The Future of Human Reproduction (Part 2)
Intro
In the first part of this series, we discussed abortion and birth control, and the impacts of both of those on human reproduction; past, present, and future. Today, we will be taking a look at trends in reproductive technologies, birth rates, and how knowledge of genetics is revolutionizing how we reproduce.
The Current State of Affairs
Across the planet, birth rates are declining rapidly. In 1950, on average, a woman would give birth to over 5 children over the course of their lifetime. 70 years later, that number now stands at around 2.5 and falling. Nations that are below replacement level (defined at 2.1 children per woman) usually need to turn towards increasing immigration in order to avert population collapse. This news may come as a surprise to many who are only used to hearing about the dangers of overpopulation.
“The Fall” of Birth Rates
There are many reasons cited for these declining trends. Some of these include expanded opportunities for women in both education and the workplace, urbanization, increased access to contraception and abortion, as well as government policies. The most famous of these policies would be China’s 1-child policy, which was in effect from the late 1970s to 2016, when it was replaced by a 2-child policy. The 1-child policy, which has been estimated to have lowered China’s population by between 400 and 600 million people, may have worked a bit too well, and China now faces an aging population and a fertility rate (1.3) that is way below replacement level. The 2-child policy was extremely short-lived and only lasted until 2021 when it was replaced by a 3-child policy. After just 2 months of that policy, China removed all restrictions and penalties for family sizes.
China isn’t alone with its population challenges, even in its geographical area. Other Asian nations including Taiwan (1.2), South Korea (1.1), Japan (1.3) and India (2.1) are also having issues with their fertility rates. And many of these nations have worse fertility rates, despite never having a population control program to begin with. With that being said, will the reversal of their decades-long family planning be enough to help solve China’s population crisis? Or is it too little too late?
“The Rise” of ART
The age that women give birth has also been cited as a factor in the declining birth rate. According to the US Census Bureau, the median age of women at birth in the United States has gone up from 27 in 1990 to 30 in 2019, which happens to be the highest on record. And while the overall fertility rate during that time period has declined, going from 70.77 births per 1000 women to 58.21, the largest shift has been between the age ranges. While the fertility rates of women between the ages of 15 and 29 have declined, they have been increasing for women between the ages of 30 and 44.
Assisted reproductive technology (ART) is one of the reasons that this surge of fertility in later years has been made possible. ART is defined as procedures whereby eggs or embryos are combined with sperm in a laboratory, and either placed back in the original woman’s body or donated to another woman. In 2019, 2.1% of infants born in the USA were conceived via ART. The most popular form of ART happens to be In vitro fertilization (IVF). While the success rate of IVF procedures drops precipitously with age when a woman uses their own eggs, the rate of success for donated eggs/embryos is around 50%. This has increased the fertility window for women and allowed them to give birth with a lower chance of defects. Virtually all of the oldest births on record (ranging from 66 years to 74) occurred via a post-menopausal IVF treatment with egg donation.
Another side effect of IVF is that they are more likely to produce multiple births. For example, even though they accounted for a small percentage of births in the USA, ART contributed to 10.6% of all multiple births (twins, triplets, etc.) in 2019. In recent memory, Nadya Suleman, more popularly known as Octomom, made history by giving birth to the first surviving set of octuplets (8 children) in recorded history. These children, along with the six previous ones she had were all conceived using IVF.
With the increased birth window combined with the increased likelihood of more children per birth, could this be the cure for the population crises many nations are facing? Some governments, such as Japan and Denmark, have already funded subsidies for IVF. However, like most things, there is more than meets the eye. Denmark, which is home to the greatest proportion of babies born through ART, boasts a rate of 10% of newborns conceived via IVF or other techniques. However, only people deemed to be “fit parents” are approved for the state funded IVF treatments, women over 40 are not eligible at all, and those over 45 are even barred from accessing IVF privately. Does a rise in state sponsored fertility treatments also equal a rise in state sponsored eugenics? Is this a pattern that we will continue to see repeating in other nations?
