Low birthweight in an urban community in Nigeria

Six thousand, one hundred and thirty-five consecutive live births in six major health centres in the city of Ibadan were studied between September 1982 and March 1983 in order to assess the incidence, distribution and causes of low birthweight (LBW) in an urban community in Nigeria. Of the 6135 live births, 504 (8.2%) were of LBW. Two hundred and thirty-six (62%) of the LBW were small-for-gestational-age (SGA), while 146 (38%) were appropriate-for-gestational-age (AGA). Two hundred and five (87%) of the SGA were term while 115 (79%) of the AGA infants were preterm. Multiple pregnancy was an important cause of LBW, occurring in 4.4% of pregnancies. One hundred and forty-six (2.6%) of the 5631 infants who weighed 2500 g or over and 122 (24.2%) of the LBW infants were products of multiple pregnancy (P less than 0.001). The young (less than 20 years), short statured (less than 155 cm) and primigravid mothers were more likely than the others to give birth to LBW infants (P less than 0.001). Of the obstetric and medical factors examined, pre-eclamptic toxaemia (PET) (P less than 0.01), ante-partum haemorrhage (APH) (P less than 0.01) and anaemia (P less than 0.02) significantly increased the risk of LBW. Pre-eclamptic toxaemia, eclampsia, hypertension and renal diseases tended to be associated with SGA while APH and anaemia were found more often with prematurity. Multiple pregnancy contributed equally to the delivery of preterm and growth-retarded infants. Although no obvious cause could be identified in about two-thirds of the cases, pre-conceptional maternal malnutrition and poor diet in pregnancy might play an important role.