POPULATION SPECIFIC BIRTH WEIGHT CENTILES
Gunasekera
D1, de Silva N-R2, Sirisena J2, de Silva
H-J2
1
University of Sri
Jayawardenepura, Colombo, Sri Lanka
2
University of Kelaniya, Ragama, Sri Lanka
Objectives: Determine birth weight
(BW) centiles for Sri Lankan babies and compare with the standard charts
used. Compare centiles of first borns and babies of subsequent birth order.
Method: Birth weights of 2560 babies
(37-42 weeks of gestation) at the University Obstetric Unit, North Colombo
Teaching Hospital, Sri Lanka, were recorded. Mothers or babies having any
medical or chronic obstetric complication were excluded. Gestational age
was calculated using the last menstrual period (LRMP). Dates of 223 babies
were validated by dating ultrasound scans. Scan dates were within 2 weeks
of the LRMP dates. Using MS Exel, 10th, 50th and 90th
centiles were constructed for males and females and compared with Child
Growth Foundation Charts (UK). Centiles were also constructed for 1st
born and subsequent birth order babies in either sex and compared with
similar Japanese charts.
Results: When compared to Standard
Charts, all Corresponding
centiles of Sri Lankan babies were lower. Mean BW of 1st born
males was 2924.9g, while that of multi para was 3032.6g (p<0.000013).
Mean BW of first born females was 2863.4g, while that of multipara was
2935.3g(p<0.001). Compared to Japanese charts, Sri Lankan babies had
lower corresponding centiles in both first born and multiparous groups.
Conclusions: In this study, normal
Sri Lankan babies weighed less than their European and Japanese
counterparts at birth. This may well apply to other populations. Babies of
multipara were heavier than their first born counterparts. Therefore,
population studies should be done to devise National Birth Weight Centile
charts more representative of the local population. This would reduce
errors of using standard charts to classify babies as Low Birth Weight or
small for gestation. First born babies and those of multipara should have
separate birth weight centile charts for each sex, considering their
significant weight differences.