1 The average birth weight of full-term twins (37 weeks or later, compared to 39-40 weeks for singletons) is around 5 ½ pounds each, though one baby often weighs more than the other. 1 The average birth weight for singletons is 7 lbs 7 oz. 2  Average birth weight of twins is 5 lbs 5 oz. for triplets 4lbs and quads 3lbs. 3  A difference in birth weight between multiples is not unusual. 1 In a twin pregnancy. the average is 37 weeks. for triplets 34 and quadruplets 32 weeks. 2  The average birth weight for singletons is 7 lbs 7 oz. 3  Average birth weight of twins is 5 lbs 5 oz. for triplets 4lbs and quads 3lbs. 4  A difference in birth weight between multiples is not unusual. The average singleton baby is about 51cm (20in) long from head to toe and weighs approximately 3.4kg (7.5 lb) at birth. However, anything between 2.5kg (5.5lb) and 3.8kg (8.4lb) is a healthy weight for newborns. Twins tend to be lighter than singleton babies. There height was 19 inches when they were born ... is it a good hieght for twins. Update: My twin boys were born at 5 lb 3 oz and 5 lb 14 oz. Approximately half (50% for height, 58% for weight) of the growth retardation from birth until 1.5 years was attributable to gestational age. Between 1.5 years and 2.5 years of age, this difference was reduced to one third: 33% for both height and weight. 1 The average duration of a regular pregnancy is 40 weeks. 2  In a twin pregnancy. the average is 37 weeks. for triplets 34 and quadruplets 32 weeks. 3  The average birth weight for singletons is 7 lbs 7 oz. 4  Average birth weight of twins is 5 lbs 5 oz. for triplets 4lbs and quads 3lbs.
http://www.fitpregnancy.com/pregnancy/getting-pregnant/two-oven http://www.twinsuk.co.uk/twinstips/18/144/multiple-birth-statistics,-facts-&-trivia/having-twins-or-triplets---interesting-&-fun-facts/ http://www.twinsuk.co.uk/twinstips/18/144/multiple-birth-statistics,-facts-&-trivia/having-twins-or-triplets---interesting-&-fun-facts/ http://www.babycentre.co.uk/36-weeks-pregnant-%20twins https://answers.yahoo.com/question/index?qid=20070629091727AANJhTP http://www.ncbi.nlm.nih.gov/pubmed/15283027 http://www.twinsuk.co.uk/twinstips/18/144/multiple-birth-statistics,-facts-&-trivia/having-twins-or-triplets---interesting-&-fun-facts/
typical height and weight for twins