Biomedical subjects

J M Wit

Publications and source records attributed to J M Wit.

At least 55 records · Page 3Linked to original sources

PubMed2002

[Once growth hormone, always growth hormone? Transition from growth hormone therapy in childhood to adulthood].

The continuation of growth hormone treatment can be indicated in young adults who have been treated with growth hormone during childhood. However, in a large part of this population the diagnosis cannot be confirmed in adulthood. Therefore a retest procedure has to be performed once the final height has been attained. This procedure is only unnecessary in patients with deficiencies of two or more other pituitary hormone axes. The retest procedure can be performed one to three months after the growth hormone treatment has been discontinued, by means of an insulin tolerance test or, in the case of contraindications, by means of a combined growth hormone-releasing hormone(GHRH)-arginine test. If the growth hormone deficiency diagnosis is re-established, growth hormone treatment can be restarted. Patients are only eligible for a reimbursement of the growth hormone treatment costs from their health insurer, if the treatment indication is validated by the Dutch National Registry of Growth Hormone Treatment in Adults and the treatment results are included in a database. With this database insights into the long-term efficacy and safety of growth hormone treatment can be gained.

Adult↗

PubMed2002

Expression of estrogen receptor alpha and beta in the epiphyseal plate of the rat.

In this study we examine the spatial and temporal expression of estrogen receptor (ER) alpha and beta mRNA and protein in the tibial growth plate of the rat after birth, as well as the hormonal regulation of their expression. Using in situ hybridization and immunohistochemistry, we demonstrated ER alpha and ER beta mRNA and protein in tibial growth plates from 1 to 40 weeks after birth. ER alpha and beta mRNA and protein were localized in late proliferating and early hypertrophic chondrocytes during early life (1 and 4 weeks of age), whereas the immunohistochemistry also showed staining for ER alpha and beta in the resting cells. A similar expression pattern was observed during sexual maturation (7 weeks of age) except that ER beta mRNA was also detected in early proliferating chondrocytes. After sexual maturation (from 12 up to 40 weeks of age) ER alpha and beta mRNA and protein expression was confined to late proliferating and early hypertrophic chondrocytes. Apart from a relatively higher ER alpha mRNA expression in males after sexual maturation, we did not detect differences in expression of ERs between genders. Expression of ER beta mRNA in epiphyseal plates was increased in growth-retarded hypophysectomized rats compared with controls. Administration of growth hormone (GH) did not reverse the increased ER expression to normal. These data suggest that ER alpha and beta are coexpressed in growth plates of the rat after birth and that the level of expression of ERs in these tissues is hormonally regulated. Furthermore, our data indicate that the absence of growth-plate closure in the rat cannot be explained by disappearance of ER alpha expression during sexual maturation per se.

Animals↗

PubMed2002

Gender differences in expression of androgen receptor in tibial growth plate and metaphyseal bone of the rat.

In this study, we investigate the expression of the androgen receptor (AR) in the tibial growth plate and metaphyseal bone of male and female rats at the mRNA and protein level. Using in situ hybridization and immunohistochemistry, AR mRNA and protein were demonstrated in proliferating and early hypertrophic chondrocytes in the growth plate of 1-, 4-, and 7-week-old male and female rats. Immunostaining for AR was observed both in the nucleus and the cytoplasm. After sexual maturation at 12 and 16 weeks of age, AR expression decreased in both genders and was confined to a small rim of prehypertrophic chondrocytes. In female rats of 40 weeks of age, this expression pattern was still visible. In most age groups there was a tendency toward an increased AR mRNA expression in male vs. female rats except in the 7-week-old animals. At the protein level, sexually maturing 7-week-old male rats demonstrated a higher staining intensity compared to their female counterparts. At this stage, AR staining in the males was mainly confined to the nucleus, whereas in females staining was predominantly found in the cytoplasm. In the tibial metaphysis, AR mRNA was detected in lining cells, osteoblasts, osteocytes, and osteoclasts at all stages of development. At the protein level, a similar expression pattern was observed, except for an absence of immunostaining in the lining cells. The staining was both nuclear and cytoplasmic. In most age groups, mRNA and protein signals were higher in males compared with females. We have demonstrated the presence of AR mRNA and protein in the tibial growth plate and the underlying metaphyseal bone during development of the rat. In male rats, the presence of higher messenger and protein staining intensities, as well as preferential nuclear staining during sexual maturation, suggests that direct actions of androgens in chondrocytes and in bone forming cells may be involved in establishing the gender differences in the skeleton.

