Table 2 Details of the studies from south Asia included in the meta-analysis
Author (year) | Site of recruitment; Type of study | Country | Study population | Sample size | Tool(s) used | Age at assessment | Key outcome(s) | Quality score |
|---|---|---|---|---|---|---|---|---|
Chaudhari (1999) [30] | Hospital; Prospective follow up | India | Infants with BW < 2000 g discharged from Neonatal special care units and full term neonates with BW > 2500 g followed up till their 6 years of age | Children with low BW- 201 Children with normal BW-71 | Stanford Binet Intelligence Scale (SBIS) School report card assessment | At 6 years of age | Mean IQ score - LBW: 94.3 (13.6) - NBW: 101.38 (10.2) Proportion with abnormal IQ (score of < 85 score) - LBW: 17% - NBW: 5.6% Proportion with poor school performance (< 35% marks obtained) - LBW: 12.6% - NBW: 1.8% | 6 |
Tandon (A)(2000) [31] | Hospital; Prospective follow up | India | Infants with BW ≤2000 g discharged from special care nursery and followed up in high risk clinics; controls were healthy term infants with BW > 2500 g followed in well baby clinics | Children with low BW:27 Children with normal BW: 28 | Stanford Binet Intelligence Scale (SBIS); Raven’s Progressive Matrices; M.E Hertzig method of assessing signs of motor dysfunction | Age range of 5 to 9 years; mean age of 7.0 (SD 1.1) years | Mean cognitive score - LBW: 105.6 (13.4) - NBW: 116 (11.6) Proportion with low IQ score (<25th percentile) - LBW: 18.5% - NBW: 0.0% Proportion with signs of motor dysfunction - LBW: 37% - NBW: 10.7% | 2 |
Tandon (B)(2000) [31] | Hospital; Prospective follow up | India | Infants with BW ≤2000 g discharged from special care nursery and followed up in high risk clinics; controls were healthy term infants with BW > 2500 g followed in well baby clinics | Children with low BW:32 Children with normal BW: 29 | Stanford Binet Intelligence Scale (SBIS); Raven’s Progressive Matrices; M.E Hertzig method of assessing signs of motor dysfunction | Age range of 9 to 13 years; mean age of 10.6 (SD 1.2) years | Mean cognitive score - LBW: 99.6 (10.8) - NBW: 110.6 (7.3) Proportion with low IQ score (<25th percentile) - LBW: 25% - NBW: 3.4% Proportion with signs of motor dysfunction - LBW: 19% - NBW: 3.4% | 2 |
Chaudhari (2004) [32] | Hospital; Prospective follow up | India | Infants with BW < 2000 g discharged from Neonatal special care units and full term neonates with BW > 2500 g and followed up till their 12 years of age | Adolescents with low BW- 180 Adolescents with normal BW-90 | Weschler’s Intelligence Scale; Movement assessment battery; School report card assessment | At 12 years of age | Mean IQ score - LBW: 89.5 (16.9) - NBW: 97.2 (14.1) Proportion with abnormal IQ (score of < 85) - LBW: 37.7% - NBW: 18.8% Proportion with poor school performance (< 50% marks obtained) - LBW: 21.6% - NBW: 10.0% Mean motor impairment score - LBW: 9.8 (3) - NBW: 7.3 (2.9) | 4 |
Juneja (2005) [33] | Hospital; Prospective follow up | India | Term infants < 2000 g and term infants with normal birth weight (> 2500 g) | Infants with BW < 2000 g-50 Infants with BW > 2500 g-30 | Bayley Scales of Infant Development (BSID II) | At 18 months | Mean mental development quotient - < 2000 g: 91.5 (16.9) - > 2500 g: 102 (8.4) Mean motor development quotient - < 2000 g: 93.2 (19.7) - > 2500 g: 99.5 (10.3) Proportion with adverse mental development outcome - < 2000 g: 20% - > 2500 g: 3.3% Proportion with adverse motor development outcome - < 2000 g: 24% - > 2500 g: 3.3% | 2 |
Taneja (2005) [34] | Community; Cross-sectional | India | Children aged 12 to 18 months enrolled in a randomized controlled trial | Children with low BW- 61 Children with normal BW-116 | Bayley Scales of Infant Development (BSID II) | At 12–18 months of age Findings of assessment at baseline used | Mean mental development quotient - LBW: 102.2 (12.26) - NBW: 102.8 (11.03) Mean motor development quotient - LBW: 100.08 (13.97) - NBW: 101.06 (12.37) Proportion with abnormal mental score (score of < 85) - LBW: 4.92% - NBW: 5.17% Proportion with abnormal motor score (score of < 85) - LBW: 13.1% - NBW: 4.3% | 7 |
Subasinghe (2006) [35] | Community; Cross-sectional | Sri Lanka | Preschool children within the age range of 36–54 months | Children with low BW: 12 Children with normal BW: 62 | Early Screening Inventory for Preschoolers (ESI-P) | 36 to 54 months of age | Mean cognitive score - LBW: 63.35 (14.5) - NBW: 65.32 (15.7) Mean gross motor score - LBW: 62.7 (7.4) - NBW: 68.81 (18.1) | 3 |
Nair (2009) [36] | Hospital; Prospective follow up | India | Adolescents with known birth weight, follow up done at 13 years of age | Adolescents with low BW-183 Adolescents with normal BW-211 | Raven’s coloured progressive matrices | At 13 years of age | Proportion with low IQ score (≤25th percentile) - LBW: 51.4% - NBW: 41.7% | 4 |
