If you just found out you're expecting twins, the first question most parents ask is — how different is this pregnancy going to be? The honest answer: quite different, especially when it comes to monitoring. A twin pregnancy scan is more frequent, more detailed, and far more specific than a routine pregnancy ultrasound. At Sonipat Fetal Medicine and Genetic Centre, we specialize in advanced multiple pregnancy care, combining expert sonology with integrated genetic counseling to give both your babies the best possible start in life.
This guide walks you through every scan you'll need, what each one checks for, and why timely scanning in a dedicated genetic clinic matters more in twin pregnancies than most parents realize.
Most people assume a twin pregnancy is simply "twice the work" of a singleton. From a scanning perspective, it's much more than that.
A standard twin pregnancy ultrasound has to assess two babies individually — their growth, position, heartbeat, and anatomy — while also evaluating the shared or separate placentas, amniotic fluid levels for each baby, and several twin-specific risk factors that simply do not exist in single pregnancies.
The biggest determining factor in how your twin pregnancy is managed is chorionicity — whether your twins share a placenta or not. This one piece of information, confirmed by an early twins ultrasound scan, shapes your entire care plan from the first trimester through delivery.
Twins who share a placenta (monochorionic) face a higher risk of serious complications. Twins with separate placentas (dichorionic) are generally lower risk but still need more monitoring than a singleton pregnancy. Understanding this early makes all the difference.
Your twin pregnancy journey begins here. This early twin pregnancy scan confirms:
● The presence and number of gestational sacs and embryos
● Individual heartbeats for each baby
● Whether the pregnancy is in the correct location (ruling out ectopic)
● Estimated due date based on each baby's crown-rump length
● An early indication of how many placentas are present
At 6–8 weeks, the babies are tiny — barely a few millimetres — but their heartbeats are already detectable. In case heartbeat is not seen, a follow-up scan a week or two later is often recommended at this stage.
This is one of the most important evaluations in a twin pregnancy and should be performed before 14 weeks. During this visit, specialists assess chorionicity, perform the Nuchal Translucency (NT) scan, and complete first-trimester screening to evaluate the health and development of both babies.
Determining chorionicity is crucial because it helps identify how the twins share the placenta and amniotic sacs, which directly affects pregnancy monitoring and risk assessment. The twins are classified as:
● DCDA (Dichorionic Diamniotic) – Two placentas and two amniotic sacs. Usually, fraternal twins are generally considered the lowest-risk twin pregnancy.
● MCDA (Monochorionic Diamniotic) – One shared placenta and two amniotic sacs. Identical twins have a higher risk of complications.
● MCMA (Monochorionic Monoamniotic) – One shared placenta and one shared amniotic sac. The rarest and highest-risk type of twin pregnancy.
The sonologist looks for specific ultrasound markers, such as the Twin Peak (Lambda) Sign for dichorionic twins and the T-Sign for monochorionic twins, to determine chorionicity accurately. Once confirmed, the team at Sonipat Fetal Medicine and Genetic Centre creates a personalized monitoring and scan schedule tailored to your pregnancy.
During the same appointment, a Nuchal Translucency (NT) Scan is performed to measure the fluid-filled space at the back of each baby's neck. Increased NT measurements may indicate a higher risk of chromosomal conditions such as Down Syndrome, Edwards Syndrome, or Patau Syndrome. Along with NT, assessment of other markers like nasal bone, Tricuspid and DV Doppler, and a detailed anatomy survey is conducted. Cervical length is checked by transvaginal scan to estimate the risk for preterm delivery.
Twin pregnancies require a more detailed assessment because:
● NT measurements are evaluated separately for each baby.
● Chorionicity (identical vs. fraternal twins) influences risk interpretation.
● Combining NT measurements with maternal blood tests (Double Marker Test) improves screening accuracy.
● Risk of congenital anomalies and preterm delivery is higher.
This stage is often when parents have the most questions. Our genetic counseling team at Sonipat Fetal Medicine and Genetic Centre provides personalized guidance to help families understand their results and available options.
