The process of pregnancy begins with sperm traveling through the uterus to the fallopian tube, where it may meet an egg released from the ovary. Fertilization, the fusion of sperm and egg, typically occurs in the fallopian tube. Following fertilization, the egg develops into an embryo, progressing through stages such as a fertilized egg, a day 3 embryo, and a day 5 blastocyst. The blastocyst has two main parts: one that will form the baby and another that will become the placenta. This embryo then hatches from its outer shell and implants into the uterus. After implantation, the embryo develops into a fetus, which subsequently grows into a baby. This sequence forms the foundational understanding for reproductive health assessments and treatments.