Also known as: Hiatal hernia
A male fetus in a twin pregnancy has a severe diaphragmatic hernia that prevents proper lung development. Addison performs risky in utero surgery to insert a balloon into the fetus's trachea to allow normal lung development, despite the serious risks to the healthy twin sister.
Also known as: Amniotic bands
During the in utero surgery on the male twin, an amniotic band is discovered around the female twin that did not appear on original scans. Addison successfully removes it during the same surgery, potentially saving both babies.
Also known as: Manic depression
Sam's sister Corinne experiences a severe manic episode with psychotic features, including pressured speech, grandiose delusions about discovering a new galaxy, and paranoia. The episode escalates to violence when she falls through a window while agitated, requiring sedation and highlighting the severity of her psychiatric condition.
Also known as: Brain attack
Erica (Mason's mother) is recovering from a previous stroke with ongoing left-sided weakness and difficulty with daily activities. Her recovery is slower than hoped, affecting both her and Mason emotionally.
Also known as: Cut
During Corinne's manic episode, she falls through a glass window sustaining multiple lacerations with embedded glass. Sam also sustains a head laceration requiring sutures while trying to restrain her.