Fetal growth velocities in Hong Kong Chinese infants

Few studies have investigated the velocities of fetal growth. The aim of the present study was to determine the pattern of 'fetal' growth velocities in a Chinese population. The gestation-specific measurements of the body weight, body length and head circumference in a representative sample of 5,045 male and 4,484 female newborns delivered between 26 and 42 weeks of gestation at 12 hospitals in Hong Kong were obtained. Peak growth velocity occurred before 30 weeks of gestation for head circumference, at week 30 for length and at week 30 for weight. When compared with data obtained from a French population, a significant difference in the growth velocity for body weight was observed below 32 weeks between French and Chinese infants, suggesting an ethnic difference in fetal growth of this parameter.     

Critical growth phases for adult shortness in Hong Kong Chinese.

OBJECTIVES: This study was designed to explore whether the influence of subnormal growth in fetal, infancy, childhood and pubertal phases on adult short stature was the same when comparing privileged and underprivileged populations. METHODS: Data came from two longitudinal growth studies: 1) Hong Kong Chinese children who were born in 1967 (n = 132), and 2) the comparatively more privileged Swedish children who were born in 1973-1975 (n = 2,850). RESULTS: 68% of Hong Kong Chinese children had two or more growth phases subnormal, much higher than the 12.4% for Swedish children. 42.4% of Hong Kong Chinese were short at final height, much higher than the 2.2% for Swedish children. Subnormal growth in any growth phase was associated with an increased risk of adult short stature in both series (p<0.01). After adjustment for mid-parental height, the place of residence (Hong Kong/Sweden) was not significant for adult shortness (p>0.05) in the pooled data. CONCLUSIONS: The impact of subnormal growth in any phase on adult shortness is similar in privileged and underprivileged populations. The much higher prevalence of subnormal growth and consequently adult short stature in developing countries is likely mainly attributable to adverse extrinsic or environmental influences.     

Trunk anthropometry of Hong Kong Chinese infants

BACKGROUND: Disturbed growth of the trunk may result in abnormal sternocostal relationship and a variety of pectus deformities. AIMS: The purposes of this study were to establish norms of trunk anthropometry for dysmorphology identification in the newborns and to evaluate chest circumference as a predictor for low birth weight for outborn infants where weighing scales were unavailable. STUDY DESIGN AND SUBJECTS: A total of 10,339 Chinese infants (5478 males, 4861 females) with gestation 24-42 weeks from 12 hospitals were included. The anthropometric measurements analyzed included chest circumference, inter-nipple distance, sternal length and abdominal circumference. OUTCOME MEASURES: The LMS method using maximum penalized likelihood was used to perform model fitting of the anthropometric centiles for these physical parameters. RESULTS: References tables of the four physical parameters for newborns were constructed. Chest circumference showed the highest correlation with birth weight (male: r = 0.866, female: r = 0.883). The cut-off points for chest circumference of 295 (male) and 299 mm (female) were the best predictor for low birth weight. There were also racial differences in these parameters. When compared with French infants, Chinese newborns had smaller chest circumference. CONCLUSION: These physical parameters provide useful references and aid dysmorphology diagnosis in newborns of ethnic Chinese origin.     

Developmental assessment of intrauterine growth retarded babies of varying maternal etiology

Head circumference was measured serially and developmental performance assessed at the age of 9 months in 41 full-term intrauterine growth retarded babies of varying maternal etiologies. 18 full term and 12 preterm babies who were appropriate for gestational age (AGA) served as controls. The IUGR babies of undernourished mothers had maximum retardation in head circumference.The IUGR babies of small sized mothers had head circumference equal to that of fullterm AGA babies. The IUGR babies of mothers with toxemia of pregnancy and idiopathic group also reached very close to that of fullterm AGA babies for head circumference demonstrating catch up growth. 19.5 per cent of IUGR (as homogenous group) babies were found to have delayed development compared to 16.7 per cent of preterm and 5.6 per cent of fullterm AGA babies. Amongst IUGR groups, babies of undernourished mothers were found to suffer most, followed by babies of mothers with toxemia of pregnancy. None of the babies in the idiopathic group and only one out of 12 in small maternal size group were found to have delayed development.     

A comparison of the growth patterns of Chinese infants in Chengdu and Hong Kong: 0-2 years

Factors affecting geographical differences in the growth of Chinese infants were examined by comparing data obtained from longitudinal growth studies on growth and feeding practices performed in two Chinese populations: Chengdu and Hong Kong infants from birth to 2 years. Their mean growth curves were fitted by the Reed model for the first year and the Count model for the second year. Chengdu mothers were significantly taller than Hong Kong mothers. Chengdu infants grew more rapidly than the Hong Kong infants during the first 6 months; it is likely that this is related to genetic differences in growth potential and earlier introduction of solids in Chengdu infants.     

