Final answer:
The umbilical cord is safeguarded by Wharton's jelly, a connective tissue that prevents the cord's blood vessels from being compressed.
Step-by-step explanation:
The nurse's best response to the woman's question about what protects the baby's umbilical cord from being squashed while inside the mother would be, 'Your baby's umbilical cord is surrounded by connective tissue called Wharton's jelly, which prevents compression of the blood vessels.'
This connective tissue provides cushioning and protection, ensuring that the essential functions of the cord are maintained. The cord itself comprises two arteries and a vein, which are critical for transporting nutrients, oxygen, and waste between the mother and the fetus. The amniotic fluid within the amniotic sac also helps to cushion and protect the fetus by allowing it to move freely and serve as a shock absorber against external pressure.