Pre-conceptional natural killer cell activity and percentage as predictors of biochemical pregnancy and spontaneous abortion with normal chromosome karyotype.

Abstract

The aim of the present study was to determine whether pre-conceptional natural killer (NK) cell activity and percentage are predictive of subsequent spontaneous abortion in women with recurrent spontaneous abortion (RSA). Pre-conceptional NK cell activity and percentage in peripheral blood of women who had a history of two or more RSA was prospectively assessed. The 51Cr release assay and flow cytometric analysis were performed. A total of 113 RSA women were recruited, and 85 conceived later. Pre-conceptional NK cell activity/percentage values in women whose next pregnancies ended in biochemical pregnancy and spontaneous abortion with normal fetal karyotype (n = 17, median 47%/17.1%), but spontaneous abortion with abnormal karyotype (n = 9, 27%/15.7%), were higher than those in live births (n = 59, 33%/13.1%). High values of pre-conceptional NK cell activity (> 46%; relative risk 3.6, 95%CI 1.6-8.0) and percentage (> 16.4%; 4.9, 1.7-13.8) were found to predict biochemical pregnancy and spontaneous abortion with normal karyotype in the next pregnancy. Pre-conceptional NK cell abnormalities were predictive of spontaneous abortion with normal fetal karyotype.