title: Prednisolone Trial: Study protocol for a randomised controlled trial of prednisolone for women with idiopathic recurrent miscarriage and raised levels of uterine natural killer (uNK) cells in the endometrium.
abstract: BACKGROUND
  Idiopathic recurrent miscarriage is defined as 3 consecutive pregnancy losses with no contributing features found on investigations. At present there are no treatments of proven efficacy for idiopathic recurrent miscarriage. Uterine natural killer (uNK) cells, the most predominant leucocyte in the endometrium are adjacent to foetal trophoblast cells and thought to be involved in implantation. The exact mechanisms of how uNK cells affect implantation are not clear but are probably through the regulation of angiogenesis. Multiple studies have shown an association between high density of uterine natural killer cells and recurrent miscarriage. We have shown that prednisolone reduces the number of uNK cells in the endometrium. The question remains as to whether reducing the number of uNK cells improves pregnancy outcome.
  
  
  METHODS
  We propose a randomised, double-blind, placebo controlled trial of prednisolone with a pilot phase to assess feasibility of recruitment, integrity of trial procedures, and to generate data to base future power calculations. The primary aim is to investigate whether prednisolone therapy during the first trimester of pregnancy is able to improve live birth rates in patients with idiopathic recurrent miscarriage and raised uNK cells in the endometrium. Secondary outcomes include conception rate, karyotype of miscarriage, miscarriages (first and second trimester), stillbirths, pregnancy complications, gestational age at delivery, congenital abnormality and side effects of steroids. The trial has 2 stages: i) screening of non-pregnant women and ii) randomisation of the pregnant cohort. All patients who fit the inclusion criteria (<40 years old, > or =3 consecutive miscarriages with no cause found and no contraindications to prednisolone therapy) will be asked to consent to an endometrial biopsy in the mid-luteal phase to assess their levels of uNK cells. Women with high levels of uNK cells (> or =5%), will be randomised to either prednisolone or placebo when a pregnancy is confirmed. Follow-up includes 2 weekly ultrasound scans in the first trimester, an anomaly scan at 20 weeks gestation, growth scans at 28 and 34 weeks gestation and a postnatal follow-up at 6 weeks.
  
  
  BACKGROUND
  Current Controlled Trials ISRCTN28090716.
authors.affiliation: School of Reproductive and Developmental Medicine, University of Liverpool, Liverpool Women's Hospital, Crown Street, Liverpool, L8 7SS, UK. atang@liv.ac.uk
authors.forename: Ai-Wei
authors.initials: AW
authors.lastname: Tang
authors.forename: Zarko
authors.initials: Z
authors.lastname: Alfirevic
authors.forename: Mark A
authors.initials: MA
authors.lastname: Turner
authors.forename: Jo
authors.initials: J
authors.lastname: Drury
authors.forename: Siobhan
authors.initials: S
authors.lastname: Quenby
mesh_terms: D000026:Abortion, Habitual / Q000188:drug therapy* / Q000276:immunology; D002985:Clinical Protocols; D004311:Double-Blind Method; D004717:Endometrium / Q000276:immunology*; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D011239:Prednisolone / Q000627:therapeutic use*; D011247:Pregnancy; D012107:Research Design; D013223:Statistics as Topic; D014599:Uterus / Q000276:immunology
chemical_list: D011239:Prednisolone