[Sensitivity and specificity of noninvasive prenatal fetal RhD genotesting: a meta-analysis]

To explore the sensitivity, specificity and clinical validity of fetal Rh genotyping from maternal blood.

A comprehensive literature search of PubMed, Embase and Web of Science was performed for describing fetal RhD determination from maternal blood. The inclusion criteria were established based on the validity criteria for diagnostic research. And the eligible entries were collected and analyzed with MetaDisc4.0.

This meta-analysis included 55 studies with a total of 17 138 samples. The random-effect model was used for analysis because of heterogeneity. The pooled sensitivity and specificity were 98.5% and 97.3% respectively. The SROC curve was plotted and the area under the curve (AUC) calculated (AUC = 0.994). The subgroup and sensitivity analyses were performed. The sensitivity of 25 studies with samples<100 (94.6%) was significantly lower than those of 19 studies with samples 100-300 (98.5%) and 11 studies with samples>300 (99.0%) (χ² = 36.800, 106.062, P < 0.05). The sensitivity of 19 studies with samples 100-300 (98.5%) was not different from that of 11 studies with samples >300 (99.0%)( χ² = 3.068, P > 0.05).

Noninvasive prenatal diagnosis of fetal RhD status from maternal blood represents a significant achievement in the application of research with high sensitivity and specificity. It may be applied for screening testing of all RhD⁻ negative pregnant women.