Fetal growth and the timing of exposure to maternal smoking

BACKGROUND: Maternal smoking during the third trimester reduces the birthweight of the full-term neonate. We assessed the relationship between the timing of exposure to maternal smoking, gestational period, weight and body length for both full-term and preterm neonates. METHODS: A retrospective study with a questionnaire was conducted in 1194 infants who participated in the official medical examination for 3-year-old infants. RESULTS: The risk of preterm birth from mothers who smoked during any trimesters was significantly increased. The body length of neonates whose mothers smoked during the third trimester was shorter than that of neonates whose mothers did not smoke during the third trimester. The weight of full-term neonates whose mothers smoked during the third trimester was lighter than that of neonates whose mothers did not smoke during the third trimester. CONCLUSIONS: Maternal smoking during any trimesters increased the risk of preterm birth. Maternal smoking during the third trimester reduced the body length of both full-term and preterm neonates, and the birthweight of the full-term neonate in a somewhat dose-dependent manner.     

Exterogestate growth: Relationship with maternal body size and dietary intakes

Ninety five lactating women, 18 to 35 yr old were subjected to anthropometric measurements (weight, height and weight for height ratio index) and dietary surveys during first 3 months of lactational period. The exterogestate growth was assessed by recording weight, crown heel length and head circumference of offsprings at birth and at the age of 3 months to find out the daily gains in these anthropometric parameters. The daily increments of various growth parameters of exclusively breast fed infants increased with increasing maternal dietary intakes. The maternal weight for height ratio index (WHRI) was found to have no significant influence on the exterogestate growth of offsprings. The offsprings of small sized monthers (WHRI<0.1772) with poor dietary intakes were born small and their daily increments did not show any catch up growth.     

Maternal smoking and body composition of the newborn

The influence on neonatal anthropometry of maternal cigarette smoking in pregnancy was investigated in 933 parous women. Anthropometric growth parameters including skinfold measurements were studied in the newborns. After adjustment for maternal age, pre-pregnancy weight, height and pregnancy weight gain, smoking had a clear dose-dependent negative effect on all anthropometric characteristics in the infant. In contrast to the results obtained in other investigations, the reduced birth weight of the infants of smoking mothers was not found to be primarily due to a reduction in lean body mass; nor was fat deposition found to be reduced. Fetal anthropometry was also negatively affected in infants born to mothers who stopped smoking during pregnancy.     

Fetal growth: relationship with maternal dietary intakes

One hundred urban and 85 rural pregnant women in third trimester were subjected for the studies of dietary intakes and the body size (weight for height ratio index). The intrauterine growth of newborn infants was assessed at birth by weight, crown-heel length and head circumference. The fetal growth improved significantly with increasing maternal caloric and protein intakes. The mean values of weight, crown-heel length and head circumference of newborn infants were significantly higher in mothers receiving more than 2000 kcals and 75g of proteins as compared to the mean values observed for newborns of mothers with dietary caloric and protein intakes less than 1500 kcals and 45.0g respectively in both urban and rural subjects. No significant difference was observed in the growth parameters of newborn infants with further increase in the maternal caloric intake above 2000 kcals. Further the total protein intake influenced the newborn's weight significantly irrespective of the animal protein content.     

The Bacon Chow study: maternal supplementation and infant growth

The effect of maternal supplementation during both gestation and lactation on infant growth from birth to 12 mth was investigated in the double-blind, randomly allocated control trial conducted in Taiwan by the late Bacon F. Chow. The supplement was a milk-based formula providing 800 kcal and 40 g protein daily. The placebo provided less than 40 kcal per diem but resembled the supplement in appearance. Supplementation was limited to mothers and began after birth of one infant and continued without interruption until weaning of a second infant. Supplement effects were tested by comparing both supplement and placebo groups and first- and second-infant groups with respect to weight, length and head circumference. Both comparisons of growth curves and analyses of variance were carried out. Both strategies agreed in failing to detect differences in growth between supplement and placebo groups. However, differences were found between first and second infants in the supplement group.     

