ContextThe cognitive and behavioral outcomes of school-aged children who were
born preterm have been reported extensively. Many of these studies have methodological
flaws that preclude an accurate estimate of the long-term outcomes of prematurity.ObjectiveTo estimate the effect of preterm birth on cognition and behavior in
school-aged children.Data SourcesMEDLINE search (1980 to November 2001) for English-language articles,
supplemented by a manual search of personal files maintained by 2 of the authors.Study SelectionWe included case-control studies reporting cognitive and/or behavioral
data of children who were born preterm and who were evaluated after their
fifth birthday if the attrition rate was less than 30%. From the 227 reviewed
studies, cognitive data from 15 studies and behavioral data from 16 studies
were selected.Data ExtractionData on population demographics, study characteristics, and cognitive
and behavioral outcomes were extracted from each study, entered in a customized
database, and reviewed twice to minimize error. Differences between the mean
cognitive scores of cases and controls were pooled. Homogeneity across studies
was formally tested using a general variance-based method and graphically
using Galbraith plots. Linear meta-analysis regression models were fitted
to explore the impact of birth weight and gestational age on cognitive outcomes.
Study-specific relative risks (RRs) were calculated for the incidence of attention-deficit/hyperactivity
disorder (ADHD) and pooled. Quality assessment of the studies was performed
based on a 10-point scale. Publication bias was examined using Begg modified
funnel plots and formally tested using the Egger weighted-linear regression
method.Data SynthesisAmong 1556 cases and 1720 controls, controls had significantly higher
cognitive scores compared with children who were born preterm (weighted mean
difference, 10.9; 95% confidence interval [CI], 9.2-12.5). The mean cognitive
scores of preterm-born cases and term-born controls were directly proportional
to their birth weight (R2 = 0.51; P<.001) and gestational age (R2 = 0.49; P<.001). Age at evaluation had
no significant correlation with mean difference in cognitive scores (R2 = 0.12; P = .20).
Preterm-born children showed increases in externalizing and internalizing
behaviors in 81% of studies and had more than twice the RR for developing
ADHD (pooled RR, 2.64; 95% CI, 1.85-3.78). No differences were noted in cognition
and behaviors based on the quality of the study.ConclusionsChildren who were born preterm are at risk for reduced cognitive test
scores and their immaturity at birth is directly proportional to the mean
cognitive scores at school age. Preterm-born children also show an increased
incidence of ADHD and other behaviors.

https://jamanetwork.com/journals/jama/articlepdf/195181/JMA10039.pdf

Cognitive and behavioral outcomes of school-aged children who were born preterm: a meta-analysis.

Background Very-low-birth-weight infants (those weighing less than 1500 g) born during the initial years of neonatal intensive care have now reached young adulthood. Methods We compared a cohort of 242 survivors among very-low-birth-weight infants born between 1977 and 1979 (mean birth weight, 1179 g; mean gestational age at birth, 29.7 weeks) with 233 controls from the same population in Cleveland who had normal birth weights. We assessed the level of education, cognitive and academic achievement, and rates of chronic illness and risk-taking behavior at 20 years of age. Outcomes were adjusted for sex and sociodemographic status. Results Fewer very-low-birth-weight young adults than normal-birth-weight young adults had graduated from high school (74 percent vs. 83 percent, P=0.04). Very-low-birth-weight men, but not women, were significantly less likely than normal-birth-weight controls to be enrolled in postsecondary study (30 percent vs. 53 percent, P=0.002). Very-low-birth-weight participants had a low...

Outcomes in Young Adulthood for Very-Low-Birth-Weight Infants

BACKGROUND Advances in perinatal care have increased the number of premature babies who survive. There are concerns, however, about the ability of these children to cope with the demands of adulthood. METHODS We linked compulsory national registries in Norway to identify children of different gestational-age categories who were born between 1967 and 1983 and to follow them through 2003 in order to document medical disabilities and outcomes reflecting social performance. RESULTS The study included 903,402 infants who were born alive and without congenital anomalies (1822 born at 23 to 27 weeks of gestation, 2805 at 28 to 30 weeks, 7424 at 31 to 33 weeks, 32,945 at 34 to 36 weeks, and 858,406 at 37 weeks or later). The proportions of infants who survived and were followed to adult life were 17.8%, 57.3%, 85.7%, 94.6%, and 96.5%, respectively. Among the survivors, the prevalence of having cerebral palsy was 0.1% for those born at term versus 9.1% for those born at 23 to 27 weeks of gestation (relative risk for birth at 23 to 27 weeks of gestation, 78.9; 95% confidence interval [CI], 56.5 to 110.0); the prevalence of having mental retardation, 0.4% versus 4.4% (relative risk, 10.3; 95% CI, 6.2 to 17.2); and the prevalence of receiving a disability pension, 1.7% versus 10.6% (relative risk, 7.5; 95% CI, 5.5 to 10.0). Among those who did not have medical disabilities, the gestational age at birth was associated with the education level attained, income, receipt of Social Security benefits, and the establishment of a family, but not with rates of unemployment or criminal activity. CONCLUSIONS In this cohort of people in Norway who were born between 1967 and 1983, the risks of medical and social disabilities in adulthood increased with decreasing gestational age at birth.

/pdf/long-term-medical-and-social-consequences-of-preterm-birth-vs5cf544nh.pdf

Long-term medical and social consequences of preterm birth.

