Middle-aged Hollywood stars and their newborns may make it seem like a fountain of youth has been discovered for women's fertility.

But researchers at Yale University School of Medicine say these stars may be giving women the wrong perception. 

Many women don't realize the consequences of delaying motherhood, the researchers found in a study published in the recent issue of Fertility & Sterility. They have unrealistic expectations that they will be able to turn to reproductive measures such as in vitro fertilization.

“There is an alarming misconception about fertility among women,”  Pasquale Patrizio, professor in the Department of Obstetrics & Gynecology at Yale School of Medicine and director of the Yale Fertility Center, said in a statement. “We also found a lack of knowledge about steps women can take early in their reproductive years to preserve the possibility of conception later in life.”

Patrizio and colleagues began the research after noticing more women visiting fertility clinics at age 43 or older expecting that pregnancy can be instantly achieved. They often turned away disappointed to learn it wasn't the magic potion they expected.

 “Their typical reaction is, ‘what do you mean you cannot help me? I am healthy, I exercise, and I cannot have my own baby?’” Patrizio said.

The women delay pregnancy to focus on careers and become more financially stable. Some are waiting on the right partner.

The growing popularity of assisted reproductive technologies has given women the impression that female fertility may be manipulated at any stage in life, Patrizio said.  The problem is exacerbated by images of older celebrities who seem to effortlessly give birth.

The number of in-vitro fertilization cycles performed for women under age 35 increased by about 9 percent between 2003 and 2009,  according to the Society for Assisted Reproductive Technologies. During this same time period, the number of IVF treatments by women aged 41 and older increased by 41 percent. But this procedure doesn’t always result in success. About 9 percent of older women had IVF treatments that resulted in pregnancy.

Older women also have a higher risk of pregnancy loss, birth defects, and other complications.