Yes, these babies are very small because they were born prematurely.
Occasionally, women conceive a multifetal gestation after fertility treatment. Carrying triplets or higher order multiples is dangerous for both the mother and fetuses. Often times women will miscarry the entire pregnancy or deliver the infants very prematurely.
Sometimes, the children are born too early to survive. If they do survive, complications related to prematurity are more likely. To avoid this situation, many couples choose to proceed with in vitro fertilization (IVF). By placing the embryos directly into a woman’s uterus we optimize the chances of achieving a pregnancy and minimize the risk for a multifetal pregnancy