Effects of maternal smoking during pregnancy on body composition in offspring

Background: The aim of the present cross‐sectional study was to use objective methods to assess the association between maternal smoking and body composition in offspring. Methods: A total of 2508 grade 4 school children were enrolled; all underwent lifestyle disease and passive smoking screening. Children were classified into four groups according to their urinary cotinine level and maternal smoking status during or before pregnancy. Items measured on lifestyle disease screening were compared among the four groups. Results: Only degree of obesity (DO) and body mass index (BMI) were significantly associated with maternal smoking during pregnancy. The prevalence of both DO >20% and DO >30%, and BMI >22% and BMI >25% was highest in children of mothers who smoked during pregnancy. These children had a tendency toward shorter height and increased weight although it was not statistically significant. There were no significant differences between maternal smoking status and lipid profile among groups. Confounders such as food, exercise and sleep were able to be eliminated Conclusion: Maternal smoking during pregnancy may be an independent risk factor of changing body composition in offspring, that is, shorter height and increased weight.     

Difference in ponderal growth and body composition among pregnant vs. never-pregnant adolescents varies by birth outcomes

Recently, we showed that following pregnancy and 6 months of lactation, adolescents cease linear growth and have reduced fat and lean mass in rural Bangladesh. Here, we examined whether these changes varied by pregnancy outcomes such as fetal loss, low birthweight (LBW) and neonatal mortality. Anthropometric measurements were taken among 12–19‐year‐old primigravidae (n = 229) in early pregnancy and at 6 months post‐partum. Never‐pregnant adolescents (n = 456) matched on age and time since menarche were also measured at the same time. Change in anthropometry among pregnant vs. never‐pregnant adolescents was compared by pregnancy outcome adjusting for confounders using mixed effects regression models. Pregnant girls, irrespective of birth outcome, did not gain in stature, while never‐pregnant girls increased in height by 0.36 ± 0.04 cm year^?1 (P < 0.05). Body mass index, mid‐upper arm circumference (MUAC) and % body fat among pregnant adolescents whose infants survived the neonatal period had decreased at 6 months post‐partum, whereas those who experienced a fetal loss or neonatal death did not change in any of the measurements. Consequently, the difference in change in ponderal size and body composition measures between pregnant and never‐pregnant girls was higher among those whose neonates survived vs. those who experienced a fetal loss/neonatal death (BMI: ?0.64 ± 0.11 vs. 0.01 ± 0.16 kg m^?2 year^?1; MUAC: ?0.96 ± 0.12 vs. ?0.35 ± 0.17 cm year^?1, both P < 0.05). LBW and preterm birth did not have a similar effect modification. Linear growth ceased among pregnant girls regardless of birth outcome. Maternal weight loss and depletion of fat and lean mass at 6 months post‐partum were more pronounced when the infants survived through the neonatal period.     

Fetal iron status in maternal anemia

Hemoglobin, serum iron, transferrin saturation and ferritin were measured on paired maternal and cord blood samples in 54 anemic (hemoglobin < 110 g/L) and 22 non-anemic (hemoglobin ≥ 110 g/L) pregnant women at term gestation. The levels of hemoglobin, serum iron, transferrin saturation and ferritin were significantly low in the cord blood of anemic women, suggesting that iron supply to the fetus was reduced in maternal anemia. The linear relationships of these parameters with both maternal hemoglobin and maternal serum ferritin indicated that the fetus extracted iron in amounts proportional to the levels available in the mother. Infants of mothers with moderate and severe anemia had significantly lower cord serum ferritin levels and hence poor iron stores at birth. It is concluded that iron deficiency anemia during pregnancy adversely affects the iron endowment of the infant at birth.     

Fetal urinary tract abnormalities detected on maternal ultrasound

Twenty-one cases of fetal urinary tract abnormalities were detected on maternal ultrasound in a 5 year period. Six fetuses died and 13 of the 15 surviving cases have had corrective urological surgery, usually during the neonatal period. Maternal ultrasound provides advanced warning of major urinary tract abnormalities in the newborn. Therefore, appropriate investigations and medical management can be instituted early and potentially destructive urological lesions can be corrected as soon as possible. As yet, antenatal intervention does not seem to be warranted as the most common cause of bilateral upper tract dilatation in the surviving cases in this series was primary reflux, and In the cases that died the urinary abnormalities were not salvagable.     

