Per-Olof Gäddlin

Asthma, lung function and allergy in 12-year-old children with very low birth weight: a prospective study.

We assessed the relationship between very low birth weight (VLBW) (≤1500 g) and the development of asthma, lung function and atopy. The study groups comprised 74 of all 86 (86%) VLBW and 64 of all 86 (74%) matched term children who were prospectively followed for 12 years. A questionnaire on asthmatic and allergic symptoms was completed and skin prick tests, spirometry and hypertonic saline provocation tests were performed at 12 years of age. Cytokine secretion was analysed in stimulated blood leukocyte cultures in 28 VLBW and 23 term children. A history of asthma was more frequent among the VLBW children, as compared with the term children at age 12 (22% vs. 9%, p = 0.046). Among the VLBW children, very preterm birth (gestational age: week 25 to 29) (RR 2.5, 95%CI 1.1–5.8), neonatal mechanical ventilation (RR 2.8, 95%CI 1.2–6.4) and neonatal oxygen supplementation (RR 4.3, 95%CI 1.3–14.0) were significantly associated with a history of asthma by the age of 12 years in univariate analyses. In multivariate logistic regression, neonatal oxygen supplementation ≥ 9 days was the only remaining significant risk factor for a history of asthma (adjusted OR 6.7, 95%CI 1.0–44). The VLBW children who required mechanical ventilation during the neonatal period were more likely to have bronchial hyperresponsiveness than those not requiring mechanical ventilation (60% vs. 28%, p = 0.050). The spirometric values were similar among the VLBW and the term children at 12 years. Very low birth weight was not significantly related to allergic rhinoconjunctivitis, eczema or positive skin prick tests. Furthermore, the levels of IL‐4, IL‐5 and IFN‐γ in stimulated cell cultures were similar in the VLBW and the term children. A history of asthma by 12 years of age was twice as common among the VLBW as the term children, and neonatal oxygen supplementation seemed to be associated with the increased risk. Furthermore, mechanical ventilation during the neonatal period was associated with bronchial hyperresponsiveness at age 12. Very low birth weight per se was not, however, related to atopy.

Morbidity and neurological function of very low birthweight infants from the newborn period to 4y of age. A prospective study from the south-east region of Sweden

All 107 infants weighing ≤ 1500 g at birth (VLBW) and born alive in the south‐east region of Sweden during a 15‐month period in 1987–88 were enrolled in a prospective study to determine the prevalence of handicap and to assess neurological function in comparison with controls. Eighty‐six (80%) infants survived. Twenty (19%) had intracranial haemorrhages (ICH) assessed by ultrasound examinations in the neonatal period and 2 (2.3%) retinopathy of prematurity stage 3 or more. The VLBW infants who survived had fewer optimal neurological responses than the controls at 40 weeks post‐conceptional age. Eighty‐two VLBW children were followed to 4y of age. Three (4%) children had a neurological handicap and 9 (11%) had a moderate neurological deviation. Neither the size of ICH nor neonatal optimality score correlated to neurological outcome at 4 y of age. The VLBW children without neurological handicap or deviation (n= 70) had a delay in psychomotor development in comparison with the controls. Mental development and school performance, in particular language development, will be examined at school age.

Very-low-birth-weight children at school age: academic achievement, behavior and self-esteem and relation to risk factors

Objective: To investigate school performance, behavior and self-esteem of children with very low birth weight (VLBW). Methods: All children with birth weight below 1501 g (VLBW) and normal birth weight controls, born in the south-east region of Sweden during a 15-month period in 1987-88, were enrolled in a prospective follow-up study. At the age of 9 years, 81% and 82%, respectively, were re-examined regarding growth, neurofunctional classification, academic achievement tests, need for special education and behavioral problems. At 12 years, 89% and 76%, respectively, were re-examined regarding growth, neurofunctional classification, visual acuity and self-esteem. Results: VLBW children were shorter and lighter, and differed from the controls with regard to neurological functional classification. They produced poorer results in most academic achievement tests. When the comparison was restricted to children with normal intelligence, almost all the differences in other academic achievements disappeared. VLBW children had more reading difficulties but were less often than expected defined as dyslexics compared to control children. We did not find any major disparity in visual acuity and self-esteem between the groups. Low Apgar scores, intracranial hemorrhage and the need for mechanical ventilation neonatally were associated with poorer results in most outcome measures. Neurofunctional assessments in early childhood were associated with most outcome measures. The mothers education was related to delayed reading skills and need for special education. Conclusions: Although VLBW children performed less well in most academic achievement tests and on some behavioral subscales, those who had a normal intellectual capacity did not differ in any important aspects from the controls.

Early rapid weight gain and current overweight in relation to asthma in adolescents born with very low birth weight.

