Monochorionic Twin Pregnancy Scan in Nagpur
Twins who share one placenta share a circulation. This is the fortnightly surveillance that finds the problems that causes — performed and interpreted by Dr. Kunda Shahane, who manages the pregnancy that follows.
A monochorionic twin pregnancy is one in which both babies share a single placenta. Almost every shared placenta contains blood vessels that join the two circulations, and those connections are what create the risks specific to these pregnancies. None of them can be prevented. All of them can be found early, and finding them early is what changes the outcome. That is why monochorionic twins are scanned every two weeks from 16 weeks rather than every four, and why each of those scans measures a specific list of things rather than simply checking that both babies are growing. At Mayflower Fetal Medicine & High-Risk Pregnancy Centre the scans are performed by Dr. Kunda Shahane herself, and the plan that follows each scan is hers.
Who performs these scans
Dr. Kunda Shahane is MBBS, MS (Obs & Gynae), FIFM, FMF (London) — an obstetrician and gynaecologist who then subspecialised in fetal medicine, with 20+ years in medicine and 14+ years in fetal medicine. She holds Fetal Medicine Foundation certification and follows FMF protocols for twin surveillance. She was the first in Vidarbha to introduce laser therapy for twin-to-twin transfusion syndrome.
Monochorionic surveillance is a long relationship, not a single appointment. From 16 weeks to delivery you are in the same room with the same person roughly every fortnight, and the value of that is cumulative: the scan that matters is usually the one where something has changed since last time, and change is only visible to someone who saw the last one. It also means the doctor watching the babies is the same one managing your blood pressure, your thyroid, your haemoglobin and your delivery plan.
At a glance
- Starts
- 16 weeks, after chorionicity is established
- Interval
- Every 2 weeks; more often if something is found
- Duration
- 30–45 minutes per visit
- Preparation
- None — no fasting, no full bladder
- Measured
- Fluid each side, both bladders, growth, Doppler
- Delivery
- Generally planned at 36+0–36+6 weeks
What monochorionic means, and what it does not
Monochorionic twins are almost always identical, having come from a single fertilised egg that divided after the placenta had begun to form. Most have a separate amniotic sac each — monochorionic diamniotic, or MCDA. A small number share one sac — monochorionic monoamniotic, or MCMA, roughly 5% of monochorionic pregnancies, which follows its own pathway.
Sharing a placenta does not mean something is wrong. Most monochorionic pregnancies never develop a serious complication and end with two healthy babies. What it means is that a group of problems becomes possible which cannot occur when each baby has its own placenta, and that those problems can appear and progress within a fortnight. The monitoring exists because of the speed, not because of the odds.
If you do not yet know whether the babies share a placenta, that comes first. See the chorionicity scan — it is the single finding on which everything on this page depends.
What the fortnightly scan is looking for
Twin-to-twin transfusion syndrome (TTTS)
Blood passes unevenly through the shared vessels, so one twin receives too much and the other too little. It complicates roughly 10 to 15 in every 100 monochorionic pregnancies. On ultrasound it shows as a growing difference in amniotic fluid — too much around one baby, too little around the other — and often an absent bladder in the smaller twin. This is why the deepest fluid pocket is measured on both sides at every single visit, and why the bladders are specifically looked for. Where treatment is needed, fetoscopic laser separates the connecting vessels; Dr. Kunda was the first in Vidarbha to introduce this.
Twin anaemia-polycythaemia sequence (TAPS)
A slower, quieter version of the same problem, in which one twin becomes anaemic and the other's blood becomes too thick, without the fluid difference that makes TTTS visible. Because the fluid looks normal, TAPS is invisible unless it is specifically screened for — which is done by measuring middle cerebral artery peak systolic velocity in both babies, from 20 weeks onwards. Fetal blood transfusion is one of the treatments, and is performed here.
Selective fetal growth restriction (sFGR)
One twin grows substantially less than the other, usually because the placenta is shared unequally rather than because anything is wrong with the smaller baby. Estimated fetal weight is calculated for each twin at every scan and the percentage difference between them is recorded, so the trend is visible rather than a single number. Umbilical artery Doppler is what separates the pregnancies that can be watched from the ones that need action.