Objectives—This report presents 2005 data on U.S. births according to a wide variety of characteristics. Data are presented for maternal demographic characteristics including age, live-birth order, race, Hispanic origin, marital status, and educational attainment; maternal lifestyle and health characteristics (medical risk factors, weight gain, and tobacco use); medical care utilization by pregnant women (prenatal care, obstetric procedures, characteristics of labor and/or delivery, attendant at birth, and method of delivery); and infant characteristics (period of gestation, birthweight, Apgar score, congenital anomalies, and multiple births). Also presented are birth and fertility rates by age, live-birth order, race, Hispanic origin, and marital status. Selected data by mother’s state of residence are shown, as well as data on month and day of birth, sex ratio, and age of father. Trends in fertility patterns and maternal and infant charac­ teristics are described and interpreted. Methods—Descriptive tabulations of data reported on the birth certificates of the 4.1 million births that occurred in 2005 are presented. Denominators for population-based rates are postcensal estimates derived from the U.S. 2000 census. Results—In 2005, 4,138,349 births were registered in the United States, 1 percent more than in 2004. The 2005 crude birth rate was 14.0, unchanged from the previous year; the general fertility rate increased slightly to 66.7. Teenage childbearing continued to decline, dropping to the lowest levels recorded. Rates for women aged 20–29 were fairly stable, whereas childbearing among women 30 years of age and older increased. All measures of unmarried childbearing rose substantially in 2005. Smoking during pregnancy continued to decline. No improvement was seen in the timely initiation of prenatal care. The cesarean delivery rate climbed to more than 30 percent of all births, another all-time high. Preterm and low birthweight rates also continued to rise; the twin birth rate was unchanged and the rate of triplet and higher order multiple births declined for the 7th consecutive year.

/pdf/births-final-data-for-2005-1h81de16ys.pdf

Births: final data for 2005.

Objectives—This report presents 2006 data on U.S. births according to a wide variety of characteristics. Data are presented for maternal demographic characteristics including age, live-birth order, race, Hispanic origin, marital status, and educational attainment; maternal lifestyle and health characteristics (medical risk factors, weight gain, and tobacco use); medical care utilization by pregnant women (prenatal care, obstetric procedures, characteristics of labor and/or delivery, attendant at birth, and method of delivery); and infant characteristics (period of gestation, birthweight, Apgar score, con­ genital anomalies, and multiple births). Also presented are birth and fertility rates by age, live-birth order, race, Hispanic origin, and marital status. Selected data by mother’s state of residence are shown, as well as data on month and day of birth, sex ratio, and age of father. Trends in fertility patterns and maternal and infant characteristics are described and interpreted. Methods—Descriptive tabulations of data reported on the birth certificates of the 4.3 million births that occurred in 2006 are presented. Denominators for population-based rates are postcensal estimates derived from the U.S. 2000 census. Results—In 2006, births and fertility rates increased for most states, age groups, and race and Hispanic origin groups. A total of 4,265,555 births were registered in the United States in 2006, 3 percent more than in 2005, and the largest number of births in more than four decades. The crude birth rate was 14.2, up slightly from the previous year; the general fertility rate was 68.5, up 3 percent. Birth rates increased for women in nearly all age groups, with the largest increases for teenagers and for women aged 20–24 and 40–44 years. Teenage childbearing increased, interrupting the 14-year decline from 1991– 2005. The mean age at first birth for U.S. women was down in 2006, to 25.0 years. The total fertility rate increased to 2,100.5 births per 1,000 women. All measures of unmarried childbearing reached record levels in 2006. Women were less likely to receive timely prenatal care in 2006. The cesarean delivery rate climbed to 31.1 percent, another all-time high. Preterm and low birthweight rates continued to rise; the twin birth rate was unchanged for the second consecutive year; the rate of triplet and higher order multiple births declined 5 percent. 2006 1996

/pdf/births-final-data-for-2006-25zmhaui0l.pdf

Births : final data for 2006

Advances in neonatal medicine have resulted in the increased survival of infants at lower and lower birth weight. While these medical success stories highlight the power of medical technology to save many of the tiniest infants at birth, serious questions remain about how these infants will develop and whether they will have normal, productive lives. Low birth weight children can be born at term or before term and have varying degrees of social and medical risk. Because low birth weight children are not a homogeneous group, they have a broad spectrum of growth, health, and developmental outcomes. While the vast majority of low birth weight children have normal outcomes, as a group they generally have higher rates of subnormal growth, illnesses, and neurodevelopmental problems. These problems increase as the child's birth weight decreases. With the exception of a small minority of low birth weight children with mental retardation and/or cerebral palsy, the developmental sequelae for most low birth weight infants include mild problems in cognition, attention, and neuromotor functioning. Long-term follow-up studies conducted on children born in the 1960s indicated that the adverse consequences of being born low birth weight were still apparent in adolescence. Adverse sociodemographic factors negatively affect developmental outcomes across the continuum of low birth weight and appear to have far greater effects on long-term cognitive outcomes than most of the biological risk factors. In addition, the cognitive defects associated with social or environmental risks become more pronounced as the child ages. Enrichment programs for low birth weight children seem to be most effective for the moderately low birth weight child who comes from a lower socioeconomic group. Continued research and attempts to decrease the rate of low birth weight and associated perinatal medical sequelae are of primary importance. Ongoing documentation of the long-term outcome of low birth weight children needs to be mandated, as does the implementation of environmental enrichment programs to help ameliorate the long-term consequences for infants who are born low birth weight.

N K Klein

Papers

Long-term developmental outcomes of low birth weight infants.