The health of babies being born with the help of fertility treatments are significantly increasing, according to a new study review.

A team of researchers reviewed the health of more than 62,000 single babies and nearly 30,000 twins born with the help of fertility treatments in Denmark, Finland, Norway and Sweden. The babies were then compared with more than 350,000 single babies and 123,000 twins born at the same time and without the help of fertility treatments, reported CBS News.

The study took place from 1988 through 2007.  

"During the 20-year period of our study, we observed a remarkable decline in the risk of being born preterm or very preterm," Dr. Anna-Karina Aaris Henningsen, of the Fertility Clinic at the Rigshospitalet, University of Copenhagen, Denmark, said in a journal news release. 

The study revealed that fewer singleton babies who were conceived through fertility treatments were born with a low birth weight of about 5.5 pounds or very low birth weight (about 3 pounds). The rates for stillbirths and deaths within the first year of life also dropped for both singletons and twins conceived through fertility treatments, reported CBS News.

The study researchers suggested that the trend of healthier babies born from fertility treatments are primarily due to policies regarding the transfer of just one embryo at a time during fertility procedures, reported CBS News. By transferring one embryo at a time, doctors can avoid multiple births and the need for reduction procedures used after successful implantation of more than one embryo. 

The study was published Jan. 21 in the journal Human Reproduction.