Fetal growth: relationship with maternal anthropometery,hemoglobin and serum albumin status

Three hundred fortyone primiparous mothers in the age group of 20 to 28 yr were subjected to anthropometery (weight, height and head circumference), hemoglobin and serum albumin estimations. Their offsprings were weighed at birth and birth weight was studied in relation to these maternal variables. The means for birth weight increased with increase in maternal weight, height, head circumference, hemoglobin and serum albumin levels. The subgroups of maternal weight, height and hemoglobin explained almost equal per cent variation in birth weight. Subgroups of gestation explained maximum per cent variation in birth weight. High degree of correlation (p<0.001) persisted between birth weight and maternal weight, height, head circumference and hemoglobin levels even after controlling gestation. The partial correlation coefficient value(r) between birth weight and serum albumin levels fell down considerably when gestation was controlled (p<0.05). Orthogonal polynomial equations were derived between birth weight(y) and maternal variables using coefficients of determination (R²) value of suitable degree.     

The effect of maternal hyperglycemia on gross body movements in human fetuses at 32–34 weeks' gestation

This study demonstrated that fetal gross body movements were not significantly altered by fluctuations in maternal plasma glucose concentration. Fetuses moved episodically a relatively constant amount of time whether mother received water orally, 50 g of glucose orally or a 25 g bolus of glucose intravenously. In addition, depending on the length of the observational epoch, the incidence of fetal gross body movements differed. As the length of the observational period increased, the chance of finding no fetal gross body movements decreased and at intervals of 24 min duration, fetal gross body movements were absent in only 2% of 24 min periods examined, irrespective of whether they had received water orally, 50 g of glucose orally or 25 g of glucose intravenously. It is concluded that maternal carbohydrate intake was not an important determinant of fetal body movements in healthy fetuses at 32–34 weeks' gestation.     

Infant weight-for-length is positively associated with subsequent linear growth across four different populations

Several studies have documented that length gain often lags behind weight gain during infancy and early childhood, suggesting that linear growth is partly regulated by initial body mass or fatness. To investigate this hypothesis, we analysed data from four longitudinal studies on growth of infants in the first 12 months: (1) U.S. breast-fed and formula-fed infants (n = 89); (2) breast-fed infants in Ghana (n = 190); (3) normal birthweight, breast-fed infants in Honduras (n = 108); and (4) term, low-birthweight breast-fed infants in Honduras (n = 119). The dependent variable was length gain during each 3-month interval (1- 4, 2-5, 3-6, 4-7, 5-8, 6-9, 7-10, 8-11 and 9-12 months). Three main independent variables were examined: initial weight-for-length z-score (W/L), weight change during the prior 3 months, and initial skinfold thickness. Controlling for maternal height, infant sex, and initial length-for-age z-score, length gain was positively correlated with initial W/L and prior weight change during all age intervals and with initial skinfold thickness at 3 and 4 months (r = 0.15-0.36; P < 0.01). There was no evidence of a threshold effect. These associations were evident in all four populations, in both boys and girls, and in breast-fed and formula-fed infants. The consistency of this relationship across studies supports the hypothesis that linear growth is partly regulated by initial body mass or fatness in infants.     

Impact of ethnicity upon body composition assessment in Sri Lankan Australian children

OBJECTIVES: Obesity is a disease with excess body fat where health is adversely affected. Therefore it is prudent to make the diagnosis of obesity based on the measure of percentage body fat. Body composition of a group of Australian children of Sri Lankan origin were studied to evaluate the applicability of some bedside techniques in the measurement of percentage body fat. METHODS: Height (H) and weight (W) was measured and BMI (W/H(2)) calculated. Bioelectrical impedance analysis (BIA) was measured using tetra polar technique with an 800 microA current of 50 Hz frequency. Total body water was used as a reference method and was determined by deuterium dilution and fat free mass and hence fat mass (FM) derived using age and gender specific constants. Percentage FM was estimated using four predictive equations, which used BIA and anthropometric measurements. RESULTS: Twenty-seven boys and 15 girls were studied with mean ages being 9.1 years and 9.6 years, respectively. Girls had a significantly higher FM compared to boys. The mean percentage FM of boys (22.9 +/- 8.7%) was higher than the limit for obesity and for girls (29.0 +/- 6.0%) it was just below the cut-off. BMI was comparatively low. All but BIA equation in boys under estimated the percentage FM. The impedance index and weight showed a strong association with total body water (r(2)= 0.96, P < 0.001). Except for BIA in boys all other techniques under diagnosed obesity. CONCLUSIONS: Sri Lankan Australian children appear to have a high percentage of fat with a low BMI and some of the available indirect techniques are not helpful in the assessment of body composition. Therefore ethnic and/or population specific predictive equations have to be developed for the assessment of body composition, especially in a multicultural society using indirect methods such as BIA or anthropometry.     

