Elysée T.M. Hille

Behavioural problems in children who weigh 1000 g or less at birth in four countries.

BACKGROUNDnThe increased survival chances of extremely low-birthweight (ELBW) infants (weighing <1000 g at birth) has led to concern about their behavioural outcome in childhood. In reports from several countries with different assessments at various ages, investigators have noted a higher frequency of behavioural problems in such infants, but cross-cultural comparisons are lacking. Our aim was to compare behavioural problems in ELBW children of similar ages from four countries.nnnMETHODSnWe prospectively studied 408 ELBW children aged 8-10 years, whose parents completed the child behaviour checklist. The children came from the Netherlands, Germany, Canada, and USA. The checklist provides a total problem score consisting of eight narrow-band scales. Of these, two (aggressive and delinquent behaviour) give a broad-band externalising score, three (anxious, somatic, and withdrawn behaviour) give a broad-band internalising score, and three (social, thought, and attention problems) indicate difficulties fitting neither broad-band dimension. For each cohort we analysed scores in ELBW children and those in normal- birthweight controls (two cohorts) or national normative controls (two cohorts). Across countries, we assessed deviations of the ELBW children from normative or control groups.nnnFINDINGSnELBW children had higher total problem scores than normative or control children, but this increase was only significant in European countries. Narrow-band scores were raised only for the social, thought, and attention difficulty scales, which were 0.5-1.2 SD higher in ELBW children than in others. Except for the increase in internalising scores recorded for one cohort, ELBW children did not differ from normative or control children on internalising or externalising scales.nnnINTERPRETATIONnDespite cultural differences, types of behavioural problems seen in ELBW children were very similar in the four countries. This finding suggests that biological mechanisms contribute to behavioural problems of ELBW children.

School performance at nine years of age in very premature and very low birth weight infants: Perinatal risk factors and predictors at five years of age

To assess the impact of both perinatal disorders and developmental problems identified at preschool age on school performance, we followed a virtually complete birth cohort of very premature (< 32 completed weeks of gestation) and very low birth weight infants until they were 9 years of age. In 84% of the survivors (n = 813), data on school performance were available for analysis. At the age of 9 years, 19% of the children were in special education. Of the children in mainstream education, 32% were in a grade below the appropriate level for age and 38% had special assistance. After correction for other perinatal items, children of low socioeconomic status and boys had significantly higher adjusted odds ratios for special education. Logistic regression with a perinatal and a 5-year time category showed that the most predictive factors for special education were developmental delay, neuromotor and speech/language function, inattention and hyperactivity score, total problem score, and reported school results at the age of 5 years. When children with disabilities were left out of the analysis, the importance of neuromotor function and total problem score disappeared. Increased risks of any school failure in nondisabled children included mild or severe developmental delay and marginal or poor school performance at the age of 5 years. Long-term follow-up with specific attention to these predictors at 5 years of age, although time-consuming, is necessary.

Microalbuminuria and Lower Glomerular Filtration Rate at Young Adult Age in Subjects Born Very Premature and after Intrauterine Growth Retardation

This prospective follow-up study of 422 19-yr-old subjects born very preterm in The Netherlands was performed to determine whether intrauterine growth retardation (IUGR) predisposes to abnormal GFR and microalbuminuria in adolescents. GFR (ml/min per 1.73 m2) was estimated using the Cockcroft-Gault equation, and albumin-creatinine ratio (mg/mmol) was calculated in a cohort of 19-yr-old subjects born very preterm (gestational age <32 wk) in 1983. Birth weights were adjusted for gestational age and expressed as standard deviation scores (sds) as a measure of IUGR. All subjects had normal renal function. Birth weight (sds) was associated negatively with serum creatinine concentration (micromol/L) (beta = -1.0 micromol/L, 95% confidence interval [CI]: -1.9 to -0.2), positively with GFR (beta = 3.0, 95% CI: 1.7 to 4.2), and negatively with the logarithm of albumin-creatinine ratio (beta = -0.05, 95% CI: -0.09 to -0.01) in young adults born very preterm. IUGR is associated with unfavorable renal functions at young adult age in subjects born very premature. These data suggest that intrauterine growth-retarded subjects born very premature have an increased risk to develop progressive renal failure in later life.

