On the campaign trail, U.S. Sen. Kirsten Gillibrand has spoken frequently about her experiences as a mother and how that role informs her policy positions. She has been talking about maternal health for some time, and she has raised the issue of racial disparities in the health care system.

In a recent tweet, the presidential candidate wrote: "A black woman in New York City is 12 times more likely to die in childbirth than a white woman. This isn’t an accident — it's a failure of policy and justice, and one we can’t accept. We have a moral responsibility to right it."

Is Gillibrand’s claim true?

Gillibrand’s spokesperson, Whitney Mitchell Brennan, referred us to a report from the pharmaceutical company Merck, as well as several news stories and editorials that repeat this statistic. A "Merck for mothers" report on maternal mortality and morbidity in New York notes that the United States is one of the "very few developed countries where deaths related to pregnancy or childbirth is increasing."

A report from the New York City Department of Health and Mental Hygiene’s Bureau of Maternal, Infant, and Reproductive Health is the source of the statistic in question.

The bureau used "enhanced surveillance" to gather the data on pregnancy-associated deaths in New York City between 2006 and 2010. That means that the bureau used "multiple data sources to identify and review deaths that occur during pregnancy or within one year from the end of pregnancy." This is the most updated data available, according to Danielle De Souza, spokeswoman for the department.

From 2006 to 2010, the pregnancy-related mortality ratio for black, non-Hispanic women was 12 times higher than that of white, non-Hispanic women, according to the report.

"This represents a widening of the pregnancy-related mortality gap from 2001 to 2005, when the (pregnancy-related mortality ratio) among Black, non-Hispanic women was seven times greater," researchers wrote.

The gap grew largely because the pregnancy-related mortality rate fell by 45 percent among white, non-Hispanic women.

From 2006 to 2010 in New York City, there were 56.3 deaths of black, non-Hispanic pregnant women per 100,000 live births. During the same period, there were 4.7 deaths of white, non-Hispanic pregnant women per 100,000 live births. The rates for both groups decreased from 2001-2005, when 61.7 black women died and 8.6 white women died per 100,000 live births.

From 2006 to 2010, Asian/Pacific Islander women were more than four times as likely and Hispanic women were more than three times as likely as a white woman to die from pregnancy-related causes, researchers found.

The report defines pregnancy-related death as "the death of a woman while pregnant or within one year of the end of pregnancy from any cause related to or aggravated by the pregnancy or its management. In these cases, the pregnancy and death are causally related."

Though Gillibrand said "childbirth" in this tweet, her spokeswoman sent us examples of the Senator using "pregnancy and childbirth" or "pregnancy-related complications" to describe the statistic in question, or related issues. These examples included other tweets and a news release.

The reasons why there are such large health disparities between black and white mothers are "not well established," researchers wrote. However, pregnancy-related deaths are associated with obesity, underlying chronic illness and poverty, which affect the city’s black population at greater rates. Researchers also wrote that the "chronic stress of racism and social inequality also likely contribute to racial disparities in health."

Government and health officials in New York City are trying to address the issue.

Our ruling

Gillibrand said that in New York City, a black woman is 12 times as likely to die in childbirth than a white woman.

Data analysis from the New York City Department of Health and Mental Hygiene show that black women are 12 times as likely to die from pregnancy-related causes than white women during pregnancy or within one year of the end of pregnancy.

Because the researchers use a broader timeframe for analyzing pregnancy-related deaths than just during "childbirth," Gillibrand’s characterization needs more context.

We rate Gililbrand’s statement Mostly True.