Indian Pediatr Suppl 2009;46: S71-S74
Low Birthweight Babies – Outcome at 13 years
MKC Nair, DS Chacko, MK Paul, Latha Nair, Babu George and
G Suresh Kumar
From Child Development Centre, Medical College,
Thiruvananthapuram, Kerala, India.
Correspondence to: Dr MKC Nair, Professor of Pediatrics
and Clinical Epidemiology and,
Director, Child Development Centre, Medical College,
Thiruvananthapuram 695 011, Kerala, India.
The study was conducted to compare growth status,
blood pressure, self esteem and intelligence of 200 low birthweight
(LBW) and 224 normal birthweight (NBW) adolescents at 13 years of age.
Intelligence scores at or below the 25th percentile (low performance)
were observed among 51.4% LBW and 41.7% NBW adolescents (<0.05).
Statistically significant lower scores for self esteem (mean difference
4.31, 95% CI 1.91-6.71) were observed among LBW adolescents. Height,
weight and body mass index (BMI) were lower among all LBW adolescents
and the difference reached statistical significance for weight and BMI
among LBW adolescent girls.
Keywords: Adolescent, Body Mass Index, Low birthweight,
Long term follow-up studies indicate that
the adverse consequences of being born low birthweight (LBW) are still
apparent in adolescence(1,2). Low birthweight survivors demonstrate
significant growth retardation reflected by lower bodyweight, height and
higher ambulatory blood pressure values and variability(3-5). Sorenson,
et al.(6) have observed that birthweight is significantly associated
with cognitive ability at age 8 years, through adolescence, and into early
adulthood, independent of social background. Adolescents born as LBW have
more cognitive, academic, behavioral problems, and lower self-esteem in
early adolescence than normal birthweight (NBW) adolescents(7). This study
compares growth status, blood pressure, self esteem and intelligence in
LBW and NBW adolescents at 13 years of age.
A total of 424 adolescents (boys 232; girls 192), 200
born low birthweight (LBW)(<2500g) and 224 born with normal birthweight
(NBW), on developmental follow-up at Child Development Centre were seen
again at 13 years of age. Outcome measurements were made by observers
masked to the birthweight status of the children.
Height and weight were recorded for each adolescent and
body mass index (BMI) was calculated. Blood pressure was also measured.
Self esteem was measured using a standardized self esteem inventory that
consisted of 25 items intended to tap self-evaluation from a wide variety
of behavioral domains, including social, academic, physical, and emotional
aspects(8). The mean raw scores for LBW and NBW adolescents were compared
separately for boys and girls. Intelligence was assessed using Raven’s
Coloured Progressive Matrices, a test of nonverbal intelligence and
classified as per test manual norms into 5 grades: superior, above
average, average, below average and intellectually impaired(9).
Statistical analysis was done using Statistical Package for Social Science
(SPSS) for Windows (version 10.0). P value <0.05 was considered as
The mean birthweight of the LBW group (LBW) was
1848±359 grams and that of NBW group 2984±430 grams. The LBW group had 105
(52.5%) boys and 95 (47.5%) girls, as against 127 (56.7%) boys and 97
(43.3%) girls in the comparison group. There were 32 (16%) adolescents
with birthweight less than 1500 grams, 81 (40.5%) with birth weight
between 1500 and 1999 grams and 87 (43.5%) with birthweight between 2000
and 2499 grams. The LBW group had 116 (58%) preterm and 84 (42%) term
babies. 94 of them were small for gestational age (SGA) and 106 were
appropriate for gestational age (AGA).
The BMI was less than 15 in 43.8% of boys and 20.9%
girls. The mean height, weight, BMI, systolic blood pressure, diastolic
blood pressure and self-esteem was lower for LBW boys when compared to the
NBW boys with the difference showing statistical significance only for
self-esteem (Table I). Similarly, except for mean systolic
blood pressure, the mean height, weight, BMI, diastolic blood pressure and
self-esteem was lower for the LBW girls when compared to the NBW girls
with the difference showing statistical significance for weight, BMI and
self esteem. On considering the group as a whole, the mean self esteem
scores of the LBW group was lower (85.9±11.6) than that of the mean scores
of the NBW group (90.2±12.6) and the difference was significant (mean
difference 4.31, 95% CI 1.91-6.71, P=0.001). There was no
significant difference in the self esteem scores between preterm and term
adolescents of the LBW group. 42.6% of LBW adolescents had a BMI of less
than 15 compared to 26.3% of NBW adolescents and this difference was
Comparison of Variables at 13 Years Among LBW and NBW Groups
Body mass index
Systolic BP (mmHg)
Diastolic BP (mmHg)
Self esteem scores
LBW: Low birthweight, NBW: Normal birthweight
Table II shows comparison of
intelligence for 183 LBW and 211 NBW adolescents; 12 adolescents, 6 from
each group could not be tested due to either severe physical or mental
handicap; and 18 adolescents did not cooperate adequately for intelligence
assessment. There was a statistically significant difference observed in
intelligence between the LBW and NBW group. On considering gender, a
significant difference between the two groups was seen only in male
adolescents (P=0.035). Only 46.2% of LBW male adolescents performed
well as compared to 59.7% of NBW males. Among the preterms, 92.2% of AGA
adolescents were in the good performance group compared to 7.8% of SGA
adolescents and this difference was also statistically significant (P=0.009).
