Natural Cycles has received its sixth FDA clearance for an updated fertility algorithm designed to personalise digital contraception.

The regulator cleared the company’s next-generation NC° Fertility Algorithm, which combines statistical modelling with machine learning to predict fertile and non-fertile days.

Natural Cycles said the algorithm was trained on tens of millions of real-world fertility data points and adapts to individual cycle patterns.

“People don’t just want effective birth control; they want a method that fits naturally into their lives,” said Dr Elina Berglund Scherwitzl, chief executive and co-founder of Natural Cycles.

“One of the unique advantages of a software-based contraceptive is that it can continue to evolve.

“As our scientific understanding of fertility grows and we continue to learn from more than a decade of real-world data, we can responsibly refine the technology through rigorous research, clinical validation, and FDA review.

“This latest clearance is the result of that work, helping us give many users more flexibility while maintaining the effectiveness they rely on.”

Evidence supporting the FDA clearance showed that the updated system maintained the app’s established safety and effectiveness while giving many users more Green Days.

Green Days are those on which the app confirms that pregnancy protection is not needed.

The birth control app remains 98 per cent effective when used as intended and 93 per cent effective with typical use, according to the company.

Natural Cycles said these rates place it in the same effectiveness category as the combined oral contraceptive pill.

Typical use includes mistakes or inconsistent use, while intended use means following the method correctly.

Digital contraception uses technology and physiological data, such as body temperature, to provide personalised fertility predictions.

Natural Cycles said its updated algorithm can identify fertile and non-fertile days more precisely than traditional fertility awareness methods, which may classify larger parts of the cycle as potentially fertile.

The changes provide more Green Days while maintaining effectiveness, improve performance for people with irregular cycles and better handle lower-quality temperature or biomarker data, the company said.

A biomarker is a measurable biological signal, such as body temperature, that provides information about processes taking place in the body.

Natural Cycles also said the system can personalise its predictions more quickly as a user’s menstrual cycle changes over time.

“Years ago, the question was whether digital contraception could work. Today, Natural Cycles has demonstrated robust clinical and real-world evidence that it can,” said Dr Kerry Krauss, senior medical adviser at Natural Cycles.

“The next chapter for digital contraception is making it more personalised and easier to use while maintaining the same high standard of safety.

“This FDA clearance demonstrates how advances in AI and machine learning can improve the user experience while preserving the scientific rigour expected of a regulated medical device.”

Natural Cycles has filed a patent application covering key innovations in the updated algorithm.

The decision follows the FDA’s first De Novo clearance of the company’s birth control app in 2018.

Later clearances allowed the app to integrate with the Oura Ring in 2021 and Apple Watch in 2023.

In 2024, the FDA cleared a Predetermined Change Control Plan, creating a regulatory pathway for future hardware integrations.

Natural Cycles said the plan has since enabled the launch of its NC° Band and other hardware integrations, including a Garmin connection introduced in March 2026.

A further clearance in 2025 allowed the birth control app to be offered both over the counter and by prescription.

The company has also received regulatory authorisations in more than eight markets worldwide, including Europe, Canada, Brazil, Australia, South Korea and Singapore.

Davunetide may significantly slow the progression of a fatal brain disease in women, according to a new analysis of clinical trial data.

The findings indicate that women and men with progressive supranuclear palsy (PSP) may respond differently to the experimental treatment.

Progressive supranuclear palsy, or PSP, is a rare and fatal neurodegenerative disease.

Researchers at Tel Aviv University led the analysis and said the results reinforce the need for sex-specific approaches to neurodegenerative diseases.

Neurodegenerative diseases are conditions in which nerve cells in the brain or nervous system gradually lose function and die.

The team reanalysed data from a 52-week international clinical trial involving more than 300 people with PSP.

The disease is caused by the abnormal accumulation of tau protein in the brain. Tau is a protein found in nerve cells that builds up abnormally in people with PSP.

There is currently no effective drug treatment for the disease.

The work was led by professor Illana Gozes of the Sagol School of Neuroscience and the Gray Faculty of Medical and Health Sciences at Tel Aviv University.

The research team included current and former students Dr Guy Shapira, Jason Blatt and Liri Guz, together with professor Noam Shomron.

The original clinical trial found that Davunetide was safe but ineffective.

However, the researchers separated female and male participants and re-examined the data using updated assessment measures recommended by the FDA.

Women treated with Davunetide experienced a significant slowing of disease progression, while no similar effect was observed in men.

The treatment helped preserve essential movement and functional abilities, including balance, fine motor skills and everyday tasks such as using cutlery, buttoning clothes and washing the face and hands.

