In Sex Without Strings, Relationships Without Rings , Rutgers University's National Marriage Project annual survey, sociologist David Popenoe reports that men and women shift their values and expectations as they go from their 20s to their 30s. Men continue to enjoy the singles scene into their 30s, living on their own or with mom and uninterested in commitment. In their 30s many women become more interested in settling down even as they become more pessimistic about finding a husband. Single motherhood often becomes more attractive. Married or not, older women are more likely to have problem pregnancies, and low birth weight babies, under 5.5 pounds.
Infertility increases with age.
But many think infertility has easy solutions. Women can now freeze their eggs or ovarian tissue before having life-saving radiation therapy, so that they may later have babies. Eggs can also be harvested from ovarian tissue and transplanted to mice. But few can afford these rare experimental procedures. In 1998 less than 5 percent of single birth babies were born at low birth weights, but 50 percent of twins and 92 percent of triplets weighed in low.