Supplemental Table.

WA-CPC participating sites

	Participating site	Type	Annual delivery volumea
1	University of Washington Medical Center: Montlake	Hospital	1900
2	University of Washington Medical Center: Northwest	Hospital	900
3	Swedish: Issaquah	Hospital	12,000 system-wideb
4	Swedish: First Hill	Hospital	b
5	Swedish: Ballard	Hospital	b
6	Swedish: Edmonds	Hospital	b
7	University of Washington Valley Medical Center	Hospital	3200
8	MultiCare: Covington Medical Center	Hospital	250
9	MultiCare: Auburn Medical Center	Hospital	1108
10	MultiCare: Tacoma General Hospital	Hospital	2921
11	MultiCare: Good Samaritan Hospital	Hospital	2227
12	MultiCare: Spokane Valley Hospital	Hospital	604
13	MultiCare: Deaconess Medical Center	Hospital	1384
14	EvergreenHealth Medical Center - Kirkland	Hospital	4600
15	PeaceHealth St. Joseph Medical Center—Bellingham	Hospital	1875
16	Providence Regional Medical Center—Everett	Hospital	4250
17	Jefferson Medical Center	Hospital	125
18	Legacy Salmon Creek Medical Center	Hospital	3600
19	Virginia Mason Memorial Hospital	Hospital	2385
20	Central WA Hospital, Confluence	Hospital	1300
21	UW Medicine Maternal-Fetal Medicine Clinic at Yakima	Clinicc	n/a
22	Yakima Valley Farm Workers Clinics: Valley Vista Medical Group	Clinic	119
23	Yakima Valley Farm Workers Clinics: Pasco Miramar Health Center	Clinic	6
24	Yakima Valley Farm Workers Clinics: Unify Community Health, Mission Avenue	Clinic	134
25	Yakima Valley Farm Workers Clinics: Unify Community Health, West Central Community Center	Clinic	48
26	Yakima Valley Farm Workers Clinics: Unify Community Health, Northeast Community Center	Clinic	122
27	Yakima Valley Farm Workers Clinics: Grandview Medical Dental Clinic	Clinic	356
28	Yakima Valley Farm Workers Clinics: Lincoln Avenue Medical Dental	Clinic	1809
29	Yakima Valley Farm Workers Clinics: Yakima Medical Dental Clinic	Clinic	1356
30	Yakima Valley Farm Workers Clinics: Mountain View Women's Clinic	Clinic	242
31	Yakima Valley Farm Workers Clinics: Toppenish Medical Dental Clinic	Clinic	1164
32	Yakima Valley Farm Workers Clinics: Family Medical Center Walla Walla	Clinic	283
33	The Vancouver Clinic	Clinicd	n/ad
34	PeaceHealth Southwest Medical Center	Hospital	2000
35	Mid Valley Hospital	Hospital	240

Lokken et al. COVID-19 disease and mortality in pregnancy. Am J Obstet Gynecol 2021.

^aCollaborating sites reported their approximate annual delivery number. The annual delivery numbers for MultiCare facilities are the 2019 actuals. The annual delivery numbers for the Yakima Valley Farm Workers Clinics are the number of women in their care who delivered in 2019

^bAnnual delivery volume is reported system-wide for Swedish Medical Center sites

^cDeliveries occur across Greater Yakima region

^dVancouver Clinic patients deliver at PeaceHealth Southwest Medical Center and Legacy Salmon Creek Medical Center. The total number of deliveries at the Vancouver Clinic do not count toward to total number of annual deliveries captured by the Washington State COVID-19 in Pregnancy Collaborative because they are included with PeaceHealth Southwest Medical Center and Legacy Salmon Creek Medical Center numbers.