One good bit of news its analysis found is that the average retirement savings balance for women was up 17 percent from a year ago, and 71 percent from 2009. Also, the gap between the average balance between women and men dropped, just a bit, to 37.8 percent in the second quarter from 40.5 percent in 2010. 

A campaign that the company ran earlier in the year to get participants to increase deferral or savings rates did better with women than it did with men. Younger women, those between 18-34, did best of all, with their response rates up 38 percent from 2013 and 55 percent from 2012. Women aged 35-54 were no slouches, though; their response rates were up 42 percent from the same time last year. 

Why the happy results? According to Elaine Sarsynski, executive vice president, MassMutual Retirement Services, the firm has been able to more tightly segment specific target markets and appeal to narrower demographic groups on their terms. Retirement-saving messages, graphics, images and photos and delivery vehicles are being tailored to fit market segments to better connect with retirement plan participants, she explained. 

That doesn't mean the battle is won, however. Women's average salary deferral or savings rates still trail those of men, 5.37 percent to 5.70 percent of compensation, respectively. However, women's deferral rates have held fairly steady since 2010, while the rates for men have fallen. 

"The longer-term trends show women are taking retirement savings more seriously and in some instances are now eclipsing men," Sarsynski said. "We're now finding that women's retirement savings account balances in defined contribution plans such as 401(k)s are climbing faster than men's."