Animals↗

PubMed2002

Skin fibroblasts of children with idiopathic short stature show an increased mitogenic response to IGF-I and secrete more IGFBP-3.

OBJECTIVE AND PATIENTS: To study differences in cellular parameters of GH and IGF-I responsiveness in skin fibroblasts of 14 children with idiopathic short stature (ISS) treated with recombinant human GH and 13 children with normal height. Secondly, to investigate whether these cellular parameters can predict the growth response to GH treatment in children with ISS. DESIGN AND MEASUREMENTS: The mitogenic responsiveness to GH and IGF-I was investigated by 3H-Thymidine incorporation. Insulin-like growth factor binding protein-3 (IGFBP-3) levels in the media were measured by radioimmunoassay (RIA). RESULTS: No significant mitogenic responses were observed to various doses of GH (1000, 5000 or 50.000 ng/ml) in children with ISS or controls. ISS fibroblasts showed an increased mitogenic response to IGF-I (10 ng/ml) compared to controls (mean +/- SD 5.9 +/- 2.4- vs. 4.2 +/- 1.5-fold stimulation, P < 0.05), and GH enhanced this effect in both groups. IGFBP-3 secretion was increased in ISS fibroblasts when compared to controls under all conditions examined (basal, 200 and 5000 ng/ml GH, 10 ng/ml IGF-I for 24 and 48 h). High IGFBP-3 levels were related to low mitogenic responses to IGF-I or to GH + IGF-I in children with ISS (r = -0.7, P < 0.05), but not in controls. Within the ISS group, an enhanced mitogenic response to IGF-I in vitro was related to more extreme short stature before GH treatment (r = -0.70, P < 0.05) and to a relatively impaired response to high dose GH treatment in vivo (r = -0.52, P < 0.05). CONCLUSION: The demonstration of high IGFBP-3 levels and enhanced mitogenic response to IGF-I shows that ISS fibroblasts have different cellular characteristics compared to controls of normal height. It is hypothesized that in ISS an alteration of the signal transduction pathway between the GH receptor and IGFBP-3 synthesis results in a local imbalance with high IGFBP-3 levels and lower IGF-I availability for the IGF-I receptor. This may be reflected by an increased IGF-I responsiveness in vitro which is associated with an impaired capacity to grow in vivo.

Adolescent↗

PubMed2002

Biochemical markers of growth hormone (GH) sensitivity in children with idiopathic short stature: individual capacity of IGF-I generation after high-dose GH treatment determines the growth response to GH.

OBJECTIVE AND PATIENTS: To assess multiple dose-response relationships between three GH doses (1.5, 3.0 and 6.0 IU/m2) and nine different biochemical markers of GH sensitivity in a well-defined group of 17 children with idiopathic short stature (ISS). DESIGN AND MEASUREMENTS: Serum levels of IGF-I, IGF-II and IGFBP-3, and peripheral markers leptin, C-terminal propeptide of type I collagen (PICP) and N-terminal propeptide of type III collagen (PIIINP), alkaline phosphatase (AP) and osteocalcin (OC) were measured at the start and after 2 and 12 weeks of periods of no treatment, GH 1.5 IU/m2 and GH 3.0 IU/m2. Twelve-week washout periods were applied between the 12-week GH-treatment periods. High-dose GH treatment was given during the second year of study and all serum markers were measured at start, after 2 and 12 weeks and 1 year of GH 6.0 IU/m2. In 18 non-GH-treated children with ISS the same parameters were measured yearly. The bone resorption marker urinary deoxypyridinoline (DPD) was measured during 12-h day and night periods at start and after 2 weeks GH 1.5, 3.0 and 6.0 IU/m2. RESULTS: All markers were GH dependent, but the timing of maximal response varied among different markers. Height SDS at start, age at start and IGF-II at baseline were inversely related to the first-year growth response (r = -0.73, P = 0.001; r = -0.53, P = 0.03; and r = -0.53, P = 0.03, respectively). Some statistically significant correlations between biochemical responses on low GH doses (1.5 or 3.0 IU/m2) and second-year growth response were found, but these showed no consistent pattern. However, all changes in IGF-I SDS after GH 6.0 IU/m2 measured either after 2 or 12 weeks or 1 year correlated significantly with the second-year growth response (r = 0.55, P = 0.02; r = 0.81, P = 0.001; and r = 0.86, P < 0.001, respectively). Baseline or GH-stimulated levels of peripheral markers did not correlate with the growth response. CONCLUSION: The individual capacity of IGF-I generation after high-dose GH treatment (6.0 IU/m2) determines the growth response on high-dose GH treatment. Peripheral markers do not seem to play a role in growth prediction of children with ISS.

