title: Incidence of delivery of low birthweight infants in twin gestations.
abstract: BACKGROUND
  Twin gestations are commonly associated with delivery of low birthweight infants. Despite the fact that Nigeria has the highest incidence of twinning in the world, there is paucity of information on the characteristics of LBW twin infants in Nigeria.
  
  
  OBJECTIVE
  To determine the incidence and document some of the characteristics of low birth weight (LBW) twin infants.
  
  
  METHODS
  A descriptive analysis of data on 119 LBW twin infants delivered between 1st January, 2000 and 31st December, 2003 in a Nigerian mission hospital in Benin City was carried out. The characteristics of the LBW twin infants was studied in relation to perinatal mortality.
  
  
  RESULTS
  The overall incidence of LBW twin infants was 51.7% with a female preponderance. Of the 107 live-born LBW twins, 74 (69.2%) compared to 33 (30.8%) were preterm and term small-for-gestational age (SGA) infants respectively (p < 0.001). Twenty six (35.1%) of the 74 preterms were very preterm (< 32 weeks gestation), corresponding to 24.3% of all LBW twin infants. The associated perinatal mortality for the two categories of LBW infants were 21.6% for preterm and 9.1% for term SGA infants (p > 0.05). Of the 119 LBW twin infants, 7.6% were extremely LBW, 10.1% very LBW while 57.1% were in 2000 2499g category. Fifty one (42.9%) of LBW twin infants weighed less than 2000 g. The risk of delivery of LBW twin infants was significantly higher in primiparous women (p < 0.001), as well as in mothers who were unbooked (p < 0.001) or lacked formal education (p < 0.01). Out of 9 growth discordant LBW twins, 6 (66.7%) had birthweight difference ≥ 30%.
  
  
  CONCLUSIONS
  In twin gestations, preterm delivery is a more important contributor to LBW than term SGA delivery with majority of these preterm infants delivered by primiparous mothers.
authors.affiliation: Department of Child Health, University of Benin Teaching Hospital, Nigeria. alpndiony@yahoo.com
authors.forename: A N
authors.initials: AN
authors.lastname: Onyiriuka
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D016519:Hospitals, Religious; D006801:Humans; D015994:Incidence; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D008423:Maternal Age; D009549:Nigeria / Q000453:epidemiology; D007752:Obstetric Labor, Premature / Q000453:epidemiology; D010298:Parity; D011159:Population Surveillance; D011247:Pregnancy; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data*; D014427:Twins; D055815:Young Adult