Maternity Nursing Q 123
The common normal site of nidation/implantation in the uterus is:
A. Upper uterine portion
B. Mid-uterine area
C. Lower uterine segment
D. Lower cervical segment
Correct Answer: A. Upper uterine portion
The embryo’s normal nidation site is the upper portion of the uterus. If the implantation is in the lower segment, this is an abnormal condition called placenta previa.
Option B: Implantation begins with apposition of the blastocyst at the uterine epithelium, generally about 2-4 days after the morula enters the uterine cavity. The implantation site in the human uterus is usually in the upper and posterior wall in the midsagittal plane.
Option C: When the implantation takes place in the lower part of the uterus, the placenta will later develop in the cervix uteri. This type of implantation is called placenta previa. A birth through the birth canal would detach the placenta before the fetus is born. This can lead to serious hemorrhages.
Option D: Aberrant implantation in the lower segment of the human uterus can occur in the cervix, cervico-isthmus (close to internal os of the uterine cervix), and previous cesarean scars. Cervical pregnancy (CP) is a rare form of ectopic pregnancy and its incidence is about 1 in 1000 to 1 in 18,000 live births