Biomarkers↗

PubMed2002

Growth hormone therapy.

Since 1958 growth hormone (GH) has been used as substitution treatment for children with GH deficiency. At present, it is clear that a dose of 0.23 mg/kg/week can lead to a final height close to target height, but in view of the wide inter-individual variation, alternative regimens based on invidualizing the dosage with the help of prediction models are being investigated. The best strategy during puberty (increase the dosage, delay puberty) is still uncertain. The value of GH in idiopathic short stature is still heavily debated, although the average final height gain on 0.33 mg/kg/week is 5-7 cm. GH is efficacious in short stature due to chronic renal failure and Prader-Willi syndrome. In other conditions insufficient data are available. There are few side-effects.

Body Height↗

PubMed2002

Longitudinal analysis of growth and puberty in 21-hydroxylase deficiency patients.

AIMS: To evaluate growth from diagnosis until final height (FH) in 21-hydroxylase deficiency patients. METHODS: A retrospective longitudinal study was performed. Only patients treated with hydrocortisone and fludrocortisone (in case of salt wasting) were evaluated. This resulted in a sample of 34 (21 male, 13 female) salt wasting patients (SW) and 26 (13 male, 13 female) non-salt wasting patients (NSW). Auxological data were compared to recent Dutch reference values. RESULTS: In the first three months of life, the mean length SDS decreased to -1.50, probably because of the high average glucocorticoid dose (40 mg/m2/day). FH corrected for target height (FH(corr)TH) was -1.25 and -1.27 SDS in females and males, respectively. Patients treated with salt supplements during the first year, had a better FH(corr)TH (-0.83 SDS). In NSW patients, FH(corr)TH was -0.96 and -1.51 SDS in females and males, respectively. In SW and NSW, age at onset of puberty was within normal limits, but bone age was advanced. Mean pubertal height gain was reduced in males. Body mass index was only increased in NSW females. CONCLUSION: In SW, loss of final height potential might be a result of glucocorticoid excess in the first three months and sodium depletion during infancy. In NSW, loss of FH potential was caused by the delay in diagnosis. In SW and NSW, the advanced bone age at onset of puberty (undertreatment in prebertal years) resulted in loss of height gain during puberty. The effect of intensive sodium chloride support in early infancy should be examined prospectively. Neonatal screening is required if the height prognosis in NSW patients is to be improved.

Adrenal Hyperplasia, Congenital↗

PubMed2002

High dose growth hormone treatment induces acceleration of skeletal maturation and an earlier onset of puberty in children with idiopathic short stature.

BACKGROUND: Long term growth hormone (GH) treatment in children with idiopathic short stature (ISS) results in a relatively small mean gain in final height of 3-9 cm, which may not justify the cost of treatment. As it is unknown whether GH treatment during puberty adds to final height gain, we sought to improve the cost-benefit ratio, employing a study design with high dose GH treatment restricted to the prepubertal period. AIMS: To assess the effect of short term, high dose GH treatment before puberty on growth, bone maturation, and pubertal onset. METHODS: Five year results of a randomised controlled study are reported. Twenty six boys and nine girls were randomly assigned to a GH treatment group (n = 17) or a control group (n = 18). Inclusion criteria were: no signs of puberty, height less than -2 SDS, age 4-8 years for girls or 4-10 years for boys, GH concentration >10 micro g/l after provocation, and normal body proportions. To assess GH responsiveness, children assigned to the GH treatment group received GH treatment for two periods of three months (1.5 IU/m2/day and 3.0 IU/m2/day), separated by three month washout periods, during the first year of study. High dose GH treatment (6.0 IU/m2/day) was then started and continued for at least two full years. When puberty occurred, GH treatment was discontinued at the end of a complete year's treatment (for example, three or four years of GH treatment). RESULTS: In response to at least two years on high dose GH treatment, mean (SD) height SDS for chronological age increased significantly in GH treated children from -2.6 (0.5) to -1.3 (0.5) after two years and -1.4 (0.5) SDS after five years of study. No changes in height SDS were observed in controls. A rapid rate of bone maturation of 3.6 years/2 years in treated children compared to 2 years/2 years in controls was observed in response to two years high dose GH treatment. Height SDS for bone age was not significantly different between groups during the study period. GH treated children entered into puberty at a significantly earlier age compared to controls. CONCLUSIONS: High dose GH treatment before puberty accelerates bone age and induces an earlier onset of puberty. This may limit the potential therapeutic benefit of this regimen in ISS.

