Sequential embryo transfer (SET)- A boon to help infertile couples attain parenthood!
What is Sequential Embryo Transfer (SET)?
SET is the transfer of two groups of embryos within the same cycle of a lady undergoing IVF treatment for infertility. A sequential or consecutive embryo transfer on Day 3 and Day 5 in patients with an adequate number of retrieved oocytes yields the advantages of successful embryo implantation rate, satisfactory pregnancy rate and multiple pregnancy rate at an equivalent time avoiding complications of blastocyst transfer like cancellation of the transfer cycle and better multiple order births. Blastocyst transfer is an approach getting to improve the IVF outcome in repeated IVF failures. But the number and quality of the embryos decide the result of this approach. Thus, the sequential transfer approach has the advantage without exposing the whole cycle to the cancellation
When is SET performed?
Sequential embryo transfer-(SET) increases pregnancy rates and implantation rates in infertile couples!
Repeated failure of IVF treatment is haunting to the patients and their clinicians. Patients who fail IVF treatment repeatedly despite good quality embryos pose a challenge. According to a study, the average pregnancy rate is about 20% for patients undergoing IVF treatment, whereas patients undergoing Sequential Embryo Transfer (SET) have a pregnancy rate of over 50%
Advantages of SET
Under the assumption that embryos that cease to develop in the uterus result in implantation failure, growing them to the blastocyst stage will serve two goals.
• First, it enables a better selection of embryos for transfer
• Secondly, it syncs with the endometrium and the capability of achieving the implantation window.
• The transfer of embryos grown to the blastocyst stage helps overcome the random selection of impaired ones. Only healthy embryos get transferred, decreasing the risk of multiple pregnancies. So this is often an approach that’s only suitable for patients who produce many embryos.
• The rationale behind sequential embryo transfer is that, during the primary day-3 transfer, the embryos (1 or 2 embryos) may induce a rise in endometrial receptivity, thereby creating a better endometrial lining for second transfer (1 blastocyst) on day 5.
Embryos talk to the uterus
SET could also be better than simply one transfer for several patients for several reasons:
• First, embryos communicate with the uterus using hormones called cytokines. The presence of those cytokines can help the uterus steel itself against implantation. The exact makeup of fluids within the oviduct and uterus could also be impossible to work out. Perhaps the embryo can tell the uterus what it must implant and develop.
• Secondly, the uterus prepared when the first group of embryos on Day 3 may help implant the second group.
• SET provides selecting the best of the extra embryos to transfer and decreases the need to cryopreserve (freeze) extra that may not be survivors. Thereby increasing the chance of implantation and pregnancy. Blastocysts not transferred fresh can still be cryopreserved and thawed later for a frozen embryo transfer (FET).
Our unit at GarbhaGudi IVF specializes in this technique. We get many patients from all over India who have failed multiple times outside with other doctors. We use this system and achieve pregnancies in most of them