If there is one area in which technology seems to have made little progress, it is that of procreation. The first successful in vitro fertilization, forty-five years ago, created an embryo outside the body. Today, about 2% of babies born in the United States are conceived this way. Over the past decade, the percentage of people born in China using medically assisted reproduction (MAP) has increased almost fivefold, from 0.5% in 2009 to 2.4% in 2018. The global market for in vitro fertilization is estimated at over $23 billion.
While the birth rate is collapsing, medically assisted procreation is becoming a tool of pro-natalist public policies. The Chinese health administration has just invited the provinces to add assisted reproduction to the baskets of care covered by public health insurance. Even though it has progressed from less than 10% in 1978 to almost 40% today, the success rate has stagnated for several years because the techniques, in particular the intracytoplasmic injection of spermatozoa, have been perfected to the maximum. This means that the process may have to be repeated several times, significantly increasing the price. Insurances against the failure of the process are even marketed, testifying to the risk inherent in the operation.
While scientists try to understand why humans, unlike the vast majority of female mammals, lose their ability to get pregnant early, others are looking for ways to answer it. In 2016, two Japanese biologists took skin cells from the tail of a mouse, reprogrammed them into stem cells, and then turned those stem cells into eggs. The eggs, once fertilized, were transferred into the uterus of female mice, which gave birth to ten pups. This experiment showed that in vitro gametogenesis, in other words the production of gametes outside the body, was possible in mammals. At the end of March, one of the two biologists repeated the experiment with skin cells from a male. The seven mice therefore have two fathers and a surrogate mother.
The lack of effectiveness of in vitro fertilization
The inefficiency of current in vitro fertilization has whetted the appetite of a new generation of companies that want to bring these technologies to the general public. Conception was created in 2018 in Berkeley by Matt Krisiloff, a close friend of Sam Altman, who we are starting to hear a lot about in this column. The company has raised $40 million to develop commercial gametogenesis for human beings by creating an ovarian environment. If the germ cells receive the right signals from this environment, they will move on to the stage of development that they would normally reach after puberty.
Obtaining a human oocyte from stem cells remains unattainable for many specialists. But Conception claims to have already succeeded in bringing her oocytes to the primary follicle stage. Gameto, a New York-based biotech founded in 2020, explores the in vitro maturation of eggs from the human body. A woman is born, in fact, with all the eggs she will ever have, these mature slowly, normally only one per menstrual cycle. The possibility of harvesting them at a young age, freezing them and accelerating them would improve the chances of procreation.
It is difficult to discuss innovations on fertility without mentioning the consequences on the engineering of the embryo. If reproduction takes place in the laboratory, it is then tempting to take advantage of manipulation to select the embryo that will express such and such a trait, or even to delete genetic sequences likely to transmit diseases. Last week the first British baby was born to have benefited from an in vitro fertilization procedure known as mitochondrial donation. The nucleus of the embryo from the sperm of the father and the egg of the mother had been placed in the egg of a third donor from which it inherited a tiny part of the genetic material, approximately 37 genes. Enough to raise a number of bioethical questions, even if there is little chance of being able to oppose the will of individuals who will always find countries more welcoming on the issue.
* Robin Rivaton is Managing Director of Stonal and a member of the Scientific Council of the Foundation for Political Innovation.