Women who give birth after age 30 have lower risk of developing endometrial cancer compared to those who become mothers in their early 20s, revealed a new study.

Researchers from the University of California have found that women who give birth after 30 are at 44 percent lower risk of developing the disease as against those having early child birth.

They found that the risk begins to decrease approximately 13 percent after age 30, for each five-year delay in last births.

Endometrial cancer is the most common type of uterine cancer that strikes the endometrium, the tissue lining the uterus (womb).

The study analysed data from over 8,600 endometrial cancer cases and 16,562 control subjects, who gave birth after age 30.

"We found that the lower risk of endometrial cancer continued for older mothers across different age-at-diagnosis groups, including under 50, 50-59, 60-69, and over 70 - which shows that the protection persists for many years," said Veronica Wendy Setiawan, assistant professor of preventive medicine at the Keck School.

"Protection also did not vary by the two types of the disease: the more common Type 1, which we think is related to estrogen exposure; and the more rare, but more aggressive and deadly, Type 2, which have been thought to develop independent of hormones," she added.

The study revealed that the findings were consistent across race and ethnicity except a small subset of black women.

Researchers believe that the discovery will help in the understanding and prevention of the endometrial cancer.

"This study shows an important protective factor for endometrial cancer, and when the exact mechanism by which it protects women from getting the disease is known, it can help our understanding of how endometrial cancer develops and thus how to prevent it," Setiawan said.