Comparison of Intelligence Scores at 13 Years
Good performance group
Low performance group
LBW (low birthweight) compared to NBW (normal
birth weight); Fisher’s Exact Test P = 0.035, Scores: superior ³95th
centile; above average ³75th centile; average, between 25th and 75th
centile; below average, at or below 25th centile;
intellectually impaired, scores at or below 5th centile.
This study showed that height and weight of the LBW
group was less than that of the NBW group, which is in agreement with
reports of many previous studies(1-4). The finding that almost half the
boys were underweight shows the need for nutrition monitoring of
early adolescent boys as well as girls.
In our study, intelligence scores at or below the 25th
percentile (low performance) were observed among 51.4% of LBW adolescents.
Many variables including intelligence, have been shown to have direct
correlation with self-esteem(10). LBW is also associated with lower
academic achievement and school functioning
in adolescence(11,12). All these might have contributed to the lower self
esteem scores observed among LBW adolescents in this study. The
significantly lower mean self esteem observed in the LBW group is
supported by Rickards, et al.(7), who reported an association
between birthweight and self esteem in early adolescence. Inferior
intelligence test achievements were seen not only in the LBW group as a
whole but in LBW males in particular. This finding is similar to findings
of Seidman, et al.(13) that low weight at birth in males had a
statistically significant independent association with inferior
intelligence test achievements.
The overall findings of our study support previous
study reports that birthweight has an important role in determining
growth, physical and psychological development of an individual and the
effects are seen even in early adolescence. It is recommended that LBW
babies should receive systematic medical and psychological follow up right
through childhood and adolescence.
We acknowledge with thanks the assistance offered
throughout the study by Lekshmi MA, Letha S and Asokan N, Child
Contributors: PMK and LN were involved in the
assessment of adolescents. CDS performed statistical analysis and drafted
the manuscript. BG and SKG assisted in planning the study. NMKC was
involved in planning the study, critically reviewed the manuscript and
would act as guarantor of the study.
Competing interests: None stated. The findings and
conclusions of this report are those of the authors and do not necessarily
represent the views of the funding agency.
What This Study Adds?
• Low birthweight adolescents have significantly
lower self esteem scores and intelligence scores at or
below 25th percentile (low performance) compared to normal
birthweight adolescents at 13 years of age.
1. Lagerstrom M, Bremme K, Eneroth P, Janson CG.
Long-term development for girls and boys at age 16-18 as related to birth
weight and gestational age. Int J Psychophysiol 1994; 17: 175-180.
2. Ghirri P, Bernardini M, Vuerich M, Cuttano AM,
Coccoli L, Merusi I, et al. Adrenarche, pubertal development, age
at menarche and final height of full-term, born small for gestational age
(SGA) girls. Gynecol Endocrinol 2001; 15: 91-97.
3. Anderson P, Doyle LW. Neurobehavioral outcomes of
school-age children born extremely low birth weight or very preterm in the
1990s. JAMA 2003; 289: 3264-3272.
4. Farooqi A, Hägglöf B, Sedin G, Gothefors L, Serenius
F. Growth and sexual maturation of low birth weight children: a 14 year
follow up. Pediatrics 2006; 118: e1452-1465.
5. Lurbe E, Torro I, Rodriguez C, Alvarez V, Redon J.
Birth weight influences blood pressure values and variability in children
and adolescents. Hypertension 2001; 38: 389-393.
6. Sorensen HT, Sabroe S, Olsen J, Rothman KJ, Gillman
MW, Fischer P. Birth weight and cognitive function in young adult life:
historical cohort study. BMJ 1997; 315: 401-403
7. Rickards AL, Kelly EA, Doyle LW, Callanan C.
Cognition, academic progress, behavior and self-concept at 14 years of
very low birth weight children. J Dev Behav Pediatr 2001; 22: 11-18.
8. Thomas I, Raj HS. Measurement of self esteem: An
inventory for secondary school pupils. Psychol Studies 1984; 29: 29-33.
9. Raven JC. Coloured Progressive Matrices. Oxford:
Psychologists Press Ltd; 1998.
10. Raj HS, Thomas I. Certain correlates of
self-esteem: A factor study. Psychol Studies 1986; 31: 119-124.
11. Saigal S, Hoult LA, Streiner DL, Stoskopf BL,
Rosenbaum PL. School difficulties at adolescence in a regional cohort of
children who were extremely low birth weight. Pediatrics 2000; 105:
12. Cooke RW. Health, lifestyle, and quality of life
for young adults born very preterm. Arch Dis Child 2004; 89:
13. Seidman DS, Laor A, Gale R, Stevenson DK, Mashiach S, Danon YL.
Birth weight and intellectual performance in late adolescence. Obstet
Gynecol 1992; 79: 543-546.