When couples experiencing fertility issues are advised to opt for IVF treatment, it often opens up a world of questions and uncertainties. The process involves numerous steps, each with its own set of challenges. Couples will frequently encounter circumstances when crucial choices must be made. For instance, during the embryo transfer stage, they may have to choose between single embryo transfer and double embryo transfer. SET vs DET is a crucial decision that impacts the success rate of the IVF cycle.
In this article, we’ll examine all the relevant aspects of these two types of embryo transfer, including safety and risks involved.
Embryo transfer is actually the final step in the IVF process. Before this step, mature eggs would have been collected and fertilised in a lab. Once the embryos have reached adequate maturity, it becomes time to select viable ones to implant or “transfer” into the woman’s uterus. This implantation is done via a quick medical procedure, typically 3 to 5 days after fertilisation.
Depending on individual circumstances, your fertility doctor may recommend either single embryo transfer or double embryo transfer.
Single embryo transfer (SET) refers to the transfer or implantation of a single embryo.
Fertility experts usually recommend SET under the following circumstances:
● If the woman is under 35, she has a better chance of achieving a successful IVF cycle.
● If the endometrial lining is sufficiently thick, there is a greater chance of implantation.
● If this is the first IVF cycle.
● If most of the embryos developed in the fertility lab look strong and viable.
● If the main goal is to have a safe pregnancy with as few problems as possible, especially if there are other health issues.
● If the embryo transfer is being conducted on day 5, when the embryo has reached the more advanced blastocyst stage, it has a much stronger chance of latching onto the uterine lining.
1. Much lower risk of pregnancy complications like pre-eclampsia, high blood pressure, gestational diabetes, etc.
2. A lesser chance of giving birth to multiple babies and undergoing associated complications.
1. Lower success rate of implantation, as only one embryo has been transferred.
2. If implantation fails and pregnancy does not occur, then couples will have to undergo more IVF attempts.
Double embryo transfer, also known as multiple embryo transfer (MET), refers to the transfer or implantation of two or more embryos.
Fertility experts usually recommend MET under the following circumstances:
● If the woman is older than 35, the quality of her eggs may have diminished.
● If there have been many unsuccessful IVF cycles in the past. In such cases, the higher the number of embryos transferred, the greater the chances of pregnancy.
● If the embryo transfer is being conducted on day 3, when the embryo is at the less-developed cleavage stage.
● If the woman has been diagnosed with a thin endometrial lining of the uterus, this assures a higher chance of implantation.
● If most of the embryos aren’t of the best quality, then transferring more than one raises the chance of implantation.
● If a multiple-birth pregnancy does not impact overall health or create pregnancy complications.
1. Higher chance of implantation and successful pregnancy, as more viable embryos have been transferred to the uterus.
2. Better outcome for couples desiring twins.
3. Improved chance of pregnancy for older women over the age of 40, especially those who have already undergone 3 to 4 unsuccessful IVF cycles.
1. Higher chance of pregnancy complications, like high blood pressure, etc., due to multiple births.
2. Higher risk of giving birth to low-birthweight or preterm babies.
3. In case of twin births, the parents may be unprepared, financially, mentally or even physically, to take care of more than one baby at a time.
So, now comes the most important question: which is safer, single or double embryo transfer?
Ultimately, this decision can only be made after a thorough discussion with fertility specialists who will assess the pros and cons at a more personalised level. For young couples just beginning their IVF journey or who have other underlying health issues, SET may be a safer option. If the present attempt fails, they can still choose to undergo more IVF cycles. However, for older couples who may have already undergone numerous unsuccessful IVF attempts, it may be best to opt for double embryo transfer, as it will give them a much higher chance of becoming pregnant. Again, though, this will rely on their general health and their physician's advice.
Before opting for double embryo transfer, take a look at some of the risks involved:
Carrying multiple babies in the womb could lead to the development of high blood pressure during pregnancy. This condition can endanger the lives of both mother and baby, thus necessitating the need for close and constant monitoring.
Gestational diabetes is yet another problem that could be faced by women implanted with two or three embryos. Since this condition can affect the unborn baby’s growth, a few dietary changes, medication, or insulin may be needed.
Issues include placenta previa (placenta covering the cervix) and pre-eclampsia (high blood pressure and organ strain), which can endanger the health of both the mother and the unborn child. These conditions may occur when multiple embryos are implanted.
It is quite possible to give birth to multiple babies due to MET. The chance of preterm birth increases when there's more than one baby developing within the uterus. Hence, babies born as a result of MET process may be born prematurely, months, weeks, or even days before the actual due date. Since twins/triplets are more likely to be born prematurely, they may require extra medical support.
Low birthweight babies are highly likely to be born to pregnant mothers who have had many embryos implanted in their uterus. Such babies may face breathing difficulties, feeding challenges, or a longer stay in neonatal care.
C-section may be needed due to complications, the positioning of the babies, or safety concerns for the mother and her baby.
It is vital to examine all IVF embryo transfer options carefully before making a choice. Ultimately, this is a personal decision, and the couple, with the help and guidance of their doctor, will have to factor in every aspect before opting for their preferred type of embryo transfer.
