Table 2 Timing of serology testing and seropositivity with respect to nasopharyngeal PCR testing1.

Serology TimingNP-PCR PositiveNP-PCR Negative
TestedSeropositive (%)TestedSeropositive (%)
Before NP-PCR test1710 (58.8)3649 (2.5)
0-6 days after NP-PCR test2615 (57.7)64716 (2.5)
7-13 days after NP-PCR test55 (100.0)80
14-20 days after NP-PCR test22 (100.0)70
≥21 days after NP-PCR test1414 (100.0)191 (5.3)
Total6446 (71.9)1,04526 (2.5)

1The table includes 1,109 women tested for serology who were also tested by nasopharyngeal PCR anytime during pregnancy up to discharge from delivery admission. NP, nasopharyngeal; PCR, polymerase chain reaction.