Table 1.

Characteristics of 45 fetal WES families included in the presented study, type of WES and rate of molecular diagnosis.

Families included	Total number	Maternal age at pregnancy (years mean, SD)	Fetal WES performed during ongoing pregnancy (N,%)	Single/Trio/Quatro WES	Families with molecular diagnosis (N,%)
Overall	45	33.5 (4.2)	22 (48.9%)	5/33/7	13 (28.9%)
(1) Abnormal prenatal US findings and positive relevant family history	18	32.4 (4)	4 (22.2%)	2/9/7	10 (55.6%)
- Two or more fetuses with abnormal prenatal US findings (∗)	15	32.1 (4.1)	2 (13.3%)	1/7/7	8 (53.3%)
- Single fetus with US abnormalities and an affected parent	3	34.3 (3.8)	2 (66.7%)	1/2/0	2 (66.7%)
(2) Single fetus with abnormal prenatal US findings and lack of relevant family history	23	34.3 (4.5)	14 (60.9%)	1/22/0	3 (13%)
(3) Fetuses without any US abnormalities	4	33.8 (2.4)	4 (100%)	2/2/0	0

In families with two or more affected fetuses, maternal age at pregnancy relates to pregnancy of the later fetus included in the WES.

^∗In one family, the father and two fetuses were affected.