Introduction
Methods
Search Strategy
Inclusion and Exclusion Criteria
Article Selection
Extraction and Categorization Strategy
Results
Publication Characteristics
References | Types | Areas | Main objectives | Method summaries | Subjects | Samples | Sex/gender focus | Summary of key findings and/or conclusions |
---|---|---|---|---|---|---|---|---|
Ahrari et al. [17] | Review | Biology | Gather information on the effects of spaceflight on male reproduction | Guidelines: PRISMA; databases: PubMed, PubMed Central, MedLine, Google Scholar, Cochran, and other sources | Both | M | Sperm motility and total count were reduced by microgravity and DNA fragmentation increased by microgravity and ionizing radiation. Testosterone levels and testicular weight were decreased by microgravity, posing a risk to male reproductive health | |
Boada et al. [30] | Empirical | Biology | Investigate the effects of microgravity on human frozen sperm | Sperm samples were frozen using glycerol and analyzed under microgravity (parabolic flights: 20 maneuvers; mean time = 8.5 s) | Human | Human (15 normozoospermic healthy donors’ sperm, age range = 26–40) | M | Frozen sperm did not show changes after exposure to microgravity in terms of (progressive) motility, vitality, morphology, DNA fragmentation, and apoptotic sperm |
Cowley [41] | Theoretical | Philosophy, ethics, and law | Argue that Mars colonization programs might be guided by “Martian Rights.” | G | There are ethical objections to raising children in space without their consent. Reproductive autonomy rights are necessary, and the right to return to Earth may need to be guaranteed. Potential Martians’ physiological and psychological changes could make a return to Earth difficult | |||
Criscuolo et al. [7] | Theoretical | Biology | Question the evolutionary implications of deep space exploration over the long-term | G | Microgravity and space radiation may affect human evolution. Sexually reproducing animal models could help to study this phenomenon. Evolutionary perspectives may help us understand and cope with space exploration | |||
Dai et al. [54] | Empirical | Biology | Investigate the effects of microgravity on porcine granulosa cells | Porcine granulosa cells were exposed to microgravity (gravite for 72 h at × 2 rpm) | Animal | Pigs (granulosa cells) | F | Simulated microgravity inhibited the growth and caused shape changes in porcine granulosa cells |
Drago-Ferrante et al. [33] | Review | Gynecology and oncology | Summarize the research on gynecological cancer risks, and highlight research directions for safer missions and the screening and management of women astronauts following long-duration spaceflight | Both | F | The impact of space radiation and microgravity on gynecologic cancer is not well understood due to the limited exposure of female astronauts to such conditions | ||
Dubé et al. [14••] | Theoretical | Sexology | Call for more research on space intimacy and sexuality. Discuss the risks and benefits of extraterrestrial eroticism. Propose a biopsychosocial framework to envision a scientific agenda on space sexology | G | Space organizations need a change in perspective to acknowledge and address the intimate and sexual needs of humans in space, as longer missions risk compromising their health. Delaying action may jeopardize wellbeing and mission success and lead to unhappy space societies | |||
Edwards [34] | Review | Biology | Review ectogenesis with cryopreserved embryos to recolonize post-apocalypse worlds and colonize exoplanets | Both | G | Artificial uteri may help with premature pregnancies, people who cannot have children, and settling space | ||
Greenall-Sharp et al. [42] | Chapter subsection | Philosophy, ethics, and law | Propose a Bill of Rights for space settlers | G | Space settlers should have a right to bodily integrity in intimacy and procreation. Genetic diversity can be maintained through autonomous pairing and new settlers. Population growth crises can be prevented through education, contraception, and a consensual one-child policy | |||
Hart [35] | Review | Biology | Discuss how development will occur in conditions that did not shape human evolution | Both | G | Humans must adapt their reproduction to space conditions | ||
Healey [45] | Theoretical | Gender studies and law | Address the journey of American women to achieve equal participation in the NASA spaceflight program and the new challenges facing female participation in spaceflight | F | There are differences between men and women in long-duration spaceflight, but NASA will not implement discriminatory policies preventing women from participating in missions | |||
Hong et al. [56] | Empirical | Biology | Provide insights into the endocrine status and ovarian cyclicity of female mice following an extended period of exposure to microgravity in the absence of reentry effects | Mice were exposed to and sacrificed on-orbit (space conditions: 37-day spaceflight) | Animal | Mice (40 females, 12-week-old adult) | F | Ovarian tissue steroid levels showed no differences in estradiol but lower progesterone in space compared to baseline. Genes involved in steroid production were not different across groups. Estrous cycle is present in spaceflight and female mice may still be fertile |
