<P> Among the exceptions are the Kupresak triplets of Mississauga, Ontario, Canada; their combined weight at birth in 2008, of 17 lbs, 2.7 ounces, set a world record . </P> <P> Cerebral palsy is more common among multiple births than single births, being 2.3 per 1,000 survivors in singletons, 13 in twins, and 45 in triplets in North West England . This is likely a side effect of premature birth and low birth weight . </P> <P> Multiples may be monochorionic, sharing the same chorion, with resultant risk of twin - to - twin transfusion syndrome . Monochorionic multiples may even be monoamniotic, sharing the same amniotic sac, resulting in risk of umbilical cord compression and nuchal cord . In very rare cases, there may be conjoined twins, possibly impairing function of internal organs . </P> <P> Multiples are also known to have a higher mortality rate . It is more common for multiple births to be stillborn, while for singletons the risk is not as high . A literary review on multiple pregnancies shows a study done on one set each of septuplets and octuplets, two sets of sextuplets, 8 sets of quintuplets, 17 sets of quadruplets, and 228 sets of triplets . By doing this study, Hammond found that the mean gestational age (how many weeks when birthed) at birth was 33.4 weeks for triplets and 31 weeks for quadruplets . This shows that stillbirth happens usually 3--5 weeks before the woman reaches full term and also that for sextuplets or higher it almost always ends in death of the fetuses . Though multiples are at a greater risk of being stillborn, there is inconclusive evidence whether the actual mortality rate is higher in multiples than in singletons . </P>

Can two out of three triplets be identical