The Common vein Copyright 2009


Mittelschmerz is the Gernam word for “middle pain”  and refers to the lower abdominal and pelvic discomfort associated with ovulation, which occurs in the middle of the menstrual cycle.  The cause of the pain may be due to the actual follicle rupturing, follicular  distension, the contraction of the fallopian tube, or the release of blood/fluid from the ruptured follicle into the abdominal or pelvic cavity.

From a structural point of view it usually is considered a visceral pain caused by stimulation of pressure receptors in the ovary, but the proximity and intimate relationship of the ovary to the peritoneum and release of fluid and blood into the peritoneal cavity may cause irritation of chemical receptors in the peritoneum, inciting somatic like pain.

Functionally it is a cruel mechanism that allows awomen ao mark the time for potential fertilization, or on the other hand to abstain from intercourse if fertilization is not desirable.

Clinically the pain classically occurs in the middle of the month, lasts between 6-8 hours but may last up to 2-3 days, occurs suddenly, is situated on one or other side of the pelvis, in the midline or sometimes in the back, usually is ill defined and is either cramp like or a deep discomfort.   It is not considered a disease state but can sometimes be quite uncomfortable.

The diagnosis rests on the timing of the pain, and the usual pattern of an individual woman, though each cyle can be uniquely different. One may be suspicious of other disorders if the pain is more severe or lasts longer than usual,  or if a mass is palpated on pelvic examination.

Ultrasound is recommended if the pain is not classical or if a mass is felt, in order to exclude other causes such as a large unruptured cyst, hemorhagic cyst, blood in the peritoneum, endometriosis, ectopic pregnancy, or torsion.

Management generally is supportive and reassurance.  If necessary, pain can be managed with NSAIDs (non steroidal anti-inflammatories) such as ibuprofen.

Ovulation and Mittelschmerz

The transvaginal ultrasound focuses on the ovary (pink oval structure) of a young woman who was complaining of midcycle pain. A decompressed Graaffian follicle (inverted teardrop shaped yellow structure in the ovary) is seen emptying its contents into the peritoneal cavity, causing a triangular shaped accumulation of fluid in the peritoneal cavity (yellow triangle).  It is the shape of the follicle and its proximity to the fluid in the peritoneum together with the concordant site of the pain that allowed the diagnosis of mittelschmerz to be made.

47025c01 young patient with known ovulation one day earlier ovary Graafian follicle rupture tear drop shape pear shaped ovulation physiology normal anatomy USscan Davidoff MD