How Many Embryos Should You Transfer for IVF?

In Spain, Law 14/2006 regarding Assisted Human Reproduction allows to transfer a maximum of 3 embryos.

The greater the number of embryos transferred, the higher the chances for embryo implantation to occur. However, it may also rise the multiple birth rate—twins or triplets—, with the subsequent risks this type of pregnancy involves both for the mother and the babies.

When making the decision of how many embryos to transfer, the following aspects should be taken into consideration:

Keeping in mind these factors altogether, among others, and medical instructions, a couple is ready to make up their minds regarding how many embryos they want to transfer. Such decision must be reached according to the couple’s own particular situation and always with the same goal: achieving a pregnancy without problems.

Thus, if there was a case in which embryo quality is not too high, it is understood that chances for embryo implantation to take place will shrink. In this sense, we can only expect that, if it is a 2-embryo transfer, just one of them is able to implant or even none of them, taking therefore for granted that the odds for both embryos implanting is too low due to their poor quality.

Guidelines by the SEF

In this area, the Spanish Society of Fertility (referred to as SEF, its initials in Spanish) has established some guidelines, although each case requires an individual approach:

  • Women over 30: ideally, a single embryo transfer; 3-embryo transfers should be avoided.
  • Women aged 30 to 37: single or two embryo transfer depending on embryo quality; three embryo transfer are only indicated after 3 failed IVF cycles.
  • Women over 38: preferably, a two embryo transfer; only in cases of poor quality will be a three embryo transfer recommended.
  • Egg donation: when donor eggs are used, they are more likely to be high quality eggs; therefore, one can only expect a better embryo quality, and subsequently greater odds for implantation. That’s why there is a preference for single or two embryo transfers, by no means is a three embryo transfer advisable.

Advances in assisted reproductive technology

Nowadays, experts in the field of reproductive medicine has reached an agreement by which the goal of every fertility treatment must be performing a single embryo transfer of high quality. This way, success rates increase because of using a high quality embryo, but at the same time we erase the risk of multiple births.

Advances in assisted reproductive technology (ART), as well as improvements made on post-thaw embryo survival rates, make it possible for assisted conception to take a step forward and get closer to its goal. Nevertheless, the effectiveness of fertility treatments and the pressure on the part of professionals and/or patients prove that there is still a lot to be done.

Risks of multiple births

For couples who have been trying to conceive for a long time, the desire to have a baby is so strong that sometimes they find shelter in the fact that chances of getting pregnant increase if more than a single embryo is transferred. The problem is, most of them do not take into account the risk of multiple births it entails. In fact, many women have a preference for this type of pregnancy.

When, on the one hand, a woman is given a pregnancy success rate of 40% with a two embryo transfer which risk of multiple birth reaches 30% and, on the other hand, lower chances of getting pregnant, but free from the risk of multiple births, most women might go for a two embryo transfer. This is because the desire to have a baby is so strong that the perception of the risk becomes blurred.

Not only the likelihood of preterm birth is higher with multiple births, but also it may lead to extreme prematurity. Besides, this type of pregnancy is linked to premature rupture of membranes (PROM)—i.e. breakage of the amniotic sac—, gestational diabetes, high blood pressure, and other side effects associated with pregnancy, such as anemia. On the other hand, there is a higher chance of having a cesarean section or C-section with twins, and miscarriage is more likely to occur as well.


  1. usuario
    Aria Terrell

    It is so true what you explain here! Making the right decision is complicated… because at first you’re totally unaware of how risky can a multiple pregnancy turn out to be… Until you get pregnant with twins. That’s my case, but I got triplet, so you can imagine how complicated it was… I encourage every woman reading this to be more sensible and give more importance to the risks a multiple pregnancy involves rather than paying only attention to their desire to be mothers, no matter how strong it is. Just make the right choice, girls! Otherwise you may put your own life in danger, what if you have your babies but you cannot live to see them grown? Is it really worth it?

  2. usuario
    Binny parekh

    Hi, I had two embryos transferred on the 23rd. I have been getting pain in the stomach on and off since then. But suddenly after two days the pain stopped completely. I am really worried, is everything ok inside???

    • avatar
      Sandra F.Fertility Counselor

      Hello Binny,

      the pain you felt in the stomach is a common symptom post embryo transfer. Given that you had it transferred on March, 23rd, it is likely to be due to ovulation induction drugs. Don’t panic, because it is a common symptom and does not indicate the transfer has been unsuccessful at all. Be patient during the 2WW. Hoping for the best!


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