Mittelschmerz
Mittelschmerz is midcycle abdominal pain due to leakage of prostaglandin-containing follicular fluid at the time of ovulation. It is self-limited, and a theoretical concern is treatment of pain with prostaglandin synthetase inhibitors, which could prevent ovulation.

Endometriosis
Pain associated with endometriosis may worsen premenstrually or during menses. Patients experience generalized lower abdominal tenderness, and associated complaints include dysmenorrhea, dyschezia, and dyspareunia. Endometriotic deposits in both the uterosacral ligaments and rectovaginal septum contribute to pain during intercourse. Painful defecation is due to infiltration of the bowel wall by endometriotic deposits. Importantly, remember that the pain associated with endometriosis is not correlated with the presence or amount of visible endometriotic tissue. In fact, prevalence of endometriosis is the same in women with and without pain. Rather, pain is related to the chemical mediators of inflammation and neural infiltration.

Ovulation suppression using different drugs has been tried in order to reduce the pain associated with endometriosis. Overall, no difference appears to exist in the efficacy of danazol, gestrinone, oral contraceptives, depot medroxyprogesterone acetate, and gonadotropin-releasing hormone (GnRH) analogs in placebo-controlled trials. However, dydrogesterone was found to be less effective.

In systematic reviews, laparoscopic ablation of endometriotic implants using diathermy or laser remains unproven as a treatment modality for pain or subfertility. However, results from one study indicate that a combination of ablation and laparoscopic uterine nerve ablation (LUNA) was more effective for relieving pain. During postoperative treatment, GnRH analogs resulted in significantly reduced pain scores in women who received treatment for 6 months.

Laparoscopic cystectomy of an endometrioma was found to be superior to simple drainage for treatment of recurring pain; it has recently been shown to result in lower recurrence of signs and symptoms of endometriomas and higher cumulative pregnancy rates.

GnRH agonists were used for 6 months as the only treatment in patients with documented endometriosis. At 5 years, more than half the patients were symptom-free. The best responses were obtained in patients with mild or moderate disease. Among those with persistent or recurrent pain, an increasing correlation existed with the severity of the endometriosis.

Primary dysmenorrhea
By definition, primary dysmenorrhea is menstrual pain associated with ovulatory cycles in the absence of structural pathology. It usually manifests in younger women, and a recent study on the natural course of dysmenorrhea found that most women are affected throughout the menstrual years. Improvement is more likely in women who bear children. Patients experience suprapubic cramping pain that may radiate to the anterior thigh or sacral region. Pain may be accompanied by autonomic symptoms such as nausea, vomiting, and syncope. The onset of primary dysmenorrhea is a few hours prior to the onset of menses, and pain usually lasts up to 72 hours. More than 80% of patients have an excellent response to treatment with prostaglandin synthetase inhibitors. Oral contraceptives may be used with equal effectiveness in patients who desire simultaneous fertility control.

Smoking was associated with a higher relative risk of severe dysmenorrhea. In a systematic review, naproxen, ibuprofen, and mefenamic acid were more effective for pain relief compared to placebo. The Cochrane reviews have analyzed various studies and found high frequency transcutaneous electrical nerve stimulation (TENS) and acupuncture to be effective for dysmenorrhea. Laparoscopic uterine nerve ablation (LUNA) is shown to be effective for women with dysmenorrhea without endometriosis. Other drugs that have been reported with some success include nitroglycerin, terbutaline, and guaifenesin.

Secondary dysmenorrhea
Secondary dysmenorrhea is cyclic menstrual pain associated with structural pathology. The most common causes are endometriosis, adenomyosis, and the presence of an intrauterine device. Pain starts 1-2 weeks prior to the onset of menses and persists for a few days after cessation of flow. Hypertonic uterine activity coupled with an excess of prostaglandins is postulated to be the cause of secondary dysmenorrhea. Patients are somewhat less responsive to nonsteroidal anti-inflammatory drugs (NSAIDs) and combination oral contraceptives compared with patients with primary dysmenorrhea. Presacral neurectomy (PSN) has been shown in a single randomized trial to improve severe dysmenorrhea due to endometriosis.

