1) Transferring embryos at the blastocyst stage on day 5 has a higher success rate than at earlier stages. Some doctors transfer multiple embryos on day 3 to increase pregnancy rates, but this increases the risk of multiple pregnancy. 2) Routinely performing blastocyst culture and single embryo transfer (SET) allows selection of top-quality embryos for transfer while avoiding multiple pregnancies. This achieves high pregnancy rates safely. 3) SET is recommended for patients under 35 with good prognosis or blastocyst quality. Two embryos may be transferred for those over 35 or who previously failed IVF. SET allows use of remaining high-quality embryos in subsequent cycles.

1. WHEN TO DO SET ( SINGLE EMBRYO TRANSFER) ?
DR. Sai, Chief Embryologist, Malpani Infertility Clinic Pvt. Ltd.
We know that transferring embryos at Blasotcyst Stage (on Day 5) has a higher success rate as compared
to transferring at 4-cell on day 2 or 8-cell on day 3.
Because the implantation rates with transferring Day 3 embryos is lower, some doctors try to
compensate for this by transferring more embryos, to try to bump up their pregnancy rates, in the hope
that one of them will implant. However, this “ hit and miss” approach just increases the risk of a multiple
pregnancy !
A good IVF Clinic does only Blastocyst transfers routinely . Not only does this signal the fact that they
have confidence in their clinical and lab skills, it also gives the patient peace of mind that they have
received state of the art medical care !
By doing Extended Culture to Day 5, we filter out the Embryos which are not going to implant , so that
we don’t give the patient false hopes by transferring these. Since we transfer only top quality
blastocysts, we need to transfer only 1 embryo at a time, and are still able to achieve an equally high
pregnancy rate.
At Malpani Infertility Clinic , we routinely do Blastocyst Transfers , and encourage all our patients to do
SETs (Single Embryo Transfers).
The Cumulative Pregnancy per patient is very high with SETs, because we can freeze the supernumerary
embryos, and use these for the next attempt if the first cycle fails – and for the next baby, if the first
cycle is successful ! The pregnancy is also much safer with a single baby, as compared to twins ( who
have a higher risk of having a preterm delivery).

2. However, one needs to be selective when doing SET and we can’t always do SETs for all patients.
PATIENT’S PERSPECTIVE
Patients usually prefer doing SET for the following reasons:
To Avoid Multiple Pregnancies:
Some patients are scared about having a multiple pregnancy. These patients are very sure that they
want only 1 baby, as they may already have 1 , and are undergoing treatment for their 2nd
child ; and
many are worried about their ability to be able to bring up to babies at a time . Twins can look cute in a
movie, but bringing them up can be very challenging – and expensive as well !
For such Patients, we should strictly do SET, as it eliminates the risk of having twins.
To be able to improve their pregnancy rates by doing multiple cycles:
1) For patients with poor ovarian reserve, we get fewer eggs , and eventually we get only 2 or 3
Blastocysts . Such patients usually prefer SET, as it allows them to undergo multiple Embryo
Transfer Cycles , thus improving their cumulative pregnancy rate, because we can freeze their
blastocysts, and transfer them one at a time.
2) Some patients are extremely scared about taking injections for a fresh stimulated cycle, and
would rather do frozen transfer ( FETs), because these don’t involve any injections at all. By
doing SETs, we can offer them the luxury of doing many cycles of FTETs
DOCTOR’S PERSPECTIVE
At Malpani Infertility Clinic , we follow these thumb rules while doing SET
PATIENT’S AGE:
If the patient is below 35 with a good prognosis, we offer them the luxury of doing SET, as their Embryo
Quality is usually good . However, If the patient is above 35, then we allow them the option to transfer 2
blastocysts at a time.
Also, for patients who have failed IVF cycles earlier, we will allow them to transfer 2 blastocysts, if they
so desire.
QUALITY OF BLASTOCYSTS:
If the Blastocysts are of top quality, then it advisable to do SET , as the chances of the embryo implanting
are excellent, and transferring 2 at a time does not improve pregnancy rates. We can preserve her
remaining Embryos for future cycles – and future babies !

3. Top Quality Blastocyst
If the quality of Blastoycst is not upto the mark, then patients may want to transfer 2 blastocysts to
improve their chances.
Poor Quality Blastocyst
ENDOMETRIUM:
SET can be done for cycles with both a good and a suboptimal endometrium.
An endometrium above 8mm (triple layer) is considered good , and transferring only a Single Blastocyst
gives a good chance for the patient.

4. For Endometrium between 7mm and 8 mm , which is considered sub-optimal, or where the texture is
not trilaminar, we can still consider a SET, as we can reserve the second embryo for the next cycle.
Howeverm if the endometrium is poor , than we suggest that the patient should just freeze all her
Embryos in the Fresh Cycle and do the ET in the Next Cycle.
ESTRADIOL LEVELS (E2):
In Fresh cycles , if the E2 levels are too high, then we usually freeze all Embryos and do not do a Embryo
Transfer at all , as high E2 levels tend to hamper the receptivity of the Endometrium . However, some
patients insist that we do a fresh ET for personal reasons ( for example, if are from overseas, and find it

5. difficult to fly back to India for a frozen ET immediately in the subsequent month) . For such patients we
consider SET , and freeze their remaining Embryos.
FRESH CYCLES VS FROZEN THAWED ETS:
For Fresh Cycles we should consider SET , as the Endometrium is somewhat affected by the high
Estradiol (E2) levels . It’s best to freeze the remaining Embryos for future Frozen Thawed Cycles.
For Frozen Thawed ETs, We should consider SET if the Embryos are Top Quality. However, if the
Blastocysts are not of top quality, we can consider transferring 2 blastocysts if the patient so desires.