Breastfeeding is the fundamental component of child survival strategy. It significantly influences neurological development of children. The study was conducted to assess whether exclusive and prolonged breastfeeding improves children's cognitive development, including low birth weight (LBW) babies, in a developing country setting like Bangladesh. This observational study was done on a cohort of newborn infants who were discharged from the special care baby unit of Dhaka Shishu Hospital during January 2006 to December 2008 with proper counseling about exclusive and prolonged breastfeeding. Their neuro-developmental follow-up was started at 4 weeks postnatal age and continued at 3-monthly intervals up to 1 year of age. At each visit, cognitive development was assessed using the Bayley Scales of Infant Development (BSID II). Cognitive development was compared between the babies of exclusive vs. non exclusive breastfeeding, normal weight vs. low birth weight and male vs. female babies. A total of 105 cases were successfully followed-up during this period. Out of these 47(44.8%) babies were exclusively breastfed up to 6 month of age and 58(55.2%) were in nonexclusive group. Overall Psychomotor Development Index (PDI) was slightly more (108.40 ± 23.06 vs. 103.23 ± 19.87) in the exclusive breast fed babies in comparison to nonexclusive breast fed babies, but was significantly more in babies having birth weight >2.5 kg in comparison to those having birth weight of <2.5 kg. Other parameters of cognitive development were more or less same in both normal and LBW groups. Mental and motor development was same in both boys and girls. In behavior ratings, cooperation was significantly high (5.89 ± 2.54 vs. 4.71 ± 3.13, p=0.05) and vocalization (5.89 ± 1.07 vs. 4.58 ± 1.16) was also high, though not significant, in girls than boys.