Jain et al. [31] | Empirical | Aerospace medicine | Determine whether female astronauts are at elevated risk of venous thromboembolism, as they sometimes use oral contraceptives | Review the longitudinal health data of female astronauts who flew short- and long-duration missions between 2000–2014, including pre- and post-flight hematological and biochemical blood markers | Human | Astronauts (38 female, median age = 43–44, 27 combined, and 11 non-combined oral contraceptive users) | F | No instances of venous thromboembolism (VTE) were found and analysis showed no evidence of elevated VTE risk in female astronauts during spaceflight, regardless of contraceptive use |
Jennings and Baker [37••] | Chapter | Gynecology | Address the gynecologic considerations associated with female astronauts | F | Data from female astronauts in spaceflights have been positive: medical or gynecologic problems can be addressed. Pregnancy delays may cause infertility or heightened risks of miscarriage. Personalized medical care and mission-specific crew training in telemedicine are necessary for long-duration missions. Preventive measures and physiological countermeasures against weightlessness are also necessary | |||
Layendecker and Pandya [27•] | Chapter | Aerospace medicine | Explores the logistical challenges associated with human sexuality and reproduction in long-duration spaceflight | G | Data on conception, gestation, and development in space are limited and conflicting. Intensive research is needed to avoid risks to maternal and fetal health, crew morale, and mission success. Comprehensive policies are needed for extended off-world journeys and settlements | |||
Lei et al. [51] | Empirical | Biology | Explore mouse preimplantation embryonic development during the spaceflight | Embryos were launched and developed in a satellite (64 h at ∼ 252 km) | Animal | Mice (1500 2-cell embryos) | G | Preimplantation mouse embryos can develop in space but with a reduced rate of blastocyst formation and quality. Embryos show severe DNA damage and hypomethylated genomes. Radiation, not microgravity, seems to be the main cause of developmental defects |
Lei et al. [39] | Chapter | Biology | Review research on reproductive science and mammalian early development under microgravity | G | Microgravity poses significant health hazards to humans. Mouse preimplantation embryos can develop in space but further study is needed on the long-term effects on offspring | |||
Levchenko et al. [43] | Theoretical | Philosophy, ethics, and law | Examine the pros and cons of Mars colonization | G | Martian reproductive policies may be difficult to design due to sociocultural differences. Transporting a sufficient number of settlers may be long and expansive, and migration may be detrimental to their health and well-being. Genetic diversity, genetic and disease screening, fetuses health monitoring, and legislative termination framework must be considered | |||
Li et al. [18] | Review | Biology | Summarize recent research on the effects of microgravity on embryonic stem cells and early embryonic development | Both | G | Microgravity affects embryonic stem cell differentiation and embryonic development in animals. Research remains limited. Further exploration is needed in signaling pathways, transcription factors, stress response, and epigenetics | ||
Loktev and Ogneva [59] | Empirical | Biology | Evaluate the methylation of CpG islands in the promoter regions of the genes encoding some cytoskeletal proteins, the total methylation and 5 hmC levels, and the levels of enzymes that regulate these processes in the testes, heart, and lungs in mice under microgravity | Mice were subjected to 30-day microgravity and 12-h recovery | Animal | Mice | M | Microgravity affects gene expression and methylation in heart, lungs, and testes tissues. Cytoskeletal genes increased in the testes, along with changes in CpG island methylation. The content of (de)methylases decreased in all tissues. The content of the deacetylase HDAC1 decreased in testes |
Matsumura et al. [62] | Empirical | Biology | Examine the effect of space environment on male reproductive organs, sperm fertilizing ability, male accessory glands, and progeny | Mice under artificial gravity (∼ 1 g) or microgravity in the ISS for 35 days | Animal | Mice (12 males) | M | There were no overt defects or changes in gene expression in mice reproductive organs exposed to microgravity. Mice sperm fertilized oocytes in vitro and resulted in comparable levels of pups, with no significant differences in growth rates or fecundity |
Mishra and Luderer [8•] | Review | Biology | Review the effects of spaceflight, microgravity, hypergravity, and space radiation on reproductive endpoints in humans and animals | Both | G | Oocytes and spermatogenic cells are highly sensitive to damage by space radiation, resulting in premature ovarian failure and decreased spermatogenesis. Microgravity can disrupt spermatogenesis and testosterone synthesis in rodents, while exposure to hypergravity during mating and neonatal periods decreases pregnancy rates and neonatal survival. More research is needed | ||
