Roughly 127,977, babies are killed each year through the process of in vitro fertilization — at least if one accepts the definition that discarding a fertilized embryo amounts to abortion and murder.
Pro-choice groups obviously don’t see it that way. More interesting, pro life groups do see it that way but rarely discuss in vitro fertilization either, perhaps because it’s a popular technique.
But a recent statement from the Vatican makes it clear that the Holy See views embryos discarded during in vitro as being abortions.
The document — Instruction Dignitatis Personae on Certain Bioethical Questions — refers to embryos disgarded during the in vitro process as abortions.
Responding to the argument that in vitro isn’t as bad because it involves incidental murder as a side effect, rather than as the main goal, the document states, “in many cases the abandonment, destruction and loss of embryos are foreseen and willed.”
Referring to the practice of creating multiple embryos to increase the odds of one leading to a birth, the document declared:

“One is struck by the fact that, in any other area of medicine, ordinary professional ethics and the healthcare authorities themselves would never allow a medical procedure which involved such a high number of failures and fatalities. In fact, techniques of in vitro fertilization are accepted based on the presupposition that the individual embryo is not deserving of full respect in the presence of the competing desire for offspring which must be satisfied.”

The full statement on In Vitro:

In vitro fertilization and the deliberate destruction of embryos
14. The fact that the process of in vitro fertilization very frequently involves the deliberate destruction of embryos was already noted in the Instruction Donum vitae.
There were some who maintained that this was due to techniques which were still somewhat imperfect. Subsequent experience has shown, however, that all techniques of in vitro fertilization proceed as if the human embryo were simply a mass of cells to be used, selected and discarded.

It is true that approximately a third of women who have recourse to artificial procreation succeed in having a baby. It should be recognized, however, that given the proportion between the total number of embryos produced and those eventually born, the number of embryos sacrificed is extremely high. These losses are accepted by the practitioners of in vitro fertilization as the price to be paid for positive results. In reality, it is deeply disturbing that research in this area aims principally at obtaining better results in terms of the percentage of babies born to women who begin the process, but does not manifest a concrete interest in the right to life of each individual embryo.
15. It is often objected that the loss of embryos is, in the majority of cases, unintentional or that it happens truly against the will of the parents and physicians. They say that it is a question of risks which are not all that different from those in natural procreation; to seek to generate new life without running any risks would in practice mean doing nothing to transmit it. It is true that not all the losses of embryos in the process of in vitro fertilization have the same relationship to the will of those involved in the procedure. But it is also true that in many cases the abandonment, destruction and loss of embryos are foreseen and willed.
Embryos produced in vitro which have defects are directly discarded. Cases are becoming ever more prevalent in which couples who have no fertility problems are using artificial means of procreation in order to engage in genetic selection of their offspring. In many countries, it is now common to stimulate ovulation so as to obtain a large number of oocytes which are then fertilized. Of these, some are transferred into the woman’s uterus, while the others are frozen for future use. The reason for multiple transfer is to increase the probability that at least one embryo will implant in the uterus. In this technique, therefore, the number of embryos transferred is greater than the single child desired, in the expectation that some embryos will be lost and multiple pregnancy may not occur. In this way, the practice of multiple embryo transfer implies a purely utilitarian treatment of embryos. One is struck by the fact that, in any other area of medicine, ordinary professional ethics and the healthcare authorities themselves would never allow a medical procedure which involved such a high number of failures and fatalities. In fact, techniques of in vitro fertilization are accepted based on the presupposition that the individual embryo is not deserving of full respect in the presence of the competing desire for offspring which must be satisfied.
This sad reality, which often goes unmentioned, is truly deplorable: the “various techniques of artificial reproduction, which would seem to be at the service of life and which are frequently used with this intention, actually open the door to new threats against life”.
16. The Church moreover holds that it is ethically unacceptable to dissociate procreation from the integrally personal context of the conjugal act: human procreation is a personal act of a husband and wife, which is not capable of substitution. The blithe acceptance of the enormous number of abortions involved in the process of in vitro fertilization vividly illustrates how the replacement of the conjugal act by a technical procedure – in addition to being in contradiction with the respect that is due to procreation as something that cannot be reduced to mere reproduction – leads to a weakening of the respect owed to every human being. Recognition of such respect is, on the other hand, promoted by the intimacy of husband and wife nourished by married love.
The Church recognizes the legitimacy of the desire for a child and understands the suffering of couples struggling with problems of fertility. Such a desire, however, should not override the dignity of every human life to the point of absolute supremacy. The desire for a child cannot justify the “production” of offspring, just as the desire not to have a child cannot justify the abandonment or destruction of a child once he or she has been conceived.
In reality, it seems that some researchers, lacking any ethical point of reference and aware of the possibilities inherent in technological progress, surrender to the logic of purely subjective desires and to economic pressures which are so strong in this area. In the face of this manipulation of the human being in his or her embryonic state, it needs to be repeated that “God’s love does not differentiate between the newly conceived infant still in his or her mother’s womb and the child or young person, or the adult and the elderly person. God does not distinguish between them because he sees an impression of his own image and likeness (Gen 1:26) in each one… Therefore, the Magisterium of the Church has constantly proclaimed the sacred and inviolable character of every human life from its conception until its natural end”.