How scientists designed this new copper IUD to be less painful

For the first time in more than 40 years, a new hormone-free intrauterine device (IUD) is coming to market in the U.S.—and it’s designed with patients’ comfort in mind, both during the insertion process and once it’s in place. 

The new IUD, called Miudella, comes from the pharmaceutical company Sebela Women’s Health Inc. It was approved by the Federal Drug Administration (FDA) in late February, and is the second hormone-free IUD to be approved since 1984, when the copper-based option Paragard first became available. With the addition of Miudella, there will now be six IUD options available in the U.S. 

Not only does this advancement provide patients seeking a hormone-free IUD with more than one option, it also marks a potentially major improvement in IUD design. By reducing insertion pain and post-insertion bleeding and cramping, Miudella is addressing two potential side effects of IUD placement that many women feel have long been overlooked.

A new option in an ultra-limited market

According to Kelly Culwell, a board-certified OB-GYN and head of research and development at Sebela Women’s Health, bringing an IUD to market, especially in the U.S., is “a very expensive and time consuming proposition.” Because of those barriers, she says, many pharma companies simply choose not to invest as much in studying women’s health.

“There really isn’t a generic IUD, and the reason for that is it’s a very time-intensive and cost-prohibitive development process, especially for companies that aren’t really putting a lot of money or time or effort into women’s health development,” Culwell explains. “A lot of the bigger pharma companies are focusing on things that could bring in a lot more money; things like oncology or neurology—so there just hasn’t been a lot of innovation [in women’s health overall].”

These factors have resulted in a limited selection of IUD options in the U.S. compared to places like Europe, Culwell says—despite the fact that IUDs are considered to be one of the most effective forms of birth control, preventing pregnancy 99% of the time or more.

Currently, there are four hormonal IUDs on the market (three of which were made by the same company) and one hormone-free IUD. Hormonal IUDs work by releasing a progestin hormone into the body, which thickens the cervical mucus and prevents sperm from entering the uterus. For patients who are sensitive to hormones, though, this might not be the best option. These patients may want to opt for a hormone-free IUD, which uses copper to prevent pregnancy. The metal is toxic to sperm, killing them before they can make it through the uterus.

The only currently available hormone-free IUD, Paragard, has a copper wire wound around the entire T-shaped structure of the device. But there’s a major drawback to that design: Copper can initiate an uncomfortable inflammatory response in the patient, resulting in side effects like cramping and heavy bleeding. Miudella, which has been in development for about 15 years, seeks to improve on both this existing hormone-free IUD model and the construction and delivery of IUDs more generally.

[Image: Sebela Women’s Health Inc.]

Designing a more flexible IUD

To start, Miudella’s developers wanted to find a way to decrease the amount of copper on the device in an attempt to lessen the side effects caused by the metal. In the past, Culwell says, other companies have attempted a similar strategy, but found that lowering the dose of copper reduced the IUD’s effectiveness. After extensive trial and error, the Miudella team found that placing copper strategically on three key points of the device could maintain effective pregnancy prevention rates while lowering the copper dose to less than half that of Paragard.

“The Miudella has copper placed right at the bottom of the IUD, which is at the internal part of the cervix, and then at the top of the arms, which is at each of the tubal openings,” Culwell says. “You don’t necessarily need copper throughout the entire uterine cavity, you just really need copper at the key places where the sperm will be going by, to basically prevent them from making their way to the egg.”

Miudella also bucks the standard material construction of IUDs. Currently, all of the IUDs on the market in the U.S. use a rigid, plastic T-frame that holds one stiff position. To account for the varying anatomies of the uterus, Miudella has swapped that plastic frame for one made of nitinol, an ultra-flexible metal alloy commonly used for procedures like cardiac stents and orthopedic implants.

“Nitinol is super elastic,” Culwell says. “It has shape memory properties, so it actually can conform nicely to varying sizes and shapes of uterus. A uterus can be narrow, it can be short, it can be wide, and so having something that’s not just a rigid T allows for some conformity there.”

Aiming for a less painful insertion process

The nitinol frame allowed Miudella’s developers to make some changes to the actual IUD insertion process, which can be painful for some women—so much so that, in 2022, TikTok saw an outpouring of stories from women who felt that their pain during the procedure had not been properly addressed. Just last August, the Centers for Disease Control and Prevention (CDC) issued its first-ever recommendation that patients should actually be counseled on pain management before the procedure, as well as permitting the use of topical lidocaine during the process.

To increase patient comfort, Miudella’s developers invented a new insertion tube designed for more gentle insertion. Because of nitinol’s compressive properties, the tube can be manufactured about a millimeter narrower than Paragard’s insertion tube. Additionally, while other IUD insertion tubes have a flat, blunt end, the Miudella tube comes with a tapered tip.

[Photo: Sebela Women’s Health Inc.]

“To have it more tapered so that it would be more comfortable for the insertion process is actually a challenge,” Culwell says. “It’s a bit difficult to create this tapered tip that you could reproduce consistently, because then you also have to be able to get the IUD out without much resistance and force. There was a lot of experimentation on getting the tip of the insertion tube to be able to be nice and tapered, but also to allow easy passage of the IUD. In fact, there’s a proprietary way that that tapered tube is designed: It has slits in the side that decrease friction during the deployment process.”

Most other IUDs, due to the rigidity of their plastic frames, have to be loaded by the practitioner within five minutes of placement to hold their shape. In the case of Paragard, the device has to be manually loaded with the fingers by pushing the two arms of the IUD down into a tube—typically while the patient is actively waiting in the stirrups. The added benefit of Miudella’s unique tube and nitinol frame is that the device can be pre-loaded before it even arrives at the doctor’s office.

Currently, Miudella has been approved for use up to three years, whereas Paragard is approved for up to 10. Culwell notes that the team at Sebela is in the process of studying Miudella’s effectiveness for up to eight years of use.

In her own practice as an OB-GYN, Culwell says, she’s glad to see that the CDC has started to offer more guidance on pain management during IUD placement. Still, she believes that women have historically “not been listened to when it comes to pain in particular,” and that the pharma industry needs to invest more in innovating with patient comfort in mind.

“We’re continuing, as a community, to do more and more research on pain management for IUD inserts,” Culwell says. “I think it lagged behind—for way too long, but there was no research done on IUD pain. So, I think continued innovation and then continued informed consent and making sure that we really offer patients pain management techniques are key, because IUDs are terrific methods for people who want them, but it can’t be torture to get them in. That shouldn’t be the trade-off.”

View the full article