March 2020: one subject. April: none. The study still finished.

723 subjects across 10 OB practices and 32 months. The four lead physicians held through the shutdown, and the program closed 19 months later at roughly a third of its pre-pandemic pace.

Research & Development Institute, Inc. (RDI Trials) RDI Trials, 16760 Stagg Street, Unit 209, Van Nuys, CA 91406. CLIA + CAP-accredited reference laboratory. Engagement: Apr 2019 – Nov 2021 (closed) · Compiled: 2026 · Correspondence: info@rditrials.com

723 subjects

Across 10 OB sites
over 32 months

461 / 723

Pre-pandemic phase
(Apr 2019 – Mar 2020)

3 months

Pandemic shutdown
(Mar – Apr 2020)

262 / 723

Post-pivot phase
(May 2020 – Nov 2021)

Abstract

Background: The sponsor — a top-tier global diagnostics manufacturer¹ — commissioned a healthy-pregnancy specimen collection program to support immunoassay verification work on pregnancy-relevant analytes across the gestational range. The program enrolled healthy pregnant subjects across an OB-clinic network and ran across an unusually long calendar window: April 2019 to November 2021. The window straddled the U.S. onset of the COVID-19 pandemic and the corresponding clinical-research operational shutdown; the program is reported here in part because the visible operational pivot through that window is a useful long-form record of how a non-COVID specimen collection program absorbed the disruption.
Methods: RDI executed the program as full-service CRO. Ten OB-clinic sites were activated across the program window, with four lead OB-physician sites (each at a single-physician practice or small-practice level) carrying the bulk of program volume. The protocol structured visits as gestational-age-anchored draws against an OB-clinic enrollment funnel; specimens were shipped to the RDI reference lab on a fixed cadence. The pandemic shutdown in March 2020 closed in-person OB-clinic enrollment for non-COVID research at all program sites; the program operationally re-opened at most sites between May and August 2020 against revised in-clinic safety protocols.
Results: Enrollment ran in two distinct phases (Fig. 1). The pre-pandemic phase (Apr 2019 – Feb 2020) delivered 460 subjects in 11 months at an average cadence of approximately 42 subjects per month, with peaks in November 2019 (+103) and May 2019 (+79). The pandemic shutdown month (March 2020) delivered 1 subject; the immediate-aftermath month (April 2020) delivered 0. The post-pivot phase (May 2020 – Nov 2021) delivered 262 subjects across 19 months at a slower average cadence of approximately 14 subjects per month, with the strongest single month coming in October 2020 (+71). Site distribution was concentrated on four lead OB-physician sites carrying 84% of program volume between them (Table 1; Fig. 2).
Conclusions: Long-window OB specimen collection programs are operationally a relationship-management problem with the lead OB-physician sites — the four lead practices carried the bulk of program volume across both pandemic-era phases. The post-pivot enrollment cadence ran at approximately one-third of pre-pandemic cadence, reflecting the underlying OB-clinic operational constraint of the pandemic period rather than any program-specific failure. The same operational frame — lead-OB-physician anchored enrollment, gestational-age visit cadence, multi-year window tolerance — transfers to other healthy-pregnancy specimen collection programs.

Keywords: in vitro diagnostics; healthy pregnancy; obstetric specimen collection; pandemic-era clinical research; gestational specimen banking; OB clinic; multi-year specimen collection.

1. Background

The sponsor commissioned a healthy-pregnancy specimen collection program to support immunoassay verification work on pregnancy-relevant analytes across the gestational range.² Healthy-pregnancy specimens are the foundation of analytical-validation work for any assay intended for use in obstetric or pregnancy-context care; the program target placed the program in the multi-year tier of the engagement series.

The program ran from April 2019 to November 2021 — an unusually long calendar window. That window straddled the U.S. onset of the COVID-19 pandemic and the corresponding clinical-research operational shutdown. The program is reported here in part because the visible operational pivot through that window is a useful long-form record of how a non-COVID specimen collection program absorbed the disruption: a March-2020 shutdown month that delivered a single subject, an April-2020 month that delivered zero, then a graduated re-open through May–August 2020 against revised in-clinic safety protocols, with post-pivot cadence running at approximately one-third of pre-pandemic cadence for the program’s remaining 19 months.

