How did two mothers both carry the same child?

According to the press, two mothers each had the same child during part of the development of the fetus.

Married women, Ashleigh and Bliss Coulter, were able to carry the developing embryo (and ultimately, for a woman, the fetus) through a relatively new fertilization technique, reported the local WFAA news channel 8 ABC on October 25th. Ashleigh gave birth to a girl. to the healthy little boy, Stetson, five months ago.

So, how did this happen?

The technique – which uses a device called INVOcell – is between in vitro fertilization (IVF) and intrauterine insemination (IUI). During IVF, scientists fertilize the eggs with sperm in a laboratory and then transfer the embryos obtained into the woman's uterus. During IUI, sperm is inserted directly into the uterus, the goal being to allow a sperm to reach and fertilize an egg more easily. [Conception Misconceptions: 7 Fertility Myths Debunked]

INVOcell is basically a form of IVF, but instead of fertilizing the egg in a laboratory, the egg and sperm are placed in a small vial inserted into a woman's vagina, with a diaphragm to ensure its stability. 2012 study that describes the procedure. There, with the help of body heat, sperm can fertilize the egg. (The woman's vagina essentially replaces the laboratory's incubator.) After five days, the doctor removes the device to check if an embryo has formed and can then implant it. in the uterus of the woman or freeze it for later.

Indeed, the case of the Texas couple is not the first time that the INVOcell technique is used; it is only the first time that it is used with two women sharing an embryo. As a rule, the technique is used for one woman only. In this case, however, the couple's doctor took advantage of INVOcell's unique design to let both mothers participate in the pregnancy process.

To briefly explain, after the incubation of the embryo in the device in the vagina of a woman, the doctor removed it and implanted it in the uterus from the other woman, who brought it to term and gave birth to a healthy baby.

"This technique is somewhat innovative," said Dr. John Couvaras, medical director of FIV Phoenix, which offers INVOcell to his firm. Couvaras was not involved in the Coulters case.

Of course, the technique is slightly more complex than simply removing an embryo from a woman and implanting it in another. For this to work, the mother who receives the five-day embryo – in other words, the woman who carries the child up to term – should have the uterine lining and levels Appropriate hormones for a five-day embryo, said Couvaras Science Live. If the whole process succeeds, it allows one parent to keep the embryo as soon as it is formed and the other to carry the child to birth. "It's a kind of trick," Couvaras added. [5 Myths About Fertility Treatments]

This fertilization technique may also have some other advantages. For a start, some doctors and clinics believe that the process of natural fertilization is more likely to generate viable embryos than IVF, although not all data support this theory. This would mean that fewer embryos need to be transferred, which allows for a more precise control of the number of children that one has. During IVF, doctors often transfer several fertilized embryos to the lab in the uterus to increase the chances of implantation and embryo development, often resulting in multiple births (like twins). or triplets). It also means that there are fewer embryos left to freeze, which avoids an ethical dilemma for some people who are not sure of the freezing of embryos. INVOcell also costs less than IVF, which can be prohibitive because of the costs of incubation and medication.

While it may still be best for some couples to try IUI in the first place, INVOcell acts as an "accelerator" to ensure the success of IVF, Couvaras said. Indeed, considering these benefits, Couvaras said that he did not really know why the method was not more popular.

It is possible, he said, that some people think the process appears regressive and less sophisticated than the very precise junction of sperm and egg cells in the laboratory.

"But if I could be the czar of infertility, I'd say we should do more low-cost approaches right off the bat, and if they do not succeed, we'll go to [IVF]," he said.

Originally published on Science live.