Intrauterine growth retardation and familial short stature

Embryonic thermal manipulation leads growth inhibition and reduced hepatic insulin-like growth factor1 expression due to promoter DNA hypermethylation in broilers

When broilers cannot adapt to a high-temperature environment through self-regulation, it will cause heat stress, resulting in a large number of deaths and substantial economic losses. Studies have shown that thermal manipulation (TM) during the embryonic stage can improve broilers' ability to resist heat stress later. However, different TM strategies produce different results on broilers' growth. In this study, yellow-feathered broiler eggs were selected and randomly divided into 2 groups between E10 and E18, which the control group was incubated at 37.8°C with 56% humidity, and the TM group was subjected to 39°C with 65% humidity. After hatching, all broilers were reared normally until slaughtered at 12 d of age (D12). During D1 to D12, body weight, feed intake, and body temperature were recorded. The results showed that TM significantly decreased (P < 0.05) the final body weight, weight gain, and average daily feed intake of broilers. Meanwhile, the serum levels of Triiodothyronine (T3) and free T3 were significantly decreased in the TM group (P < 0.05). The expressions of hepatic growth regulation-associated genes, growth hormone receptor (GHR), insulin-like growth factor1, and 2 (IGF1 and IGF2) were significantly down-regulated in the TM group (P < 0.05). In addition, TM altered hepatic DNA methylation, resulting in a significant increase (P < 0.05) in the methylation of the IGF1 and GHR promoter regions. The above results indicated that TM during the embryonic stage decreased the serum thyroid hormone level and increased the methylation level of the IGF1 and GHR promoter regions to down-regulate the expression of growth-related genes, resulting in early growth inhibition of broilers.

Early diagnosis and treatment referral of children born small for gestational age without catch-up growth are critical for optimal growth outcomes

Approximately 10% of children born small for their gestational age (SGA) fail to show catch-up growth and may remain short-statured as adults. Despite treatment guidelines for children born SGA that recommend referral for growth hormone (GH) therapy evaluation and initiation by ages 2 to 4 years, the average age of GH treatment initiation is typically much later, at ages 7 to 9 years. Delayed referral for GH treatment is problematic as studies show younger age at GH treatment initiation in children born SGA is an independent predictor for responses such as optimal growth acceleration, normalization of prepubertal height, and most importantly, adult height (AH). This review discusses the importance and associated challenges of early diagnosis of children born SGA who fail to show catch-up growth, contrasts the recommended age of referral for these patients and the average age of GH treatment initiation, and discusses studies showing the significant positive effects of early referral and treatment with GH on AHs in short-statured children born SGA. To optimize the eventual height in short-statured SGA children who fail to manifest catch-up growth, a lowering of the average age of referral for GH therapy evaluation is needed to better align with consensus recommendations for SGA management. The importance of increasing parental and physician awareness that most children born SGA will do well developmentally and will optimally benefit from early initiation of GH treatment when short-statured is addressed, as is the need to shift the age of referral to better align with consensus recommendations.

Growth and growth hormone in children born small for gestational age

Although most children born small for gestational age catch up in growth by age 2 y, up to 14% remain more than 2 standard deviations below the mean for height. Recombinant growth hormone is approved by the US Food and Drug Administration and by the European Agency for Evaluation of Medicinal Products for the treatment of children born small for gestational age who fail to manifest catch-up growth by 2 y or 4 y, respectively.

CONCLUSION

We conclude from clinical studies that growth hormone therapy can induce catch-up growth in these children.

Genetic analysis of tall stature

Tall stature is less often experienced as an important problem than short stature. However, a correct diagnosis may be of eminent importance, especially when interventions are planned, or to know the natural history. Overgrowth can be caused by endocrine disorders and skeletal dysplasias, but also by several genetic syndromes. Despite a systematic diagnostic approach, there will be patients with tall stature who do not fit a known diagnosis. In this group of patients possibilities of genetic analysis do exist, but are not common practice. The FMR1 gene should be analyzed in patients with tall stature and mental retardation, and in these patients the NSD1 gene can be considered whenever some features of Sotos syndrome do exist. In tall patients without mental retardation and some features of Sotos or Beckwith-Wiedemann syndrome it may still be useful to look for mutations in the NSD1 gene, but also for changes in the 11p15 region. The various possibilities are discussed and placed in a flowchart.

The Webster Technique: a chiropractic technique with obstetric implications

OBJECTIVE

To survey members of the International Chiropractic Pediatric Association (ICPA); regarding the use of the Webster Technique for managing the musculoskeletal causes of intrauterine constraint, which may necessitate cesarean section.

METHODS

Surveys were mailed to 1047 US and Canadian members of the ICPA.

