Hank Greely: ​How babies (will) get made

Episode Summary

Executive Summary: The episode examines how advances in genomics, stem cells, IVF, and embryo screening could shift human reproduction from sex-based conception to clinic-based selection. Russ Altman and Hank Greely discuss likely benefits—fewer genetic diseases, cheaper health care, and better-informed parents—alongside major risks: inequality, coercion, demographic distortion, disability stigma, and the eventual line between selecting embryos and editing them.

Main Topics: From sex to clinic-based reproduction (Priority: 5/5): Greely predicts that in 20–40 years, many people with good health coverage will conceive through clinics rather than intercourse, using sperm plus eggs derived from skin cells and then screened as embryos. Pre-implantation genetic testing and whole-genome sequencing (Priority: 5/5): The conversation explains how embryo selection could expand from testing a few genes to sequencing the whole genome of many embryos, enabling parents to choose based on disease risk and potentially traits like sex, height, or eye color. Access, cost, and health-system incentives (Priority: 4/5): Greely argues this technology may become broadly covered because preventing serious genetic disease could save insurers and national health systems money, though access will be uneven globally. Ethics, autonomy, and the ‘playing God’ critique (Priority: 4/5): The hosts debate whether selecting embryos is a natural extension of existing reproductive and medical interventions or an unacceptable form of human control over reproduction. Genetic prediction limits and uncertainty (Priority: 5/5): The discussion emphasizes that some diseases are highly predictable, others only probabilistically so, and many traits remain beyond reliable prediction; embryo selection cannot guarantee a healthy baby. Social consequences: discrimination, disability, and demographics (Priority: 5/5): The speakers explore how widespread selection could reduce births of people with certain diseases, weaken advocacy and research communities, and alter sex ratios or other population-level outcomes. Selection versus gene editing (Priority: 4/5): The episode distinguishes embryo selection from CRISPR-style editing, with Greely suggesting selection will come first and cover most use cases, while editing raises additional safety and governance concerns.

Key Arguments: Embryo selection could replace many conceptions from intercourse for people with good access to health care, because clinics may provide safer, more informed reproductive choices. Using induced pluripotent stem cells from skin could eliminate the need for painful and risky egg retrieval in many cases. Whole-genome sequencing of embryos will make it possible to assess many diseases and some traits before implantation, though not with perfect accuracy. Some serious genetic diseases are predictable enough that selecting embryos could prevent substantial suffering and reduce health expenditures. The system should generally allow parents to choose, rather than forcing government definitions of what counts as a ‘serious’ condition. Availability may be broad in wealthy and middle-income countries, but international disparities will persist. Population-level use of selection could skew sex ratios or reduce the prevalence of rare diseases enough to affect social support, research, and disability communities. Ethical objections like ‘playing God’ are not sufficient, by themselves, to ban technologies that may produce healthier children. Embryo editing and embryo selection should remain distinct policy issues; most goals can likely be achieved through selection alone for the foreseeable future. Strong genetic counseling and malpractice protections will be needed because predictions will sometimes be wrong and can be misunderstood by parents.

Data Points: Timeline for clinic-based conception: 20 to 40 years - Greely’s prediction for when sexual intercourse may no longer be used for conception among people with good health coverage. Embryos created in example workflow: 100 embryos - Projected number of embryos a clinic might create and sequence for parental selection. Estimated cost per baby: under $10,000 - Greely’s rough estimate for the cost of making a baby under the new system. Serious genetic diseases prevented to save $1 million: about 0.2 - Greely’s cost-effectiveness example comparing embryo selection with old-fashioned conception. Human genome size: 3.2 billion letters - Referenced as the scale of whole-genome sequencing of embryos. Genetic disorders avoidable through selection: about 6,000 - Greely’s estimate of the number of early-onset, mostly genetic diseases that could be avoided. Share of births affected: 1% to 2% - Greely’s estimate of the portion of births represented when those rare diseases are combined. Huntington’s predictability: effectively certain - Example of a fully genetic disease that can be predicted in the embryo stage. Early-onset Alzheimer’s share: about 1 in 1,000 - Greely’s estimate for cases linked to a presenilin-1 mutation with near-certain prediction. Alzheimer’s risk from APOE: about 25% of the population - People with higher Alzheimer’s risk due to APOE variants.

Pivotal Quotes: "My firmest prediction is we will continue to be having sex. We just want to have sex to make babies nearly as often as we do today." — Hank Greely: Clarifying that ‘the end of sex’ means the end of sex as the main method of reproduction, not the end of sex itself. "People who want to have kids going to the clinic, making 100 embryos. And for each of those embryos, their whole genomes are sequenced." — Hank Greely: Describing the envisioned future workflow of reproductive clinics. "The question is, is that a good enough reason to prevent other people who don't feel that way from using the technology in order to get healthier, better babies?" — Russ Altman: Framing the ethical debate over autonomy versus cultural or religious discomfort.

Implications: The episode suggests reproductive medicine may soon become more predictive, more personalized, and more regulated. It could reduce inherited disease and costs, but also intensify debates over equity, disability rights, parental freedom, and whether society should permit or limit embryo choice and editing.