We help you:
● Understand what the NT measurements mean for each baby.
● Risks specific to your pregnancy.
● Discuss Non-Invasive Prenatal Testing (NIPT) options in twin pregnancies.
● Explore diagnostic procedures such as Chorionic Villus Sampling (CVS) or Amniocentesis when indicated.
● Understand whether findings affect one twin or both babies.
Parents often feel overwhelmed during this phase. Our counselors provide clear, unbiased, and compassionate support, ensuring every decision is made with confidence and a complete understanding of the available information.
Also called the anatomy scan or morphology scan, this is the most detailed structural assessment of both babies. Each baby is evaluated individually for:
● Brain structure (ventricles, cerebellum, corpus callosum)
● Spine and neural tube
● Heart structure and rhythm (fetal echocardiography)
● Kidneys, bladder, and abdominal organs
● Limb length and bone structure
● Facial features (lip, palate)
In addition to fetal anatomy, this multiple pregnancy scan also checks:
● Placenta position and grade for each placenta (or shared placenta)
● Umbilical cord insertion sites
● Amniotic fluid levels (AFI) for each baby
● Cervical length of the mother — important for assessing preterm labor risk
This scan typically takes 45–60 minutes for twins, compared to 20–25 minutes for a singleton. At Sonipat Fetal Medicine and Genetic Centre, our fetal medicine specialists are trained in advanced echocardiography and structural evaluation to ensure nothing is missed.
From the mid-second trimester, growth monitoring becomes a regular part of your twin pregnancy care.
For dichorionic twins: Scans every 4 weeks from 20 weeks.
For monochorionic twins: Scans every 2 weeks from 16 weeks, given the higher risk of TTTS and sFGR.
Each growth scan evaluates:
● Estimated fetal weight of each baby (and the difference between them)
● Growth percentile — flagging if one twin is falling behind
● Amniotic fluid volume — excess or shortage can signal complications
● Doppler assessment of the umbilical artery, the middle cerebral artery, and the ductus venosus blood flow
● Cervical length – to see if there is shortening of cervical length.
● Evaluation of late evolving anomalies.
Doppler scans are particularly critical in twin pregnancies because abnormal flow patterns often precede visible signs of fetal distress by days or even weeks.
TTTS affects around 10–15% of monochorionic twin pregnancies. It occurs when blood flows unequally through shared placental blood vessels — one twin (the "donor") loses blood volume while the other (the "recipient") receives too much.
Without a regular twin pregnancy ultrasound, TTTS can progress rapidly and go undetected leading to loss of one or both fetuses. Caught early, it can often be managed with laser ablation surgery at a specialized fetal medicine center.
● Large difference in amniotic fluid levels between the two sacs
● Significant size difference between the twins
● Bladder visible in one twin but not the other
● Discrepancy in Doppler parameters
● Cervical length
When one twin grows significantly slower than the other — usually more than 25% difference in estimated weight — it points to unequal placental sharing. Doppler assessment during the twins' ultrasound scan can detect early warning signs before complications develop.
TAPS is a chronic, slowly developing complication of monochorionic twins where one baby becomes severely anemic, and the other has excess red blood cells. Unlike TTTS, fluid levels may appear normal, making it detectable only through middle cerebral artery (MCA) Doppler measurements — one reason why regular, specialized scanning matters so much.
Twin pregnancies face a unique challenge in genetic screening: results must be interpreted for two individuals, and decisions about further testing are rarely straightforward.
Our genetic counseling team at Sonipat Fetal Medicine and Genetic Centre provides:
● Pre-test counseling — understanding what each screening test can and cannot tell you
● Post-result counseling — interpreting NIPT, NT scan, or anomaly scan findings
● Risk-based guidance — tailored recommendations when one twin has a finding and the other does not
● Diagnostic pathway support — guiding families through amniocentesis or CVS decisions
● Emotional support — because genetic findings in pregnancy can be deeply stressful
Our genetic clinic works in full coordination with fetal medicine specialists, ensuring that every scan result is reviewed holistically — not just as a number, but as part of your complete pregnancy story.
