Diagnosis & Treatment

Anatomy Scan

Weeks 15-19 of our twin pregnancy  (blog post of  how we found out) were filled with checkups, saltines, naps and an ever-expanding belly. The twins were doing fantastic and around week 17 we found out we were having identical twin girls! We were so excited for a life with 3 daughters.

At 19 weeks I had an ultrasound to check the growth of the babies and the Dr. thought their fluid levels looked a little off and asked that I come again in one week to have everything checked out in more detail instead of waiting 2 weeks as originally planned. Ryan and I knew a fluid imbalance was a bad sign for our Mo-Di pregnancy and the next week was filled with anxiety as we waited for the next appointment and read all we could about TTTS.

The 20-week anatomy scan was over 2 hours long and at the end the Dr. came in to review the results with me and said there definitely was a fluid imbalance and, in addition to that, there was an abnormal reading on one of the blood flow readings in their brains that had her concerned. She was sending the results to the Fetal Intervention Team at Texas Children’s Hospital (TCH) to get their opinion on next steps. She led me to a private room in case I wanted to wait until she heard back from them and/or make some phone calls.

A short time later I learned that Dr. Espinoza from the TCH Fetal Intervention Team had reviewed my results and wanted to meet with me as soon as possible that afternoon and would be calling me with a time. He was concerned about Twin to Twin Transfusion (TTTS) and also something called TAPS. I was told to head home and wait for a call. TTTS I was prepared for…but TAPS? This was something I’d never heard of before and, unfortunately, could not find much about on the internet.

Less than 15 minutes into a numb drive home I received a call that I should come back to the hospital for an appointment with Dr. Espinoza that afternoon and be prepared to stay overnight and to not eat or drink anything until we’d met with him. In a flurry Ryan and I cancelled the rest of our work day and our weekend plans and called family members in case we needed someone to come stay with our 2-year-old daughter.

Diagnosis

NOTE: Baby A and Baby B were the clinical names used by the Dr’s during this time. Ryan and I had discussed names for the girls but were keeping these private and so I will refer to them as Baby A and Baby B until later posts.

In that first appointment Dr. Espinoza informed us that we were in the very early stages of TTTS, Stage 1 to be exact. Our daughters shared blood vessels across the placenta that caused a fluid imbalance and a discordance of blood flow and nutrients to the girls. Baby A was our “recipient twin” receiving a large amount of fluid and nutrients. Baby B was our “donor twin” and was slowly becoming a stuck twin with very little amniotic fluid around her and was struggling to grow without the nutrients she needed.

At this point Baby A had 8.1 cm of fluid and our smaller Baby B had 2.3 cm of fluid. They had a growth difference of 22%.


Staging Twin-Twin Transfusion Syndrome

  • Stage I: Significant difference in amniotic fluid volume in each twin’s sac
  • Stage II: Inability to see the smaller baby’s bladder by ultrasound
  • Stage III: Abnormal blood flow through the umbilical cord or fetal vessels around the heart
  • Stage IV: An abnormal fluid accumulation in more than one body cavity, also known as hydrops. This can be present in one or both twins.
  • Stage V: The death of one or both twins

Complicating matters further, our twins had a rare condition called Twin Anemia Polycythemia Sequence (TAPS). This meant that in addition to uneven blood/fluid flow between the twins, our girls had uneven blood counts as well. Baby A was suffering from very thick blood (polycythemia) and Baby B had progressive blood loss (anemia). TAPS occurs in 3-5% of Mo-Di pregnancies spontaneously and in up to 13% of Mo-Di pregnancies as a complication of laser surgery to treat TTTS. Our case was spontaneous and diagnosed through a measurement of blood flow in the Middle Cerebral Artery (MCA) of the brain. Baby A had a measurement of <20 and Baby B was >60.


