There were more test-tube babies born in the United States in 2012 than ever before, according to a report released Monday from the Society for Assisted Reproductive Technology, a group of medical officials.

The SART report, released every year, also found that test-tube babies accounted for a higher percentage of total births ever since the fertility technique was first developed in the 1980s, Reuters reported.

Test-tube babies, officially known as in vitro fertilization, are produced when a woman's eggs are fertilized outside the body in a lab dish. The eggs can either come from the child's genetic mother or from another donor, Reuters reported.

More than 90 percent of the infertility clinics in the country, which are also SART members, were involved in the study.

The 379 clinics said that 61,740 babies were born out of 165,172 in vitro fertilization procedures performed in 2012.  The number of babies born was 2,000 more than the number of babies in 2011.

Furthermore, out of the 3.9 million babies born in the U.S. in 2012, the number of test-tube babies was 1.5 percent, the highest percentage ever, Reuters reported.

Despite the higher than ever numbers, critics say the success rates of IVF is an illusion.

"It's important for people to understand that women over 35 have the highest percentage of failures," said Miriam Zoll, author of "Cracked Open: Liberty, Fertility and the Pursuit of High Tech Babies," Reuters reported.

The higher number of test-tube births shows that women in the U.S. are waiting until they are older to have babies, since infertility problems increase with age. The average age for a woman to have her first child was 21.4 years in 1970. Now, it's close 26, Reuters reported.

Women in their 20s who try IVF are ten times more likely to give birth than women over 42.

Zoll said the treatments have not improved since the first test-tube baby was born in England in 1978, according to Retuers.

"These treatments have consistently failed two-thirds of the time since 1978," Zoll said.