A study of low birthweight infants delivered at the University Teaching Hospital in Lusaka

Low birth weight refers to infants born with a weight of less than 2,500 grams. The weight of a neonate at birth has a significant prognostic value and is a major determinant of child survival. Neonatal mortality and morbidity tends to increase proportionately with reduced neonatal birth weight.Causes of low birthweight in neonates can be multi-factorial. Maternal factors may include her age, marital status, parity, social economic factors, preterm labour, multiple pregnancy, possible complications in the index pregnancy, necessitating pregnancy interruption before term e.g. pre-eclampsia, twinning, antepartum haemorrhage, and others.This was a retrospective study to: establish the incidence of low birthweight infants delivered at the UTH in Lusaka over a period of twelve months from January to December 1998 and document maternal and infant characteristics (including immediate outcome). There were 11,042 infants born from 10,525 deliveries in 1998 (difference accounted for by multiple pregnancy). There were 2,552 infants born with low birthweight (23.1% of all infants) from 2,279 pregnancies (21.7% of all pregnancies).
Almost a quarter (24.5%)) were born to mothers with an age between 13-19 (who were mainly single). 37.7% of mothers with low birthweight were primiparas. 62.6%) of pregnancies with low birthweight were preterm. Over half of the low birthweight infants were between 2000-2500g (54.7%), while 6.7% were extremely low birthweight (<1000g). 19.3%) of all singleton pregnancies were complicated by low birthweight, but 68.2% of twin pregnancies and all triplet pregnancies were. The odds ratio of a multiple pregnancy being associated with low birthweight was 9.14 (95% CI, 7.15<OR<11.14). An infant born as a twin or triplet had an odds ratio of 6.46 (95% CI, 5.66<OR<7.41) of being low birthweight.7.5% of low birthweight infants were stillborn and a ftirther 8.6%) had a poor Apgar score (between 1-6) at 5 minutes However, 67.8%) had an Apgar score of 9 or 10 at 5 minutes. An infant with low birthweight was slightly more likely to be stillborn compared to other infants - odds ratio 1.22 (95% CI, 1.02<OR<1.45). Preterm delivery was the commonest clinical factor associated with low birthweight followed by pre-eclampsia.The study had documented the magnitude of low birthweight at UTH. Recommendations have been made to follow up with a prospective study to include the district and study in depth maternal and pregnancy risk factors, reasons for preterm delivery and later neonatal outcome.