What is the initial management for conservative treatment of threatened abortion?

Conservative Management of Threatened Abortion

Initial Diagnostic Confirmation

The cornerstone of initial management is transvaginal ultrasonography to confirm fetal viability and rule out ectopic pregnancy or subchorionic hematoma. 1

• Transvaginal ultrasound is the diagnostic method of choice and must be performed to assess cardiac activity, gestational sac characteristics, and detect subchorionic hematoma 1
• Serial β-hCG measurements can supplement ultrasound findings when viability is uncertain 2, 3
• The ultrasound must specifically exclude ectopic pregnancy before proceeding with conservative management 1

Core Conservative Management Protocol

Activity and Symptomatic Care

• Complete bed rest should be maintained until 48 hours after cessation of bleeding 4
• Avoid strenuous physical activity and sexual intercourse during the bleeding episode 5
• Monitor for progression of symptoms including increased bleeding, passage of tissue, or worsening cramping 2

Pharmacologic Support

• Progesterone supplementation is the most important hormonal treatment for maintaining early pregnancy, particularly in cases of luteal phase deficiency 5
• Folic acid supplementation should be initiated immediately 4
• Uterine sedatives (tocolytics) may be administered to reduce uterine cramping 4
• Hormonal treatment can be continued until 28 weeks of gestation in selected cases 4

Rh Immunoglobulin Considerations

• There is no evidence-based recommendation for anti-D immunoglobulin administration in threatened abortion with a viable fetus, and many physicians do not treat when there is a live embryo 1
• However, if pregnancy loss occurs, administer 50 μg of anti-D immunoglobulin to all Rh-negative women with documented first-trimester loss 1, 2

Follow-Up Surveillance

• Serial ultrasound examinations must be performed to assess ongoing fetal viability, growth, and development 1
• Repeat ultrasound within 7-14 days if initial scan shows viable pregnancy with subchorionic hematoma 4
• Continue monitoring throughout pregnancy as threatened abortion increases risk of subsequent complications including antepartum hemorrhage (7.5%), preterm labor, and intrauterine growth restriction (13.2%) 4, 6

Prognostic Indicators

• Subchorionic hematoma size >20 cm² is associated with higher spontaneous abortion rates 4
• Approximately 75-80% of threatened abortions continue to term with conservative management 4
• Spontaneous abortion occurs in less than 30% of cases following threatened abortion 4

Critical Pitfalls to Avoid

• Do not delay ultrasound evaluation—ectopic pregnancy must be ruled out immediately 1
• Do not provide treatment that would permit chromosomally or anatomically abnormal embryos to survive, as 50-60% of spontaneous abortions are due to chromosomal abnormalities 5
• Recognize that conservative management is only appropriate when the cervix remains closed and fetal cardiac activity is confirmed 2
• Be vigilant for signs of progression to inevitable abortion (cervical dilation) or infection (fever, purulent discharge, maternal tachycardia) which require immediate intervention 2