Former president of the Medical Association for Life and member of the pro-Yucatan network, Gumersindo Vasquez Castillo, stated that promoters of the morning-after pill are using "resourceful linguistics" to promote the drug as non-abortive. He also noted that human life begins at conception.

Speaking to a local radio station, the doctor explained that the World Health Organization’s definition of "pregnancy" is "derived from the International Federation of Gynecology, whose understanding comes from an agreement by the American College of Gynecologists in 1934.” This group defined that a woman is pregnant when the embryo becomes implanted in the uterus.
 
“This happens seven days after a baby has been fertilized, which is to say that after these seven days, pregnancy begins, but not life. Life begins with the egg from the mother and the sperm from the father unite,” he explained. The doctor also mentioned that this “gimmick” is used by the promoters of the morning-after pill who say that the drug is not abortive as “pregnancy” has not yet begun.
 
"This is really just a word game. From conception, life has already begun and if we do something that ends this life, it is murder. The word is ugly, and for that reason, those who promote the drug utilize terms such as “terminate the pregnancy,” he said.
 
Vasquez Castillo, who has more than 20 years of medical experience, recalled that when a sperm joins with an egg, a new human being who is completely different from his father and mother is formed. "He is new, unique person, with his or her own identity which has never been and never will be repeated," he said.

The doctor warned that the morning-after pill works by cutting "the supply of food and nourishment that the baby needs, it strips the glycogen that lines the endometrial cavity which is where the baby would continue to grow.” He explained that “the baby is killed by starvation. He has nowhere to go inside the body of the mother and is thus expelled." 
 
"Doctors should not promote this product. A doctor is a person who promises to watch over and care for the health of all human beings. This is a product which not only kills a human being, but also causes damage to the women who receive it, though they may not know it," Vazquez Castillo affirmed.