Postpartum factors and natural fibroid regression

Am J Obstet Gynecol. 2011 Jun;204(6):496.e1-6. doi: 10.1016/j.ajog.2011.02.018. Epub 2011 Apr 14.


Objective: Many fibroids regress with pregnancy or postpartum involution. We sought to identify factors that might inhibit or enhance this natural regression.

Study design: We used a prospective cohort of women with fibroids (n = 494) determined by ultrasound screening during the early first trimester identified from the Right from the Start study. Ultrasounds were repeated 3-6 months postpartum (n = 279). Logistic regression analyses were used to identify factors associated with fibroid regression (>50% reduction in volume).

Results: Postpartum progestin users had significantly less fibroid regression (P = .01), whereas there was no association for combined estrogen-progestin use. Cesarean delivery and fever (hypothesized to inhibit regression) and breast feeding (hypothesized to enhance regression) were not associated with fibroid regression.

Conclusion: Progestin use in the postpartum period may limit regression of fibroids, consistent with prior literature on progesterone's role in fibroid development. Research into progestin-only treatments in critical reproductive periods is needed.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Breast Feeding
  • Female
  • Humans
  • Leiomyoma
  • Neoplasm Regression, Spontaneous*
  • Postpartum Period
  • Pregnancy
  • Pregnancy Complications, Neoplastic*
  • Prospective Studies
  • Uterine Neoplasms*