Lennart Nilsson, a renowned Swiss photographer, has used the endoscope to look inside the fetal sac and obtain more accurate and beautiful pictures, connecting a light tube to an endoscopic camera and taking thousands of pictures of the fetus in the womb. Sperm swimming in the fallopian tube Egg cell The decisive encounter Only one sperm out of 200 million unites with the egg A longitudinal section of a sperm with genetic material stored in the head of the sperm One week later, the union produces an embryo that slips into the uterus One more week later, the newly conceived embryo attaches itself to the endometrium 22 days later, the embryo develops The heart of the fetus Day 28 after fertilization The 5-week-old fetus. At this time the fetus is only about 9 mm long, the face is developing, and the mouth, nostrils, and eyes are forming 40 days later, the outer embryonic cells fuse with the loose uterine surface to form the placenta Week 8 Week 10. The eyelids are half-closed at this time and will close completely within a few weeks 14 weeks. The fetus can already use its hands to explore its surroundings Week 16. Blood vessels are clearly visible through the thin skin Week 18. The fetus can perceive sounds from outside Week 19. Week 20. The fetus is about 20 cm long. Hair begins to appear on the head Week 24 Sixth month Week 36. After one month, the baby will come into the world.