Functional outcomes and participation in young adulthood for very preterm and very low birth weight infants: the Dutch Project on Preterm and Small for Gestational Age Infants at 19 years of age.

OBJECTIVE. Young adults who were born very preterm or with a very low birth weight remain at risk for physical and neurodevelopmental problems and lower academic achievement scores. Data, however, are scarce, hospital based, mostly done in small populations, and need additional confirmation. METHODS. Infants who were born at <32 weeks of gestation and/or with a birth weight of <1500 g in the Netherlands in 1983 (Project on Preterm and Small for Gestational Age Infants) were reexamined at age 19. Outcomes were adjusted for nonrespondents using multiple imputation and categorized into none, mild, moderate, or severe problems. RESULTS. Of 959 surviving young adults, 74% were assessed and/or completed the questionnaires. Moderate or severe problems were present in 4.3% for cognition, 1.8% for hearing, 1.9% for vision, and 8.1% for neuromotor functioning. Using the Health Utility Index and the London Handicap Scale, we found 2.0% and 4.5%, respectively, of the young adults to have ≥3 affected areas in activities and participation. Special education or lesser level was completed by 24%, and 7.6% neither had a paid job nor followed any education. Overall, 31.7% had ≥1 moderate or severe problems in the assessed areas. CONCLUSIONS. A total of 12.6% of young adults who were born very preterm and/or with a very low birth weight had moderate or severe problems in cognitive or neurosensory functioning. Compared with the general Dutch population, twice as many young adults who were born very preterm and/or with a very low birth weight were poorly educated, and 3 times as many were neither employed nor in school at age 19.

Is Blood Pressure Increased 19 Years After Intrauterine Growth Restriction and Preterm Birth? A Prospective Follow-up Study in the Netherlands

Objective. To determine whether intrauterine growth restriction (IUGR) is a predisposing factor for high blood pressure (BP) in 19-year-olds who were born (very) preterm. Methods. A prospective follow-up study was conducted at age 19 in individuals who born preterm in the Netherlands in 1983. Systolic, diastolic, and mean BP values and plasma renin activity concentration were obtained in 422 young adults who were born with a gestational age (GA) <32 weeks. BP values were also measured in 174 individuals who born with a GA of ≥32 weeks and a birth weight of <1500 g. Results. An increased prevalence of hypertension and probably also of prehypertensive stage was found. IUGR, birth weight, GA, and plasma renin activity were not associated with BP. Current weight and BMI were the best predicting factors for systolic BP at the age of 19 years. Conclusions. The prevalence of hypertension is high in individuals who were born preterm when compared with the general population. In the individuals who were born very preterm, no support to the hypothesis that low birth weight is associated with increased BP at young adult age can be given.

Association Between Age at Diagnosis and Disease-Specific Mortality Among Postmenopausal Women With Hormone Receptor–Positive Breast Cancer

CONTEXTnIn addition to classic tumor-related prognostic factors, patient characteristics may be associated with breast cancer outcome.nnnOBJECTIVEnTo assess the association between age at diagnosis and breast cancer outcome in postmenopausal women with hormone receptor-positive breast cancer.nnnDESIGN, SETTING, AND PATIENTSnStudy analysis of 9766 patients enrolled in the TEAM (Tamoxifen Exemestane Adjuvant Multinational) randomized clinical trial between January 2001 and January 2006. Age at diagnosis was categorized as younger than 65 years (n=5349), 65 to 74 years (n=3060), and 75 years or older (n=1357).nnnMAIN OUTCOME MEASURESnPrimary end point was disease-specific mortality; secondary end points were other-cause mortality and breast cancer relapse.nnnRESULTSnDuring median follow-up of approximately 5.1 years, there were a total of 1043 deaths. Disease-specific mortality, as a proportion of all-cause mortality, decreased with categorical age group (78% [<65 years], 56% [65-74 years], and 36% [≥75 years]; P < .001). In multivariable analyses, compared with patients younger than 65 years, disease-specific mortality increased with age for patients aged 65 to 74 years (hazard ratio [HR], 1.25; 95% CI, 1.01-1.54); and patients aged 75 years or older (HR, 1.63; 95% CI, 1.23-2.16) (P < .001). Similarly, breast cancer relapse increased with age for patients aged 65-74 years (HR, 1.07; 95% CI, 0.91-1.25 and patients aged 75 years or older (HR, 1.29; 95% CI, 1.05-1.60) (P = .06). Other-cause mortality increased with age in patients aged 65 to 74 years (HR, 2.66; 95% CI, 1.96-3.63) and patients aged 75 years or older (HR, 7.30; 95% CI, 5.29-10.07) (P < .001).nnnCONCLUSIONnAmong postmenopausal women with hormone receptor-positive breast cancer, increasing age was associated with a higher disease-specific mortality.