Mishra et al. [49] | Empirical | Biology | Examine whether charged-iron-particle irradiation induces ovarian tumorigenesis in mice and the molecular characterization of ovarian tumors | Mice were exposed to 0 cGy or 50 cGy iron ions and aged to 18 months | Animal | Mice (females, 3-month-old) | F | Female mice exposed to radiation had increased weight gain with age and showed signs of ovarian failure. Half of the irradiated mice developed ovarian tumors, compared to 14% of controls |
Moustafa [60] | Empirical | Biology | Explore the effects of hindlimb unloading on testicular functions and spermatogenesis | Rats were subjected to normal loading or hindlimb unloading for 30 days | Animal | Rats (20 Sprague–Dawley) | M | 30-day hindlimb unloading caused a decrease in body weight, testicular and epidydimal weights, and all semen parameters in rats |
Ogneva [61] | Empirical | Biology | Explain the effect of microgravity on the motility of insect and mammal spermatozoa | Fruit fly and mouse sperm were exposed to microgravity for 6 h | Animal | Drosophilia melanogaster (2-days-old, spermatozoa) and mice (21 males, 12-week-old, spermatozoa) | M | Microgravity increases the speed of fly spermatozoa by 30% and decreases that of mouse spermatozoa by 29%. These effects were prevented by specific compounds. Alpha-actinin decreased in fly sperm and increased in mouse sperm. Phosphorylation mediates the effect of microgravity on mouse sperm motility, while dephosphorylation regulates fly sperm motility |
Ogneva and Usik [55] | Empirical | Biology | Determine the cellular respiration and contents of the main cytoskeletal proteins in the ovaries of flies that underwent an oogenesis cycle under microgravity and after oral administration of essential phospholipids | Fruit flies were exposed to zero gravity (gravite) | Animal | Drosophilia melanogaster (ovaries) | F | Microgravity increased cellular respiration in fruit fly ovaries after a full cycle of oogenesis. There were no changes in oocyte size or protein content in the respiratory chain. Changes were found in the relative protein content of the actin cytoskeleton. There were no changes in essential phospholipids |
Ogneva et al. [64] | Empirical | Biology | Determine the effect of microgravity and hypomagnetic conditions for on sperm motility | Fruit flies were exposed to microgravity and hypomagnetism for 1, 3, and 6 h | Animal | Drosophilia melanogaster (spermatozoa) | M | Microgravity increased sperm tails’ movement speed after 6 h. Essential phospholipids had a similar effect on sperm motility. Hypomagnetic conditions decreased motility and cellular respiration; this was prevented in flies that received phospholipids. Cellular respiration increased after 1 h under hypomagnetic conditions, including in the fly sperm receiving phospholipids |
Ogneva et al. [65] | Empirical | Biology | Determine the effect of simulated micro- and hypergravity on mouse sperm motility and its mechanisms | Mouse sperm were exposed to microgravity and hypergravity (2 g) using a centrifuge for 1, 3, and 6 h | Animal | Mice (spermatozoa) | M | Hypergravity had a greater impact on sperm motility than microgravity. After 1 h, sperm speed decreased, and after 3 h, the number of motile cells began to decrease. Under microgravity, speed did not change, but the number of motile spermatozoa decreased after 6 h |
Ogneva et al. [63] | Empirical | Biology | Analyze the effect of gravity on the structure of germinal tissue | Mice were exposed to spaceflight conditions for 21–24 days | Animal | Mice (duct deferens and testes) | G | No changes in the levels of proteins related to the cytoskeleton, sperm, DNA methylation, or histone modification. There were changes in gene expression (i.e., an increase in the demethylase Tet2 and a decrease in the histone deacetylase Hdac1) |
Ogneva et al. [53] | Empirical | Biology | Assess the state of spermatozoa after a spermatogenesis cycle under spaceflight conditions | Fruit flies were exposed to a 12-day spaceflight on the ISS | Animal | Drosophilia melanogaster (spermatozoa) | M | Sperm motility was reduced by 20% after spaceflight and upon landing, likely due to overloads and readaptation to Earth’s gravity. Cellular respiration and protein expression were not affected. Kinase inhibitors restored the speed of spermatozoa |
Proshchina et al. [19•] | Review | Biology | Review various aspects of reproduction and early development of vertebrates in spaceflights | Animal | G | Geckos and other reptiles can be used as models for studying reproduction and development in weightlessness. Some fishes and amphibians can mate and fertilize eggs in space. Early embryogenesis may be sensitive to spaceflight conditions. Anomalies have been observed in the development of vertebrates in space (e.g., delays). Microgravity may lead to neurological alterations | ||