Sonipat Fetal Medicine and Genetic Centre is a dedicated fetal medicine and genetic clinic serving Sonipat, Haryana, and surrounding regions, including Panipat, Rohtak, and the NCR belt. We offer:
● Expert twin pregnancy scans at every trimester
● First-trimester chorionicity assessment with high-resolution ultrasound
● Integrated NT scan and first-trimester screening
● Detailed anomaly scan by fetal medicine specialists
● Regular growth and Doppler scans with same-day reporting
● Comprehensive genetic counseling in Hindi and English
● NIPT coordination for chromosomal screening in twins
● Supportive, judgment-free environment for all prenatal decisions
● Amniocentesis/CVS/Selective fetal reduction where required.
We understand that a twin pregnancy brings both excitement and anxiety. Our goal is to give you accurate information, expert monitoring, and the confidence to enjoy this journey.
✅ Viability scan confirmed before 10 weeks
✅ Chorionicity and NT scan between 11–13+6 weeks
✅ Genetic counseling completed before or after NT scan
✅ Anomaly scan booked at 18–22 weeks
✅ Growth scans every 2–4 weeks from mid-pregnancy
✅ Doppler assessment and cervical length included in each growth scan
A twin pregnancy scan is not a single appointment — it's a carefully planned series of assessments, each building on the last to ensure both your babies are growing safely and healthily. From the first viability scan to regular third-trimester Doppler checks, every step matters.
At Sonipat Fetal Medicine and Genetic Centre, our specialists combine advanced twin pregnancy ultrasound technology with expert genetic counseling to provide the most comprehensive twin pregnancy care in the region. Whether you're just starting or seeking a specialist opinion mid-pregnancy, we're here for both of your babies — and for you.
Contact Sonipat Fetal Medicine and Genetic Centre today to schedule your twin pregnancy scan and take the first step towards a safe, well-monitored pregnancy.
Your first twin pregnancy scan should ideally be done between 6 and 10 weeks of pregnancy. This early scan — also called a viability or dating scan — confirms how many babies are present, checks for individual heartbeats, rules out ectopic pregnancy, and gives an accurate estimated due date. The earlier you start, the sooner your doctor can plan a customized monitoring schedule for your twin pregnancy.
Twin pregnancies require significantly more scans than singleton pregnancies. Most parents can expect 8–12 or more ultrasound scans across the pregnancy. Dichorionic twins are typically scanned every 4 weeks from 20 weeks onwards, while monochorionic twins require scans every 2 weeks from 16 weeks onwards. Your scan frequency may increase further if complications are detected at any stage.
Monochorionic twins share a single placenta and are always identical. Dichorionic twins each have their own placenta and are usually (but not always) fraternal. The distinction is made through a specialized twin ultrasound scan before 14 weeks, using markers like the "T-sign" (monochorionic) or "twin peak sign" (dichorionic). Monochorionic twins carry a higher risk of complications like TTTS and require more frequent monitoring throughout pregnancy.
Genetic counseling is strongly recommended for all twin pregnancies, especially if the NT scan shows elevated risk, if you are over 35 years old, or if there is a family history of chromosomal or genetic conditions. At our genetic clinic, counseling helps parents understand their screening results, evaluate their options for further testing, and make informed decisions — particularly in complex situations where one twin has a finding, and the other does not.
Yes — TTTS can be detected early through regular twin pregnancy ultrasound with Doppler assessment, particularly in monochorionic twins. Signs include a marked difference in amniotic fluid levels between the two babies, growth discrepancy, absence of a visible bladder in the donor twin or Doppler abnormalities. At Sonipat Fetal Medicine and Genetic Centre, we monitor monochorionic twins every 2 weeks from 16 weeks specifically to catch TTTS and other complications at the earliest possible stage.