Adenomyosis
Adenomyosis typically manifests in women in their 40s and is essentially a clinical diagnosis. It coexists with endometriosis and fibroids, and a recent study found that prior uterine surgery was significantly associated with increased risk of adenomyosis.12 Dysmenorrhea is associated with dyspareunia, dyschezia, and acyclical uterine bleeding. The uterus is soft and tender, especially around the time of menstruation. Magnetic resonance imaging shows an enlarged junctional zone and myometrial cysts, whereas ultrasonography shows heterogenous abnormal myometrial echogenicity in patients with adenomyosis. Histopathologic correlation with the clinical diagnosis can be found in only half the cases. For reproductive-aged women, treatment includes NSAIDs, combination oral contraceptives, progesterone-only pills, levonorgestrel intrauterine contraceptive devices, and GnRH agonists. Hysterectomy is a last resort.

Synonyms and related keywords:  pelvic pain, uterine pain, cervix pain, cervical pain, uterus pain, pelvis pain, vulvar pain, vulvovaginitis, vaginitis, acute pelvic pain, ischemia, ectopic pregnancy, adnexal mass, corpus luteum hematoma, corpus luteum rupture, paratubal cyst, ruptured ovarian cyst, dermoid cyst, cystadenoma, endometrioma, ovarian torsion, pelvic inflammatory disease, PID, tuboovarian abscess, tubo-ovarian abscess, uterine fibroids, fibroid mass, mittelschmerz, endometriosis, endometrioma, primary dysmenorrhea, secondary dysmenorrhea, adenomyosis, intrauterine device, IUD, pelvic adhesions, pelvic relaxation, uterine malposition, uterine retroversion, adnexal pathology, adnexal prolapse, ovarian remnant syndrome, myofascial pain, Interstitial cystitis, IC
urethral syndrome, posthysterectomy syndrome, contact vulvitis, atrophic vaginitis, microbial vaginitis, vulvodynia, vulvar vestibulitis, vestibulodynia, thermal bowel injury, abortion, pelvic thrombophlebitis, ovarian vein thrombosis, pelvic congestion, pelvic support defects, polyps, bladder stones, suburethral diverticulitis, urethral diverticulum, ovarian hyperstimulation syndrome, urethral syndrome, trigonitis, constipation, appendicitis, bowel obstruction, diverticulitis, cholelithiasis, coccydynia, mesenteric ischemia, mesenteric artery ischemia, levator ani syndrome, osteoporosis, scoliosis, porphyria, lead toxicity, lead poisoning, mercury toxicity, mercury poisoning, abdominal angina, aneurysm, hyperparathyroidism, substance abuse, cocaine abuse, sexual abuse, domestic violence, physical abuse, sickle cell disease, sickle cell anemia, somatization disorder, somatoform disorder, tabes dorsalis, sympathetic dystropy, salpingo-oophoritis

Author: Dharmesh Kapoor, MD, MBBS, MRCOG, Subspecialty Fellow, Department of Gynecology, Derriford Hospital

Coauthor(s): Gamal Mostafa Ghoniem, MD, FACS, Fellowship Program Director, Clinical Professor of Surgery, Head, Section of Voiding Dysfunction, Female Urology and Reconstruction, Cleveland Clinic Florida; Willy Davila, MD, Head, Section of Urogynecology and Reconstructive Pelvic Surgery, Chairman, Department of Gynecology, Cleveland Clinic Florida

Editors: Jordan G Pritzker, MD, Assistant Professor of Obstetrics, Gynecology, and Women’s Health, Women’s Comprehensive Health Center, Albert Einstein College of Medicine; Physician-In-Charge, Dept of Obstetrics and Gynecology, Long Island Jewish Medical Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Frederick B Gaupp, MD, Consulting Staff, Department of Family Practice, Assumption Community Hospital; Michel E Rivlin, MD, Associate Professor, Coordinator, Quality Assurance/Quality Improvement, Department of Obstetrics and Gynecology, University of Mississippi School of Medicine