Preschool Mathematics and Literacy Skills and Educational Attainment in Adolescents Born Preterm and Full Term.

OBJECTIVES: To test whether preschool academic skills were associated with educational attainment in adolescence and whether associations differed between individuals born preterm and at full term. STUDY DESIGN: This prospective cohort study comprised 6924 individuals, including n = 444 (6.4%) adolescents born preterm (<37 weeks of gestation) from the Avon Longitudinal Study of Parents and Children. Preschool academic (mathematics and literacy) skills were rated by teachers at 4-5 years. Educational attainment at 16 years was informed by attaining a General Certificate of Secondary Education (GCSE) in key subjects mathematics and English. Logistic regressions assessed the association between preterm birth, preschool mathematics, and GCSE Mathematics and between preterm birth, preschool literacy, and GCSE English. RESULTS: Similar numbers of adolescents born preterm and at term achieved a GCSE in mathematics and English (53.6 % vs 57.4% and 59.5% vs 63.9%, respectively; P values > .05). Higher preschool academic skill scores in mathematics were associated with greater odds of attaining GCSE Mathematics and preschool literacy skills were associated with GCSE English. Adolescents born preterm with higher preschool mathematics (OR: 1.51, CI: 1.14, 2.00) and literacy skills (OR: 1.57, CI: 1.10, 2.25) were more likely to attain GCSEs in the respective subject than their term-born counterparts with equal levels of preschool skills. CONCLUSIONS: Preschool academic skills in mathematics and literacy are associated with educational attainment of preterm and term-born individuals in adolescence. Children born prematurely may benefit more from preschool mathematics and literacy skills for academic and educational success into adolescence than term-born individuals.

Risk-Taking Behavior of Adolescents and Young Adults Born Preterm.

OBJECTIVES: To study sexually transmitted Chlamydia trachomatis infections (STCTs), teenage pregnancies, and payment defaults in individuals born preterm as proxies for engaging in risk-taking behavior. STUDY DESIGN: Our population-based register-linkage study included all 191 705 children alive at 10 years (8492 preterm [4.4%]) born without malformations in Finland between January 1987 and September 1990 as each mother's first child within the cohort. They were followed until young adulthood. We used Cox regression to assess the hazards of STCTs, teenage pregnancies, payment defaults, criminal offending, and substance abuse by gestational age. Gestational age was considered both as a continuous and categorical (extremely, very, moderately, late preterm, early term, post term, and full term as reference) exposure. RESULTS: A linear dose-response relationship existed between gestational age and STCT and teenage pregnancy; adjusted hazard for STCT decreased by 1.6% (95% CI, 0.7%-2.6%), and for teenage pregnancy by 3.3% (95% CI, 1.9%-4.8%) per each week decrease in gestational age. Those born extremely preterm (23-27 completed weeks) had a 51% (95% CI, 31%-83%) lower risk for criminal offending than their full-term born counterparts, and those born very preterm (range, 28-31 weeks) had a 28% (95% CI, 7%-53%) higher hazard for payment defaults than those born at full term. Gestational age was not associated with substance abuse. CONCLUSIONS: The lower risk-taking that characterizes people born preterm seems to generalize to sexual and to some extent criminal behavior. Those born very preterm are, however, more likely to experience payment defaults.

Brain Volumes and Abnormalities in Adults Born Preterm at Very Low Birth Weight.

OBJECTIVES: To assess radiographic brain abnormalities and investigate volumetric differences in adults born preterm at very low birth weight (<1500 g), using siblings as controls. STUDY DESIGN: We recruited 79 adult same-sex sibling pairs with one born preterm at very low birth weight and the sibling at term. We acquired 3-T brain magnetic resonance imaging from 78 preterm participants and 72 siblings. A neuroradiologist, masked to participants' prematurity status, reviewed the images for parenchymal and structural abnormalities, and FreeSurfer software 6.0 was used to conduct volumetric analyses. Data were analyzed by linear mixed models. RESULTS: We found more structural abnormalities in very low birth weight participants than in siblings (37% vs 13%). The most common finding was periventricular leukomalacia, present in 15% of very low birth weight participants and in 3% of siblings. The very low birth weight group had smaller absolute brain volumes (-0.4 SD) and, after adjusting for estimated intracranial volume, less gray matter (-0.2 SD), larger ventricles (1.5 SD), smaller thalami (-0.6 SD), caudate nuclei (-0.4 SD), right hippocampus (-0.4 SD), and left pallidum (-0.3 SD). We saw no volume differences in total white matter (-0.04 SD; 95% CI, -0.13 to 0.09). CONCLUSIONS: Preterm very low birth weight adults had a higher prevalence of brain abnormalities than their term-born siblings. They also had smaller absolute brain volumes, less gray but not white matter, and smaller volumes in several gray matter structures.

