An intrauterine device (IUD) is one of the most effective forms of long-acting, reversible contraception, providing pregnancy protection exceeding 99% effectiveness. This small, T-shaped device is inserted into the uterus and has thin nylon or polyethylene threads, known as strings, that extend through the cervix into the top of the vaginal canal. These strings allow the patient to check for the device’s presence and enable a healthcare provider to remove it. When an IUD is used alongside a barrier method like a condom, a common concern arises about the physical interaction between the strings and the condom material.
Answering the Safety Question: The Physical Interaction
The risk of IUD strings puncturing or tearing a latex or polyurethane condom is considered extremely low, approaching negligible. The strings are manufactured from soft, flexible plastic polymers, such as polyethylene, which are specifically designed to be biocompatible and non-abrasive. This material is not sharp or rigid enough to compromise the integrity of a well-lubricated condom through normal friction.
The design and placement of the IUD strings further minimize any potential for damage. After insertion, the strings are typically trimmed to a length of approximately two inches and naturally curl up near the cervix. During intercourse, the strings remain in this area, reducing direct, forceful contact with the condom surface. Condom failure is more commonly caused by improper use, oil-based lubricants, or rough handling, not IUD strings.
Rare instances of perceived condom damage often correlate with other factors, not the inherent material of the strings. If the strings were cut at a sharp angle by an inexperienced provider, they may feel momentarily stiff or pokey, which could cause discomfort to a partner. However, even a stiff string is unlikely to have the tensile strength or rigidity necessary to puncture a condom, which is engineered to withstand significant pressure and friction. The consensus is that the worry over IUD strings causing condom failure is largely theoretical, unsupported by clinical evidence.
Managing String Length and Partner Comfort
While the strings pose almost no threat to the condom’s structural integrity, they can sometimes cause discomfort for a sexual partner, particularly during deep penetration. This discomfort often presents as a prickling or poking sensation. Discomfort is often higher when the strings have been cut too short, leaving a blunter end exposed, or shortly after insertion before the strings have had time to soften.
A healthcare provider trims the strings immediately after the IUD is placed to an appropriate length. If a partner experiences persistent irritation, the first step is to communicate this to the provider. A simple in-office visit allows the provider to assess the string length and trim them slightly shorter if necessary to increase comfort.
String length is a balance; while shorter strings reduce partner discomfort, strings that are too short may curl fully into the cervix, making it difficult for the patient to check their IUD or for the provider to remove it later. The strings naturally soften over the first few months. If trimming does not resolve significant discomfort, the provider may suggest leaving the strings slightly longer during a replacement insertion, as longer strings are often less noticeable because they are more pliable.
Action Steps Following Suspected Condom Damage
If a condom failure is suspected, immediate action is necessary to prevent unintended pregnancy and the transmission of sexually transmitted infections (STIs). Emergency contraception (EC) should be considered immediately if pregnancy is a concern. The copper IUD can be used as a highly effective form of EC if inserted by a provider within five days of the unprotected sexual encounter.
Alternatively, emergency contraceptive pills can be taken up to five days after unprotected sex, though their effectiveness decreases the longer the wait. The IUD offers excellent pregnancy protection but does not protect against STIs, which is the primary reason for using a condom alongside the IUD. If the condom failed and the partner’s STI status is unknown, seeking STI screening is recommended.
After a suspected failure, the patient should perform a routine IUD string check to confirm they can still feel the threads. The presence of the strings confirms the device is likely still in the correct location, as displacement or expulsion is a separate, more significant risk than string abrasion. If the strings cannot be felt, a healthcare provider should be contacted promptly to check the IUD’s position using an ultrasound or other diagnostic tools.