By Dr. Karen Johnson / 11 News--Click Here for Video

When a couple is trying to start a family and is unable to do so, their infertility cannot be explained about a quarter of the time.

Juan and Gladys are a busy career-oriented couple. Gladys,36, is the Latin American Sales Manager for a major airline.

"I was going to be a student for life. I wanted to learn and learn and learn," says Gladys.

Then she and her 33-year-old husband Juan, an airline pilot, wanted to start family. Juan looks forward to being a father.

"Teaching them to ride a bike, skiing. Just the reflection of what we have together," Juan says.

Reproductive experts say that if a woman is a woman is over 35 and has been trying to conceive a for over six months, then the couple is defined as being infertile.

They sought the help of Dr. Sonja Kristiansen, a reproductive endocrinologist.

"You have to rule out hormonal problems through various blood tests, you have to rule out structural problems such as blocked fallopian tube or a blocked cervix and you also have to rule out a male factor which is done through a semen analysis," says Dr. Kristiansen.

They elected to have artificial insemination. Gladys is taking medicine to increase the number of eggs she produces and because Juan travels as a pilot, his sperm will be frozen and ready to implant in Gladys if he's away.

"The pregnancy rate will be higher with inseminations because what you are doing is you are getting all the normal shaped living sperm and placing them up into the uterus," Dr. Kristiansen.

Their chances of conceiving a pregnancy are 60 percent with this approach.

So if you are thinking about becoming pregnant, don't wait too long. The biological clock is ticking.