RESUMEN
A retrospective study was done to compare infant mean birth weight between twin pregnancy in 60 adolescent and 120 adult gravidas who delivered at Siriraj Hospital during January, 1985 to December 1993. Adolescent twin pregnant women had significantly (p <0.01) lower infant mean birth weight (2,040.0 + 520.7 and 1,963.8+ 695.3 grams of the first and second twins respectively) than did adults (2,311.0+ 432.5 and 2,226.6+ 496.1 grams of the first and second twins respectively). However, the mean infant birth weight of the first and second twins of each group was not significantly different (p >0.05). Length of gestation was the predominant contributor to effect birth weight of the first and second twins while parity was the predominant contributor to effect only birth weight of the second twins.