Twin Pregnancy Fetal Medicine
In short
Twin pregnancies are monitored by chorionicity, not simply by being twins. Identical twins sharing one placenta need scans every two weeks from 16 weeks because of the risk of unequal blood flow; twins with separate placentas are scanned less often. Chorionicity is best established in the first trimester. Fetal sex is neither determined nor disclosed, as per the PC-PNDT Act.
Twin pregnancies require specialised fetal medicine input throughout, particularly for monochorionic twins who face risks unique to shared placental circulation.
Critical first-trimester finding
Chorionicity (one placenta or two) determines pregnancy risk and surveillance protocol. Best determined at 11-13 weeks by ultrasound (T-sign vs lambda sign). Monochorionic pregnancies carry significantly higher risk than dichorionic.
TTTS, sIUGR, TAPS, TRAP
TTTS (twin-to-twin transfusion) affects 10-15 percent of monochorionic twins – unequal blood sharing requiring laser treatment.
sIUGR (selective intrauterine growth restriction) – unequal placental sharing.
TAPS (twin anaemia-polycythaemia sequence) – chronic small blood transfer.
TRAP (twin reversed arterial perfusion) – rare but specific to monochorionic twins.
How we monitor twins
Monochorionic twins: scan every 2 weeks from 16 weeks. Dichorionic twins: every 3-4 weeks from 20 weeks. Growth, Doppler, and amniotic fluid assessed at each scan.
Your fetal-medicine specialist
Your twin pregnancy is monitored by a clinician dedicated to fetal medicine, with a direct pathway to senior gynaecologist Dr. Priyadatt Patel for any pregnancy that needs obstetric care.
Dr. Mayank Chaudhary
An ISUOG-trained fetal-medicine consultant who monitors twin pregnancies with serial growth and Doppler surveillance, especially for monochorionic twins.
Standards & further reading. Our approach aligns with the ISUOG guidelines and the NHS pregnancy ultrasound guide.
Related fetal-medicine pages
NT ScanAnomaly Scan (TIFFA)Doppler ScanNIPTPrenatal GeneticsAmniocentesisCVSCVS vs AmniocentesisFetal MedicinePregnancy Care
Frequently asked
Why twin pregnancies need closer monitoring
A twin pregnancy is a higher-risk pregnancy, and the single most important question is the chorionicity — whether the twins share a placenta. This is established on an early scan and shapes the entire monitoring plan.
Shared-placenta (monochorionic) twins
Twins that share a placenta carry specific risks — most importantly twin-to-twin transfusion syndrome and selective growth restriction — and need more frequent, specialist ultrasound surveillance (typically fortnightly from the second trimester). Early detection is what allows timely intervention.
What we watch for across all twins
Growth discordance, pre-eclampsia, anaemia, preterm labour and complications of delivery are all more common with twins. A structured scan-and-review schedule, individualised to your chorionicity, lets us act early rather than react late.
Planning delivery
Timing and mode of delivery depend on chorionicity, growth, and your obstetric history; we plan this with you well in advance rather than leaving it to chance, and coordinate neonatal support for the birth.
Frequently asked questions
Are twin pregnancies always high risk?
Can twin pregnancy problems be treated before birth?
When are twins typically delivered?
Dr. Priyadatt Patel
Senior Gynecologist · Advanced Laparoscopic Surgeon · IVF and Endometriosis Programme Lead
MS OBGyn · Pregnancy Care · Advanced Gynaecological Ultrasound · Fertility Preservation
ESHRE / ESGE / AAGL / ASRM guideline-aligned practice. 3D Karl Storz precision technique. Fertility-preservation-first philosophy. Evidence-based decisions, honest counselling, long-term outcomes orientation.
Science City Road, Ahmedabad 380060
Mon–Sat 11:00–20:00 · +91 97234 31544
Naranpura, Ahmedabad
Mon–Sat 08:30–10:30 · +91 70460 02566
