Zona Pellucida

The outer layer of the egg that persists and surrounds the embryo until about 4-5 days after fertilisation.

Uterus

Womb / Hollow muscular organ in the woman that holds and nourishes the foetus until the time of birth.

Ultrasound

Use of high-frequency sound waves for creating an image of internal body parts. Used to monitor the development of follicles and to detect and monitor pregnancy.