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: Work out where the pregnancy should be.
A six week gap since the last period places this woman early in pregnancy, a stage where a normal intrauterine pregnancy should already show a visible sac inside the uterus on ultrasound.

Step 2: Notice what is missing.
Here the uterine cavity is empty. If the pregnancy is real but not inside the uterus, it must be growing somewhere else, most commonly in the fallopian tube.

Step 3: Explain the fluid in the pouch of Douglas.
Free fluid behind the uterus in a pregnant woman with pain usually means blood has leaked into the pelvis. A tubal pregnancy that is leaking or has ruptured bleeds into this space, which fits exactly with what the scan shows.

Step 4: Test the alternatives against these two findings.
A twisted ovarian cyst would show a cystic mass on the ovary, not an empty uterus tied to a missed period, so it does not fit. Threatened abortion and missed abortion both need a pregnancy sac sitting inside the uterus on the scan, which is the opposite of what is described here.

Step 5: Conclude.
An empty uterus with amenorrhea and pelvic free fluid is the signature picture of ectopic pregnancy.
\[ \boxed{\text{Ectopic pregnancy}} \]