Prednisolone reduces preconceptual endometrial natural killer cells in women with recurrent miscarriage

Fertil Steril. 2005 Oct;84(4):980-4. doi: 10.1016/j.fertnstert.2005.05.012.


Objective: To test the hypothesis that high numbers of uterine natural killer (uNK) cells in the endometrium of women with recurrent miscarriage (RM) could be reduced with prednisolone.

Design: A before and after study.

Setting: A tertiary referral teaching hospital.

Patient(s): Eighty-five women with idiopathic RM recruited from all over the UK and 18 women attending for sterilization (controls).

Intervention(s): An endometrial sample was taken on day 21 +/- 2 of the menstrual cycle. Immunohistochemistry was used to identify uNK (CD56+, CD16-, CD3-). Twenty-nine women with RM and >5% uNK agreed to take 20 mg oral prednisolone daily from day 1 to 21 of their menstrual cycle, when a second biopsy was obtained and analyzed.

Main outcome measure(s): The percentage of stromal cells that were uNK. The normal range was defined using control samples as <5%.

Result(s): Women with RM had significantly more uNK than the controls (P=.008). Prednisolone treatment significantly reduced the number of CD56 cells in the endometrium, from a median of 14% (before) to 9% (after) (P=.0004).

Conclusion(s): We have demonstrated that high numbers of uNK in preimplantation endometrium of women with recurrent miscarriage can be reduced with administration of prednisolone.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abortion, Habitual / drug therapy*
  • Abortion, Habitual / immunology
  • Abortion, Habitual / pathology
  • Adult
  • Endometrium / drug effects*
  • Endometrium / immunology
  • Endometrium / pathology
  • Female
  • Fertilization / drug effects*
  • Fertilization / immunology
  • Humans
  • Killer Cells, Natural / drug effects*
  • Killer Cells, Natural / immunology
  • Killer Cells, Natural / pathology
  • Middle Aged
  • Prednisolone / pharmacology*
  • Prednisolone / therapeutic use
  • Pregnancy
  • Statistics, Nonparametric


  • Prednisolone