A team of University of California, San Francisco, obstetricians and bioengineers is building a wireless device that can be inserted into a pregnant woman’s vagina to monitor her cervix and, when necessary, send an alert that the woman may be going into premature labor.
The device, which will be similar in size and shape to a diaphragm used for birth control, would be the first early-warning system for preterm labor, which is the main cause of death among newborns worldwide.
It’s still in early development, but the device, called the Smart Diaphragm, just got $2.7 million from the Bill & Melinda Gates Foundation to start manufacturing and expand clinical trials. A prototype has been tested in about 15 pregnant women at UCSF, and a larger study is planned for this summer.
“We need a way to have an early heads up – who needs to be seen by a doctor, who needs surveillance. That’s what drove us,” said Dr. Larry Rand, an obstetrician and the lead developer of the diaphragm.
“For 30 years, we’ve been doing research on preventing preterm birth,” Rand said. “But we’ve been focusing too much on the uterus and the contractions, and that’s sort of like trying to treat a heart attack after someone has chest pains.”
Monitoring the cervix at a molecular level, he said, may be the answer. Rand believes the cervix may be critical for understanding preterm birth because it undergoes subtle molecular changes a long time – weeks, perhaps- before labor begins.
When preterm labor is detected now – either because a woman has started having contractions or because an ultrasound has detected a change in the size or shape of her cervix – it’s usually so far advanced that there aren’t many options for doctors to stop it.
The cervix softens when the collagen starts to break up. Ordinarily, collagen forms a tight crisscross pattern, like a basket weave, that keeps the cervical tissue stiff. But something causes that basket weave to loosen.
Rand’s device cups the cervix and monitors the collagen, ideally revealing when the basket weave starts to come undone. The device is embedded with two types of sensors – one to monitor electric currents moving through the cervical tissue, and one to monitor fluorescent light. As collagen breaks down, electrical currents move more easily through the tissue and the tissue bounces back light in a different pattern.
“We’re measuring multiple times throughout pregnancy. We’re getting in essence a virtual biopsy of the cervix,” said Mozziyar Etemadi, a postdoctoral bioengineer from UCSF and UC Berkeley who’s working with Rand on building the diaphragm. “This wasn’t possible even 10 years ago. The tools that we’re using didn’t exist – the electronics and the wireless connectivity were not there.”
The idea is to insert the diaphragm into a woman’s vagina at some point early in the pregnancy to get a baseline reading on her cervix. Then, the woman would reinsert the diaphragm periodically during pregnancy – maybe every few days or so – to get more readings.
The data would be transmitted wirelessly to cloud storage, where it would be accessible by the patient and doctors. If her collagen structure was changing enough to raise concern, an alert would go out, either to the patient or her doctor, or both.