local Balami proved far superior in almost all traits considered. The use of the Sudan Desert here is definitely not econmically justifiable or rational.     

Patterns of low birth weight in the Bengali newborns

This paper examines the distribution of low birth weight (2500 g or less) by gestation time, sex, maternal age, parity (birth order), socioeconomic conditions, and season of birth among 5117 single live births born to Bengali mothers at the Ramakrishna Mission Seva Pratisthan Hospital in Calcutta, India. Preterm infants have low birth weight significantly more often than their full term counterparts. Female infants have low birth weights significantly more often than male infants. The infants of poor mothers have lower birth weights in higher order births more often than infants of higher orders born to well-off mothers. Teenaged mothers produce low birth weight babies significantly more often than older mothers. Although the relationship is not significant, low birth weight infants occur more often among 1st and late born infants and less often among 2nd born infants. The season of birth is not significantly associated with birth weight. Less than 10% of low birth weight infants are pre-term, while the rest are full term. The great majority of low birth weight infants are small-for-gestational-age; the minority are small due to curtailed gestational age. The proportion of infants weighing less than 2001 g is only 9%; this figure tallies closely with earlier studies of India.     

Birth weight and cognitive function in the British 1946 birth cohort: longitudinal population based study

Objective: To examine the association between birth weight and cognitive function in the normal population. Design: A longitudinal, population based, birth cohort study. Participants: 3900 males and females born in 1946. Main outcome measures: Cognitive function from childhood to middle life (measured at ages 8, 11, 15, 26, and 43 years). Results: Birth weight was significantly and positively associated with cognitive ability at age 8 (with an estimated standard deviation score of 0.44 (95% confidence interval 0.28 to 0.59)) between the lowest and highest birthweight categories after sex, father's social class, mother's education, and birth order were controlled for. This association was evident across the normal birthweight range (>2.5 kg) and so was not accounted for exclusively by low birth weight. The association was also observed at ages 11, 15, and 26, and weakly at age 43, although these associations were dependent on the association at age 8. Birth weight was also associated with education, with those of higher birth weight more likely to have achieved higher qualifications, and this effect was accounted for partly by cognitive function at age 8. Conclusions: Birth weight was associated with cognitive ability at age 8 in the general population, and in the normal birthweight range. The effect at this age largely explains associations between birth weight and cognitive function at subsequent ages. Similarly, the association between birth weight and education was accounted for partly by earlier cognitive scores.     

Weights and growth rates in the Mountain hare Lepus timidus scoticus

Mountain hares were weighed during live trapping on a study area near Dufftown, Banffshire, from June 1958 to August 1966. Hares shot or killed by other means on the study area and elsewhere were also weighed. Females were heavier than males throughout the year and this difference became apparent in juveniles by August of their year of birth. Male hares lost weight during the breeding season (January to June) but regained it in late summer. Young hares gained weight initially at about 14 g per day, then at about 6 g per day to adult weight. Small juveniles, or those born late in the season, tended to become small adults, large or early juveniles to become large adults. Small hares moulted less completely andjbegan to breed later in the season than large hares. The effects of disease, starvation, severe weather and injury on hare weights were considered. Female weights were greater when the population was small, due to more late pregnancies or more embryos per female. Weight could not be used to distinguish between adult and juvenile hares above 2.1 kg, nor between young and older adults.     

Epidemiology of spontaneous premature rupture of membranes: factors in pre-term births

The frequency of spontaneous premature rupture of membranes (PROM) was determined in the pregnancies of 1,848 white mothers and their singleton infants, born at the University of Kansas Medical Center between April 1975 and April 1978. The frequency of PROM increased significantly from a low of 34/707 (4.8 percent) among low-risk mothers, to 40/444 (9.0 percent) among mothers smoking one to 60 cigarettes a day, to 21/204 (10.3 percent) among mothers with multiple adverse maternal practices, and to 12/46 (26 percent) among mothers with selected complications of their pregnancies. The proportion of low birth weight (LBW) (less than 2,500 g) pre-term infants born to PROM mothers increased among the risk factor groups in a similar manner, from a low of 2/34 (6 percent) in low-risk pregnancies to 8/40 (20 percent) among mothers smoking one to 60 cigarettes a day, to 7/21 (33 percent) among mothers with multiple adverse practices, and to 7/12 (58 percent) among mothers with selected complications of pregnancy. The increased incidence of low birth weight pre-term infants born to mothers with PROM was associated with evidence of growth retardation among full-term infants in the high-risk groups. This finding was manifested by reductions in mean birth weights of full-term infants born to high-risk mothers but not observed in full-term infants born to low-risk mothers. The attained growth at birth of low birth weight pre-term infants could not be determined, because appropriate birth weight standards for pre-term infants born to mothers with low-risk pregnancies are not available. These results suggest that growth retardation in fetuses increased the probability of the mothers having PROM prior to the onset of labor, and, if PROM did occur, of having a premature delivery. We hypothesize that the tensile strength of the amnion and chorion is diminished by the same conditions that retard fetal growth, and that this reduction in strength of the fetal membranes contributes to premature rupture of membranes and pre-term delivery.     

