Webinar: TAPS Twins At Birth

What happens to TAPS twins at birth? In the second webinar we held, we asked this vital question, and also what happens in the NICU. How do you tell the differences between Acute TTTS and TAPS? What blood tests are needed? Is there different treatments? In this section of our webinar series, we’re going to look at these important questions and answer your questions.

Behind NICU Doors

When a red and white twin pair is born, many doctors are puzzled as to whether it is TAPS, or acute TTTS. The treatments are vastly different to those for acute TTTS, so it’s important to know which disease you are treating, and what impact the wrong treatments can have.

Webinar: TAPS Twins At Birth

Meet Prof. Enrico Lopriore, neonatologist and world leader in TAPS research. He covers what needs to happen at birth, including the testing, and the treatment that TAPS babies need. Twin Anemia Polycythemia Sequence requires different tests to diagnose it at birth, to differentiate it from Acute TTTS, and treatment priorities are also vastly different.

In part 2, Dr. Lopriore answers your questions about TAPS and the NICU

Diagnosing TAPS Twins At Birth

If you’re confronted with a pair of twins who look like this at birth, it’s important to remember a few vital tests need to be made to establish if this is either Acute Peripartum TTTS (Acute TTTS), or Twin Anemia Polycythemia Sequence (TAPS).

twin anemia polycythemia sequence taps twins at birth

The first thing is that blood needs to be drawn, and the babies’ hemoglobin, and reticulocyte (promille) counts need to be done. TAPS is diagnosed on the difference between the hemoglobin between the babies, AND the difference in the reticulocyte ratios. The table below shows the differences between the stages.

Postnatal TAPS StageHemoglobin Difference
Stage 1Hemoglobin difference of more than 8.0 g/dL
Stage 2 Hemoglobin difference of more than 11.0 g/dL
Stage 3Hemoglobin difference of more than 14.0g/dL
Stage 4Hemoglobin difference of more than 17.0 g/dL
Stage 5Hemoglobin difference of more than 20.0 g/dL
The stages also require a difference of more than 1:1.7 in reticulocytes (promille). To come to this number, you divide the donor’s count by the recipient’s, and it means that donors have more than 1.7 times more reticulocytes than their sibling.
Webinar: TAPS Twins At Birth

TAPS Placentas

TAPS placentas are a roadmap when it comes to a diagnosis There are tiny connections less than 1mm thick, and the maternal side shows a big difference between donors and recipients. It’s important to flip them over and look. In acute TTTS, these differences are not present.

taps-placenta-dyed-acute-ttts-taps-twin-anemia-polycythemia-sequence-1
Webinar: TAPS Twins At Birth

What’s also important is dye injecting the placenta to look for the tiny connections, particularly if it’s post-laser TAPS. This tells you where the laser surgery was incomplete by highlighting the connection that was missed. (Think of it as a training tool). This video shows the process, and also how it highlights the connections.

TAPS Treatments At Birth

It’s really important to establish if it’s TAPS or acute TTTS first – as the treatments for both are very different and have the potential to cause harm, or even be fatal if the wrong treatment is used. Donors may receive blood transfusions, recipients may have partial exchange transfusions, or light therapy. It’s important to remember that it depends on the stage of TAPS, and what the babies need at the time. Treatments vary on a case by case basis.

It’s also important to know if it was TAPS, or TTTS just simply because there are long-term effects for TAPS patients that need to be addressed, such as a high risk of neurodevelopmental impairment for donor twins, as well as spontaneous TAPS donors are at risk of deafness. For more information on this, you can visit part 2 of the webinar on YouTube, or our page on Donor Twins and Deafness.

Important Resources

We’ve compiled a list of important papers and resources for you to help with understanding twin anemia polycythemia sequence, and how it’s diagnosed after birth. You can also always reach out to research@tapssupport.com for more help, and to be connected to experts.

Twin Anemia–Polycythemia Sequence in Two Monochorionic Twin Pairs Without Oligo-Polyhydramnios Sequence. Lopriore et al, 2007

Twin Anemia-Polycythemia Sequence: Diagnostic Criteria, Classification, Perinatal Management and Outcome. Slaghekke et al, 2010

Hematological disorders at birth in complicated monochorionic twins. Verbeek et al, 2017