Fewer women than men are saving for retirement, and those that are have less than half the savings of men, according to BlackRock’s annual Global Investor Pulse Survey.

In the U.S., 53 percent of women have started saving for retirement, compared with 65 percent of men. And they have accumulated less than half the savings as men, an average of $34,900 versus $76,800, according to the survey.

The survey found there is also a gap in savings behaviors. Close to half of men (45 percent) are willing to take on higher risks in order to achieve higher returns compared to just 28 percent of women. Also, cash represents a greater proportion of women’s total investments than men, 68 percent versus 59 percent. 

Reduced employment due to child care obligations seems to have a significant impact on women’s ability to save successfully for retirement, according to the survey. For example, only about half of women age 25 to 44 are working full-time, compared with more than three-quarters of men that age.  

The proportion of middle-aged and older women saving for retirement begins to match those of men, according to the survey. But the late start means women enter preretirement with less saved. Women age 55-64 have accumulated just $81,300 in retirement savings compared with $118,400 for men that age.  

This gap is particularly troubling given that women live longer than men—at birth, the life expectancy for U.S. women is about 79 compared to 72 for men, according to the report.

“With lower savings rates and less willingness to take risks, many women are faced with greater financial obstacles in retirement than men,” said Hollie Fagan, head of BlackRock’s RIA business.

BlackRock compared the savings habits of millennial women to baby boomer women and found things are changing. Millennial women are twice as likely to describe themselves as active investors (31 percent versus 15 percent). And they are nearly twice as likely to say they are willing to take on higher risks to achieve higher returns (41 percent versus 22 percent).

“Luckily, more and more women are becoming engaged investors, especially at a young age,” said Fagan.  “That engagement will be crucial to helping provide retirement income in our increasingly long lives.”

BlackRock interviewed 4,000 American investors as part of a poll that included 27,500 investors worldwide.