Twin Pregnancy Care
Current Guidance Update
Chorionicity Assessment
Chorionicity determination at 11–14 weeks is mandatory for all multiple pregnancies to guide surveillance and management.
Twin Pregnancy Scans
DCDA twins require fortnightly scans from 20 weeks, while MCDA twins require fortnightly scans from 16 weeks.
Monochorionic Pregnancy Care
All monochorionic twin pregnancies should be managed in a fetal medicine unit because of the risks of TTTS and selective IUGR (sIUGR).
Recommended Delivery Timing
Recommended delivery timing is 38 weeks for DCDA, 36–37 weeks for MCDA, and 32–34 weeks for MCMA twin pregnancies in hospital.
Introduction
Twin Pregnancy Management
Types of Twin Pregnancy
DCDA twins have separate placentas and sacs with the lowest risk.
MCDA twins share one placenta and have risks of TTTS and selective growth restriction.
MCMA twins share both placenta and sac and carry the highest risk including cord entanglement.
Determining Chorionicity
Accurate determination at 11–14 weeks is the most important assessment. DCDA twins show the Lambda Sign, while MCDA twins show the T-Sign on ultrasound.
Twin-to-Twin Transfusion Syndrome
Occurs in approximately 10–15% of MCDA pregnancies. Laser photocoagulation is the preferred treatment with approximately 65–70% survival for both twins.
Other Specific Complications
Monitoring Schedule
Recommended Delivery Timing
DCDA
38+0 Weeks
MCDA
36–37+0 Weeks
MCMA
32–34+0 Weeks
Frequently Asked Questions
Are all twins identical?
No. Dizygotic (non-identical) twins are always dichorionic. Monozygotic (identical) twins can be either dichorionic or monochorionic depending on when the split occurs.
Can I deliver twins vaginally?
Vaginal delivery is appropriate in selected cases, primarily when both twins are cephalic, determined by presentation, gestational age, and maternal factors.
Conclusion
Twin pregnancy requires a level of specialist vigilance and clinical expertise that significantly exceeds routine obstetric care. Families expecting twins deserve evidence-based surveillance and management to optimise outcomes for both babies and the mother.
Sources & References
This article draws on guidance current at the time of writing from the following bodies and publications:
- RCOG GTG 51 (2016, updated 2023)
- NICE NG137 (updated 2023)
- FIGO (2023)
- ACOG (2023 Practice Bulletin #231)
General reference bodies for women's health guidance:
RCOG
rcog.org.ukACOG
acog.orgFIGO
figo.orgWHO
who.intNICE
nice.org.uk⚠ IMPORTANT DISCLAIMER
This article is provided for general knowledge and reference purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. No medication, treatment, or change to your healthcare should be undertaken based on this content without first consulting a qualified doctor. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition.