Cardiac and structural assessment
Congenital heart disease is commoner in monochorionic twins than in singletons, so fetal cardiac assessment is part of the pathway rather than an optional extra, and detailed anatomy for both babies is done at the anomaly scan at around 20 weeks. See fetal echocardiography.
The schedule
11–14 weeks
Chorionicity and amnionicity confirmed and an image stored. Dating from the larger crown–rump length. Nuchal translucency for both babies, and the twins labelled by position, placental site and cord insertion so the same baby is followed at every later scan.
16 weeks onwards, every 2 weeks
Deepest vertical pocket of fluid around each twin. Both bladders. Estimated fetal weight and the discordance between the twins. Umbilical artery Doppler. From 20 weeks, middle cerebral artery peak systolic velocity in both babies to screen for TAPS.
Around 20 weeks
Detailed anomaly scan for both babies with cardiac assessment, alongside the fortnightly surveillance. Cervical length is measured, since preterm birth is commoner in twins.
Delivery
An uncomplicated MCDA pregnancy is generally delivered between 36+0 and 36+6 weeks. Monoamniotic twins are delivered by caesarean section, usually between 32 and 34 weeks, because cord entanglement is present in nearly every monoamniotic pair.
The interval shortens the moment anything changes. A widening fluid difference, a rising middle cerebral artery velocity or a deteriorating umbilical artery Doppler moves you to weekly or more frequent scans, and sometimes to admission. The fortnightly figure is a floor, not a ceiling.
What happens at each appointment
- Last scan firstThe previous measurements are on screen before the probe touches you. Monochorionic surveillance is about the direction of travel, and a single set of numbers cannot show it.
- Fluid on both sidesThe deepest vertical pocket around each baby, measured separately, and both bladders looked for. This is the single most informative measurement in the whole pathway.
- Growth of each babyHead circumference, abdominal circumference and femur length for both twins, an estimated weight for each, and the percentage difference between them recorded against the trend.
- DopplerUmbilical artery in both babies at every visit, middle cerebral artery peak systolic velocity from 20 weeks, and ductus venosus where the findings call for it.
- The conversationWhat has changed since last time, what it means, and what would have to happen before the plan changes. You leave knowing the date of the next scan and what it is looking for.
- If something is foundNothing is deferred to another appointment or another doctor. The finding is explained the same day, the interval is shortened, and where a procedure is needed it is discussed in person — not communicated through a report.
The equipment, and why it matters here
Scans are performed on a GE Voluson Signature Expert (GE HealthCare). Monochorionic surveillance leans on Doppler more heavily than any other obstetric scan: middle cerebral artery peak systolic velocity is a measurement where small errors change the interpretation, and it has to be reproducible on the same equipment fortnight after fortnight for the trend to mean anything. Stored images and consistent settings across visits are as important here as image quality on any single day.
Cost
Monochorionic surveillance is a series of appointments, not one, so the honest answer is that the cost depends on how long the pregnancy runs and what each visit includes:
| What each visit includes | What changes the cost |
|---|---|
| Fluid, bladders and growth for both babies | Whether Doppler is added — routine from 20 weeks |
| Doppler and the discordance calculation | Whether the anomaly scan or fetal echo falls in that visit |
| Findings explained and the plan updated | Whether the interval has been shortened for a finding |
Published scan charges are listed on the pregnancy scan cost page. For what a full monochorionic pathway is likely to cost from where you are now, WhatsApp 8087471244 with how many weeks pregnant you are.
Who looks after the pregnancy afterwards
A monochorionic pregnancy is a high-risk pregnancy on the maternal side as well as the fetal side. Anaemia, hypertensive disorders and gestational diabetes are all commoner than in a singleton pregnancy, and the surveillance is worth less if nobody is managing those alongside it. The same doctor who performs the scans does that.
If you are already booked with another obstetrician, that arrangement continues: you are seen here for the fetal medicine surveillance and referred back to your own gynaecologist with the findings and the schedule after each visit. Women booked under Dr. Kunda’s own care have their delivery, including caesarean section, conducted by her at a hospital in Dhantoli.
