A new study from Finland says the size of a baby can be linked to how the embryos were prepared during IVF or in vitro fertilization treatments. Scientists compared the length of time the embryos grew in culture before being transferred to the mother’s wombs.
They compared embryos that were cultured between two to three days and embryos cultured between five to six days. The longer they stayed in culture, around five to six days, the more likely babies were to be heavier than normal for their gestational age.
Studies have previously shown babies born from IVF treatments were at an increased risk for preterm birth and low birth weight. However, very few studies have looked at relation between culture time and the baby’s weight.
Researchers from the University of Helsinki looked at 1,079 singleton babies, not twins, who where born using IVF. During an IVF procedure, eggs from the mother are fertilized in a laboratory and grown in a culture for one to six days before being transferred to the mother. The American Pregnancy Association says the time in culture is usually two to three days according to Live Science.
The researchers found that 80 percent of the babies were normal weight, 10 percent were small, and 10 percent were bigger. The average weight of the babies were 7.7 pounds. Researchers focused on the embryos that were cultured five to six days. Almost 19 percent of them were large for their gestational age and three percent were small for their gestational age.
The risks for the babies with both high and low weights for gestational age are at risk for complications later in life. Smaller babies are at risk for low blood sugar, neurological disabilities, and heart disease. The larger babies have an increased risk for adult obesity.
Researchers aren’t sure why baby weight is influenced by IVF treatments and that there needs to be additional studies according to Yahoo News.