Most dramatic moments yet on '16 and Pregnant' Tyler Baltierra gives up his daughter, Carly, on the first season of "16 & Pregnant." A new season of MTV's incredibly popular docuseries "16 & Pregnant" kicks off Tuesday night. The show's fourth season promises to bring even more chaotic situations, with one girl mourning the death of her baby's father and another who must deal with a baby daddy who has a drug problem. Still, the new girls will have a tall order to fill if they want their stories to bring the dramatic moments that the show's previous subjects have delivered. Since its debut in June 2009, "16 and Pregnant" has seen its share of intense scenes - from arrests to over-the-top grandparents to complete relationship breakdowns, all of which were captured on camera and served up to MTV viewers. There have been 35 girls who have appeared on the show to date, and while each of their episodes have included climactic moments, here are five that had "16 & Pregnant" viewers talking for days. Chelsea gets attacked by her baby's dad (season two) Future "Teen Mom 2" star Chelsea Houska was not only dealing with the stress of being a new mother, but also trying to keep her crumbling relationship with her baby's father, Adam, intact, despite the fact that he did little to help with their daughter, Aubree. After Chelsea confronted him for his lack of interest in her and Aubree, Adam went on a text-messaging rampage, firing off multiple hate messages attacking Chelsea's mothering skills, her post-baby body and even calling their baby a "mistake." Unfortunately Adam has not changed much since then. He would later go on to refer to Aubree as "the little bastard" during the second season of "Teen Mom 2." Watch the full episode. Ashley can't let go (season two) Ashley Salazar struggled throughout her entire episode with her decision to place her daughter, Callie, up for adoption. After giving birth, she signed over parental rights to her aunt and uncle who had agreed to raise the baby. The next day Ashley changed her mind and was overwhelmed with regret, so she went to her aunt and uncle's house to pick up her daughter. Although Ashley did attempt to parent Callie, she later realized that her original decision to go ahead with the adoption was the best for her daughter and once again surrendered custody of the baby. Allie vs. the drug-addicted grandma (season three) With her own mother living in another state, Allie Mendoza moved in with her boyfriend Joey's family after she discovered that she was pregnant. However, not everyone was happy with the arrangement, especially Joey's mother, Yolanda, whose substance abuse problem made her quite vocal in her hate for Allie. Yolanda exploded on Allie one day, calling her names, telling her to abort her baby and even attempting to fight the pregnant teen before Joey stepped in. After that incident, the couple moved in with Joey's grandmother. Be warned: There's a bit of bleeped adult language in the clip. Jennifer's roadside baby-daddy drama (season three) Jennifer Del Rio and her baby's father, Josh, proved to be one of the show's most tumultuous couples ever. Though they got engaged at the beginning of the episode, things turned ugly after Jennifer gave birth to their twins. The couple got into a heated argument while driving, causing Jennifer to demand that Josh pull the car over and let her and the twins out. However, Josh drove off before she could get the babies out of the car, leaving Jennifer standing on the side of the road, screaming. He came back and, after physically lifting Jennifer away from the car, was arrested. As he was led away in handcuffs, Jennifer screamed that he would never be allowed to see his kids again. Catelynn and Tyler give up their daughter (season one) Catelynn Lowell and her boyfriend, Tyler Baltierra, decided to give their daughter, Carly, up for adoption in hopes that she would be raised in a better environment than they were. Despite their parents" objection, the couple was content with their decision. However, when the moment came for them to actually hand over their daughter to her adoptive parents, things got extremely emotional. In what is often called the most dramatic moment in "16 & Pregnant" history, Catelynn and Tyler broke down as they watched their daughter be driven away to her new life. Viewers later followed the young couple as they learned to cope with the adoption on the popular spinoff "Teen Mom." The new season of "16 and Pregnant" premieres with back-to-back episodes on Tuesday, March 27, at 10 p.m. on MTV. Which episode shocked or brought you to tears?