Summary of findings 5. Performance of gNIPT for detection of 45,X.

Performance of gNIPT for detection of 45,X
Test strategy	Number of studies	Number of affected pregnancies (Number of unaffected pregnancies)a	Sensitivity % (95% CI)	Specificity % (95% CI)	Median prevalenceb % (range)	Missed cases (FN)c	False positives (FP)d
Selected high‐risk pregnant women
MPSS	12	119 (7440)	91.7 (78.3 to 97.1)	99.6 (98.9 to 99.8)	1.04 (0.27 to 18.58)	86	396
TMPS	4	79 (985)	92.4 (84.1 to 96.5)	99.8 (98.3 to 100)		79	198
Difference between MPSS and TMPS			‐0.74 (‐11.1 to 9.60)	‐0.23 (‐0.82 to 0.36)	NA
Implications	1039 of 100,000 pregnancies expected to be affected by 45X; 953 and 960 cases will be detected while 86 and 79 cases will be missed by MPSS and TMPS, respectively; and of 98,961 expected unaffected by 45X, 396 and 198 pregnant women will undergo unnecessary invasive test with MPSS and TMPS, respectively.

45,X: Turner syndrome, MPSS: massively parallel shotgun sequencing, NA: not applicable, TMPS: targeted massively parallel sequencing.

^aUnaffected pregnancies: we included patients with any other aneuploidy than the one under analysis with all euploid cases as "unaffected" pregnancies.

^bThe median prevalence and range were calculated by using all prospective or retrospective studies for each category considered.

^cMissed cases per 100,000 tested. FN: false negatives.

^dFalse positives per 100,000 tested. A false positive result may lead to unnecessary invasive tests depending on choices by the pregnant woman.