New York: Pregnant women who lived near the World Trade Centre and were exposed to dust from the 9/11 attack were more likely to have given birth prematurely and delivered babies with low birth weight, says a study.

These women experienced higher-than-normal negative birth outcomes.

Their babies — especially boys — were also more likely to have been admitted to neonatal intensive care units after birth, said researchers from Princeton University’s Woodrow Wilson School of Public and International Affairs.

“Our work suggests that women who lived in neighbourhoods exposed to the 9/11 dust cloud had very different experiences than women in other parts of New York City,” said Janet Currie, director of the Wilson School’s centre for health and wellbeing.

The collapse of the two towers created a zone of negative air pressure that pushed dust and smoke into the avenues surrounding the site.

Using data on all births that were in utero on September 11, 2001, in New York City, researchers found that for mothers in their first trimester during 9/11, exposure to this catastrophe more than doubled their chances of delivering a baby prematurely.

Of the babies born, boys were more likely to have birth complications and very low birth weights.

The neighbourhoods most affected by the 9/11 dust cloud included Lower Manhattan, Battery Park City, SoHo, TriBeCa, Civic Centre, Little Italy, Chinatown and the Lower East Side.

Past studies have shown that environmental exposure to the World Trade Centre dust cloud was associated with significant adverse effects on the health of adult community residents and emergency workers.

The study was released by the US National Bureau of Labour Economics.