Development of Late Circadian Preference: Sleep Timing From Childhood to Late Adolescence.

OBJECTIVES: To assess differences relating to circadian preference in objectively measured sleep patterns from childhood to adolescence over a 9-year period. We hypothesized there is developmental continuity in sleep timing and duration according to circadian preference. STUDY DESIGN: Young participants (N = 111, 65% girls) from a community-based birth cohort underwent sleep actigraphy at mean ages 8.1 (SD = 0.3), 12.3 (SD = 0.5), and 16.9 (SD = 0.1) years. A short version of Morningness-Eveningness Questionnaire was administered in late adolescence. At each follow-up, sleep midpoint, duration, wake after sleep onset, sleep efficiency, and weekend catch-up sleep were compared between those reporting morning, intermediate, and evening preferences in late adolescence. RESULTS: Mixed model analyses indicated that sleep timing was significantly earlier among morning types compared with evening types at all ages (P values < .04). The mean differences in sleep midpoint between morning and evening types increased from a mean of 19 minutes (age 8), 36 minutes (age 12), to 89 minutes (age 17). The largest change occurred from age 12 to 17 years. Sleep duration, wake after sleep onset, sleep efficiency, and catch-up sleep did not differ according to circadian preference. CONCLUSIONS: This study found significant continuity in sleep timing from childhood to adolescence over 9 years, indicating that late circadian preference reported in late adolescence begins to manifest in middle childhood. Further studies are needed to establish whether sleep timing has its origins at an even earlier age.

Sleep and Lipid Profile During Transition from Childhood to Adolescence.

OBJECTIVES: To assess the longitudinal effects of sleep duration and quality on lipid profiles during the transition from childhood to early adolescence, over a 4-year-period. STUDY DESIGN: A cohort study of children born in 1998 examined at 8 years of age (SD, 0.3; n = 105) and 12 years of age (SD, 0.5; n = 190). Sleep duration, wake after sleep onset, sleep efficiency, and weekend catch-up sleep were measured with actigraphs for 7 (8 years of age) and 8 (12 years of age) nights. Fasting serum samples were collected at 12 years of age. Covariates included age, pubertal development, socioeconomic status, body mass index, and physical activity. RESULTS: In girls, shorter sleep duration at 8 and 12 years of age was associated with lower high-density lipoprotein-cholesterol and higher triglycerides at 12 years of age. Poorer sleep quality at 8 years of age and longer weekend catch-up sleep at 12 years of age was associated with higher triglycerides at 12 years of age. From 8 to 12 years of age, improvement in sleep quality associated with higher total cholesterol, and a decrease in sleep duration with lower lipid levels. In boys, longer sleep duration at 8 years of age, and a larger decrease in sleep duration from 8 to 12 years of age was associated with higher levels of triglycerides at 12 years of age. CONCLUSIONS: Poorer sleep during transition to early adolescence is associated with an atherogenic lipid profile in early adolescent girls, and such effects are less prominent in boys. Poor sleep may have long-term associations with health, which are not mitigated by the amount of physical activity.

Objectively measured physical activity in young adults born preterm at very low birth weight.

Unimpaired adults born preterm at very low birth weight (<1500 g) consistently have lower conditioning physical activity than those born at term. We used wrist-worn accelerometers to measure objectively physical activity in 57 very low birth weight and 47 control subjects aged 25 years. We found no difference in any physical activity measures.

Infant growth after preterm birth and neurocognitive abilities in young adulthood.

OBJECTIVES: To examine whether faster growth from birth to term (40 postmenstrual weeks) and during the first year thereafter was associated with better neurocognitive abilities in adults born preterm with very low birth weight (VLBW; <1500 g). STUDY DESIGN: Weight, length, and head circumference data of 103 VLBW participants of the Helsinki Study of Very Low Birth Weight Adults were collected from records. Measures at term and at 12 months of corrected age were interpolated. The participants underwent tests of general neurocognitive ability, executive functioning, attention, and visual memory at mean age of 25.0 years. RESULTS: Faster growth from birth to term was associated with better general neurocognitive abilities, executive functioning, and visual memory in young adulthood. Effect sizes in SD units ranged from 0.23-0.43 per each SD faster growth in weight, length, or head circumference (95% CI 0.003-0.64; P values <.05). After controlling for neonatal complications, faster growth in head circumference remained more clearly associated with neurocognitive abilities than weight or length did. Growth during the first year after term was not consistently associated with neurocognitive abilities. CONCLUSIONS: Within a VLBW group with high variability in early growth, faster growth from birth to term is associated with better neurocognitive abilities in young adulthood. Neurocognitive outcomes were predicted, in particular, by early postnatal head growth.

