A new drug - Letrozole - increases birth rate in women suffering from Polycystic Ovary Syndrome (PCOS), according to a Penn State study.

PCOS, also known as hyperandrogenic anovulation, is a common hormonal problem among women of reproductive age. Currently, patients are administered Clomiphene citrate - a drug known to stimulate ovulation. But, the new study found letrozole to be more efficient than the current infertility treatment drug.

"Clomiphene has its drawbacks," said Dr. Richard Legro, professor of obstetrics and gynecology and lead author on the study, in a statement. "It's only 22 percent successful with up to six cycles of treatment in producing a successful birth, it has a high multiple-pregnancy rate in comparison to unassisted conception, and it has side effects including hot flashes and mood changes."

For the study, researchers randomly gave either clomiphene or letrozole to 750 infertile women with PCOS, aged between 18-40 years. The participants were asked to follow the medication for five cycles - dosage increasing with each cycle.

The researchers found that women, who popped letrozole, were associated with high birth rate of 27.5 percent as compared to 19.1 percent with clomiphene medication. The ovulation rate was also higher in the letrozole group.

The researchers also observed fewer twin pregnancies among those taking letrozole. Both the drugs were identified with certain side-effects. Comiphene intake caused higher rate of hot flashes, while letrozole resulted in higher incidence of fatigue and dizziness. Birth defects were rare and the rate was similar in the two medications.

The finding is published in New England Journal of Medicine.