Estrogen Receptor and Progesterone Receptor As Predictive Biomarkers of Response to Endocrine Therapy: A Prospectively Powered Pathology Study in the Tamoxifen and Exemestane Adjuvant Multinational Trial

PURPOSEnThe Tamoxifen and Exemestane Adjuvant Multinational (TEAM) trial included a prospectively planned pathology substudy testing the predictive value of progesterone receptor (PgR) expression for outcome of estrogen receptor-positive (ER-positive) early breast cancer treated with exemestane versus tamoxifen.nnnPATIENTS AND METHODSnPathology blocks from 4,781 TEAM patients randomly assigned to exemestane versus tamoxifen followed by exemestane for 5 years of total therapy were collected centrally, and tissue microarrays were constructed from samples from 4,598 patients. Quantitative analysis of hormone receptors (ER and PgR) was performed by using image analysis and immunohistochemistry, and the results were linked to outcome data from the main TEAM trial and analyzed relative to disease-free survival and treatment.nnnRESULTSnOf 4,325 eligible ER-positive patients, 23% were PgR-poor (Allred < 4) and 77% were PgR- rich (Allred ≥ 5). No treatment-by-marker effect for PgR was observed for exemestane versus tamoxifen (PgR-rich hazard ratio [HR], 0.83; 95% CI, 0.65 to 1.05; PgR-poor HR, 0.85; 95% CI, 0.61 to 1.19; P = .88 for interaction). Both PgR and ER expression were associated with patient prognosis in univariate (PgR HR, 0.53; 95% CI, 0.43 to 0.65; P < .001; ER HR, 0.66; 95% CI, 0.51 to 0.86; P = .002), and multivariate analyses (P < .001 and P = .001, respectively). A trend toward a treatment-by-marker effect for ER-rich patients was observed.nnnCONCLUSIONnPreferential exemestane versus tamoxifen treatment benefit was not predicted by PgR expression; conversely, patients with ER-rich tumors may derive additional benefit from exemestane. Quantitative analysis of ER and PgR expression provides highly significant information on risk of early relapse (within 1 to 3 years) during treatment.

Preterm birth and later insulin resistance: effects of birth weight and postnatal growth in a population based longitudinal study from birth into adult life

Aims/hypothesisAn increased risk of type 2 diabetes mellitus is associated with low birthweight after full-term gestation, including amplification of this risk by weight gain during infancy and adult body composition. Premature birth is also associated with insulin resistance, but studies conducted so far have not provided follow-up into adulthood. We studied the effects of (1) lower birthweight (as standard deviation score [SDS]) and infancy weight gain on insulin resistance in 19-year-olds born before 32xa0weeks of gestation, and (2) the interaction between lower birthweight SDS and infancy weight gain, as well as between lower birthweight and adult body composition, on insulin resistance.MethodsThis was a prospective follow-up study in 346 subjects from the Project on Preterm and Small-for-gestational-age infants cohort, in whom fasting glucose, insulin and C-peptide levels were measured at 19xa0years. Insulin resistance was calculated with homeostatic modelling (homeostatic model assessment for insulin resistance index [HOMA-IR]).ResultsBirthweight SDS was unrelated to the outcomes. Rapid infancy weight gain until 3xa0months post-term was weakly associated with higher insulin level (p=0.05). Adult fatness was positively associated with insulin and C-peptide levels and HOMA-IR (all p<0.001). On these parameters, there was a statistical interaction between birthweight SDS and adult fat mass (p=0.002 to 0.03).Conclusions/interpretationIn subjects born very preterm, rapid infancy weight gain until 3xa0months predicted higher insulin levels at 19xa0years, but the association was weak. Adult obesity strongly predicted higher insulin and C-peptide levels as well as HOMA-IR. The effect of adult fat mass on these parameters was dependent on its interaction with birthweight SDS.