Early catch‐up growth and subsequent overweight are suggested to be associated with later cardiovascular diseases and later type II diabetes. However, the impact of early catch‐up growth and childhood overweight on the development of asthma has been less studied, particularly in children born with very low birth weight (VLBW). A birth cohort of 74 VLBW children (birth weight ≤ 1500 g) was followed from birth and investigated on asthma at 12 yr of age. Early rapid weight gain was in one way defined as an increase of weight ≥1 standard deviation score (SDS) at 6 months of corrected postnatal age. Current overweight was defined by body mass index (BMI) exceeding 21.2 and 21.7 kg/m2, respectively, for boys and girls at 12 yr of age. Current asthma was diagnosed by a pediatrician, according to asthma ever in combination with a positive response to hypertonic saline bronchial provocation test and/or wheeze at physical examination at 12 yr old. Being overweight at 12 yr of age was associated with an increased risk for current asthma in the VLBW children [crude odds ratio (OR): 5.5, 95% confidence interval (CI): 1.3–22.2]. After adjustment for early weight gain and neonatal risk, the OR of overweight increased nearly three times (adjusted OR: 15.3, 95% CI: 2.5–90.6). Early rapid weight gain seemed to be inversely associated with current asthma (adjusted OR: 0.49 for an increase of weight equal to 1 SDS, 95% CI: 0.23–1.02, p = 0.06). In addition, early rapid weight gain was inversely associated with the magnitude of bronchial responsiveness at 12 yr (coefficient −1.15, p < 0.01). There was a strong and positive association between overweight and asthma at 12 yr of age in the VLBW children. This strong association had been reduced by early rapid weight gain, possibly via the reduction of bronchial responsiveness.

Hospital readmissions and morbidity in a fifteen-year follow-up of very low birthweight children in Southeast Sweden

Aim: To study the effect of very low birthweight on hospital care and morbidity, and their relationship to gender, birthweight and neonatal complications.

Academic achievement, behavioural outcomes and MRI findings at 15 years of age in very low birthweight children

Aim: To assess cognitive, academic and behavioural functions in 15‐year‐old very low birthweight (VLBW) children and relate results to gender, neonatal risk factors, growth and magnetic resonance imaging (MRI) findings.

The prevalence of reading disabilities among very‐low‐birth‐weight children at 9 years of age—dyslexics or poor readers?

In this study, 70 very-low-birth-weight (VLBW) children (<1500 g) were compared with 72 normal-birth-weight (NBW) children on different academic achievement tests and behavioural skills. The purpose was to address both the prevalence and type of reading difficulties displayed in a sample of VLBW children, and thus the validity of the IQ–achievement discrepancy definition for developmental dyslexia. The results showed that VLBW children performed statistically more poorly on most academic achievement tests. The data also indicated that VLBW children were less likely to be defined as dyslexic compared with NBW children, despite the fact that the number of poor readers was larger in the VLBW group. Finally, there were no differences between poor readers with low intelligence and poor readers with normal intelligence on eight out of nine different tests measuring cognitive processes underlying reading skills. Instead, differences between subgroups of poor readers were found for behavioural variables, indicating that differences between poor readers and dyslexics are mainly restricted to areas outside the reading domain. Thus the results confirm that the distribution of reading skills of poor readers of both high and low intelligence is very similar and that the use of IQ–achievement discrepancy definitions does not constitute a valid approach to define subgroups of poor readers. Copyright

Follow-up studies of very low birthweight children in Sweden

Follow‐up studies are essential to our knowledge of outcome in very low birthweight (VLBW) or extremely preterm (EPT) infants because those children have a greater risk for developing neurosensory disabilities and behavioural and educational problems and have decreased probability for an optimal transition into adulthood compared to term controls. Outcome data are of interest not only to healthcare professionals but also to parents, schoolteachers and society. The aim of this review is to describe the follow‐up studies of seven populations of VLBW or EPT infants performed in Sweden and published between 1995 and 2009.

A long-term follow-up study of men born with very low birth weight and their reproductive hormone profile

ABSTRACT Environmental factors during the fetal period may adversely affect reproductive functions in men being born with very low birth weight (VLBW, <1500 g). The objective of this prospective, controlled cohort study was to investigate if VLBW men have an altered reproductive hormone profile compared with men born at term. The study group initially consisted of all VLBW boys live-born between 1 February 1987 and 30 April 1988 in the south-east region of Sweden (n = 47). A control child was chosen born at term, at the same hospital, with the same parity, without malformations, and next in order after each VLBW child who survived the first four weeks (n = 45). The present follow-up was performed when the men were 26–28 years of age and included measurements of serum hormone levels, hair testosterone concentration, and anthropometric data. Also life-style questionnaires were collected from 26 VLBW men and 19 controls. The VLBW group (n = 26) had higher median levels of serum estradiol, 84.5 pmol/L than controls (n = 19), 57.5 pmol/L (p = 0.008). There was no significant correlation between serum estradiol and BMI (r = 0.06, p = 0.74). There were no differences in other hormone levels or the reproductive pattern between the groups. In conclusion, even though there was a statistically significant difference in estradiol levels between the groups, both groups had low normal mean levels of questionable clinical significance. The reproductive pattern was similar in the two groups and in this study being born VLBW does not seem to affect these measured aspects of reproduction. Abbreviations: ADHD: attention deficit hyperactive disorder; AGA: average for gestational age; BMI: body mass index; CP: cerebral palsy; DHT: dihydrotestosterone; FSH: follicle stimulating hormone; LBW: low birth weight; LH: luteinizing hormone; SAD: sagittal abdominal diameter; SGA: small for gestational age; SHBG: sex hormone binding globulin; TSH: thyroid stimulating hormone; T3: triiodothyronine; T4: thyroxin; VLBW: very low birth weight