A prospective study on intrauterine cannabis exposure and fetal blood flow

Background

Cannabis is commonly used among pregnant women. It is unclear whether cannabis exposure causes hemodynamic modifications in the fetus, like tobacco does.

Aims

This study aims to ascertain fetal blood redistribution due to intrauterine cannabis exposure.

Methods

This study was embedded in the Generation R Focus Study, a population-based cohort of parents and children followed from pregnancy onwards. In late pregnancy, fetal hemodynamics was assessed with ultrasound measurements in cannabis-exposed and non-exposed fetuses. Pregnant women reported about substance use during pregnancy. A distinction was made between continued cannabis use (n = 9), cannabis use only in early pregnancy (n = 14), continued tobacco use (n = 85), tobacco use only in early pregnancy (n = 92), and no tobacco or cannabis use during pregnancy (n = 85).

Results

Continued cannabis use was associated with an increased pulsatility and resistance index of the uterine artery, while discontinued cannabis use was associated with a decreased pulsatility, and resistance index, as compared to controls. Additionally, continued cannabis exposure resulted in a significantly higher uterine pulsatility index and uterine resistance index compared to tobacco exposure. Continued cannabis use was found to be associated with a smaller aortic diameter, as well. No association between intrauterine cannabis exposure and the fetal cerebral vascular system was found.

Conclusions

Our findings suggest that intrauterine cannabis exposure was associated with changes in hemodynamic programming of the vascular system of the fetus in late pregnancy mainly due to tobacco exposure, but intrauterine cannabis exposure did demonstrate a specific effect on the uterine blood flow.     

Vitamin D status of Hong Kong Chinese infants

Vitamin D deficiency is a common nutritional problem of weaning infants in many parts of the world. Hong Kong infants, who are fed with traditional rice-based weaning foods and live in crowded high rise flats, might be expected to suffer from this nutritional problem. Yet a study of 150 bottle fed infants revealed that the vitamin D intake from fortified milk and cereals was more than half of the recommended amount throughout the first 18 months and that the serum 25-OH vitamin D concentration of the infants at 18 months was normal. The effect of sunlight was also evident.     

Vitamin D Status of Hong Kong Chinese Infants

ABSTRACT. Vitamin D deficiency is a common nutritional problem of weaning infants in many parts of the world. Hong Kong infants, who are fed with traditional rice-based weaning foods and live in crowded high rise fiats, might be expected to suffer from this nutritional problem. Yet a study of 150 bottle fed infants revealed that the vitamin D intake from fortified milk and cereals was more than half of the recommended amount throughout the first 18 months and that the serum 25-OH vitamin D concentration of the infants at 18 months was normal. The effect of sunlight was also evident.     

Reliability of pubertal self-assessment in Hong Kong Chinese children

Aim:   To validate a Tanner stages self-assessment questionnaire using gender-specific line drawings and brief explanatory text in Chinese.
Methods:   Design: A cross sectional study design. Setting: One primary and two secondary schools. Participants: 172 boys and 182 girls aged between 8 and 18 years. Main outcome measures: Students' self-assessments of pubertal maturation were compared with assessments made by a same gender rater using visual depiction physical examination. Raters' physical examinations were performed after the children had answered the self-assessment questionnaire individually and in private. Raters were blinded to the self-assessment results. Accuracy rates and weighted kappa statistic were used to evaluate the degree of agreement between children and raters.
Results:   Substantial to almost perfect agreement was found between self- and rater's assessments of breast development and pubic hair growth in girls [weighted kappa 0.72 ( P  < 0.0001, 95% CI 0.66, 0.79) and 0.83 ( P  < 0.0001, 95% CI 0.78, 0.87) respectively]. Moderate to substantial agreement was found between self- and rater's assessments of male genital development and pubic hair growth [weighted kappa 0.58 ( P  < 0.0001, 95% CI 0.48, 0.68) and 0.80 ( P  < 0.0001, 95% CI 0.74, 0.86) respectively]. Most agreements between self- and rater's assessments differed by only one Tanner stage. Agreement was higher for girls than boys. Girls tended to overestimate their breast stages and boys tended to underestimate their genitalia development.
Conclusion:   This study confirms that a Tanner pubertal self-assessment questionnaire with line drawings and explanatory Chinese text can reliably estimate sexual maturation status in Hong Kong Chinese children.     

