Question

22 year old nullipara presents with 1 and half months amenorrhea, abdominal pain. USG reveals empty uterine cavity and free fluid in the pouch of Douglas. What is the likely diagnosis?

• A. Twisted ovarian cyst
• B. Threatened abortion
• C. Ectopic pregnancy
• D. Missed abortion

Hint:

Match the missed period, empty uterus, and pelvic free fluid to a pregnancy growing outside the uterus.

Answer 1

The Correct Option is C

Step 1: List the key facts in the case.
This is a 22 year old woman who has never delivered before. She has missed her period for about six weeks, which by itself already suggests early pregnancy, and she now has abdominal pain.

Step 2: Read the ultrasound findings.
The uterine cavity is empty, meaning no pregnancy sac is seen inside the uterus even though she should be around six weeks pregnant based on her missed period, a stage where an intrauterine sac is usually visible. There is also free fluid in the pouch of Douglas, the space behind the uterus, which points to blood or fluid collecting in the pelvis.

Step 3: Put the picture together.
Amenorrhea with an empty uterus plus free pelvic fluid is the classic pattern for a ruptured or leaking ectopic pregnancy, where the pregnancy has implanted outside the uterus, most often in the fallopian tube, and is bleeding into the pelvis.

Step 4: Rule out a twisted ovarian cyst.
A twisted ovarian cyst causes sudden severe pain from a cyst mass, but it does not explain the amenorrhea or an empty uterus, and a cyst would usually be visible on scan rather than an empty cavity.

Step 5: Rule out threatened abortion.
In a threatened abortion, the pregnancy is inside the uterus, so the scan would show an intrauterine sac, sometimes with a bit of bleeding around it, not an empty cavity.

Step 6: Rule out missed abortion.
A missed abortion means the pregnancy has died but is still retained inside the uterus, so the uterus would show a sac or fetal pole on the scan, again not an empty cavity, and it would not typically cause free fluid in the pouch of Douglas.

Step 7: Final answer.
The combination of amenorrhea, an empty uterine cavity, and free fluid in the pouch of Douglas points to ectopic pregnancy.
\[ \boxed{\text{Ectopic pregnancy}} \]