"Call the Midwife" Season 4 has finally arrived on U.S. soil and it's going to premiere its first new episode by the end of the month. What are the new changes in the upcoming fourth season that fans should watch out for?

In Season 4 of "Call the Midwife," the sad stories of the nurses at the Nonnatus House continue to take center stage. However, in this season, fans can see the nurses move forward with their lives, particularly Trixie.

In the first episode, Trixie gets up close and personal with an impoverished child. According to the synopsis, this will make Trixie see the "unfamiliar darker side of life." Nevertheless, after going through the ordeal, there will be a romantic surprise waiting for her. It appears that her boyfriend Tom Hereward is ready to take their relationship one notch higher. Tom will propose to Trixie and there's no sign of Trixie not saying yes.

Also in the upcoming Season 4 pilot episode, a new nurse will be introduced into the story. "Nonnatus House welcomes a new resident, Nurse Barbara Gilbert," the synopsis read.

According to KenW, Nurse Barbara Gilbert will be off to a rough start, but later, she will be faced with a challenge of helping a new mother. Her efforts and actions will earn the respect of the other nurses at the Nonnatus House.

In the other spoilers, Shelagh will show how she balances work and being a mother. Shelagh brings her child to work and this shows how much she values being a mother and a hard worker at the same time, says CarterMatt. Further, Sister Evangeline will get her abdominal pain checked. Could it be something serious?

"Call the Midwife" Season 4 will premiere on March 29 on PBS.