. Author manuscript; available in PMC: 2023 Mar 26.

Published in final edited form as: Sci Transl Med. 2017 Aug 30;9(405):eaan1240. doi: 10.1126/scitranslmed.aan1240

Table 3.

Distribution of total samples across trimesters compared to the number and frequency of RATs.

Trimester (weeks)	Cohort 1		Cohort 2		P ^*
Trimester (weeks)	Total cases, n (%)	RATs, n (as % of trimester totals)	Total cases, n (%)	RATs, n (%)	P ^*
First (10–13)	47,829 (65.6)	163 (0.34)	15,643 (92.6)	53 (0.34)	1.000
Second (14–27.9)	24,133 (33.1)	78 (0.32)	1,230 (7.3)	6 (0.49)	0.299
Third (28–40)	970 (1.3)	5 (0.52)	12 (0.1)	1 (8.3)	0.083
Total	72,932 (100)	246 (0.34)	16,885 (100)	60 (0.36)	0.122

Between frequencies of RATs in cohorts 1 and 2.