Bone Development↗

PubMed2002

Adult height in patients with early onset of Crohn's disease.

BACKGROUND: Growth impairment during childhood and adolescence is a common problem faced by patients with an early onset of Crohn's disease. AIMS: To establish how the final adult height is affected in patients with early onset of symptoms of Crohn's disease. METHODS: Information on height, parental height, and disease history was obtained from 135 patients with Crohn's disease who reached their adult height (men 22-40 years, women 18-40 years) using a questionnaire and by outpatient measurement of height where possible. Subsequently, adult heights were expressed as standard deviation scores, with and without correction for the expected target height. RESULTS: Patients with onset of disease before puberty were shorter compared with patients with onset in adulthood (p<0.01). This difference was not statistically significant when adult heights were corrected for parental height. Also, height standard deviation scores for those patients with onset of disease before puberty were significantly lower than those with onset of disease during puberty (p<0.05) but after correction for parental height the difference was not significant. The site of disease had no influence on adult height. Patients who had used corticosteroids during puberty were significantly shorter than patients who had not (p=0.005). This was also true when corrected for target height (p=0.007). CONCLUSIONS: Although there was a trend indicating a deficit in adult height in patients with an early onset of Crohn's disease, once adjustment was made for parental height, this difference was not significant. Use of corticosteroids in puberty resulted in lower adult height.

Adolescent↗

PubMed2002

Catch-up growth and endocrine changes in childhood celiac disease. Endocrine changes during catch-up growth.

Childhood celiac disease may lead to a failure of statural growth. After institution of a gluten-free diet most patients exhibit catch-up growth. Catch-up growth is a remarkable phenomenon characterized by a supranormal height velocity. One of the hypothetical mechanisms of catch-up growth is that an increased activity of the somatotrophic axis is involved. In order to provide further insight in the physiology of catch-up growth, auxological and endocrine changes were prospectively studied in 28 children with newly diagnosed celiac disease. The results demonstrate a malnutrition-like state of the somatotrophic axis at the time of diagnosis and a rapid recovery of this axis towards normal functioning after institution of the gluten-free diet. Although several correlations between these endocrine alterations and auxological parameters were detected, it is questionable whether the endocrine changes are the driving force behind catch-up growth.

Body Height↗

PubMed2002

Sex steroid metabolism in the tibial growth plate of the rat.

To assess whether growth plate-specific production of sex steroids is possible, we have surveyed the presence of several key-enzymes involved in androgen and estrogen metabolism in the tibial growth plate of female and male rats during development. Using in situ hybridization, mRNAs of aromatase p450, type I and II 17beta-hydroxysteroid dehydrogenase (HSD), steroid sulfatase (STS), and 5alpha-reductase were detected in proliferating and hypertrophic chondrocytes of the growth plate. The former three were strongly up-regulated around sexual maturation (7 wk), whereas the latter two were expressed at a relatively constant level during development. These data were supported by measuring aromatase, type I 17beta-HSD, and STS enzyme activities in chondrocytes collected from tibial growth plates at 1 and 7 wk of age. Of the enzymes studied, there were minor differences between the sexes in aromatase and 5alpha-reductase expression only. In conclusion, our findings clearly indicate the presence of various enzymes involved in sex steroid metabolism in the tibial growth plate, especially in sexually maturing rats, a timepoint at which sex steroids have major effects on longitudinal growth. Our data suggest that intracrinology in the rat growth plate can occur and may be a major source of local sex steroid delivery.

17-Hydroxysteroid Dehydrogenases↗

PubMed2002

A 43-year-old male with untreated panhypopituitarism due to absence of the pituitary stalk: from dwarf to giant.

A 43-yr-old male was referred because of an x-ray made after a fall, which showed open epiphysis of the arm. The man had always been short for his age; during childhood he once consulted a pediatrician because of short stature, but thereafter he never sought medical attention. At age 18 yr he was not allowed to join the army because of his height of 147 cm. He continued to grow steadily and finally reached 193 cm. He had no complaints and considered himself reasonably fit. Physical examination showed a disproportional man with a body mass index of 29.3 kg/m(2) and Tanner stage P1G1. Laboratory investigations showed hormone levels consistent with multiple pituitary deficiency, with dynamic tests consistent with hypothalamic or pituitary stalk disease. Magnetic resonance scanning of the brain showed a small anterior pituitary remnant, no pituitary stalk, and an ectopic neurohypophysis. This case of untreated panhypopituitarism shows a particular growth curve with an average growth velocity of 2 cm/yr, resembling patients with estrogen receptor mutation or aromatase deficiency. A literature study of other adult patients with untreated panhypopituitarism shows a variable growth pattern. Some speculations about possible reasons for this variability in clinical characteristics are presented.

