Most triplets do well long-term, but the tiniest ones can lag.
By the age of 5, most triplets are on par with their peers in mental and emotional development, but those born at the lowest weights may still lag behind, according to a study published Monday.
Israeli researchers found that among the 126 singletons, twins and triplets they followed from birth to age 5, triplets generally trailed behind their peers in cognitive development over the first two years of life.
By age 5, however, many triplets had bridged the gaps in both IQ and social development, the researchers report in the journal Pediatrics.
The exception was triplets who'd been particularly growth-restricted in the womb -- those who, at birth, had weighed more than 15 percent less than the sibling with the highest birthweight. At age 5, these children were still developmentally behind both their siblings and peers.
Until now, there had been no well-designed studies following the development of triplets over the first few years of life. And the catch-up seen among most triplets in this study is "excellent news," lead researcher Dr. Ruth Feldman, of Bar-Ilan University, told Reuters Health.
Parents of triplets, she said, should be aware that their children may be slower to reach developmental milestones in infancy, but most are likely to close that gap during the preschool years.
Children who were born substantially smaller than their siblings may not catch up, however.
At age 5, the study found, these children typically scored at the lower end of the normal range for intellectual, emotional and social development.
For instance, Feldman explained, average verbal IQ was about 95, which, while within normal range, would make it difficult for a child to get through standard schooling.
Growth restriction was common among the 21 sets of triplets in the study. In 65 percent, one sibling was born weighing more than 15 percent less than the heaviest sibling. The findings on development point to the importance of giving these children extra attention from infancy onward, according to Feldman.
"Knowing that these children respond to parental investment already in the first months of life tells parents to be especially sensitive and responsive to these children," Feldman explained.
In addition, she said, the children's development during infancy and preschool should be continuously monitored, and parents and children should receive extra help when needed -- such as interventions to help children regulate their emotions and cultivate social skills, or to improve their attention and concentration abilities.
More studies are also needed, the researchers note, to see whether the developmental gaps persist into later childhood and adolescence.