Ultrasound and magnetic resonance imaging-based investigation of the role of perfusion and oxygen availability in menstrual pain.

BACKGROUND: The mechanisms responsible for menstrual pain are poorly understood. However, dynamic, noninvasive pelvic imaging of menstrual pain sufferers could aid in identifying therapeutic targets and testing novel treatments. OBJECTIVE: To study the mechanisms responsible for menstrual pain, we analyzed ultrasonographic and complementary functional magnetic resonance imaging parameters in dysmenorrhea sufferers and pain-free controls under multiple conditions. STUDY DESIGN: We performed functional magnetic resonance imaging on participants with and those without dysmenorrhea during menses and outside menses. To clarify whether regional changes in oxygen availability and perfusion occur, functional magnetic resonance imaging R2∗ measurements of the endometrium and myometrium were obtained. R2∗ measurements are calculated nuclear magnetic resonance relaxation rates sensitive to the paramagnetic properties of oxygenated and deoxygenated hemoglobin. We also compared parameters before and after an analgesic dose of naproxen sodium. In addition, we performed similar measurements with Doppler ultrasonography to identify if changes in uterine arterial velocity occurred during menstrual cramping in real time. Mixed model statistics were performed to account for within-subject effects across conditions. Corrections for multiple comparisons were made with a false discovery rate adjustment. RESULTS: During menstruation, a notable increase in R2∗ values, indicative of tissue ischemia, was observed in both the myometrium (beta ± standard error of the mean, 15.74±2.29 s-1; P=.001; q=.002) and the endometrium (26.37±9.33 s-1; P=.005; q=.008) of participants who experienced dysmenorrhea. A similar increase was noted in the myometrium (28.89±2.85 s-1; P=.001; q=.002) and endometrium (75.50±2.57 s-1; P=.001; q=.003) of pain-free controls. Post hoc analyses revealed that the R2∗ values during menstruation were significantly higher among the pain-free controls (myometrium, P=.008; endometrium, P=.043). Although naproxen sodium increased the endometrial R2∗ values among participants with dysmenorrhea (48.29±15.78 s-1; P=.005; q=.008), it decreased myometrial R2∗ values among pain-free controls. The Doppler findings were consistent with the functional magnetic resonance imaging (-8.62±3.25 s-1; P=.008; q=.011). The pulsatility index (-0.42±0.14; P=.004; q=.004) and resistance index (-0.042±0.012; P=.001; q=.001) decreased during menses when compared with the measurements outside of menses, and the effects were significantly reversed by naproxen sodium. Naproxen sodium had the opposite effect in pain-free controls. There were no significant real-time changes in the pulsatility index, resistance index, peak systolic velocity, or minimum diastolic velocity during episodes of symptomatic menstrual cramping. CONCLUSION: Functional magnetic resonance imaging and Doppler metrics suggest that participants with dysmenorrhea have better perfusion and oxygen availability than pain-free controls. Naproxen sodium's therapeutic mechanism is associated with relative reductions in uterine perfusion and oxygen availability. An opposite pharmacologic effect was observed in pain-free controls. During menstrual cramping, there is insufficient evidence of episodic impaired uterine perfusion. Thus, prostaglandins may have protective vasoconstrictive effects in pain-free controls and opposite effects in participants with dysmenorrhea.

Association of Progestogens and Venous Thromboembolism Among Women of Reproductive Age.

OBJECTIVE: To evaluate associations between use of seven progestogens and incident acute venous thromboembolism (VTE) among women of reproductive age. METHODS: This nested matched case-control study identified women aged 15-49 years from January 1, 2010, through October 8, 2018, in the IBM MarketScan databases, a nationwide sample of private insurance claims in the United States. After exclusions, 21,405 women with incident acute VTE (case group), identified by diagnosis codes, were matched 1:5 by year of birth and index date through risk set sampling to 107,025 women without prior VTE (control group). From lowest to highest systemic dose based on a modified hierarchy, progestogens studied were levonorgestrel-releasing intrauterine device (LNG-IUD), oral norethindrone, etonogestrel implant, oral progesterone, oral medroxyprogesterone acetate, oral norethindrone acetate, and depot medroxyprogesterone acetate (DMPA). Conditional logistic regression models adjusted for 16 VTE risk factors were used to estimate odds ratios and 99% CIs for incident acute VTE associated with current progestogen use compared with nonuse. The primary analysis treated each progestogen as a binary exposure. Dose, which varied for oral formulations, and chronicity were explored separately. Significance was set at P <.01 to allow for multiple comparisons. RESULTS: Current use of higher-dose progestogens was significantly associated with increased odds of VTE compared with nonuse (oral norethindrone acetate: adjusted odds ratio [aOR] 3.00, 99% CI 1.96-4.59; DMPA: aOR 2.37, 99% CI 1.95-2.88; and oral medroxyprogesterone acetate: aOR 1.98, 99% CI 1.41-2.80). Current use of other progestogens was not significantly different from nonuse (LNG-IUD, etonogestrel implant, and oral progesterone) or had reduced odds of VTE (oral norethindrone). Sensitivity analyses that assessed misclassification bias supported the primary findings. CONCLUSION: Among reproductive-aged women using one of seven progestogens, only use of norethindrone acetate and medroxyprogesterone acetate-considered higher-dose progestogens-was significantly associated with increased odds of incident acute VTE. The roles of progestogen type, dose, and indication for use warrant further study.

Hysterectomy for Chronic Pelvic Pain.

For well selected patients with chronic pelvic pain (CPP), 74% to 95% of women will report complete or significant improvement in pain after hysterectomy. A thoughtful history, examination, and review of imaging can improve success by linking pain complaints to discrete pathology, menstrual activity, or uterine tenderness. All patients with CPP should be evaluated for chronic overlapping pain conditions (COPCs) (eg, irritable bowel syndrome (IBS), fibromyalgia) and risk factors for persistent pain or chronic postsurgical pain (eg, depression, pain catastrophizing, central sensitization), and offered treatment as indicated. There are special considerations for preoperative planning and enhanced recovery for patients with chronic pain.