A cross-sectional study of growth, puberty and endocrine function in patients with thalassaemia major in Hong Kong

Methodology: A cross-sectional study of growth, puberty and endocrine function was performed on 35 girls and 33 boys with thalassaemia major.
Results Despite regular transfusion and chelation therapy, 75% of the girls and 62% of the boys over the age of 12 years were below the third percentile for height. Hypogonadotropic hypogonadism was found in a similar percentage of patients. Moderate to marked zinc deficiency secondary to chelation therapy was considered unlikely because normal serum zinc levels were found in all but three of our patients, but we could not exclude the possibility of a marginal status of zinc nutrition causing growth failure. Growth hormone deficiency and diabetes mellitus were sometimes encountered but hypothyroidism, hypoparathyroidism and adrenal insufficiency were rare among our patients. Most of the patients with growth failure had normal growth hormone (GH) response to insulin induced hypoglycaemia. The serum insulin-like growth factor-1 (IGF-1) levels were low in our patients and no significant difference in the serum IGF-1 levels was found between prepubertal children with or without growth failure (0.4±0.1 mU/mL vs 0.37±0.11 mU/mL, P = 0.39). Similarly, no difference in the serum IGF-1 levels was found between pubertal children with or without growth failure (0.48 ± 0.2 U/mL vs 0.56 ±0.14 U/mL, P= 0.26).
Conclusions Delayed sexual maturation and a possible defect in growth unrelated to the GH-IGF-1 axis may be responsible for the growth failure in adolescent children with thalassaemia major.     

Peripheral blood leucocyte zinc depletion in babies with intrauterine growth retardation.

The zinc content of peripheral blood leucocytes from the cord blood of 63 normal and 20 preterm babies, and of 27 babies with evidence of idiopathic intrauterine growth retardation (IUGR) was measured. Leucocyte zinc depletion was present in babies with acute IUGR (IUGR babies compared with controls, mean 47.8 v 51.5 ng zinc/mg dry weight), but was especially severe in those with prolonged IUGR (mean 43.2 ng zinc/mg dry weight), while preterm babies were normal (mean 51.9 ng zinc/mg dry weight). We suggest that this fetal tissue zinc depletion is caused by maternal zinc depletion, and may reflect a reduction of whole body zinc status.     

Severe chronic neutropenia in Chinese children in Hong Kong

OBJECTIVE: Severe chronic neutropenia (SCN) is a rare and heterogeneous disorder in children. The epidemiology, clinical features and outcomes of SCN in Chinese children were reviewed. METHODOLOGY: A retrospective analysis of case records was undertaken for 18 children with SCN managed during a 12-year period in a university teaching hospital in Hong Kong. RESULTS: The median (range) age of the patients at initial presentation was 6.5 months (4 days-19 months). The initial and lowest median absolute neutrophil counts (ANC) were 0.29 x 109 /L and 0.06 x 109 /L, respectively. Patients with congenital SCN had significantly fewer neutrophils in peripheral blood at diagnosis. Only five subjects received granulocyte colony-stimulating factor (G-CSF) treatment. All children were free from serious infection on follow up for 51 months. Only one child suffered from long-term infection-related morbidity. One patient with chronic neutropenia was subsequently shown to have common variable immunodeficiency. CONCLUSIONS: Most children with SCN in our series had favourable clinical outcomes. Our results support the recommendation that G-CSF should be used only in those with recurrent or severe infections.     

Breath methane excretion in Hong Kong Chinese children.

The factors which determine whether an individual is a methane excretor or a nonexcretor are not clearly understood. Genetic makeup, ethnic origin, diet, environment, or an interaction of all these factors have been implicated. In order to delineate the incidence, the age of onset, and environmental factors that may influence the excretion of methane in our community, we investigated a total of 425 Chinese children in Hong Kong (204 females, 221 males). End-expiratory breath samples were collected after an overnight fast and measured by gas-chromatography using a flame ionization detector. Thirty one children (7.3%) excreted at least 1 ppm methane above the ambient level (median = 6.4, range = 1.8-26.0 ppm). There was no difference in methane excretion status and pattern between the sexes or between children who lived at home and those who lived at an institution. There was a general increase in the number of methane excretors with age, but a statistically significant increase was reached only after 14 years of age. The amount of methane excreted was unrelated to age and there were no excretors detected under the age of 5 years. It is concluded that the methane excretion pattern of these children was generally similar to those previously reported from other regions, but the incidence is much lower and the age of onset appears to be more gradual.     

Incidence of ABO haemolytic disease of the newborn in a group of Hong Kong babies with severe neonatal jaundice

Two methods were used to determine the incidence of ABO haemolytic disease of the newborn (ABO-HDN) among Hong Kong Chinese infants. The first method employed the Lui elution technique to elute anti-A,B from cord blood of Group A and B babies with a Group O mother, and set out to correlate the titration score of the eluate with the serum bilirubin of the neonates. This method proved to be a failure because of the poor correlation. The second method was mathematical. By comparing the 'expected' frequency of various mother-infant ABO combinations (based on the ABO distribution of our local population) with the 'observed' frequency of a cohort of infants with severe neonatal jaundice, it was found that only two combinations (O-A and O-B mother-infant pairs) were responsible for ABO-HDN, for which the incidence was 1 in 5 among infants with a serum bilirubin level of 300 mumols/L or more.