How complete pregnancy care works here · Twin pregnancy monitoring · Twin-to-twin transfusion syndrome
Questions parents of monochorionic twins ask
Why do monochorionic twins need scans every two weeks?
Because the problems specific to a shared placenta can appear and progress within a fortnight. Twin-to-twin transfusion syndrome in particular can move from a normal-looking scan to a serious one in under two weeks. Fortnightly scanning from 16 weeks is what makes it possible to find these changes while there is still something useful to do about them.
Does sharing a placenta mean my babies will have problems?
No. Most monochorionic pregnancies do not develop a serious complication and end with two healthy babies. The close monitoring is a response to how quickly these problems can develop, not a prediction that they will.
When do the scans start and when do they stop?
They start at 16 weeks, once chorionicity has been established at the 11 to 14 week scan, and continue until delivery. An uncomplicated pregnancy with two babies in separate sacs is generally delivered between 36 and 37 weeks.
What is measured at each visit?
The deepest pocket of amniotic fluid around each baby, whether each bladder is visible, the estimated weight of each baby and the difference between them, and umbilical artery Doppler. From 20 weeks, middle cerebral artery peak systolic velocity is added for both babies.
What is TAPS and why is it screened for separately?
Twin anaemia-polycythaemia sequence is a slow, uneven transfer of blood in which one twin becomes anaemic and the other's blood thickens, without the fluid difference that makes twin-to-twin transfusion syndrome visible. Because the fluid looks normal, it is missed unless middle cerebral artery Doppler is specifically measured, which is why that measurement is routine from 20 weeks rather than done only when something looks wrong.
Can twin-to-twin transfusion syndrome be treated?
Yes, and the treatment depends on the stage and the gestation. Fetoscopic laser separates the connecting vessels in the shared placenta and is the established treatment for the more advanced stages in the second trimester. Dr. Kunda was the first in Vidarbha to introduce it. Earlier stages are sometimes monitored intensively rather than treated immediately.
My twins share a sac, not just a placenta. Is that different?
Yes. Monoamniotic twins are about 5 percent of monochorionic pregnancies and need closer, individualised surveillance, because the cords are almost always entangled. These pregnancies are delivered by caesarean section, usually between 32 and 34 weeks. Dr. Kunda manages monoamniotic twin pregnancies herself.
Will I need to be admitted to hospital?
Not routinely. Admission is considered when a complication needs monitoring more often than an outpatient visit allows, when a procedure is planned, or as delivery approaches in a monoamniotic pregnancy. Most monochorionic pregnancies are followed entirely as outpatient visits.
Are so many scans safe for the babies?
Diagnostic obstetric ultrasound has been in routine use for decades with no evidence of harm to the baby when performed by trained operators using standard output settings. The scans are kept as short as the measurements allow, which is a general principle of obstetric ultrasound rather than something specific to twins.
What should I bring, and what should I watch for between scans?
Bring all previous reports and images, particularly the earliest one, and any IVF records. Between visits, come in the same day rather than waiting for your appointment if you notice reduced movements, a sudden increase in abdominal size, tightening, bleeding or fluid loss.
When two babies share a single placenta, we have to be much more vigilant. I tell parents upfront that we will need to do ultrasounds much more frequently. The goal isn’t to frighten you; it’s to monitor closely and ensure that both babies are receiving an equal blood supply right on time.Dr. Kunda Shahane MBBS, MS (Obs & Gynae), FIFM, FMF (London)
Written and medically reviewed by Dr. Kunda Shahane, MBBS, MS (Obs & Gynae), FIFM, FMF (London) · Last reviewed: 9 September 2026
Related pages
Sharing one placenta? Start the fortnightly surveillance.
If your scan report says monochorionic, or says nothing about chorionicity at all, book before 16 weeks so the schedule starts on time. If you are already past that point, come in now rather than waiting for the next routine scan.
Mayflower Clinic, Surdham Complex, Behind Silver Palace Building, 2nd Lane from Panchsheel Square, Opp. Yashwant Stadium, Dhantoli, Nagpur – 440012 · Monday–Saturday, 10:00 AM – 6:00 PM · Sunday closed
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