Przystupski et al. [32] | Empirical | Biology and oncology | Investigate whether altered gravity affects the drug susceptibility of cancer cells | Human ovarian cancer cells were exposed to microgravity (× 10 rpm for 2 h) | Human | Human (drug-resistant ovarian cancer cells SKOV-3) | F | Microgravity affected cell morphology, increased apoptotic cell percentage, caused cell cycle arrest, and altered cell proliferation and migration. Altered gravity seems to affect cellular mechanisms involved in cisplatin resistance, resulting in higher sensitivity of cancer cells to chemotherapy |
Rose [38] | Expert opinion | Obstetrics and gynecology | Review data suggesting that being a female astronaut shortens the interval to menopause and suggest solutions to mitigate this problem | F | Radiation may damage women’s primordial follicles, reduce ovarian reserve, and lead to a decrease in the time interval to her menopause and an increase in risks of early mortality. Solutions may include estrogen replacement therapy, oocyte cryopreservation, and cortical tissue freezing | |||
Ruden et al. [20] | Review | Biology | Review mammalian early developmental outcomes, and enzymatic and epigenetic mechanisms known to mediate developmental responses to microgravity | Animal | Four reports | G | Microgravity may deleteriously affect preimplantation embryos. No mouse embryos developed beyond the two-cell stage in spaceflight, whereas 20% of controls reached the late blastocyst stage. Testing the effects of microgravity on the ISS could minimize confounding variables | |
Schwartz [46] | Theoretical | Philosophy and ethics | Discuss ethical concerns raised by worldship travel | G | We must accommodate diverse forms of intimate relationships and child-rearing. We need worldship populations large enough to be genetically stable and provide opportunities for personal growth, education, vocation, gender identity, sexual orientation, and reproductive autonomy | |||
Steller et al. [9] | Review | Biology | Review the effect of spaceflight-induced oxidative stress on female reproduction development | Both | F | Microgravity and radiation may increase risks of complications, such as miscarriage, preterm birth, and gestational diabetes. More research is needed on the effects of space conditions on reproduction | ||
Steller et al. [21•] | Review | Obstetrics and gynecology | Review the pre-, in-, and post-flight clinical evaluation, management, and prevention considerations for reducing gynecologic and reproductive risks in female astronauts | Guidelines: N/A; databases: Ovid, Medline, Web of Science, medical libraries, and NASA archives | Human | F | Gynecological and reproductive health concerns during long-duration spaceflights include abnormal uterine bleeding, anemia, bone mineral density loss, ovarian cysts, venous thromboembolism, contraception, fertility, and health maintenance. The effects of the space on gynecological/reproductive health are largely unknown | |
Steller et al. [22] | Review | Obstetrics and gynecology | Examine spaceflight-related gynecological risks to develop systems/protocols that mitigate said risks and support astronauts’ reproductive autonomy | Guidelines: N/A; databases: Ovid, Medline, Web of Science, medical libraries, and NASA archives | Human | F | The desirability of contraception or menstrual suppression, the risk-benefits of hormonal modalities, and the impact on onboard mass, volume, and engineering considerations must be considered in the decision-making process related to menstrual management, pregnancy prevention, and gynecologic-related pathology in space. The final decision should be left to the astronauts. More research is needed | |
Szocik [48•] | Theoretical | Philosophy and ethics | Introduce space bioethics as a new branch in space philosophy | G | Bioethical issues related to space reproduction include limited resources, hazardous environments, altered gravity, and space radiation, which may lead to the limitation of human (reproductive) rights. Issues of abortion, sterilization, gene editing, embryo selection, prebirth screenings, crew selection policies, and equal access to space are discussed. A feminist bioethics approach to space philosophy and ethics is needed | |||
Szocik et al. [11•] | Theoretical | Philosophy and ethics | Explore the challenges involving human reproduction on Mars | G | Social and ethical challenges related to reproduction on Mars, include the value of human life, abortion policy, the problem of value, and sexual selection and artificial genetic engineering. Microgravity and radiation may affect reproduction and embryonic development. The minimum viable population has been estimated at 5000 people. Healthcare and assisted reproductive technology solutions may be needed | |||
Szocik and Reiss [47] | Theoretical | Philosophy and ethics | We examine the bioethical issues arising from long-duration space missions | G | Biological risks include radiation and low gravity exposure. Socio-reproductive constraints may include reproduction constraints, limited partner selection, and liberal or conservative abortion/contraceptive policies. Ethical issues related to space reproduction may disproportionately impact women/females (e.g., pregnancy and coercion). Respecting reproductive autonomy may be challenging. Modifications or enhancements may be needed to ensure viability | |||
