OG11.1 | Multiple Pregnancy — Summary & Reflection

KEY TAKEAWAYS

Multiple Pregnancy — Key Points:

• Epidemiology: Incidence rising due to ART; twins ~1 in 80 natural conceptions in India; perinatal mortality 5–6× higher than singleton.
• Classification: DZ (70%, always DCDA) vs MZ (30%, chorionicity by split timing); chorionicity is the dominant prognostic factor.
• Chorionicity by USS (11–14 weeks): Lambda (twin peak) sign = DCDA; T-sign = MCDA; absent inter-twin membrane = MCMA. Determine at first trimester or accuracy is lost.
• Complications (maternal): Anaemia, GDM, PIH/pre-eclampsia, APH, PPH (atony from overdistension), preterm labour, operative delivery.
• Complications (fetal): Prematurity, FGR/sIUGR, TTTS (MC only), cord entanglement (MCMA), congenital anomalies.
• TTTS (MC twins only): Quintero Stages I–V; treatment = fetoscopic laser ablation (Stages II–IV); amnioreduction in centres without laser.
• Surveillance: DCDA — 4-weekly USS, deliver at 38 wks; MCDA — 2-weekly USS from 16 wks, deliver 36–37 wks; MCMA — inpatient from 28–30 wks, CS at 32–34 wks.
• Delivery: Twin 1 cephalic = vaginal delivery feasible (DCDA/MCDA); CS mandatory for MCMA, conjoined, both non-cephalic.
• Prepare: Blood products + active third stage management for all twin deliveries (PPH risk is high).

REFLECT

Reflect using Kolb's cycle:

Concrete Experience: Recall the two patients from the opening hook — Mrs Priya (lambda sign, DCDA) and Mrs Lakshmi (T-sign, MCDA). Now that you have completed the module, explain in your own words why their surveillance schedules and delivery plans are fundamentally different, even though both have twin pregnancies.

Reflective Observation: What would you look for at the 20-week scan in Mrs Lakshmi that you would not specifically look for in Mrs Priya? What would prompt you to refer Mrs Lakshmi urgently to a fetal medicine centre?

Abstract Conceptualisation: At the mechanistic level, why does a shared placenta (monochorionic) create the risk of TTTS? Why can this only happen between twins, not between mother and fetus (even though mother and fetus share the placenta)? (Hint: the vascular communications in TTTS are within the fetal circulation, not the maternal-fetal interface.)

Active Experimentation: On your next antenatal clinic posting, ask to see an USS report from a twin pregnancy. Try to identify whether the chorionicity has been documented. If the patient is MCDA, check whether her next appointment is in 2 weeks — and whether it includes a Doppler assessment. If not, ask your supervisor why not.