6 Facts Men Should Know About Their Partner's IUD

If your partner is using an intrauterine device (IUD) as her method of birth control, you may think of it the same way you think of her handbag: You know it's there and it's often mutually beneficial—she's the one who holds it and sometimes she carries your stuff—but you really don't know much about its inner workings or how it feels.

IUDs rest inside the uterus, past the cervix. If you're a visual person, picture a longhorn skull: The uterus is the top of the skull, and this is where the IUD rests. The fallopian tubes are the horns with ovaries at the end, and the cervix and vagina are down in the steer's nose.

One of the most appealing aspects of IUDs is that they last anywhere from five to 12 years, which means your partner doesn't have to think about it on a day-to-day basis like with birth control pills.

Curious to learn more about your partner's IUD? You should be. Here are six must-know facts about this form of contraception.

Fact No. 1

There are two different types of IUDs

The first question you should ask your partner about their IUD is whether it's the hormonal or nonhormonal (copper) device. A hormonal IUD releases low doses of the hormone progesterone into the body. This hormone thins the lining of the uterus so an egg is less likely to implant.

"[Progesterone] thickens the cervical mucus, which makes it more difficult for sperm to move through the cervix. For some women, ovulation is also inhibited," explained Gunvor Ekman-Ordeberg, M.D., an OB-GYN and the co-founder of DeoDoc Swedish Intimate Skin Care in Stockholm.

The copper IUD releases zero hormones. Instead, it works more as a barrier that prevents sperm from reaching the egg. Both types of IUDs are small, plastic and shaped like a T, but in the copper version, the base of the T is wrapped in copper wiring.

Why? Copper is a natural spermicide and copper ions inhibit the movement of sperm. Copper IUDs also last longer than their hormonal counterparts.

Fact No. 2

IUDs may change her menstrual cycle, and that's OK

If you realize your partner never talks about having her period, it's because she may not be having one.

"Some IUDs might cause irregular periods. Some might cause no period for a few months," said Daniel Roshan, M.D., a high-risk maternal-fetal OB-GYN with NYU Langone Health in New York City.

Both of these scenarios are normal.

A bleeding disorder is the most common side effect of hormonal IUDs, Ekman-Ordeberg said, adding that spotting is frequent and common for the first three to four months after insertion.

"After the first few months, most women develop sparse regular bleeding or amenorrhea [absence of menstruation], but this is, of course, different for each individual," she said.

On the flip side, sometimes the nonhormonal copper IUD can cause cramping and heavy bleeding in the first few months after its insertion, but Roshan said those side effects should resolve on their own in a few months.

Fact No. 3

IUD side effects can include mood changes

Typically, the copper IUD does not cause noticeable mood changes because it does not manipulate hormones. In some cases, however, you may notice your partner's mood change slightly with the hormonal IUD.

"The most common mood side effects are depression, low libido, feeling of sadness, irritability and low mood, which are, of course, specific to each individual," Ekman-Ordeberg said.

Roshan added that while the amount of progesterone released is small, in some cases it can still cause bloating, breast tenderness or a small amount of weight gain, especially in the beginning.

Fact No. 4

You probably won't feel an IUD or knock it out during sex

Settle down, big boy—it's very rare for a man to physically knock out an IUD during sex, regardless of your size. Properly placed, the device should be too far up in the uterus to be reached during sex. It can move, but usually, this is because of a problem with insertion. Roshan advises patients to go back to their doctor three months after insertion to make sure it's in the right spot.

At most, a man may feel the strings that hang down from his partner's IUD past the cervix. They are there for ease of removal. They shouldn't cause any issues, but if they are bothersome to you—and if your partner is comfortable with the idea—the doctor may be able to trim the strings.

Fact No. 5

IUDs do not protect against sexually transmitted infections

While it's very effective in preventing unwanted pregnancy, an IUD does nothing to prevent STIs. Literally zero. So if you're nonmonogamous or you and your partner haven't been tested recently, it's a good idea to use a condom, even if it feels redundant.

Fact No. 6

In (very) rare cases, pregnancy can still occur

It's extremely rare, but there have been instances of women with IUDs getting pregnant. This is usually the result of the IUD shifting out of place, which is another reason it's important your partner gets it checked or at least feels for the strings periodically.

This rarity is nonetheless important to mention because if your partner does get pregnant with an IUD, she should get checked by her doctor immediately as the risk of ectopic pregnancies is higher for people with IUDs, according to Roshan. An ectopic pregnancy is a pregnancy in which the fertilized egg implants outside the uterus. A 2022 study found the incidence rate of ectopic pregnancy among women using a low-dose hormonal IUD was substantially higher than that in women using other types of hormonal contraception.

IUDs are generally about 99 percent effective at preventing pregnancy, which is higher than most contraceptives' rates, largely because there is little room for user error, like forgetting the pill for a few days or having a condom break.