When the embryo attaches to the uterus, which takes place around the fourth week of pregnancy approximately, it starts releasing hCG hormone.
hCG is the hormone that is responsible for the first pregnancy symptoms, including morning sickness and nausea. On the other hand, beta-hCG is the hormone detected by pregnancy tests. When hCG is detected, pregnancy tests show a positive result.
Read the full article on: The first month of pregnancy: initial symptoms and maternal care ( 79).
By Blanca Paraíso M.D., Ph.D., M.Sc. (gynecologist), Carmen Ochoa Marieta M.D., Ph.D., M.Sc. (gynecologist), Daniel Sosa M.D., M.Sc. (gynecologist), Silvia Azaña Gutiérrez B.Sc., M.Sc. (embryologist), Zaira Salvador B.Sc., M.Sc. (embryologist), Michelle Lorraine Embleton B.Sc. Ph.D. (biochemist) and Cristina Algarra Goosman B.Sc., M.Sc. (psychologist).
Last Update: 02/21/2018