What is the most appropriate treatment plan for a patient presenting with vaginal bleeding and abdominal cramping at 9 weeks gestation with a closed cervix and a viable intrauterine pregnancy confirmed by transvaginal ultrasound?

Threatened Abortion with Viable Intrauterine Pregnancy

The most appropriate treatment plan is C: Reassure and evaluate after 1 week's duration. This patient has a threatened abortion (first-trimester bleeding with a closed cervix and viable intrauterine pregnancy), which requires expectant management with close follow-up rather than active intervention 1, 2.

Clinical Diagnosis

This presentation represents a threatened abortion, characterized by:

• Vaginal bleeding in the first trimester 1
• Closed cervix on pelvic examination (critical distinguishing feature) 1
• Viable intrauterine pregnancy confirmed by ultrasound with positive fetal cardiac activity 1, 2
• Crown-rump length appropriate for gestational age (9 weeks) 1

The closed cervix is the key finding that differentiates threatened abortion from inevitable, incomplete, or complete abortion, all of which would show cervical dilation 1, 2.

Why Reassurance and Follow-up is Appropriate

Expectant management is the standard of care for threatened abortion with documented fetal cardiac activity 2, 3. The presence of a viable embryo with cardiac activity at 9 weeks gestation indicates:

• The pregnancy has passed the critical early developmental milestones 1
• No immediate intervention is needed or beneficial 2, 3
• Many threatened abortions resolve spontaneously with continuation of viable pregnancy 4, 3

Follow-up ultrasound in 1 week allows assessment of:

• Continued fetal cardiac activity 1, 2
• Appropriate interval growth of the embryo 1
• Resolution or progression of bleeding 2, 3

Why Other Options Are Incorrect

Option A (Oxytocin infusion) is contraindicated because:

• Oxytocin is used to augment labor or manage postpartum hemorrhage, not first-trimester bleeding 3
• This would actively harm a viable pregnancy that the patient presumably desires to continue 2, 3

Option B (Admit and initiate antibiotic therapy) is inappropriate because:

• There is no evidence of infection (septic abortion would present with fever, purulent discharge, and typically an open cervix) 1, 3
• Antibiotics have no role in uncomplicated threatened abortion 3

Option D (Admit, stabilize, and prepare for possible termination) is incorrect because:

• The pregnancy is viable with documented cardiac activity 1, 2
• The cervix is closed, indicating the pregnancy is not actively miscarrying 1, 3
• Termination would only be considered if the patient desired elective abortion or if the pregnancy became nonviable on follow-up 3

Management Algorithm

Immediate assessment:

• Confirm hemodynamic stability (vital signs, quantify bleeding) 2
• Document ultrasound findings precisely: gestational sac size, crown-rump length, and presence of cardiac activity 1, 2
• Evaluate adnexa to exclude heterotopic pregnancy (though extremely rare in spontaneous conception) 1

Patient counseling:

• Approximately 50-60% of threatened abortions with documented fetal cardiac activity will continue as viable pregnancies 4
• Instruct patient to return immediately for heavy bleeding (soaking >2 pads/hour), severe pain, fever, or dizziness 2, 3
• Pelvic rest (avoid intercourse, tampons, douching) is commonly recommended though evidence is limited 3

Follow-up protocol:

• Repeat transvaginal ultrasound in 7-14 days to confirm continued viability 1, 2
• If cardiac activity persists and appropriate growth is documented, transition to routine prenatal care 3
• If cardiac activity is absent on follow-up, diagnose early pregnancy loss and offer expectant, medical, or surgical management options 2, 3

Critical Pitfall to Avoid

Do not make management decisions based solely on bleeding in the presence of a viable intrauterine pregnancy with closed cervix 1, 3. First-trimester bleeding is common (occurring in 20-25% of pregnancies) and does not automatically indicate pregnancy failure when fetal cardiac activity is documented 4, 3. Premature intervention could result in iatrogenic loss of a desired viable pregnancy 2, 3.