Situation: The nurse works in the prenatal clinic and antepartum ward of a provincial hospital. A 20-year-old is followed with weekly serum human chorionic gonadotropin (hCG) tests after suction evacuation of a complete hydatidiform mole. She takes combined oral contraceptive pills and has no symptoms. Her results are: Week 1: 52,000 mIU/mL Week 2: 8,400 mIU/mL Week 3: 1,020 mIU/mL Week 4: 1,010 mIU/mL Week 5: 1,000 mIU/mL Week 6: 990 mIU/mL Which items should the nurse include in her plan now? 1. Report the trend to the physician for evaluation of gestational trophoblastic neoplasia 2. Continue her combined oral contraceptive pills 3. Tell her the hCG is still falling and change testing to monthly 4. Arrange insertion of an intrauterine device at this visit

From week 3 to week 6 the hCG changes by only about 3% across four weekly values, which is a plateau (four values over 3 weeks within about 10% of each other). A plateau or rise after molar evacuation signals gestational trophoblastic neoplasia and must be reported for evaluation and chemotherapy. Monthly testing starts only after hCG becomes undetectable, reliable hormonal contraception continues, and an intrauterine device is not placed while hCG is abnormal.

Clinical situation A 20-year-old patient is being monitored with weekly serum hCG after suction evacuation of a complete hydatidiform mole. Her values fall sharply from 52,000 mIU/mL to 1,020 mIU/mL over the first three weeks, but then remain essentially flat: 1,020, 1,010, 1,000, and 990 mIU/mL across weeks 3 through 6. This pattern is not a continued decline; it is a plateau.

Why this is a plateau, not a falling hCG The change from week 3 to week 6 is only about 3% across four weekly values. In postmolar surveillance, a plateau is defined as four values obtained over at least three weeks that stay within approximately 10% of one another. A plateau or a rise in hCG after molar evacuation is a diagnostic criterion for gestational trophoblastic neoplasia (GTN) and must be reported for evaluation. The initial sharp drop reflects clearance of the molar trophoblastic tissue, but the subsequent flattening indicates that some trophoblastic cells remain active and are producing hCG.

Pathophysiology link In a complete hydatidiform mole, trophoblastic tissue proliferates abnormally and secretes hCG. After suction evacuation, most of this tissue is removed, so hCG falls rapidly. When the decline stops and the level plateaus, it means residual or transformed trophoblastic cells are persisting. These cells may invade the myometrium or metastasize, which defines gestational trophoblastic neoplasia. GTN after a complete mole is highly responsive to chemotherapy when diagnosed early, so recognizing the plateau promptly is the priority nursing action ^[1][3].

Interpreting each option

Option	Correct?	Rationale
1. Report the trend to the physician for evaluation of GTN	Yes	A plateau meets the diagnostic threshold for GTN. The physician must be notified so staging and chemotherapy can be planned without delay [1][3].
2. Continue her combined oral contraceptive pills	Yes	Reliable hormonal contraception is recommended during postmolar follow-up because a new pregnancy would raise hCG and make it impossible to tell whether the rise is from GTN or a new gestation. Combined oral contraceptives do not increase the risk of GTN and are appropriate to continue .
3. Tell her the hCG is still falling and change testing to monthly	No	The hCG is not falling; it is plateaued. Monthly testing is appropriate only after hCG becomes undetectable. While hCG remains abnormal, weekly testing continues .
4. Arrange insertion of an intrauterine device at this visit	No	An intrauterine device should not be placed while hCG is abnormal. Insertion carries a risk of uterine perforation in the setting of residual trophoblastic disease, and the device would complicate interpretation of bleeding symptoms [1].

Key point! The combination of a plateau in hCG plus continued reliable hormonal contraception is the correct plan. Reporting the plateau for GTN evaluation is the urgent action, while continuing combined oral contraceptives prevents a confusing new pregnancy.

Watch out! Do not mistake a plateau for a slow decline. A change of only 3% over three weeks is not a meaningful fall. Also, do not place an intrauterine device while hCG is abnormal; this is contraindicated during active postmolar surveillance ^[1].

Clinical reasoning for the nursing plan The nurse should first recognize that the hCG trend has changed from a decline to a plateau. This triggers the need for physician notification and evaluation for GTN. At the same time, the patient should continue her combined oral contraceptive pills because they are safe in this setting and essential for accurate hCG interpretation. Monthly testing is not appropriate yet, and intrauterine device insertion is deferred until hCG normalizes. The correct answer is therefore options 1 and 2.