Sidhu (2010) [37] | Community; Cross-sectional | India | Children aged 2 to 35 months recruited from a urban center | Children with low BW: 57 Children with normal BW: 196 | Clinical Linguistic Auditory Milestone Scale (CLAMS) | 2–35 months of age; mean age of 14.15 months | Mean Language Quotient (LQ)a - LBW: 85.07 (16.6) - NBW: 94.66 (16.6) | 3 |
Hoque (2012) [38] | Hospital; Prospective follow up | Bangladesh | Newborns discharged from a special care baby unit and followed till 12 months of age | Infants with low BW: 25 Infants with normal BW: 80 | Bayley Scales of Infant Development (BSID II) | At 12 months of age | Mean mental score - LBW: 114.18 (12.80) - NBW: 117.11 (12.04) Mean motor score - LBW: 96.14 (25.12) - NBW: 108.41 (19.69) | 4 |
Khan (2012) [39] | Hospital; Prospective follow up | Pakistan | Neonates discharged from neonatal intensive care unit and followed till 6 months of age | Infants with low BW: 92 Infants with normal BW: 18 | Denver Development Screening Test (DDST II) | At 6 months of age | Proportion with delayed development (development quotient < 60)b - LBW: 38% - NBW: 0% | 4 |
Tofail (2012) [40] | Community; Secondary data analysis from a randomized controlled trial | Bangladesh | Live born singletons | Low BW infants- 66 Normal BW infants- 183 | Bayley Scales of Infant Development (BSID II) | At 10 months of age | Mean mental index score - LBW: 99.5 (7) - NBW: 102.9 (8) Mean motor index score - LBW: 96.8 (10) - NBW: 102.7 (10) | 7 |
Modi (2013) [41] | Hospital; Prospective follow up | India | VLBW admitted to a neonatal intensive care unit prospectively followed till 1 year of corrected age. A cohort of term, birth weight (≥2500 g) infants born during same period was enrolled for comparison. | VLBW-37 NBW-35 | Developmental Assessment Scale for Indian Infants (DAS II) | At 12 months of age | Mean mental index score - VLBW: 92.9 (8.0) - NBW: 98.4 (6.1) Mean motor index score - VLBW: 90.1 (9.6) - NBW: 96.6 (5.8) | 5 |
Chaudhari (2013) [42] | Hospital; Prospective follow up | India | Infants with BW < 2000 g discharged from Neonatal special care units and full term neonates with BW > 2500 g and followed up till their 18 years of age | Adolescents with low BW-161 Adolescents with normal BW-73 | Raven’s Progressive Matrices | At 18 years of age | Mean IQ scorea - LBW: 39.3 (29.9) - NBW: 52.5 (29.9) Proportion with low IQ score (<25th percentile) - LBW: 24.2% - NBW: 12.7% Poor school performance (failed at least in one standard in school) - LBW: 25.5% - NBW: 5.5% | 4 |
Avan (2014) [43] | Community; Cross-sectional | Pakistan | Low birth weight and normal birth weight infants | Low BW infants-86 Normal BW infants-566 | Bayley Scales of Infant Development (BSID II) | Within 3 years of age | Mean psychomotor development index score - In low BW: 94.13 (18.13) - In normal BW: 98.47 (15.84) | 6 |
Nair (2014) [44] | Hospital; Prospective follow up | India | Infants discharged from Neonatal special care units and followed up with 12 months of age | Infants with low BW- 170 Infants with normal BW-429 | Developmental Assessment Scale for Indian Infants (DAS II) | At 12 months of age | Mean mental index scorea - LBW: 107.83 (11.04) - NBW: 110.51 (8.38) Mean motor index scorea - LBW: 99.72 (14.28) - NBW: 104.17 (10.86) | 5 |
Christian (2014) [45] | Community; Prospective follow up | Nepal | Children aged 7 to 9 years who were part of an earlier nutrition supplementation trial | Children with low BW-764 Children with normal BW-1163 | UNIT for general intelligence; Finger tapping test for fine motor | At 7 to 9 years of age (mean age of 8.4 years) | Mean Intelligence score (UNIT) - LBW: 47.6 (9.4) - NBW: 51.6 (10.1) Mean fine motor score - LBW: 35.8 (5.4) - NBW: 36.9 (5.1) Mean motor impairment score - LBW: 9.98 (6.73) - NBW: 7.62 (5.59) | 8 |
Chattopadhyay (2015) [46] | Hospital; Prospective follow up | India | Newborns discharged from SNCU | Children with low BW- 206 Children with normal BW-181 | TDSC DDST II Visual and hearing assessment | Under 3 years of age | Proportion with developmental delay - LBW: 38.8% - NBW: 20.9% | 4 |
Singh (2017) [47] | Community; Cross-sectional | India | Children under 2 years of age from an urbanized village | Children with low BW- 43 Children with normal BW-153 | Ages and Stages questionnaire, 3rd Edition | Under 2 years of age | Proportion with development delay - LBW: 16.3% - NBW: 2.0% | 4 |
Kvestad (2017) [48] | Community; Prospective follow up | Nepal | Infants aged 2–12 months enrolled through a cross-sectional survey and followed up till 5 years of age | Children with low BW: 124 Children with normal BW: 193 | Ages and Stages Questionnaire, 3rd edition | At 5 years of age | Mean cognitive score - LBW: 52.68 (6.9) - NBW: 51.61 (9.1) Mean motor score - LBW: 53.44 (6.1) - NBW: 53.37 (7.5) | 4 |