Table 2. The percentage of porcine reproductive and respiratory syndrome (PRRS) virus detection by age of fetuses.

Age of fetuses	N	PRRS virus detection	Genotypes of PRRS virus
			Genotype 1	Genotype 2	Mixed
<70 days	20	11/20 (55.0%)a)	0/20 (0.0%)	7/20 (35.0%)	4/20 (20.0%)
≥70 days	69	49/69 (71.0%)a)	17/69 (24.6%)	16/69 (23.2%)	16/69 (23.2%)
Total	89	60/89 (67.4%)	17/89 (19.1%)	23/89 (25.8%)	20/89 (22.5%)

a, b) Different superscripts within columns indicate statistically significant differences (P<0.05).