More and more couples are waiting to expand their families until the woman is into her 30s or older. Work, travel and saving money before having a baby are all factors in the decision.

But delaying pregnancy can carry a number of consequences

Obstetrician and gynecologist Michael Randell confirmed this statement.

He said, "There is a lot of an anxiety among patients. I have 20-year olds coming to me concerned whether or not they can conceive."

"Statistics are against you," Randell told CNN.com. "You only have a 15 percent chance of conceiving each month. About 85 percent of people will conceive in the first year of trying."

"The reason why it is more difficult to get pregnant these days is because more people are waiting longer."

He also blamed the monthly timing. Patients don't know that they only have a small opportunity to conceive each month. The optimal time for ovulation is 14 days after the first day of the last menstrual period, he said.

Experts say that women over 35 struggle most to get pregnant. As a woman ages, the quality of eggs decreases and she may not ovulate as frequently.

Certain lifestyle changes may help impto get her body ready long before she planned to get pregnant.

Smoking affects both women and men fertility and so can drugs, so quit them both.

The American College of Obstetricians and Gynecologists suggest trying to lose weight if you are obese, eat a healthy diet and exercise regularly.

Take foods rich in folic acid to avoid birth defects.