RESULTS

One hundred eighty-seven surveys were returned from 1047 ICPA members, constituting a return rate of 17.86%. Seventy-five responses did not meet the study inclusion criteria and were excluded; 112 surveys (11%) provided the data. Of these 112 surveys, 102 (92%) resulted in resolution of the breech presentation, while 10 (9%) remained unresolved.

CONCLUSION

The surveyed doctors reported a high rate of success (82%) in relieving the musculoskeletal causes of intrauterine constraint using the Webster Technique. Although the sample size was small, the results suggest that it may be beneficial to perform the Webster Technique in month 8 of pregnancy, when breech presentation is unlikely to spontaneously convert to cephalic presentation and when external cephalic version is not an effective technique. When successful, the Webster Technique avoids the costs and/or risks of external cephalic version, cesarean section, or vaginal trial of breech.In view of these findings, the Webster Technique deserves serious consideration in the health care management of expectant mothers exhibiting adverse fetal presentation.

Angiogenesis and intrauterine growth restriction

Human placental development involves co-ordinated angiogenesis and trophoblast outgrowth that are compromised in intrauterine growth restriction. Adaptive angiogenesis in IUGR placental villi is a result of an imbalance in the orderly progression of the expression profile of vascular endothelial growth factor, placenta growth factor and angiopoietin during placental development. VEGF receptors and the angiopoietin receptor Tie-2 are expressed on trophoblast, and their activation leads to trophoblast proliferation, migration and production of nitric oxide. Thus, these vascular factors act as autocrine regulators of trophoblast behaviour in the development of the utero-/feto-placental circulation, an action independent of their well-established roles in vascular endothelium.

A discrepancy between gestational age estimated by last menstrual period and biparietal diameter may indicate an increased risk of fetal death and adverse pregnancy outcome

OBJECTIVE

To determine if the discrepancy between gestational age estimated by last menstrual period and by biparietal diameter (GALMP - GABPD) is associated with adverse pregnancy outcome.

DESIGN

Population-based follow up study.

POPULATION

Singleton pregnancies were studied when a reliable date of last menstrual period and biparietal diameter measured between 12 and 22 weeks of gestation was available (n = 16,469).

METHODS

Logistic regression analysis and Kaplan-Meier survival analysis were used to analyse the association between GALMP - GABPD and adverse pregnancy outcome.

MAIN OUTCOME MEASURES

Adverse outcome was defined as abortion after 12 weeks of gestation, still-birth or postnatal death within one year of birth, delivery < 37 weeks of gestation, a birthweight < 2,500 g or a sex-specific birthweight lower than 22% below the expected.

RESULTS

The risk of death was more than doubled if GALMP - GABPD of > or = 8 days was compared with GALMP - GABPD of < 8 days (OR 2.2; 95% CI 1.6-3.1). The risk of death was a factor of 6.1 higher if GALMP - GABPD of > or = 8 days was combined with increased (> 2 x multiple of median) maternal alpha-fetoprotein measured in the 2nd trimester.

CONCLUSIONS

A discrepancy between GALMP and GABPD generally reflects the precision of the two methods used to predict term pregnancy. However, a positive discrepancy of more than seven days, particularly with high maternal alpha-fetoprotein, might indicate intrauterine growth retardation and an increased risk of adverse perinatal outcome.

Differences in late fetal death rates in association with determinants of small for gestational age fetuses: population based cohort study

OBJECTIVE

To examine differences in late fetal death rates in association with determinants of small for gestational age fetuses.

DESIGN

Population based cohort study.

SUBJECTS

1 026 249 pregnancies without congenital malformations.

SETTING

Sweden 1983-92.

MAIN OUTCOME MEASURE

Late fetal death rate.

RESULTS

Depending on underlying determinants late fetal death rates were greatly increased in extremely small for gestational age fetuses (range 16 to 45 per 1000) compared with non-small for gestational age fetuses (1.4 to 4.6). In extremely small for gestational age fetuses late fetal death rates were increased from 31 per 1000 in mothers aged less than 35 years to 45 per 1000 in older mothers, and from 22 per 1000 in women <155 cm in height to 33 per 1000 in women >=175 cm tall. Late fetal death rates were also higher in extremely small for gestational age fetuses in singleton compared with twin pregnancies and in non-hypertensive pregnancies compared with pregnancies complicated by severe pre-eclampsia or other hypertensive disorders. Slightly higher late fetal death rates were observed in nulliparous compared with parous women and in non-smokers compared with smokers.

CONCLUSIONS

Although the risk of late fetal death is greatly increased in fetuses that are extremely small for gestational age the risk is strongly modified by underlying determinants-for example, there is a lower risk of late fetal death in a small for gestational age fetus if the mother is of short stature, has a twin pregnancy, or has hypertension.

