Peripheral natural killer cell activity as a predictor of recurrent miscarriage: large cohort study

Abstract

ObjectiveTo confirm the predictive value of pre-conceptional peripheral blood natural-killer (pNK) cell activity in patients with recurrent miscarriage (RM).DesignCohort study.Materials and MethodsPatients: 552 patients with a history of 2-6 consecutive miscarriages, who had their subsequent pregnancy, in the OG/GYN clinic of our university hospital. Main outcome measurement: The predictive value of pre-conceptional pNK cell activity for subsequent miscarriage was analyzed using multivariate logistic regression analysis, with the age, number of previous miscarriages, presence/absence of previous live births and bed rest as covariates. The effect of bed rest from 4 to 8 weeks of gestation was also examined.ResultsAge, but not high pNK cell activity and number of previous miscarriages, was confirmed to be independent risk factors for a subsequent miscarriage. The live birth rate of patients with normal NK cell activity tended to be higher than that of patients with low NK cell activity (OR: 0.559; 95% confidence interval [CI]: 0.311-1.003, p=0.051). No effect of bed rest and previous live birth on the likelihood of live birth was observed (OR: 1.280; 95% CI: 0.812-2.016, OR: 0.908; 95% CI: 0.519-1.587).ConclusionLow, but not elevated pNK cell activity was found to be a marginally independent risk factor for subsequent miscarriage. Clinicians should not measure the plasma NK activity as a systematic RM examination, because its clinical significance is yet to be established. ObjectiveTo confirm the predictive value of pre-conceptional peripheral blood natural-killer (pNK) cell activity in patients with recurrent miscarriage (RM). To confirm the predictive value of pre-conceptional peripheral blood natural-killer (pNK) cell activity in patients with recurrent miscarriage (RM). DesignCohort study. Cohort study. Materials and MethodsPatients: 552 patients with a history of 2-6 consecutive miscarriages, who had their subsequent pregnancy, in the OG/GYN clinic of our university hospital. Main outcome measurement: The predictive value of pre-conceptional pNK cell activity for subsequent miscarriage was analyzed using multivariate logistic regression analysis, with the age, number of previous miscarriages, presence/absence of previous live births and bed rest as covariates. The effect of bed rest from 4 to 8 weeks of gestation was also examined. Patients: 552 patients with a history of 2-6 consecutive miscarriages, who had their subsequent pregnancy, in the OG/GYN clinic of our university hospital. Main outcome measurement: The predictive value of pre-conceptional pNK cell activity for subsequent miscarriage was analyzed using multivariate logistic regression analysis, with the age, number of previous miscarriages, presence/absence of previous live births and bed rest as covariates. The effect of bed rest from 4 to 8 weeks of gestation was also examined. ResultsAge, but not high pNK cell activity and number of previous miscarriages, was confirmed to be independent risk factors for a subsequent miscarriage. The live birth rate of patients with normal NK cell activity tended to be higher than that of patients with low NK cell activity (OR: 0.559; 95% confidence interval [CI]: 0.311-1.003, p=0.051). No effect of bed rest and previous live birth on the likelihood of live birth was observed (OR: 1.280; 95% CI: 0.812-2.016, OR: 0.908; 95% CI: 0.519-1.587). Age, but not high pNK cell activity and number of previous miscarriages, was confirmed to be independent risk factors for a subsequent miscarriage. The live birth rate of patients with normal NK cell activity tended to be higher than that of patients with low NK cell activity (OR: 0.559; 95% confidence interval [CI]: 0.311-1.003, p=0.051). No effect of bed rest and previous live birth on the likelihood of live birth was observed (OR: 1.280; 95% CI: 0.812-2.016, OR: 0.908; 95% CI: 0.519-1.587). ConclusionLow, but not elevated pNK cell activity was found to be a marginally independent risk factor for subsequent miscarriage. Clinicians should not measure the plasma NK activity as a systematic RM examination, because its clinical significance is yet to be established. Low, but not elevated pNK cell activity was found to be a marginally independent risk factor for subsequent miscarriage. Clinicians should not measure the plasma NK activity as a systematic RM examination, because its clinical significance is yet to be established.