Nonresponse bias in a follow-up study of 19-year-old adolescents born as preterm infants

Objective. To assess the effect of demographic and neonatal risk factors and outcome at the last available assessment on the probability of full responders, postal responders (those who only responded to the mailed questionnaire), or nonresponders in a follow-up study of 19-year-old adolescents who were born as preterm infants. Design. The 19-year follow-up program was part of a large ongoing collaborative study in the Netherlands on the long-term effect of prematurity and dysmaturity on various medical, psychological, and social parameters. In the original cohort, 1338 infants (94%) with a gestational age of <32 weeks and/or a birth weight of <1500 g were enrolled. Neonatal mortality was 23% (n = 312), and another 67 children had died between the ages of 28 days and 19 years, leaving 959 survivors (72% of the original cohort) for follow-up at the present assessment. To study the effect of nonresponse, we divided the 959 survivors into 3 groups: full responders (596 [62.1%]), postal responders (109 [11.4%]), and nonresponders (254 [26.5%]). In the 3 groups we compared demographic and neonatal data, as well as outcome at the last available assessment. Results. The odds ratios (ORs) for male versus female for the probabilities of nonresponse and postal response were statistically significant: 2.7 (95% CI: 1.9–3.9) and 1.6 (95% CI: 1.0–2.5), respectively. The same holds for the ORs for non-Dutch versus Dutch and low versus high maternal education for nonresponse: 2.0 (95% CI: 1.3–3.2) and 3.7 (95% CI: 2.0–6.7), respectively. Special education and severe handicap showed a statistically significant influence on nonresponse (OR: 1.6; 95% CI: 1.1–2.4 and OR: 2.6; 95% CI: 1.3–5.2) and postal response (OR: 2.0; 95% CI: 1.2–3.3 and OR: 4.4; 95% CI: 2.0–9.9), respectively. At the age of 19 years, primary school and special education were found significantly more frequent in the postal responders than in the full-response group (20% and 21% vs 6% and 12%). The full responders, on the other hand, were higher educated than were the postal responders. Conclusions. In this follow-up study at the age of 19 years, boys, non-Dutch adolescents, and low maternal education were overrepresented in the nonresponse and postal-response groups. Nonresponse decreased the proportion of infants with adverse outcome in assessed children. To be able to present reliable results for the total group of survivors in long-term follow-up studies, the nonresponse bias needs to be quantified. Therefore, it is evident that more research using statistical methods such as imputation of missing data is needed.

Catch-up growth up to ten years of age in children born very preterm or with very low birth weight.

BackgroundImproved survival due to advances in neonatal care has brought issues such as postnatal growth and development more to the focus of our attention. Most studies report stunting in children born very preterm and/or small for gestational age. In this article we study the growth pattern of these children and aim to identify factors associated with postnatal catch-up growth.Methods1338 children born with a gestational age <32 weeks and/or a birth weight of <1500 grams were followed during a Dutch nationwide prospective study (POPS). Subgroups were classified as appropriate for gestational age and <32 weeks (AGA) or small for gestational age (<32 wks SGA and ≥32 wks SGA). Data were collected at different intervals from birth until 10 years for the 962 survivors and compared to reference values. The correlation between several factors and growth was analysed.ResultsAt 10 years the AGA children had attained normal height, whereas the SGA group demonstrated stunting, even after correction for target height (AGA: 0.0 SDS; SGA <32 wks: -0.29SDS and ≥32 wks: -0.13SDS). Catch-up growth was especially seen in the SGA children with a fast initial weight gain. BMI was approximately 1 SD below the population reference mean.ConclusionAt 10 years of age, children born very preterm AGA show no stunting. However, many children born SGA, especially the very preterm, show persistent stunting. Early weight gain seems an important prognostic factor in predicting childhood growth.