Familial Mediterranean fever (FMF) is a condition that is characterized by sudden episodes of intense, high fever (38-40°C;100.4-104°F) and pain in the abdomen and other body parts (for example joints), usually lasting from 48 to 96 hours. FMF is rare in western countries over all, but it is common among particular ethnic groups. In certain populations of Armenians, for instance including Armenians of southern California (as well as Armenians in Lebanon), FMF occurs in 1 out of every 500 people. This is on account of a mutation of the MEFV gene, present in 1 out of 7 people. In Turkish populations, the rate of FMF is between 1 per 150 to 1 per 10,000 people. The condition also is common among Sephardic Jews, which have a rate between 1 per 250 and 1 per 1,000 people. High rates of FMF are reported in Jews hailing from Arab countries. Arabs, Italians, and Greeks also have high rates of FMF, but the precise numbers are controversial. As for Ashkenazi Jews, FMF occurs at a rate of only 1 per 73,000. Thus, if you are Armenian, Jewish, or have roots in a Middle Eastern or Mediterranean country, it is possible that you could have FMF, in which case it is possible that FMF will affect you during pregnancy.
An attack of FMF can lead to confusion, because it can resemble acute appendicitis, cholecystitis (inflammation of the gallbladder), or kidney stones; these are fairly common conditions that also feature fever and pain in various parts of the abdomen. FMF is notorious for causing unnecessary surgical procedures, such as an appendectomy on a healthy appendix, or a cholecystectomy of healthy gallbladder. FMF episodes also can produce arthritis and gastrointestinal symptoms, and a problem called amyloidosis that causes disease in organs, such as the kidneys, and is related to the presence of a substance called amyloid-A in the blood. Episodes of FMF result from an autoimmune process (inappropriate action of the body’s own immune system) against the outer layers of various organs which is inherited. Consequently, FMF is seen in particular ethnic groups based on the presence of certain genetic sequences, notably mutations within a gene called MEFV. Since FMF symptoms almost always begin prior to age 40 (and often by the teenage years), the condition can easily coincide with pregnancy.
If you have a history of fever episodes and abdominal pain or pain in other locations in the body, if no other condition has been diagnosed, if you have had a healthy appendix or healthy gallbladder removed, and if you are part of an ethnic group that is known to have a high rate of FMF, the level of suspicion will be high that you may have FMF. For this reason, physicians and genetic counselors will offer you genetic testing to look at the MEFV gene. There are many known mutations of this gene, and findings of any of them will support a diagnosis of FMF.
In some women with FMF, the condition improves during pregnancy, but in other women FMF can get worse in terms of the intensity of the attacks of pain and fever. The pain attacks in the abdomen can be the result of peritonitis, which also can trigger very early contractions of the uterus, leading to a spontaneous abortion (miscarriage), resulting in fetal death. In addition to high fever potentially causing dehydration, some studies have suggested that fever during pregnancy can increase a baby’s risk of having congenital defects involving the heart and other organs. Also, a recent study identified maternal fever as possible risk for the baby developing autism spectrum disorder. Furthermore, the amyloid A that circulates in the blood in connection with FMF can lead to damage and ultimately failure of internal organs, such as (but not limited to) the kidneys.
Treatment for FMF consists of colchicine, an anti-inflammatory drug that is thought to be safe for the fetus and for nursing infants.
The most important thing for you to remember about FMF is that it related to ethnicity and can be confused easily with certain abdominal conditions that are considered emergencies and that are treated with surgery. Physicians will want to discuss your history and family history at regular office visits. However, if you show up in the emergency room, or the delivery room, with fever and abdominal pain, and in a geographic location with few people from Mediterranean or Middle Eastern lands, it is possible that FMF might not be considered. Consequently, you should be aware of the FMF possibility and bring it up in a conversation with the examining physician.