2. Constraints encountered

Three constraints shaped the execution plan, with the pandemic-era constraint dominating the second half of the program window:

OB-clinic patient flow as the binding constraint

Healthy-pregnancy enrollment is paced by the OB-clinic’s patient flow at routine prenatal visits. The protocol’s gestational-age-anchored visit cadence required that subjects be enrolled within specified gestational windows; missing a gestational window means waiting for the next eligible subject at that gestational age. Site selection had to weight OB-clinic patient flow heavily, particularly at the gestational ages that defined the protocol’s draw windows.
Pandemic shutdown of in-person clinical research (March 2020)

The U.S. onset of the COVID-19 pandemic in March 2020 closed in-person clinical-research enrollment at OB-clinic sites. The program’s March 2020 cadence (+1 subject) and April 2020 cadence (+0 subjects) reflect that closure: not a program-specific failure but the universal operational reality of non-COVID clinical research in those months. The pandemic constraint was structural, not protocol-level.
Reduced post-pivot OB-clinic throughput

Post-pivot enrollment ran at approximately one-third of pre-pandemic cadence (~14 subjects per month vs. ~42 pre-pandemic) across the remaining 19 months of the program. The reduction reflected reduced OB-clinic patient throughput in pandemic-era operations: longer per-visit times, distancing protocols, reduced clinic capacity, and patient-side reluctance to come in for non-essential research participation. The program plan accommodated this slower post-pivot cadence and ran the program for 19 additional months to deliver the remaining 262 subjects.

Pre-pandemic phase: 460 subjects in 11 months at ~42/month. Pandemic shutdown: 1 subject across March 2020 and April 2020 combined. Post-pivot phase: 262 subjects in 19 months at ~14/month, approximately one-third of pre-pandemic cadence.

3. Methods

RDI executed the program as full-service CRO across the 32-month window. Three operational moves are reported here in order of implementation.

3.1. Lead-OB-physician site model (pre-pandemic)

Ten OB-clinic sites were activated across the program window, with four lead OB-physician sites carrying the bulk of program volume. Site A (lead OB-physician practice) carried 247 subjects; Site B carried 140; Site C carried 118; Site D carried 99. The four lead sites combined: 604 subjects, 84% of program volume. The remaining six sites contributed 119 subjects across the program window, in the 17–32 subject range each at the most active practices.

3.2. Pandemic operational pivot (March–August 2020)

The U.S. pandemic onset in March 2020 closed in-person clinical-research enrollment at all program sites. The program operationally paused for two months (March 2020: +1, April 2020: +0). Re-opening followed a graduated path through May–August 2020 as individual sites re-implemented in-clinic research operations against revised safety protocols. Site B re-opened first (May 2020); Sites A, C, and D re-opened across June–August 2020. By September 2020 the program was running at pandemic-era operational cadence.

3.3. Multi-year program management with the lead practices

The post-pivot phase ran for 19 months (May 2020 – November 2021) at approximately one-third of pre-pandemic cadence. Multi-year program management with the lead OB-physician practices — protocol amendments, sponsor reporting cadence, audit readiness, freezer-bank inventory accounting — ran in parallel with the slower enrollment cadence. The program closed against its protocol-defined target in November 2021.

Pre-pandemic operating model

In-person OB-clinic enrollment at routine prenatal visits. Gestational-age-anchored draws. ~42 subjects per month average cadence. Standard pre-pandemic clinical-research operational tempo at OB sites.

Post-pivot operating model (May 2020 onward)

In-person OB-clinic enrollment under revised safety protocols. Same gestational-age-anchored visit cadence. ~14 subjects per month average cadence (approximately one-third of pre-pandemic). 19-month long-tail to complete remaining target.

4. Results

Enrollment ran in two distinct phases separated by the March 2020 pandemic shutdown (Fig. 1). The pre-pandemic phase (April 2019 – February 2020) delivered 460 subjects across 11 months. The strongest single months were May 2019 (+79), August 2019 (+87), and November 2019 (+103). Average pre-pandemic cadence: approximately 42 subjects per month.

The pandemic shutdown was visible across two months: March 2020 (+1) and April 2020 (+0). Re-opening followed a graduated path through May–August 2020. The post-pivot phase (May 2020 – November 2021) delivered 262 subjects across 19 months. The strongest post-pivot month was October 2020 (+71); average post-pivot cadence was approximately 14 subjects per month, with the cadence trending downward through 2021 as cohort enrollment caps approached saturation. Cumulative crossed 700 subjects in November 2020 and reached the program target in November 2021 with a closeout tail.

Site distribution was concentrated on four lead OB-physician practices (Table 1; Fig. 2): Site A 247 subjects (34%), Site B 140 (19%), Site C 118 (16%), Site D 99 (14%); the four-lead-site share was 604 of 723 subjects (84%). The remaining six sites contributed 119 subjects across the program window.