Growth↗

PubMed2002

Final height gain by GH therapy in children with idiopathic short stature is dose dependent.

Recombinant human GH therapy to children with idiopathic short stature (ISS) increases growth velocity, but its effect on final height (FH) is still uncertain. The aim of this study was to investigate the effect of recombinant human GH on FH of patients with ISS who were treated according to two protocols in comparison to untreated historical controls. In study 1 (n = 24), all patients were treated with 14 IU (4.6 mg)/m(2) body surface x wk in the first year; thereafter the dosage was doubled if the growth response was insufficient. In study 2 (n = 34), patients were randomized into three arms: 18 IU (6 mg)/m(2) x wk; 27 IU (9 mg)/m(2) x wk; and 18 IU/m(2) x wk in the first year, followed by 27 IU/m(2) x wk thereafter. Observed or estimated FH was available for 53 patients. Thirty-four untreated controls from the same centers were available for comparison. Mean FH SD score in GH-treated children was -2.1, vs. -2.4 in controls (-2.4) (NS), but height SD score gain (1.3 vs. 0.7) and the difference between FH and predicted adult height (4.0 vs. 0.8 cm) were significantly greater. The growth response on an initial dosage of 27 IU/m(2) x wk (6.9 cm) was significantly better than on other regimens (2.8 cm). We conclude that a GH dosage of 27 IU (9 mg)/m(2) x wk to prepubertal children with ISS leads to a mean FH gain of approximately 7 cm, whereas regimens starting on lower dosages are less efficacious.

Body Height↗

PubMed2002

Evidence for genomic and nongenomic actions of estrogen in growth plate regulation in female and male rats at the onset of sexual maturation.

Recently, both estrogen receptor (ER) alpha and beta were detected in growth plate chondrocytes of rats before sexual maturation, implying a role for estrogen at this stage. In this study, therefore, we investigated the effects of ovariectomy (OVX) or estrogen supplementation on parameters of longitudinal growth in 26-day-old rats, which were sexually immature at the start of the experiment. OVX caused an increase in body weight gain, tibial length and growth plate width due to an increased proliferating zone. This increase correlated with an increase in cell number, with a decrease in cell diameter and with increased proliferating cell nuclear antigen (PCNA) immunostaining compared with sham. Interestingly, the increase in proliferation was not caused by an increase in insulin-like growth factor-I (IGF-I) mRNA expression in the growth plate as assessed by real-time PCR. In contrast to OVX, 17beta-estradiol (E(2)) supplementation (0.5 mg/21 days) of 26-day-old female rats caused a strong decrease in body weight gain, tibial length and growth plate width. The latter was explained by a reduction of the proliferating zone width, which correlated with a reduced number of PCNA-positive cells (not significant) and by a reduction of the hypertrophic zone width. In male rats supplemented with E(2), similar effects were observed compared with the females. ERalpha and beta immunostaining was found predominantly in late proliferating and early hypertrophic chondrocytes. OVX did not affect ER expression but E(2) supplementation strongly decreased immunostaining for both ERalpha and beta in both sexes. Besides E(2), desoxyestrone (DE), an activator of nongenomic estrogen-like signaling (ANGEL) and 2-methoxyestradiol (2-MeO-E(2)), a tissue-selective naturally occurring metabolite of E(2), were administered to female and male rats of the same age. Compared with E(2), these compounds had less pronounced, though significant, effects on some parameters of longitudinal growth in both sexes, especially on growth plate characteristics. In conclusion, E(2) may exert effects on longitudinal growth before and at the onset of sexual maturation, despite very low endogenous serum levels at these stages. There may be a role for nongenomic signaling in body weight gain, tibial length and growth plate width but genomic signaling prevails.

2-Methoxyestradiol↗

PubMed2001

[From gene to disease; POU1F1- and PROP1-mutations in pituitary hormone deficiency].