Twin Anemia Polycythemia Sequence: What You Need to Know
  • TAPS is a rare condition of monochorionic (identical twin) pregnancies characterized by an imbalance in red blood cells and hemoglobin levels.
  • In TAPS, amniotic fluid levels remain in balance. This sets it apart from classical TTTS, a similar condition which can sometimes bring on TAPS.
  • If some of the interconnected blood vessels were not completely disconnected during laser ablation surgery for TTTS, TAPS can occur.
MCA_peak_systolic_velocity_in_TAPSBy FetalTherapyLUMC – Own work, CC BY-SA 3.0, https://en.wikipedia.org/w/index.php?curid=40757688

In typical TTTS cases there is a period of “wait and see” to determine if fetal intervention is needed. If the TTTS stays in Stage 1 there may be no need to take action and conditions for surgery are more ideal once the TTTS has moved into Stage 2. We were told to come back the next day for a fetal echocardiogram to determine if the TAPS was already beginning to damage the organs, specifically the hearts, and if earlier intervention would be needed.

Fetal Intervention Treatments

The next day the TTTS numbers had progressed slightly. We were bordering between Stage 1 and Stage 2 but a small bladder could still be seen on Baby B. Unfortunately, the MCA levels had increased slightly and the fetal echo revealed mild to moderate leakage in the heart valves of both Baby A and Baby B. Dr. Espinoza and his team reviewed our treatment options and recommended Selective Fetoscopic Laser Photocoagulation surgery to stop the progression of TTTS and, hopefully, reverse the effects of TAPS.

We went in for surgery early the next morning on March 25, at 20 weeks 2 days of our pregnancy. There were risks of preterm labor or that one or both of the twins would not survive the procedure but our babies were still very strong so the odds looked good and there was around an 80% chance that both babies would survive and 95% chance that one would. I was under heavy sedation but awake for the surgery. Since we were still in Stage 1 of TTTS the surgical team ended up needing to drain the remaining fluid from Baby B in order to successfully complete the procedure. They were able to disconnect 13 offending vessels causing TTTS but also had to perform a microseptostomy, creating a small hole in the membranes separating the babies to help balance out the fluid between the two.

As the first 48 hours were the most critical we spent the next 3 nights in the hospital monitoring the babies’ fluid levels, heart rates and anemia levels. On day 2 post-surgery we learned that Baby B had gone through the small hole in the membrane from the microseptostomy and our babies were now in the same amniotic sac. This is something that happens 3% of the time after this type of procedure. Cord entanglement was now something else we would need to monitor but not a large concern. Overall the surgery was a success! The blood flow from the placenta was stabilizing between the twins and both girls had survived. The MCA (anemia levels) and stress on the hearts would need to be monitored very closely to see if the girls would recuperate on their own or if additional intervention would be required. As far as the TTTS was concerned, we had eliminated the connections and Baby B had enough to “piece of the pie” to survive.

That following Wednesday we had another fetal echo and learned that Baby A’s heart was stabilizing but, unfortunately, the heart leakage in Baby B had increased to a “severe” level due to the TAPS. Fluid was starting to gather around her heart and she was dangerously anemic. To save Baby B we would need to do an intrauterine blood transfusion immediately to help her struggling heart. Another intervention so soon was not ideal but, again, the odds were good that our girls would survive and the anemia could be reversed if they survived the procedure.

The next morning we went in for the blood transfusion and again I was heavily sedated but awake for the procedure. The first goal was to test the level of anemia by inserting a needle into a very small vein in the umbilical cord of Baby B to draw blood and determine the amount of blood required to help her anemia. Once the level of anemia was determined they would slowly administer blood into the same tiny vein. The target was small and it was possible they would not be able to reach the vein at all to test the anemia level. In that case they would just slowly administer blood through her abdomen. This wasn’t ideal but would still get her the blood she needed to reduce the strain on her heart. Surprisingly, the surgical team was able to successfully reach the tiny vein on the first try and found her anemia level was even worse than they’d suspected. Her hemoglobin measured at a level of 2.8 g/dL, requiring approximately 22 cc of blood to fully compensate the anemia. Unfortunately, her heart rate began to spike about halfway through the transfusion and they were only able to administer half the blood she required but they hoped it would give her the boost she needed.

We spent another night in the hospital and were thrilled to find that Baby B had survived the procedure, her heart rate had stabilized and her MCA level was beginning to decrease. Our sweet Baby B was still very sick and it was likely she would need another transfusion down the line but for the moment our girls looked better, I had no signs of preterm labor and we could go home and come back for another echo on their hearts the next week. This would tell us if the leakage was improving to show the TAPS was reversing.

Results of our treatments can be found on the Outcome page.

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