Fine motor skills are the small, precise movements needed for tasks involving the fingers and hands.

Treated women also showed significant improvements in language ability, working memory and overall cognitive function.

Cognitive function covers mental abilities such as memory, attention, language and problem-solving.

The analysis also identified profound molecular differences between women and men.

The relationship between levels of pathological tau in cerebrospinal fluid and clinical symptoms was completely reversed between the sexes.

Cerebrospinal fluid is the clear liquid surrounding the brain and spinal cord. A biomarker is a measurable sign that can indicate disease activity.

For example, language abilities declined significantly as tau pathology increased in women, but not in men.

The researchers said this suggests the disease mechanisms may work differently in women and men, potentially explaining their different responses to treatment.

According to professor Gozes, overlooking biological differences between the sexes may hide a genuine treatment effect.

“Our data show that analysing women and men separately is not merely a statistical exercise, but an essential tool for developing more effective treatments for neurodegenerative brain diseases,” she said.

The researchers believe the findings provide a strong scientific basis for future clinical trials and treatment protocols designed from the outset to account for patients’ sex.

These trials could evaluate Davunetide as a targeted treatment for women with PSP.

They said the approach may also pave the way for more precise treatments for tau-related diseases, including Alzheimer’s disease and other neurodegenerative brain disorders.

The study was supported by ExoNavis Therapeutics, which is developing Davunetide for brain diseases under licence from Ramot, Tel Aviv University’s technology transfer company.

A preeclampsia study has found unusual cell activity in mothers and babies that could reveal new targets for treatment.

The condition affects 2 to 4 per cent of pregnancies worldwide and is a leading cause of maternal and foetal mortality.

There is currently no cure, and severe cases can put both the mother and baby at risk.

Scientists from UCL and University College London Hospitals found that stressed placental cells, poorly functioning blood vessels and an overactive immune response all contribute to the condition.

Preeclampsia causes high blood pressure during pregnancy. It can affect blood flow to the baby and cause symptoms such as swelling, headaches, blurred vision and pain under the ribs.

Without treatment, it can damage the mother’s health, slow the baby’s growth and, in severe cases, become life-threatening.

Previous research has focused only on the placenta, the organ that develops during pregnancy to support the baby’s growth, rather than the tissues around it.

The researchers said the findings could reveal new therapeutic targets, which are biological processes that future treatments could be designed to alter.

Senior author professor Sara Hillman, of the UCL EGA Institute for Women’s Health, said: “We studied individual cells from both the mother and the baby to see how their activity changes in healthy pregnancies compared with preeclampsia.

“This helped us to confirm some changes already suspected in the condition and also discover new ones.”

The team studied 20 pregnant women recruited at UCLH, including 10 with severe preeclampsia and 10 without the condition.

They used genomic testing to examine individual cells in the placenta and other tissues where cells from the developing baby and mother come into contact.

Genomic testing examines genetic information to help researchers understand how cells behave and the roles they may play.

The other tissues studied were the myometrium, the muscular layer of the womb, and the chorioamniotic membranes, which surround the baby during pregnancy.

The team compared cells from healthy pregnancies and those affected by preeclampsia at different gestational ages, meaning different stages of pregnancy.

They used technology that can read the genetic information of thousands of individual cells at the same time, allowing them to see what each cell was doing and where it was located in the tissue.

In preeclamptic pregnancies where babies were born prematurely, before 37 weeks, during the third trimester, placental cells showed signs of stress and low oxygen levels.

The cells also did not use energy in the normal way.

Some cells responsible for reshaping the mother’s blood vessels were not working properly, the researchers found, which may affect blood flow to the baby.

There were also signs of an overactive immune response in the placenta, nearby tissues and the mother’s blood.

The researchers said this response, together with other stress molecules released by the placenta, helps explain why preeclampsia affects the whole body and can become serious.

They hope the findings will help researchers find treatments for the condition and potentially save lives.

Co-lead author Dr Yara Sanchez Corrales, of the UCL Great Ormond Street Institute of Child Health, said: “These findings point to specific biological processes that could be targeted with treatments. Acting early in pregnancy, especially in more severe early-onset cases, could help improve outcomes and reduce the high risks associated with severe preeclampsia.

“We hope that our findings may set us on the path to reducing premature births and fatalities associated with preeclampsia.”

Co-lead author Mr Theodoros Xenakis, of the UCL Great Ormond Street Institute of Child Health, said: “Future studies may provide an even clearer picture of the biological changes linked to the disease by including more participants and using even more precise methods.”