Effects of recombinant human growth hormone treatment in intrauterine growth-retarded preterm newborn infants on growth, body composition and energy expenditure

The effects of recombinant human growth hormone treatment during the early postnatal period on growth, body composition and energy expenditure were studied in seven intrauterine growth-retarded newborns. Seven infants were studied as controls. No differences were seen in bodyweight or height gain (15.9 ± 1.5g/kg per day and 1.02 ± 0.24cm/week in the treated and 16.3 ± 1.4g/kg per day and 1.11 ± 0.30 cm/week in the control group). Skinfold growth rate was 0.52 ± 0.20 mm/week in the treated vs. 0.56 ± 0.28 mm/week in the control group. Total body water (as a percentage of body-weight, 80 ± 3.0% vs. 80 ± 4.0%) and energy expenditure (67.5 ± 7.4 vs. 66.7 ± 6.4kcal/kg per day) using ²H₂¹⁸O showed identical results in both groups. We conclude that recombinant human growth hormone treatment directly after birth in intrauterine growth-retarded newborn infants results neither in an increase in growth rate nor a change in body composition or energy expenditure during the early postnatal period.     

Revised intrauterine growth curves for an Australian hospital population

ABSTRACT. Intrauterine growth curves require periodic revision because of changes in population, socio-economic factors and technology used in obstetric care. Anthropometric measurements were derived from consecutive livebirths in the Royal Women's Hospital in 1979 and all those born before 35 weeks in 1977 and 1978; at gestational ages less than 30 weeks, data previously published was also incorporated. Infants were included if an ultrasonic examination of the uterus had been performed in the first 20 weeks of pregnancy or gestation based on "certain" menstrual history was confirmed clinically. From data on 3120 infants, intrauterine growth curves from 24--42 weeks' gestation were prepared; compared with births in the same hospital in 1966, there was generally an elevation of all centiles, particularly so for the 10th centile for weight after 37 weeks' gestation. Factors in the infant such as sex and ethnic origin and also maternal factors, especially pregnancy weight and height should be considered when using standard intrauterine growth charts.     

Influence of respiratory distress syndrome on body composition after preterm birth

AIM—To observe changes in body composition during the first week after birth, in preterm neonates with and without respiratory distress syndrome (RDS), so as to be able to provide optimal fluid and energy intake.
METHODS—Twenty four babies with RDS and 19 healthy preterm babies, with gestational ages ranging from 26-36 weeks, were studied daily for the first week after birth. Total body water (TBW) was measured using bioelectrical impedance analysis. The babies were weighed daily and a record made of fluid and energy intake. Body solids were calculated as the difference between body weight and TBW.
RESULTS—There was a highly significant reduction in body weight by the end of the week, with the RDS babies losing more than the healthy babies (RDS 7.6%; non-RDS 3.7%). There was no significant difference in the amount of TBW at birth in the babies with and without RDS (RDS 85.1%; non-RDS 85.5%) and both groups lost the same amount of body water (RDS 10.9%; non-RDS 9.9%) by the end of the first week. The amount of total body water lost was unrelated to the volume of fluid administered. There was a loss of body solids during the first day in the RDS group, but, overall, there was a highly significant increase in both groups between birth and day 7, which was greater in the healthy babies (RDS 13.0%; non-RDS 42.7%).
CONCLUSIONS—Loss of body water after birth occurs to the same extent in healthy preterm neonates and in babies with RDS and is unrelated to the volume of fluid administered. Given adequate nutritional support, an increase in body solids can accompany early postnatal weight loss and begins almost immediately after birth, in both healthy preterm babies and babies with RDS.