What is ovulation pain or Mittelschmerz?

Mittelschmerz is German for "middle" and "pain," and is known colloquially as ovulation pain. Mittelschmerz is a one-sided lower abdominal pain, but can switch to the other side the next month or stay on the same side for several months in a row. This is because ovulation, the ejection of the egg from the ovary, can happen on the same side or different sites. 

Ovulation pain might last a few minutes here and a few minutes there or it could last for more than an hour or even a day or so. Often stress levels can influence the length and severity of the pain. Women suffer from Mittelschmerz on varying levels. Some feel just a tiny bit of pain at the beginning of their menstrual cycle and others feel extreme pain for hours and possibly days. 

Mittelschmerz is due to swelling and stretching of the surface of the ovary in the area of the follicle, leakage of the follicular fluid or blood, or from enzymes that dissolve the outer wall of the ovary surrounding the follicle to let the egg escape. (With ovulation induction, the ovaries can swell and pain at that time may be related to post-ovulation ovarian enlargement.) It normally is caused by the follicular cyst in the ovary swelling and then rupturing to release the egg after your body’s surge in luteinizing hormone (LH).

After the egg is released, the fallopian tube contracts to help it reach awaiting sperm for fertilization. Blood and other fluid from the ruptured follicle may also enter the abdominal cavity and pelvis during this process and cause irritation.

Ovulation pain typically can range from a dull ache to sharp twinges. It may be accompanied by spotting or other discharge.

Does ovulation pain come before or after ovulation?

Mittelschmerz is the result of the distention of the ovary either shortly before, during, or after ovulation. When you feel Mittelschmerz, it may mean that you are either about to ovulate or you ovulated already. Some women only feel it for minutes, exactly at the time of ovulation, though that is not the rule. Many women who ovulate regularly do not have Mittelschmerz, and you can still ovulate normally and never experience it.

Some women with endometriosis experience pain well before ovulation. Keep in mind, Mittelschmerz is too nonspecific to be a reliable enough indicator of ovulation, which can better be assessed with the BBT curve, ultrasound, OPKs, or an elevated postovulatory blood progesterone level.

Symptoms of Mittelschmerz:

• One-sided lower abdominal pain
• Pain onset is shortly before, during, or right after ovulation
• Recurrent or with similar pain in past
• Duration is typically seconds or minutes to a few hours but may extend as long as 24 to 48 hours
• It is usually sharp, cramping, distinctive pain
• Rarely pain can be severe
• Pain may switch sides from month to month or from one episode to another since eggs are released randomly from the left or right ovary each month

Pain in your right lower abdominal area can also indicate other more severe problems such as appendicitis. If you have this severe pain, especially if it is accompanied by fever, you should immediately call your doctor or go to the emergency room.

Could mittelschmerz or ovulation pain have other causes?

Pelvic pain, ovulation pain and mittelschmerz could be caused by other multiple health problems that could cause pelvic or abdominal pain. These include:

• Endometriosis where tissue from the lining of the uterus grows outside the uterine cavity. Areas affected become irritated when the lining tissue responds to hormones during your cycle, causing bleeding and inflammation outside of the uterus. You may develop scar tissue or endometriosis adhesions that are particularly painful during your period.
• Scar tissue or adhesions outside the uterus after surgery or infections (eg after cesarean, appendix surgery, ovarian or adnexal surgery, bowel surgery, pelvic infections)
• Intrauterine adhesions, also known as Asherman syndrome, can develop if you’ve had previous surgery like a dilation and curettage (D & C) or cesarean delivery. A prior infection in the uterus can also cause these adhesions. You can also develop Asherman syndrome with no known cause.
• Infections of the uterus or other pelvic organs. Sometimes a urinary tract infection (UTI) might cause general pelvic pain.

Since doctors can’t see these conditions during a routine ultrasound, your doctor may order a hysteroscopy or laparoscopy. These are surgical procedures that allow doctors to directly see inside your uterus or pelvis. 

If the pain occurs every month during the time you should be ovulating and there are no other symptoms, and it's short-lasting less than 24-48 hours, there is a good chance it is Mittelschmerz.

If there are other symptoms or the pain occurs at a time other than your ovulation cycle, you could be having menstrual cramps or some other problem and should consult your doctor.