Evaluation of attention before and after 2 years of growth hormone treatment in intrauterine growth retarded children

The objective of this study was to assess attention in children with short stature following intrauterine growth retardation (IUGR), at baseline and after 2 years of growth hormone (hGH) treatment. At baseline, all of the children had a birth height and a current height below the third centile. The attention measures (Sonneville Visual Attention Tasks: SVAT) of the IUGR group were compared with those of a comparison sample. In the baseline analyses, 48 children with IUGR and 119 comparison children were included; the 2-year follow-up analyses involved 41 children with IUGR and 68 comparison children. At baseline, children with IUGR showed deficits in divided, focused, and sustained attention. They were less accurate, exhibited more variability in reaction time, and performed more slowly and more impulsively than did the children in the comparison sample. After 2 years of hGH treatment, the IUGR group exhibited deficits in divided and sustained attention. They were still less accurate and showed more variability in reaction time and more impulsiveness. Current head circumference, the type of delivery, and global intelligence of children with IUGR were significantly correlated with attention measures. We hypothesize that short stature following IUGR and attention deficits are related, and that hGH treatment seems to have some beneficial effect on attentional capacity.

Endogenous and stimulated GH secretion, urinary GH excretion, and plasma IGF-I and IGF-II levels in prepubertal children with short stature after intrauterine growth retardation. The Dutch Working Group on Growth Hormone

OBJECTIVE

The pathophysiological mechanisms underlying the failure of catch up-growth in children with short stature after intrauterine growth retardation (IUGR) remain obscure. Since GH secretion disturbances might play a role in the growth retardation of these children we have investigated various aspects of the GH/IGF axis.

DESIGN

Cross-sectional study in one group of patients.

PATIENTS

Forty prepubertal children (15 girls/25 boys; mean age (range) 7.5 years (3.4-10.8)) with short stature (height below the third centile) after IUGR, defined as a birth length below the third centile for gestational age, were studied.

MEASUREMENTS

GH secretion was determined by a 24-hour plasma GH profile (sampling every 20 minutes) and, on a separate occasion, by a standard arginine provocation test (ATT). Plasma IGF-I and IGF-II levels were measured at the start of the GH profile. Urine was collected to measure urinary GH levels. Plasma and urinary GH were determined by double antibody RIA. IGF-I and IGF-II were determined by specific RIA after acid chromatography. The 24-hour GH profiles were analysed using Pulsar.

RESULTS

Endogenous GH secretion was similar for boys and girls. Boys had significantly lower mean GH levels compared to healthy controls. Forty per cent of the children met our criteria for a normal 24-hour GH profile (group A; n = 16) and 60% (n = 24) did not. We subdivided these 24 children into two groups: group B (n = 14) (children with either mean GH levels less than controls but with at least one spontaneous GH peak above 20 mU/l and children with normal mean GH levels but with no GH peak above 20 mU/l (subnormal 24-hour GH profile)) and group C (n = 10) (children with mean GH levels less than controls and no GH peak above 20 mU/l (low 24-hour GH profile)). The GH secretory abnormalities were due to a decrease in pulse amplitude, not in pulse frequency. Mean (SD) maximal GH response during ATT was 22.3 (12.1) mU/l. Nineteen children (47.5%) had a maximal GH value < 20 mU/l. Moderate, but significant, correlations were found between several 24-hour GH profile characteristics and the maximal GH response during ATT (r = 0.31-0.35; P < 0.05). Mean (SD) overnight urinary GH excretion was 3.8 (2.1) and 4.4 (3.5) microU/night for boys and girls, respectively. Compared to healthy schoolchildren, overnight urinary GH was lower in boys, but not in girls. Mean (SD) IGF-I and IGF-II SDS levels for chronological age were -0.88 (1.40) and -0.64 (1.48), respectively. Plasma IGF-I and IGF-II levels were significantly reduced compared to controls. Height SDSCA or height velocity SDSCA did not correlate with either spontaneous or stimulated GH secretion, urinary GH excretion or plasma IGF-I or IGF-II levels.

CONCLUSIONS

Our study indicates that 50-60% of children with short stature after intrauterine growth retardation have 24-hour GH profile abnormalities and/or subnormal responses to arginine provocation, while mean plasma IGF-I and IGF-II levels are significantly reduced, indicating GH insufficiency. Urinary GH excretion is lower in boys, but not in girls. The precise mechanism of the failure to catch up growth needs further elucidation. It seems justified to start clinical trials in order to investigate whether treatment with exogenous GH might be beneficial for these children.