Apr 2019 Program open

Nov 2019 Pre-pandemic peak (+103)

Mar 2020 Shutdown (+1)

May–Aug 2020 Graduated re-open

Oct 2020 Post-pivot peak (+71)

2021 Long tail at ~14/month

Nov 2021 Program close (723)

Table 1 Site-level enrollment across the 32-month program window. Four lead OB-physician sites carried 84% of program volume across both pre-pandemic and post-pivot phases. The remaining six sites contributed at lower volumes and shorter active windows.
Site	Setting	Enrolled	Share
Site A	Lead OB-physician practice; deep prenatal patient panel and standing clinical-research apparatus	247	34%
Site B	OB-physician practice; prenatal-care patient panel	140	19%
Site C	OB-physician practice; prenatal-care patient panel	118	16%
Site D	OB-physician practice; prenatal-care patient panel	99	14%
Lead-site subtotal	4 OB-physician practices carrying the bulk of program volume	604	84%
Site E	Multi-specialty clinical research center with OB track	32	4%
Site F	Multi-physician clinical-research-organization OB track	26	4%
Site G	OB-physician practice within a multi-clinic women’s-health network	22	3%
Site H	Standalone clinical-research organization with OB enrollment capability	20	3%
Site I	OB-physician practice within a multi-clinic women’s-health network	17	2%
Site J	Multi-physician clinical-research-organization OB track	2	<1%
Supplementary network subtotal	6 sites; shorter active windows and lower per-site volume	119	16%
All sites at program close (Nov 2021)	10 sites total across the 32-month window	723	100%

Fig. 1 Cumulative enrollment (orange line) and monthly enrollment (gray bars) across the 32-month program window. The pandemic shutdown is visible as a flat segment in March–April 2020 (tinted region); pre-pandemic cadence ran at ~42 subjects per month, post-pivot cadence ran at ~14 subjects per month for 19 additional months. Cumulative reached 723 at program close in November 2021. Source: RDI Salesforce enrollment dashboard at program close, November 2021.

Fig. 2 Site contribution across the 32-month program window. Four lead OB-physician sites (orange-tan; A–D) carried 604 of 723 subjects (~84%); the six-site supplementary network (navy; E–J) contributed 119 subjects across shorter active windows. Lead-site share remained stable across pre-pandemic and post-pivot phases. Source: RDI Salesforce enrollment dashboard at program close, November 2021.

5. Discussion

Three observations bear noting. First, multi-year OB specimen collection programs are operationally a relationship-management problem with the lead OB-physician sites. The four lead practices carried 84% of program volume across both pre-pandemic and post-pivot phases — the same lead-site set anchored both phases. Lead-OB-physician relationship continuity through the pandemic shutdown was the single most consequential factor in the program completing on its remaining 19-month tail.

Second, the pandemic operational pivot is documented here as a structural fact, not a program-specific failure. The March 2020 shutdown month delivered 1 subject; April 2020 delivered 0. May 2020 delivered 7 as Site B re-opened first; cadence at the four lead practices recovered through August 2020 against revised in-clinic safety protocols. Post-pivot cadence settled at approximately one-third of pre-pandemic cadence and held there for the remaining 19 months — a reduction reflecting reduced OB-clinic patient throughput in pandemic-era operations rather than any program-specific issue.

Third, multi-year programs require operational tolerance for slow phases that are structural rather than program-specific. The program target was achievable on its slower post-pivot cadence given a long-enough remaining window; the program plan absorbed the cadence reduction by extending the calendar window rather than by reactivating additional sites mid-pivot. The lead-OB-physician practices were the right operational anchor across both phases — not because the supplementary network failed, but because the four lead practices’ OB-clinic infrastructure was the part of the program network that scaled with the protocol’s gestational-age-anchored visit cadence.

6. Conclusion

Long-window healthy-pregnancy specimen collection programs are operationally a lead-OB-physician relationship-management problem. A four-lead-OB-physician anchor + a six-site supplementary network delivered 723 subjects across a 32-month window that straddled the COVID-19 pandemic shutdown. Pre-pandemic cadence ran at approximately 42 subjects per month; post-pivot cadence ran at approximately 14 subjects per month for 19 additional months until the program target was reached. The same operational frame — lead-OB-physician anchored enrollment, gestational-age visit cadence, multi-year window tolerance — transfers to other healthy-pregnancy specimen collection programs.

Notes & References

Sponsor identity withheld per confidentiality terms. Specific protocol code, target counts, analyte panel composition, and assay platform names omitted. Sponsor descriptor reflects the sponsor’s category.
Healthy-pregnancy specimen collection at the gestational-range scale supports verification work on a wide range of pregnancy-relevant analytes; the specific analyte panel for this program is protocol-confidential and not reported here.
The pandemic shutdown is described here as a structural fact of U.S. clinical-research operations in March–April 2020; reference to it is not a sponsor-specific or program-specific characterisation.
Endpoint counts (723 subjects across 10 sites at program close November 2021; pre-pandemic 460 / post-pivot 262 / shutdown 1 across March–April 2020) are taken from the RDI Salesforce enrollment dashboard.
Site labels in Table 1 and Fig. 2 are anonymised. Site descriptors reflect the site’s clinical setting category.
No human subjects data, identifiers, or laboratory results are reported. This is an operations report, not a clinical-results publication.

Suggested citation. RDI Trials. March 2020: one subject. April: none. The study still finished. RDI Trials & Operations Reports, 2026;12. RDItrials.com.