Carrying twins is an experience that brings double the joy and, in some cases, double the complexity. For families expecting identical twins in Jhansi and across Bundelkhand, one condition stands out as particularly important to understand: twin-to-twin transfusion syndrome, commonly known as TTTS. It is a serious complication that affects a specific group of twin pregnancies, and it is a condition where early detection through expert fetal medicine monitoring makes the difference between a well-managed pregnancy and a catastrophic outcome. At Jhansi Diagnostics & Fetal Medicine Centre, Dr Furquan Ahmad, MBBS MD, screens for TTTS as a standard part of monitoring all monochorionic twin pregnancies, giving families in Jhansi access to the specialist vigilance this condition demands.
Here is a complete guide to what TTTS is, why it happens, and how it is detected.
What Is Twin-to-Twin Transfusion Syndrome?
Twin-to-twin transfusion syndrome is a serious complication that occurs exclusively in identical twin pregnancies where both babies share a single placenta. This type of pregnancy is called monochorionic, meaning one chorion, the outer membrane that surrounds both babies. In a monochorionic twin pregnancy, the shared placenta contains blood vessel connections between the two babies’ circulations. In most cases these connections are balanced and cause no problems. In TTTS, the connections become unbalanced, causing blood to flow preferentially from one twin to the other.
The twin that loses blood is called the donor twin. The twin that receives the excess blood is called the recipient twin. Over time, the donor twin becomes anaemic, produces less urine, and has reduced amniotic fluid around it. The recipient twin receives too much blood, its heart works harder to handle the increased volume, it produces excess urine, and it accumulates too much amniotic fluid. Left untreated, this imbalance progressively worsens and can result in the loss of one or both babies.
TTTS affects approximately 10 to 15 percent of monochorionic twin pregnancies. It can develop rapidly, sometimes within days, which is why regular and frequent monitoring of monochorionic pregnancies is not optional. It is essential. You can read more about the fetal medicine services at Jhansi Diagnostics & Fetal Medicine Centre on the dedicated page.
Why Does TTTS Only Affect Monochorionic Twins?
The key factor is the shared placenta. Dichorionic twins, whether identical or fraternal, have separate placentas and therefore separate circulations. There is no physical connection between their blood supplies, so TTTS cannot develop. TTTS is exclusively a complication of monochorionic twin pregnancies, where the shared placenta creates the possibility of inter-twin blood vessel connections.
This is why the first and most important piece of information Dr Furquan Ahmad establishes when a twin pregnancy is confirmed at Jhansi Diagnostics & Fetal Medicine Centre is chorionicity, meaning whether the twins share one placenta or have two. This determination is most accurately made in the first trimester between 11 and 14 weeks, when the appearance of the membrane between the twins and the placental tissue allows clear identification of the type of twin pregnancy. After 14 weeks, determining chorionicity becomes progressively more difficult.
Knowing chorionicity from early in the pregnancy sets the entire monitoring plan. Monochorionic twins require far more frequent and detailed surveillance than dichorionic twins precisely because of the risk of TTTS and other complications unique to shared placenta pregnancies.
What Are the Signs of TTTS?
In its early stages, TTTS produces no symptoms that the mother can feel. This is one of the most challenging aspects of the condition. A mother carrying monochorionic twins may feel perfectly well while the imbalance between her babies is already developing. By the time symptoms become noticeable to the mother, such as a rapidly enlarging abdomen, breathlessness, or abdominal tightness caused by excess amniotic fluid around the recipient twin, the condition has often already progressed significantly.
This is precisely why the diagnosis of TTTS relies entirely on ultrasound monitoring rather than maternal symptoms. Waiting for the mother to feel something is not a safe approach with this condition. Regular scans are the only way to catch TTTS at a stage where intervention is still possible.
In more advanced cases, mothers may notice a sudden increase in abdominal size, difficulty breathing due to uterine distension, or a sensation of tightness and pressure in the abdomen. Any of these symptoms in a monochorionic twin pregnancy should prompt an immediate scan rather than waiting for a scheduled appointment. The FAQs page at Jhansi Diagnostics & Fetal Medicine Centre has more information on what to do if you notice these symptoms.
How Is TTTS Detected on Ultrasound?