Physical activity and psychiatric problems in children.

We studied whether physical activity, measured by wrist-worn accelerometers, is associated with mother- and teacher-rated psychiatric problems in 8-year-old children (n = 199). Higher overall physical activity and more time spent in more intense physical activity were associated with lower odds for psychiatric problems in emotional, social, and behavioral domains.

Parental bonding after preterm birth: child and parent perspectives in the Helsinki study of very low birth weight adults.

OBJECTIVE: To examine whether parenting behavior recalled by very low birth weight (VLBW) adults or their parents differs from that of term-born control subjects or their parents. STUDY DESIGN: A total of 164 VLBW and 172 control adults (mean age 22.5 years, SD 2.2) assessed retrospectively the parenting behavior of their parents by the Parental Bonding Instrument, which includes dimensions of care, protectiveness, and authoritarianism. A subgroup of 190 mothers and 154 fathers assessed their own parenting behavior by the Parent Behavior Inventory, which includes dimensions of supportive and hostile parenting. RESULTS: The VLBW women assessed their mothers as more protective and authoritarian than the control women. The VLBW and control men did not differ from each other. Both mothers and fathers of the VLBW adults assessed their own parenting as more supportive than those of the control subjects. CONCLUSIONS: Preterm birth at VLBW may promote a more protective, as well as more supportive, parenting style.

Adults born at very low birth weight exercise less than their peers born at term.

OBJECTIVE: To study the effects of very low birth weight (VLBW, <1500 g) birth on physical activity, an important protective and modifiable factor. STUDY DESIGN: VLBW participants (n=163) with no major disability and 188 individuals born at term (mean age, 22.3 years; range, 18.5-27.1) completed a standardized questionnaire of physical activity. RESULTS: VLBW participants reported less leisure-time conditioning physical activity. They were 1.61-fold more likely to "not exercise much," 1.61-fold more likely to exercise infrequently (once a week or less), 2.75-fold more likely to exercise with low intensity (walking), and 3.11-fold more likely to have short exercise sessions (<30 minutes). The differences were present even in subjects with no history of bronchopulmonary dysplasia or asthma and were only slightly attenuated when adjusted for height, parental education, lean body mass, and percent body fat. CONCLUSIONS: Unimpaired adults who were VLBW exercise less during their leisure time than adults born at term. Promoting physical activity may be particularly important in the VLBW population to counteract the risks of chronic disease in adult life.

Reduced body size and shape-related symptoms in young adults born preterm with very low birth weight: Helsinki study of very low birth weight adults.

OBJECTIVE: To test the hypothesis that being born prematurely with very low birth weight (VLBW) (birth weight

Ambulatory blood pressure in young adults with very low birth weight.

OBJECTIVE: We hypothesized that, as compared with a matched control group born at term, young adults with very low birth weight (VLBW <1.5 kg) would have higher 24-hour ambulatory blood pressure. STUDY DESIGN: We studied 118 18- to 27-year-old subjects born with VLBW within the greater Helsinki area and 120 term-born control subjects with similar age, sex, and birth hospital. The mean birth weight for VLBW subjects was 1.1 kg (standard deviation [SD], 0.2) and for controls, 3.6 kg (SD, 0.5). Gestational ages were 29.2 (SD, 2.3) and 40.1 (SD, 1.0) weeks. Current education of higher-educated parents served as an indicator of childhood socioeconomic status. Ambulatory blood pressure was measured during a 24-hour period with an oscillometric device (Spacelabs 90207). RESULTS: VLBW subjects had, with sex, age, and body mass index adjustment, a 2.4 mm Hg (95% confidence interval, 0.2 to 4.6) higher 24-hour systolic pressure. We found hypertension in 11 VLBW subjects and in 3 term-born subjects, giving an adjusted odds ratio of 4.0 (1.1 to 14.8). When socioeconomic status was taken into account, results remained unchanged. CONCLUSIONS: Higher rates of hypertension and higher 24-hour blood pressure among young adults with VLBW may indicate higher risk for adverse cardiovascular outcomes.