"Teen Mom 2" brings the drama in a first Season 7 trailer.

The preview sees Jenelle Evans attempt to regain custody of son Jace from her mom Barbara while balancing a relationship with her new beau, David Eason.

Leah Messer and ex-husband Corey Simms also battle for daughters Ali and Aleeah, while Kailyn Lowry and husband Javi Marroquin struggle with the aftermath of Lowry's miscarriage and Marroquin's impending deployment.

Chelsea Houska, meanwhile, is happily engaged to Cole DeBoer, although her daughter Aubree isn't impressed by their displays of affection.

Evans told TMZ she may be forced to leave "Teen Mom 2" in an interview Monday. The 24-year-old reality star is seeking treatment for unexplained joint pain and hot flashes and said her "health comes first" before the show.

Evans, Messer, Lowry and Houska came to fame on Season 2 of MTV series "16 & Pregnant" before starring on "Teen Mom 2." Season 7 will premiere Mar. 21 at 10 p.m. ET.