Postpartum Uterine Regression

Uterine leiomyomas are the leading cause of hysterectomy in the United States, accounting for over 200,000 procedures each year. Most epidemiologic studies of uterine leiomyoma show that parity has a protective association with leiomyoma, but the mechanism is not known. Both epidemiologic data and data from an animal model indicate that the protective association is not an artifact resulting from reduced fertility among women with fibroids. We hypothesize that the process of uterine regression following delivery results in loss of small fibroids due to selective apoptosis of transformed cells and the extensive remodeling of the entire uterus.

Sex

Female

Minimum age

18 Years

Maximum age

45 Years

* INCLUSION CRITERIA:

Participants in the Right From The Start Study must be 18 years old or older, pregnant, enrolled by 10 weeks of gestation, planning to carry pregnancy to term, no plans to move before delivery, and English speaking. Those who are found to have fibroids at either their 7-week, or 22-week ultrasound examination are eligible for this further postpregnancy study.

A small substudy of 30 women having MRIs to evaluate the sensitivity of the ultrasound imaging will include only participants with a single fibroid found at the early pregnancy ultrasound.

EXCLUSION CRITERIA FOR MRI:

Exclusion criteria for the MRI are weight greater than 250 pounds, currently pregnant, metal of specific types in the body (an artificial hip, a clip for brain aneurysm, a medical implant in the ear, metal fragment in the eye, or a pacemaker), history of claustrophobia, previous severe reaction to MRI contrast, and chronic kidney disease. A severe reaction would consist of bronchospasm (shortness of breath/difficulty breathing) or shock (sudden loss of blood pressure). Risk is less than 1/100,000 with Gd based contrast material. Any potential subject with a history of kidney disease will be excluded from the study.

• BACKGROUNDBrett KM, Marsh JV, Madans JH. Epidemiology of hysterectomy in the United States: demographic and reproductive factors in a nationally representative sample. J Womens Health. 1997 Jun;6(3):309-16. doi: 10.1089/jwh.1997.6.309. PMID 9201665
• BACKGROUNDCramer SF, Patel A. The frequency of uterine leiomyomas. Am J Clin Pathol. 1990 Oct;94(4):435-8. doi: 10.1093/ajcp/94.4.435. PMID 2220671
• BACKGROUNDChen CR, Buck GM, Courey NG, Perez KM, Wactawski-Wende J. Risk factors for uterine fibroids among women undergoing tubal sterilization. Am J Epidemiol. 2001 Jan 1;153(1):20-6. doi: 10.1093/aje/153.1.20. PMID 11159141