What is the management plan for a dichorionic/diamniotic twin pregnancy with a fetal demise at 7 weeks 2 days, with the surviving fetus (Fetus A) having a normal heart rate and appropriate growth for gestational age?

Management of Dichorionic/Diamniotic Twin Pregnancy with Single Fetal Demise

For a dichorionic/diamniotic twin pregnancy with early fetal demise of one twin at 7 weeks and a healthy surviving twin at 14 weeks, expectant management with regular ultrasound surveillance every 3-4 weeks is recommended, with full-term delivery at 39 weeks if no complications arise. 1

Risk Assessment for the Surviving Twin

• In dichorionic twin pregnancies with single fetal demise, the prognosis for the surviving twin is generally excellent, especially when the demise occurs early in pregnancy (first trimester) 1
• Unlike monochorionic twins, dichorionic twins do not share placental circulation, significantly reducing the risk of neurological injury to the surviving twin 1
• The surviving twin still has a higher risk than singletons for complications including growth restriction, low birth weight, and preterm delivery 1

Recommended Surveillance Protocol

• Perform regular ultrasound assessments every 3-4 weeks for dichorionic twins without complications 1
• Each ultrasound should include:
  • Fetal biometry to monitor growth of the surviving twin 1
  • Amniotic fluid volume assessment 1
  • Umbilical artery Doppler studies after 20 weeks 1
• Consider transvaginal ultrasound for cervical length assessment to evaluate risk for preterm delivery 1
• Increase surveillance frequency if any signs of growth restriction or other complications develop 1

Growth Assessment Considerations

• Calculate and document estimated fetal weight (EFW) discrepancy at each scan from 20 weeks onward (comparing to growth charts) 1
• Be vigilant for signs of selective intrauterine growth restriction (sIUGR), defined as EFW below the 10th percentile 1
• Growth restriction may be predicted by earlier scans - discordance in abdominal circumference by >10% between 14-22 weeks is a predictor of subsequent adverse outcomes 1

Timing of Delivery

• With no other obstetric complications, dichorionic pregnancies with previous single fetal demise can be delivered at term (39 weeks) 1, 2
• Earlier delivery may be indicated if complications develop such as:
  • Abnormal Doppler findings 1
  • Growth restriction of the surviving twin 1
  • Maternal complications 1

Special Considerations

• Evaluate for any signs of maternal complications that may have contributed to the fetal demise, such as hypertensive disorders 3
• Ensure Rh-negative women receive Rh immunoglobulin (RhoGAM) to prevent alloimmunization 4
• Document the confirmed fetal demise and discuss expectations regarding the retained demised fetus 4
• Provide psychological support, as single fetal demise can be emotionally challenging for parents 5

Common Pitfalls to Avoid

• Avoid unnecessary early delivery - unlike monochorionic twins, dichorionic twins with single fetal demise do not benefit from preterm delivery in the absence of other complications 1, 2
• Don't confuse management protocols for dichorionic and monochorionic twins - they require different surveillance schedules and have different risk profiles 1
• Ensure adequate documentation of chorionicity determination, as this fundamentally guides management 1
• Don't overlook the potential psychological impact of continuing a pregnancy with a demised twin 5