By Amy Kramer of the National Campaign to Prevent Teen and Unplanned Pregnancy

A lot has changed since we first met Maci Bookout and Catelynn Lowell on "16 and Pregnant" in 2009: Catelynn and her fiancé Tyler Baltierra recently welcomed a baby girl, and Maci and her boyfriend Taylor McKinney have a daughter on the way.

But back when the "Teen Mom" cast members were teenagers, they were understandably overwhelmed by their respective situations. Cate didn't have a stable or supportive family to help her through the pregnancy, while Maci didn't have a partner as committed to parenthood as she was. Neither of them planned on starting their families when they were 16 years old -- and neither of them had the life experience they have now.

Although every situation is unique with its own specific set of circumstances, research tells us that in general, babies born to teenagers -– especially teenagers who aren't yet 18 -– face challenges that babies born to even slightly older women do not. For example, young teen moms are more than twice as likely to have a child placed in foster care before that child's fifth birthday as compared to women who have their first child at age 20 or 21. Young teen moms are twice as likely to have a reported case of abuse or neglect versus slightly older moms. Sons of young teen moms are more than twice as likely to spend time in prison, and daughters of young teen moms are far more likely to become teen moms themselves.

Having a baby as a young teenager is also hard on the teen mom. Young teen moms are far less likely to finish high school than slightly older moms, and they're also less likely to finish at least two years of college. Keeping that in mind, it's not surprising that by age 35, women who were young teen moms have also earned much less money working than women who were just a few years older when they started their families.

For years, we've watched as Catelynn and Maci worked to prevent getting pregnant again at a young age. Catelynn was the first of the girls to get an IUD, while Maci has talked extensively about the importance of birth control and her experience using various methods. But now, they've both made the mature decision that this is the appropriate time to expand their families -- and we're extremely happy for these courageous ladies.