Multiple pituitary hormone deficiency can be caused by mutations in at least three pituitary transcription factors: POU1F1 (formerly called PIT1), PROP1 or HESX1. The role of the various pituitary transcription factors in pituitary ontogeny has been elucidated in part for the mouse. In humans, mutations in POU1F1 result in a total deficiency of growth hormone and prolactin, and a variable deficiency of TSH. Cases of mutations in PROP1 exhibit the same deficiencies, with additional deficiencies of gonadotrophins and a variable deficiency of ACTH. In the Netherlands, cases of multiple pituitary hormone deficiency are not only detected on the basis of the classical signs and symptoms of pituitary deficiency, but also by means of screening on congenital hypothyroidism with an incidence of approximately 1:20,000.

Animals↗

PubMed2001

[Increased prevalence of overweight and obesity in Dutch children, and the detection of overweight and obesity using international criteria and new reference diagrams].

OBJECTIVE: To determine the prevalence of overweight and obesity in Dutch children in 1980 and 1997 according to international criteria, and to design new reference diagrams for overweight and obesity in children. DESIGN: Descriptive. METHOD: The prevalence of overweight and obesity, based on height and weight data from the Fourth Dutch Growth Study (1997), was determined according to international criteria for age and sex. RESULTS: In 1997, the prevalence of overweight and obesity increased in both boys and girls compared to 1980: in 1997, the prevalence of overweight ranged between 7.1 and 15.5% for boys, and between 8.2 and 16.1% for girls. Both the prevalence of overweight and obesity was higher in girls than in boys. CONCLUSION: By applying the international criteria for overweight and obesity and reference growth diagrams based upon the 1997 Dutch growth study, the prevention and detection of overweight and obesity has to be implemented with vigour in Dutch youth health care.

Adolescent↗

PubMed2001

Quality of life in preschool children born preterm.

The relationship of preterm birth to health-related quality of life (HRQoL) was examined for children aged 1 to 4 years. Three gestational age groups with a NICU history were selected, <32 weeks (n=65), 32 to 36 weeks (n=41), 237 weeks (n=54), and a reference group from the open population (n=50). The main instrument was the TNO-AZL Preschool Quality Of Life (TAPQOL) questionnaire, which was completed by the parents. In addition, other outcome measures obtained from parents or neonatologists were investigated. Children born <32 weeks had significantly lower HRQoL than the reference group in the scales for lungs, stomach, eating disorders, motor functioning, communication, and anxiety. Parental feelings towards the child were related to the child's HRQoL. We found differences between the neonatologists' and parents' perceptions of the children's situation, which can have clinical consequences (e.g. different opinions about what needed treatment). Neonatal intensive care after birth has HRQoL implications for all children, particularly in children born at <32 weeks of gestation.

Anxiety↗

PubMed2001

An analysis of intra-uterine growth retardation in rural Malawi.

OBJECTIVE: (1) To describe the sex-specific, birth weight distribution by gestational age of babies born in a malaria endemic, rural area with high maternal HIV prevalence; (2) to assess the contribution of maternal health, nutritional status and obstetric history on intra-uterine growth retardation (IUGR) and prematurity. METHODS: Information was collected on all women attending antenatal services in two hospitals in Chikwawa District, Malawi, and at delivery if at the hospital facilities. Newborns were weighed and gestational age was assessed through post-natal examination (modified Ballard). Sex-specific growth curves were calculated using the LMS method and compared with international reference curves. RESULTS: A total of 1423 live-born singleton babies were enrolled; 14.9% had a birth weight <2500 g, 17.3% were premature (<37 weeks) and 20.3% had IUGR. A fall-off in Malawian growth percentile values occurred between 34 and 37 weeks gestation. Significantly associated with increased IUGR risk were primiparity relative risk (RR) 1.9; 95% CI 1.4--2.6), short maternal stature (RR 1.6; 95% CI 1.0--2.4), anaemia (Hb<8 g/dl) at first antenatal visit (RR 1.6; 95% CI 1.2--2.2) and malaria at delivery (RR 1.4; 95% CI 1.0--1.9). Prematurity risk was associated with primiparity (RR 1.7; 95% CI 1.3--2.4), number of antenatal visits (RR 2.2; 95% CI 1.6--2.9) and arm circumference <23 cm (RR 1.9; 95% CI 1.4--2.5). HIV infection was not associated with IUGR or prematurity. CONCLUSION: The birth-weight-for-gestational-age, sex-specific growth curves should facilitate improved growth monitoring of newborns in African areas where low birth weight and IUGR are common. The prevention of IUGR requires improved malaria control, possibly until late in pregnancy, and reduction of anaemia.

Anemia, Iron-Deficiency↗