Understanding the Need for New Contraceptive Options
Many people seeking birth control want non-hormonal options, but choices remain limited. In the United States, about 45% of pregnancies are unintended, and most result from either not using contraception or using it incorrectly. Hormonal contraceptives are not suitable for everyone, so there is a strong demand for new, non-invasive alternatives.
The Cervix: A Natural Barrier to Fertility
The cervix acts as a gateway to fertility. Sperm must pass through cervical mucus to reach the uterus and fallopian tubes for fertilization. Cervical mucus changes throughout the menstrual cycle, becoming thinner during ovulation to allow sperm passage, and thickening after ovulation to block sperm and pathogens. This natural barrier presents a promising target for new contraceptive methods.
Building a Lab Model to Study Cervical Mucus
A research team led by Dr. Leo Han at Oregon Health & Science University (OHSU) and the Oregon National Primate Research Center (ONPRC) has developed a new lab-based (in vitro) model to study how cervical mucus changes during the menstrual cycle. Using cells from rhesus macaques, which have cervical structures similar to humans, the team grew and treated these cells with hormones to mimic different cycle phases.
Key Findings: Genes That Regulate Fertile Mucus
By analyzing genetic activity in these cultured cells, the researchers identified hundreds of genes that play a role in mucus production and consistency. They discovered that these genes respond differently depending on hormone levels, revealing potential drug targets for blocking sperm without hormones. One important protein, MUC5B, helps form the gel-like structure of mucus, while ion channels influence hydration and thickness.
A Powerful Tool for Future Contraceptive Research
This new lab model allows scientists to study cervical mucus in a controlled environment, making it easier to understand the molecular mechanisms that regulate fertility. The team is now testing non-hormonal compounds that could inhibit fertile mucus production in nonhuman primates, moving a step closer to new non-hormonal birth control options.
Promoting Reproductive Justice
Lead author Dr. Katrina Rapp emphasizes that expanding contraceptive choices is especially important for marginalized and disadvantaged populations, who are more likely to experience unplanned pregnancies. By focusing on non-hormonal, non-invasive methods, this research could help promote reproductive justice and improve health equity.
Research Support and Ethical Oversight
This work was supported by the National Institutes of Health, March of Dimes Foundation, and other partners. All animal research at OHSU is reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) to ensure ethical standards and scientific value.

