Key notes
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Evidence is lacking from south Asian setting on magnitude of cognitive and motor deficits in low birth weight (LBW) individuals compared to those with normal birth weight (NBW).
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Our meta-analysis showed that LBW children < 10 years of age had 4.56 points lower cognitive and 4.16 points lower motor scores compared to children with NBW.
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Early child development interventions in south Asia should emphasize on children born LBW
Introduction
Methods
Primary objective(s) of the systematic review
Objective of the additional analysis
Search strategy and selection criteria
For the primary objective
1. | (Neurodevelopmental OR Neurodevelopment OR Neurobehavioral OR Neurobehavioural OR Cognitive OR Intellectual OR Developmental OR Learning OR Language OR Behaviour OR Behavior OR Motor OR Motor Skill OR Movement OR Intelligence OR Psychomotor OR Psychomotor performance OR Developmental coordination OR Mental OR Memory OR Disability OR Disabilities OR Manifestations OR Disorder OR Dysfunction OR Outcome OR Retardation OR Neuropathology OR Cerebral Palsy OR Attention deficit OR Attention deficit hyperactivity disorder OR school performance OR Child development OR Infant development OR Developmental Delay OR Long term Outcome) |
2. | (birthweight OR birth weight) |
3. | (#1 AND #2) Filter: Customized country filter (India OR Bangladesh OR Pakistan OR Nepal OR Bhutan OR Sri Lanka OR Maldives OR Afghanistan OR south Asia) |
For the additional analysis
Data analysis
Results
Characteristics of the included studies
Author (year) | Site of recruitment; Type of study | Country | Study population | Sample size | Tool(s) used | Age at assessment | Key outcome(s) | Quality score |
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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 |
Findings of the cognitive score
Outcomes | No. of studies | No. of subjects | Age range | Pooled RR (95% CI) | I 2 Statistic |
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Low cognitive scorea | 4 | 584 | < 10 years | 2.69 (1.34, 5.39) | 12.7% |
Motor impairmentb | 3 | 312 | < 10 years | 3.32 (1.56, 7.06) | 0.0% |
Developmental delayc | 3 | 693 | ≤3 years | 1.97 (1.41, 2.73) | 69.3% |
Findings of the motor score
Findings of cognitive and motor scores in a sub-group of LBW (< 2000 g)
Outcomes | No. of studies | No. of subjects | Age range | Effect size (95% CI) | I 2 Statistic |
---|---|---|---|---|---|
Cognitive score | 4 | 479 | < 10 years | WMD −7.23 (−9.20; −5.26) | 8.7% |
3 | 407 | < 10 years | RR 3.59 (1.55; 8.32)a | 0.0% | |
Motor score | 2 | 152 | < 10 years | WMD −6.45 (−9.64; −3.27) | 0.0% |
2 | 135 | < 10 years | RR 3.72 (1.32; 10.54)b | 0.0% |