“Its in the Genes”
The mapping of the human genome via the Human Genome Project has opened up a lot of doors in areas of healthcare, and human reproduction is no exception. In 2016, a couple from Jordan gave birth to a child that literally had 3 genetic parents. Due to the mother of the child being a carrier for Leigh syndrome, the daughter they gave birth to 11 years earlier had been born with the disease, which affects the developing nervous system, and had unfortunately succumbed to the syndrome at the age of 6. It was also believed that this disease had played a role in their fertility challenges. In order to solve this problem, and not have this disease passed down to any child that was conceived, doctors relied on a “three-parent technique”, also known as mitochondrial replacement therapy, which had been around since the 1990s.
Pronuclear transfer, one of the “three parent techniques” that is legal in only two nations (UK and Australia), involves fertilizing both the mother’s egg and a donor egg with the father’s sperm, and replacing the nucleus from the donor’s fertilized egg with the one from the mother’s, before both of them start dividing into early stage embryos. The specific technique utilized by the doctors for the Jordanian parents involved removing the nucleus from the mother’s egg and inserting it into the donor egg before fertilization. Mitochondrial replacement therapy is extremely controversial, which is why it was only legal in UK until 2022, when Australia legalized it. Other nations are sure to follow, without a doubt. Here in the USA, it’s been banned since 2015, but there is a growing push to make it legal. Personally, I think it’s not a matter of if, but when this technology, as well as emerging ones, such as CRISPR, which allows for on demand gene editing, to be legalized for reproductive purposes.
Last but not least, I’d like to discuss the role that genes are playing in modern day dating & marriage. In my ancestral homeland of Nigeria, which is located in West Africa, Sickle Cell Disease (SCD) affects 2% of newborns per year. SCD, which is the world’s most common hereditary blood disorder, can cause excessive fatigue or irritability, swelling and pain in hands and feet, as well as frequent infections. According to data, approximately one in four Nigeria adults are sickle cell carriers. When both parents are carriers, there is a 25% chance that a pregnancy will result in a child who is affected with SCD. And unfortunately, 50–80% of children born with SCD will die before reaching adulthood. It goes without saying that this is a major public health crisis.
In response to this dire situation, Nigerians have begun turning to methods that would probably be seen as taboo in other nations. It has become more common for churches to demand to see the sickle cell genotype before conducting the wedding ceremony, and discouraging if not outright refusing to marry couples if both of them are carriers. As someone who recently got married in Nigeria, I can attest to this practice. States in Nigeria have also begun to make genotype testing compulsory before marriage. However, more and more individuals are taking matters into their own hands, and not even waiting for the wedding before requesting this vital information. It is becoming normalized for Nigerian singles to ask their potential romantic partners about their genotype early in the process.
While SCD is something that is more prevalent in those with sub-Saharan African ancestry, there are a number of other disorders that have similar adverse effects on their populations. With the rise of DNA services such as 23andme, LivingDNA, etc, people are becoming more aware of what they are carriers for. I believe that in the near future, we will see the rise of “DNA Dating” services that will combine aspects of dating apps and sites like Match, Tinder, EHarmony, etc with the aforementioned DNA companies.
In the next part, we will focus on emerging technologies such as CRISPR, artificial wombs, “designer babies”, as well as other topics about the future of human reproduction.
References
https://ourworldindata.org/fertility-rate
https://www.weforum.org/agenda/2021/06/birthrates-declining-globally-why-matters/
https://www.nbcnews.com/news/motherhood-deferred-us-median-age-giving-birth-hits-30-rcna27827
https://www.washingtonpost.com/politics/2022/06/25/dodds-roe-ivf-infertility-embryos-egg-donation/
https://www.bbc.com/news/world-europe-45512312
https://www.volusonclub.net/empowered-womens-health/a-global-view-of-ivf-treatment-and-access/
https://www.cdc.gov/art/state-specific-surveillance/index.html
https://www.cnn.com/2019/07/10/health/genotype-dating-nigeria-intl/index.html
