In most ectopic pregnancies, the blastocyst implants in the lining of the
A. uterus. B. oviduct. C. ovaries. D. vagina.
The correct answer and explanation is:
The correct answer is B. oviduct.
Ectopic pregnancy occurs when a fertilized egg implants outside the uterus, most commonly in the fallopian tubes, also known as the oviducts. The fallopian tubes are the usual site of fertilization, where the sperm meets the egg. After fertilization, the zygote typically travels down the tube into the uterus, where it implants into the uterine lining. However, in an ectopic pregnancy, the zygote fails to reach the uterus and instead implants in the fallopian tube.
This condition is dangerous because the fallopian tube is not equipped to support a growing embryo. As the embryo grows, it can cause the tube to rupture, leading to severe internal bleeding. The rupture is a medical emergency and can be life-threatening if not treated promptly. Ectopic pregnancies can also occur in other locations such as the ovaries, cervix, or abdominal cavity, but these instances are much rarer than implantation in the fallopian tubes.
Risk factors for ectopic pregnancy include previous tubal surgery, pelvic inflammatory disease (PID), endometriosis, and certain fertility treatments. Women who have had an ectopic pregnancy are at increased risk of having another one. Symptoms of an ectopic pregnancy can include abdominal pain, vaginal bleeding, and dizziness or fainting. Diagnosis is typically confirmed through ultrasound and blood tests to measure levels of human chorionic gonadotropin (hCG).
The treatment for an ectopic pregnancy depends on the location and size of the embryo. In some cases, medication (methotrexate) can be used to stop the growth of the embryo, while in more severe cases, surgery may be necessary to remove the embryo and repair any damage to the fallopian tube.