When the pregnancy occurs outside the womb, it is ectopic. This occurs because the embryo gets implanted outside the uterus. Sperm fertilizes the egg inside the fallopian tube in a natural pregnancy process. The conceived embryo moves via the tube. After 3 to 4 days, this embryo reaches the uterine cavity.
The embryo travels down the tube as a result of smooth muscle contractions of the fallopian tube. But, sometimes blockage or damage results in the tube. This prevents the embryo from reaching the womb, and implantation occurs in the tube. This results in tubal pregnancy.
An ectopic pregnancy frequently occurs in the fallopian tube. Implantation can also take place in abdominal areas, in the ovaries, or the cervix.