**Question:** Tubal patency is checked by all of the following except:

A. Transvaginal ultrasound
B. Hysterosalpingography (HSG)
C. Serum pregnancy test
D. Laparoscopy

**Core Concept:** Tubal patency refers to the ability of the fallopian tubes to allow the passage of sperm and ova. Tests performed to evaluate tubal patency include transvaginal ultrasound, HSG, and laparoscopy. Serum pregnancy test is used to detect a pregnancy and not specifically to evaluate tubal patency.

**Why the Correct Answer is Right:** The correct answer is **C. Serum pregnancy test**. A serum pregnancy test is a blood test that detects the presence of human chorionic gonadotropin (hCG) in the blood. hCG is produced by the placenta after fertilization of the egg, and not specifically related to tubal patency evaluation.

**Why Each Wrong Option is Incorrect:**

**A. Transvaginal ultrasound:** This test involves using ultrasound to visualize the fallopian tubes and assess their patency. It is a reliable method for evaluating tubal patency.

**B. Hysterosalpingography (HSG):** HSG is a radiological procedure that involves injecting contrast material into the uterus and fallopian tubes to visualize their patency on X-ray imaging. This test is used to evaluate tubal patency.

**D. Laparoscopy:** Laparoscopy is an invasive surgical procedure that involves inserting a camera into the abdominal cavity to visualize the fallopian tubes and assess tubal patency. Although it can confirm tubal patency, it is not the primary test for this purpose.

**Clinical Pearl:** Evaluating tubal patency is essential in assessing female fertility and reproductive health. The correct tests for tubal patency assessment include transvaginal ultrasound, HSG, and laparoscopy. Serum pregnancy tests are not used for this purpose.