Prevention of Unexplained Recurrent Spontaneous Abortion Using Intravenous Immunoglobulin: A Prospective, Randomized, Double‐Blinded, Placebo‐Controlled Trial

The efficacy of intravenous immunoglobulin (IVIG) for treatment of unexplained recurrent spontaneous abortion was assessed in a prospective, randomized, double-blinded, and placebo-controlled study.The study took place in a provincial recurrent pregnancy loss clinic, located in a tertiary/quaternary care academic center. The study subjects were women with a history of two or more documented consecutive spontaneous pregnancy losses under 20 weeks of gestation, excluding any associated with aneuploidy by karyotype analysis, and with no evidence of genetic, endocrine, infectious, anatomic, or autoimmune factors associated with a history of recurrent spontaneous abortion. The subjects were randomized to receive either intravenous immunoglobulin (Gamimune N) as treatment or normal saline as placebo. Randomization was stratified for primary, secondary, and unclassified unexplained recurrent spontaneous abortion. Success was defined as an ongoing pregnancy beyond 20 weeks of gestation.Sixty-two subjects enrolled in the trial. There were 37 index pregnancies and 6 cross-over pregnancies. There was no clinically significant difference between the treatment arm and the placebo arm in terms of subsequent pregnancy success. There seemed to be a higher success rate with the stratified analysis of couples with secondary unexplained recurrent spontaneous abortion, but the trial did not have sufficient power to confirm this.Based on this trial and three similar trials in the literature, a multicentered trial is needed to determine conclusively whether IVIG is effective in the treatment of unexplained recurrent spontaneous abortion.