Motherhood changes every woman from within, it is perhaps one of the best things happens to a woman.

But there are lot of factors associated with pregnancy which may leave deep impact in the long run, both for mother and the baby.

One recent study that was carried out by Princeton University's Woodrow Wilson School of Public and International Affairs reported that pregnant women who lived close to the World Trade Center during 9/11 trauma had gone through higher-than-normal negative birth outcomes.

Researchers found that babies of such mothers were born prematurely and they had significantly low birth weights. Also the baby boys were on the higher risk of getting admitted to neonatal intensive care units after birth.

According to the report by Science Daily, this research led by Janet Currie and Hannes Schwandt was released through the National Bureau of Labor Economics.

"Our work suggests that the women who lived in neighborhoods exposed to the 9/11 dust cloud had very different experiences than women in other parts of New York City," said Curie.

Previous studies reported that the dust and smoke came out after 9/11 disaster left huge adverse impacts on the health of adult emergency workers.

The neighborhoods mostly affected by the 9/11 dust cloud were Lower Manhattan, Battery Park City, SoHo, TriBeCa, Civic Center, Little Italy, Chinatown and the Lower East Side.

The scientists analysed on all births that were in utero on Sept. 11, 2001 and concluded that for mothers who were in their first trimester during 9/11, exposure to this life-shattering event more than doubled their chances of giving premature birth.

But at the same time, motherhood is not just about counting risk factors and unknown anxieties. Motherhood is celebration, motherhood is joy.

And pregnant celebrities from Hollywood keep coming up with unique ways to express their happiness on being a mother.

Renowned celebrities like Demi Moore, Cindy Crawford, Brooke Shields, Britney Spears, Monica Bellucci and Christina Aguilera posed nude with their heavily pregnant bodies on different magazine covers.

According to the report by Daily Mail, Christina was quoted saying, "As a woman, I'm proud to embrace my body through all stages of life, staying fearless and confident in surrendering to the unknowns the future has in store.”

Pride, purity and peace, every mother celebrates them at the same time.