The diagnosis of TTTS is made on ultrasound based on specific criteria that Dr Furquan Ahmad assesses at every monitoring scan for monochorionic twin pregnancies. The two key diagnostic criteria are a discrepancy in amniotic fluid volume between the two sacs and a discrepancy in bladder filling between the two babies.
In TTTS, the donor twin has reduced amniotic fluid around it, a condition called oligohydramnios, and its bladder may be absent or very small because it is producing little urine. The recipient twin has excess amniotic fluid around it, a condition called polyhydramnios, and has a large, persistently full bladder due to the high volume of urine it is producing.
On ultrasound, the donor twin is often seen pressed against the wall of the uterus with very little fluid around it, sometimes described as being stuck. The recipient twin floats freely in its large pool of fluid. This combination of findings, one twin with too little fluid and one with too much, alongside the bladder discrepancy, meets the diagnostic criteria for TTTS.
Once TTTS is diagnosed, it is staged using the Quintero staging system, which grades the severity from Stage 1 to Stage 5 based on the Doppler blood flow findings, fetal cardiac function, and fetal wellbeing. Dr Furquan Ahmad assesses Doppler blood flow through the umbilical arteries of both twins, the middle cerebral artery of the donor twin, and the ductus venosus to determine the stage and guide management decisions. You can learn more about Doppler studies available at the centre on the ultrasound page.
How Often Should Monochorionic Twins Be Scanned?
Given the speed with which TTTS can develop and progress, monochorionic twin pregnancies require fortnightly ultrasound monitoring from 16 weeks of pregnancy onwards. This means a scan every two weeks throughout the second and third trimester, with additional scans if any concern arises between appointments.
Dr Furquan Ahmad follows this monitoring schedule rigorously at Jhansi Diagnostics & Fetal Medicine Centre for all monochorionic twin pregnancies under his care. Each fortnightly scan includes measurement of amniotic fluid in both sacs, assessment of both bladders, biometric measurements of both babies, and Doppler studies. The combination of these assessments gives the earliest possible warning if TTTS is beginning to develop.
For families in Jhansi and Bundelkhand carrying monochorionic twins, having access to this level of monitoring locally rather than travelling to a metro city for every fortnight appointment makes an enormous practical difference. Consistency of monitoring is critical with TTTS, and missed or delayed scans create gaps in surveillance that the condition can develop within.
What Happens If TTTS Is Diagnosed?
If TTTS is confirmed on ultrasound, the management depends on the stage at diagnosis and the gestational age. Early-stage TTTS at Stage 1, where the fluid discrepancy is present but Doppler studies are still normal, may be managed with intensified monitoring, scanning weekly or more frequently, to detect any progression early.
More advanced TTTS, particularly from Stage 2 onwards, typically requires referral to a specialist fetal medicine unit for consideration of fetoscopic laser photocoagulation. This is a minimally invasive procedure where a fine telescope is introduced into the uterus and a laser is used to seal the abnormal blood vessel connections on the surface of the shared placenta, separating the two babies’ circulations and stopping the transfusion process. It is the most effective treatment for TTTS and significantly improves survival and outcome for both twins when performed at the right stage.
Dr Furquan Ahmad at Jhansi Diagnostics & Fetal Medicine Centre provides the detailed staging assessment and documentation that specialist referral centres require. Families receive a thorough scan report, a clear explanation of the findings, and guidance on next steps before leaving the centre. The full range of pregnancy monitoring services is available on the our services page.
What Should Families with Monochorionic Twins Do?
If you are carrying identical twins or have been told you have a monochorionic twin pregnancy, the single most important thing you can do is ensure your monitoring is in the hands of a fetal medicine specialist who understands this condition and follows the correct scanning protocol.
Book your chorionicity scan in the first trimester to confirm the type of twin pregnancy you are carrying. Ensure fortnightly monitoring scans begin by 16 weeks. Report any sudden change in abdominal size, breathlessness, or reduced fetal movements immediately rather than waiting for your next scheduled appointment.
At Jhansi Diagnostics & Fetal Medicine Centre, Dr Furquan Ahmad provides the specialist-level monitoring that monochorionic twin pregnancies require. You can book your appointment through the website or reach the team through the contact us page with any questions. You can also read more about Dr Furquan Ahmad and the centre’s approach on the about us page.