Plasmodial pigmentation of placenta and outcome of pregnancy in West African mothers.

In a region where falciparum malaria is endemic and where pregnant women traditionally receive only curative treatment for parasitaemias and no chemoprophylaxis 65 placental biopsy specimens were examined histologically for malaria pigment. Twenty seven placentas had pigment, but parasitaemias had been diagnosed antenatally in only 12 of these women despite their frequent attendance at antenatal and other clinics. The incidence of parasitaemia in pregnant primigravidas was 17.7%, seven times greater than that in lactating primiparous mothers; pregnant primigravidas also had the highest incidence (67%) of pigmented placentas. First born babies with pigmented placentas had a mean (SD) birth weight of 2580 (260) g, significantly less than the 3150 (400) g of unaffected first babies. All babies weighing less than 2500 g at birth had pigmented placentas. Pigmentation was associated with parasitaemias in the second half of pregnancy, and, although some recovery from early parasitaemias may occur, the fetoplacental unit is inadequately protected by curative treatment alone. Chemoprophylaxis currently remains the procedure of choice.     

Weight growth in infants born to mothers who smoked during pregnancy.

OBJECTIVE--To determine whether maternal smoking during pregnancy causes impairment in growth after birth. DESIGN--Longitudinal study. SETTING--Six medical university centres of six towns of north, central, and south Italy. SUBJECTS--12,987 babies (10,238 born from non-smoking mothers, 2276 from mothers smoking one to nine cigarettes a day, and 473 from mothers smoking > or = 10 cigarettes a day) entered the study. MAIN OUTCOME MEASURES--Difference in weight gain between children born to smoking mothers and those born to non-smoking mothers. Weight was measured at birth and at 3 and 6 months of age. Maternal smoking habit was derived from interview on third or fourth day after delivery. RESULTS--Compared with children born to mothers who did not smoke during pregnancy, the birth weights of children born to mothers who smoked up to nine cigarettes a day were 88 g (girls) and 107 g (boys) lower; in children born to mothers who smoked > or = 10 cigarettes a day weights were 168 g and 247 g lower. At six months of age for the first group the mean weight for girls was 9 g (95% confidence interval -47 g to 65 g) higher and for boys 64 g (-118 g to -10 g) lower than that of children born to mothers who did not smoke. The corresponding figures for the second group were 28 g (-141 g to 85 g) lower for girls and 24 g (-136 g to 88 g) lower for boys. CONCLUSIONS--The deficits of weight at birth in children born to mothers who smoked during pregnancy are overcome by 6 months of age. These deficits are probably not permanent when smoking habit during pregnancy is not associated with other unfavourable variables (such as lower socioeconomic class).     

Influence of the dam and sire on size at birth and subsequent growth, milk production and fertility in dairy heifers

Genetic selection has resulted in larger cows with high milk production potential but a tendency for poor fertility. In multiparous cows fetal development competes for nutrients with concurrent milk production. This study tested the hypotheses that (a) maternal age and milk yield during pregnancy alter calf birth size and (b) birth weight influences subsequent productivity and fertility. Concurrently born Holstein-Friesian heifers (n=65) with multiparous dams and three sires were monitored from birth to the end of their first lactation to assess effects of birth weight on growth, milk production and fertility. Calves were analyzed as three subgroups: low (L), average (A) and high (H) birth weight (BW) calves (n=21-22 per group). LBW calves were born 10 kg lighter than HBW calves and remained significantly lighter throughout the study. They were generally smaller in other measured indices (length, height, girth, ponderal index) between birth and 9 months and were more likely to have older dams (lactations 3-6) with higher peak yields (>42 kg/day). Milk production parameters were indistinguishable between the 3 birthweight groups and metabolic parameters (IGF-I, insulin, glucose) measured around first calving were unaffected. HBW offspring were more likely to have persistent corpora lutea following their first calving and other fertility parameters also tended to be worse. Sire influenced gestation length but not birth size. Sire heritability estimates showed that weight, IGF-I and insulin concentrations after first calving and fertility in the first lactation were all heritable. The results support the hypothesis that high milk production in the dam may predispose to birth of a smaller calf. Smaller birth size did not, however, have any subsequent adverse effects on productivity or fertility in the first lactation and sire was more influential at this stage.