Tăiatu [44] | Chapter | Philosophy, ethics, and law | Raise legal questions on the extension of human rights to the persons on Mars, focusing on childbirth in space | G | Human rights related to women’s sexual and reproductive health include the right to life, health, privacy, education, and freedom from discrimination. States have the obligation to protect these rights, including in space. Vulnerable/marginalized groups require special care. Risks include ectopic pregnancy, childbirth, and developmental anomalies. Informed consent legal aspects may be challenging in space | |||
Usik & Ogneva [57] | Empirical | Biology | Study the protein and mRNA content of cytoskeletal and sperm-specific genes in mice sperm and testis cells | Mice exposed to microgravity for 30 days with 12-h recovery | Animal | Mice (42 males, spermatozoa and testes) | M | Antiorthostatic suspension caused a decrease in the number of mature, mice spermatozoa. This decrease was prevented by essential phospholipids |
Usik and Ogneva [58] | Empirical | Biology | Determine the expression levels of the genes encoding cytoskeletal proteins by quantitative PCR, the methylation level by the restriction analysis, the content of 5-hydroxymethylcytosine by the dot blotting method, as well as the content of enzymes ensuring the establishment/maintenance of the appropriate level of methylation by the Western blotting method in mice spermatozoa under microgravity | Mice exposed to microgravity for 30 days with 12-h recovery | Animal | Mice (21 males, spermatozoa) | M | Gene expression of actin cytoskeleton proteins increased after 12 h of recovery, while methylation of CpG islands decreased. Essential phospholipids reversed these changes. The expression of the beta-tubulin gene decreased and was not affected by recovery or essential phospholipids. The methylation level was reduced in the 12-h recovery group, and histone acetylation increased |
Wakayama et al. [50] | Empirical | Biology | Examine the reproductive potential of mouse freeze-dried spermatozoa stored on the ISS for the longest period in biological research | Freeze-dried sperm samples were stored on the ISS for 9 months, 2 years, and 9 months and for 5 years and 10 months | Animal | Mice (12 males, 24 freeze-dried sperm samples) | M | Space radiation did not affect sperm DNA or fertility after preservation on the ISS. Genetically normal offspring were obtained without reducing the success rate compared to the control group. The sperm can be stored for more than 200 years in space |
Wang and Yasuda [23] | Review | Biology | Review the effects of high-LET particles on the reproductive system and embryonic/fetal development | Both | G | Radiation effects depend on the dose and developmental stage. Radiation can suppress ovulation, reduce sperm count, and cause sterility. Radiosensitivity increases with age. Ovaries, embryos, and fetuses are very radiosensitive. Radiation effects include embryonic and fetal death, congenital malformations, microcephaly, growth delays, cognitive impairments, epilepsy, and neurobehavioral effects | ||
Wanjek [66] | Chapter subsection | General | Mention sex in space and some of its potential challenges | G | No astronaut has had sex in space. Sex in space is a nonissue. Sex in zero gravity may be challenging partly due to weightlessness, which may influence blood flow, arousal, and lubrication. Garments like the 2suit could bring/keep partners together | |||
Zhang et al. [36] | Review | Biology | Summarize the literature on the biological effects of HMF and calculate the magnitude of the effect | Both | G | Hypomagnetic field impairs multiple animal systems, especially in the central nervous system. Hypomagnetic field is a stress factor in plant growth and reproduction. Further studies are needed on countermeasures, the intensity–effect relationship, and combined effects with other factors (e.g., radiation and microgravity) | ||
Zhao et al. [40] | Commentary | Biology | Discuss the space environmental factors that contribute to early embryonic developmental abnormalities and the health risks to mammals after short-term space travel | G | Environmental stressors may contribute to embryonic developmental defects during short-term spaceflight. Short-term spaceflight can enhance the risks of miscarriage and neonatal mortality. Radiation and microgravity may induce different degrees of oxidative stress and DNA damage. More research is needed, including to differentiate their impact and to develop solutions | |||
Zhu and Stone [52] | Empirical | Biology | Assess the life history characteristics of Grevenius annulatus post-exposure to space conditions | (Un)shielded Grevenius annulatus were exposed to UVB and UVC radiation for 30 min using a planetary environment simulator | Animal | Grevenius annulatus (160) | G | Survivorship was lower in the unshielded group compared to the control and Kevlar and polyethylene shielded groups. Cumulative egg production was lowest in the unshielded group, but egg viability and average egg production rate were highest. Kevlar and polyethylene are effective in reducing the impact of nonionizing radiation |