The intrauterine device (IUD) is a small plastic device that is fitted within the uterus in order to prevent pregnancy. The standard IUD, discussed here, is coated with copper. The IUD that releases progesterone is discussed here.
The IUD exists in many forms around the world, with availability differing by country. There are small variations in size, composition, and method of insertion. For example, the Gynefix, which is unavailable in the U.S., is inserted so that the tip is embedded in the uterine wall.
The IUD is inserted via the cervix in a compressed manner and opens to its full shape (often similar to the letter T) inside the uterus. When open, the IUD is wider than the opening of the uterus and thus should remain in place until medically removed. Two small strings are left protruding from the cervix to allow confirmation that the device has not spontaneously slipped out. These strings also facilitate removal when desired.
The efficacy of the IUD in prevention of pregnancy is approximately 99%. It remains effective for a number of years, depending on the brand. For example, Paragard (the IUD currently available in the US) is approved for 10 years of use.
The exact mechanism of the IUD is still not completely understood. The most recent and widely accepted theory is that the copper-coated IUD prevents conception by altering the environment within the uterus and fallopian tubes so that fertilization cannot take place. The IUD was once thought to prevent implantation, i.e., the sperm and ovum unite and begin dividing but the resulting embryo does not become embedded in the uterine lining. This earlier theory appears to be accurate in only a small minority (about 1%) of cases.
In the decades that IUDs have been available, a number of health concerns have been raised. In the 1970s there were cases of death associated with the use of one brand of IUD (the Dalkon Shield). This has not been reported with currently available devices, despite their very common use worldwide. Older studies raised the fear of increasing pelvic inflammatory disease, which could lead to sterility due to blockage of the fallopian tubes from post infection scarring ("tubal infertility"). Recent studies with the new copper intrauterine devices have found no increase in tubal infertility and an overall low rate of pelvic inflammatory disease. Another concern raised with the IUD was whether it increases the incidence of ectopic pregnancy (pregnancy outside the uterus). Recent studies seem to indicate that the device does not cause ectopic pregnancies, but does a better job preventing uterine pregnancies than extra-uterine pregnancies. Currently, the IUD is felt to be a safe and efficacious method of contraception and is in fact the most common method of reversible female contraception outside the US.
Bleeding and Staining
Menstrual blood loss increases by approximately 50% during use of the copper IUD. This can either be heavier menses or irregular bleeding. Heavy menses result in additional days of staining before a woman can do a hefsek taharah. Irregular bleeding can cancel out the blood-free days that she has counted so far, leading to prolonged periods of niddah, or can make her a niddah again soon after she has immersed in the mikveh. Some women may also experience changes in the length of the menstrual cycle.
The degree of irregular bleeding decreases over a number of months of use and for most women it reaches acceptable levels within 3-6 months. However, women who use an IUD need to be prepared for a difficult beginning, and should take precautions to avoid becoming niddah unnecessarily due to staining (see Ketamim).
The different theories as to the mechanism of action and past health concerns have had implications for the halachic desirability of this form of contraception. If the IUD primarily prevents fertilization, then it presents few halachic problems in a situation where contraception itself is permissible. On the other hand, if the IUD prevents implantation of the fertilized ovum, then the more serious issue of abortion is raised. Furthermore, health risks are always a halachic concern. Currently, the IUD is considered by many rabbis to be the method of birth control second in line after hormonal contraception, although controversy does exist.
There is halachic debate as to whether inserting or removing an IUD renders a woman niddah. There are two possible concerns: uterine dilation, and bleeding caused by the procedure.
Uterine dilation, even without bleeding, renders a woman niddah. Halachic authorities differ regarding the degree of dilation required; opinions range from approximately 4 mm to approximately 20 mm. An IUD within an introducer may reach 4 mm in diameter (although one can always ask one's physician for the exact measurements). This would make a woman niddah according to the more stringent opinions.
Vaginal bleeding following IUD insertion or removal may sometimes be considered dam makkah (bleeding from trauma), which does not make a woman niddah. In other cases, such bleeding does make her niddah.
Each case is unique, and halachic authorities differ in their approaches. Therefore, it is best for each woman to ask an individual question to her rabbi to determine whether she will become niddah from the procedure. Rabbi Yehuda Henkin, the posek for this website, rules as follows:
Uterine dilation through insertion of an instrument less than 19mm in diameter does not make a woman niddah. Therefore, IUD insertion or removal does not make one niddah due to uterine dilation.
Vaginal bleeding following removal is assumed to be from the trauma of the procedure (dam makkah), and does not make a woman niddah.
Vaginal bleeding following insertion, with no clear indication that it is from trauma, cannot automatically be attributed to trauma from the procedure. However, bleeding following insertion can be attributed to trauma in any of the following cases:
- A tenaculum was used to grasp the cervix.
- The physician ascertained before the procedure that there was no bleeding, inserted the IUD, and stated that there might be bleeding from the procedure.
- The physician ascertained before the procedure that there was no bleeding, and bleeding began immediately following the procedure.
Bleeding that continues longer than one day after insertion, or two days after removal, cannot be attributed to trauma from the procedure. Bleeding that begins more than one day after either procedure also cannot be attributed to trauma.
Medically, physicians prefer to insert the IUD when the cervix is slightly open, either at the end of a menstrual period or about 4-6 weeks after delivery. Removal can generally be performed at any time of the cycle.
If one follows the opinion that the procedure itself makes one niddah, then it is best to have the IUD inserted when one is niddah anyway. A woman should ask her physician how early in the cycle he is willing to insert the device so that the time she is niddah (if she is) from the procedure will overlap the bleeding of menses. The physician may not want to do the procedure too early if he feels that the heavy bleeding at the beginning of menstruation would make it more difficult to see the cervix and thus insert the device.
If one follows the opinion that the insertion does not make one niddah, it is best to have the IUD inserted after mikveh immersion so that the mild bleeding from the procedure does not lead to confusion during the bedikot of the shivah neki'im. We would recommend insertion at least a week before any veset days and their attendant bedikot.
Before having these procedures at any point in the cycle, please see our article on stains for some helpful guidelines to avoid halachic problems. At all times, but especially after any gynecological procedure, it is important to wear only colored underwear and to avoid looking at toilet paper.