One other factor to consider is that children exposed to second-hand smoke often had intra-uterine exposure as well, which has been linked to increased risks of learning and behavioral problems.
It also applies to women experiencing an intra-uterine fetal death, stillbirth, early neonatal birth, and where a baby is born with a life-limiting condition.
The sextuplets were conceived using intra-uterine insemination with ovulatory stimulating drugs, according to the family's website and a hospital statement.
