COVID-19 Vaccines International Pregnancy Exposure Registry (C-VIPER)
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ClinicalTrials.gov Identifier: NCT04705116 |
Recruitment Status :
Recruiting
First Posted : January 12, 2021
Last Update Posted : April 19, 2022
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The objective of the COVID-19 Vaccines International Pregnancy Exposure Registry (C-VIPER) is to evaluate obstetric, neonatal, and infant outcomes among women vaccinated during pregnancy with a COVID-19 vaccine.
Specifically, the C-VIPER will estimate the risk of obstetric outcomes (spontaneous abortion, antenatal bleeding, gestational diabetes, gestational hypertension, intrauterine growth restriction, postpartum hemorrhage, fetal distress, uterine rupture, placenta previa, chorioamnionitis, Caesarean delivery, COVID-19), neonatal outcomes (major congenital malformations, low birth weight, neonatal death, neonatal encephalopathy, neonatal infections, neonatal acute kidney injury, preterm birth, respiratory distress in the newborn, small for gestational age, stillbirth, COVID-19), and infant outcomes (developmental milestones [motor, cognitive, language, social-emotional, and mental health skills], height, weight, failure to thrive, medical conditions during the first 12 months of life, COVID-19) among pregnant women exposed to single (homologous) or mixed (heterologous) COVID-19 vaccine brand series from 30 days prior to the first day of the last menstrual period to end of pregnancy and their offspring relative to a matched reference group who received no COVID-19 vaccines during pregnancy.
Condition or disease | Intervention/treatment |
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Covid19 | Biological: COVID-19 vaccine |

Study Type : | Observational [Patient Registry] |
Estimated Enrollment : | 6000 participants |
Observational Model: | Cohort |
Time Perspective: | Prospective |
Target Follow-Up Duration: | 21 Months |
Official Title: | COVID-19 Vaccines International Pregnancy Exposure Registry (C-VIPER) |
Actual Study Start Date : | June 1, 2021 |
Estimated Primary Completion Date : | December 31, 2026 |
Estimated Study Completion Date : | December 31, 2026 |

Group/Cohort | Intervention/treatment |
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Vaccinated pregnant women
Pregnant women who received at least one dose of a COVID-19 vaccine from 30 days prior to the first day of the LMP to end of pregnancy.
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Biological: COVID-19 vaccine
At least one dose of a COVID-19 vaccine. |
Non-vaccinated pregnant women
Pregnant women who have not received a COVID-19 vaccine during pregnancy.
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- Obstetric outcomes [ Time Frame: 1 year ]Number of pregnant women vaccinated against COVID-19 and number of pregnant women not vaccinated against COVID-19 who experience spontaneous abortion, antenatal bleeding, gestational diabetes, gestational hypertension, intrauterine growth restriction, postpartum hemorrhage, fetal distress, uterine rupture, placenta previa, chorioamnionitis, Caesarean delivery, or COVID-19.
- Neonatal outcomes [ Time Frame: 1 year ]Number of newborns of women vaccinated against COVID-19 and number of newborns of women not vaccinated against COVID-19 during pregnancy who are diagnosed with major congenital malformations, low birth weight, neonatal death, neonatal encephalopathy, neonatal infections, neonatal acute kidney injury, preterm birth, respiratory distress in the newborn, small for gestational age, stillbirth, or COVID-19.
- Infant weight [ Time Frame: 1 year ]Change in length and weight from birth to 3, 6, 9, and 12 months of age among newborns of women vaccinated against COVID-19 during pregnancy and among newborns of women not vaccinated against COVID-19 during pregnancy.
- Infant developmental milestones [ Time Frame: 1 year ]Change in developmental milestones from baseline at 6, 9, and 12 months based on the tool Caregiver Reported Early Development Instruments among the offspring of women vaccinated against COVID-19 during pregnancy and among offspring of women not vaccinated against COVID-19 during pregnancy.
- Infant COVID-19 diagnosis [ Time Frame: 1 year ]Number of newborns of women vaccinated against COVID-19 during pregnancy and number of newborns of women not vaccinated against COVID-19 during pregnancy diagnosed with failure to thrive, medical conditions, or COVID-19 during the first year of life.
- Infant height [ Time Frame: 1 year ]Change in height from birth to 3, 6, 9, and 12 months of age among newborns of women vaccinated against COVID-19 during pregnancy and among newborns of women not vaccinated against COVID-19 during pregnancy.

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Ages Eligible for Study: | 18 Years to 50 Years (Adult) |
Sexes Eligible for Study: | Female |
Gender Based Eligibility: | Yes |
Gender Eligibility Description: | Persons assigned gender female at birth. |
Accepts Healthy Volunteers: | Yes |
Sampling Method: | Non-Probability Sample |
Inclusion criteria:
Vaccinated population:
- Pregnant at time of enrollment
- Age ≥18 years at time of enrollment
- Signed the informed consent form and submitted the baseline module "COVID-19 Vaccination During This Pregnancy"
- Received at least one dose of a COVID-19 vaccine during pregnancy or within the 30 days prior to the first day of the LMP
- Resident of a country where a Central Institutional Review Board (IRB) or Ethics Committee provided approval to conduct the study or clearance that approval is not required to conduct the study
Efforts will be made to obtain documentary evidence of COVID-19 vaccination.
Comparison population:
- Pregnant at time of enrollment
- Age ≥18 years at time of enrollment
- Signed the informed consent form and submitted the minimum required data in the initial baseline questionnaire
- Have not received a COVID-19 vaccine during pregnancy or within the 30 days prior to the first day of the LMP
- Resident of a country where a Central IRB or Ethics Committee provided approval to conduct the study or clearance that approval is not required to conduct the study
Exclusion criteria:
- Not pregnant at time of enrollment
- Age <18 years at time of enrollment

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04705116
Contact: Diego Wyszynski, MD, MHS, PhD | 18006163791 | c-viper@pregistry.com |
United States, California | |
Pregistry | Recruiting |
Los Angeles, California, United States, 90045 | |
Contact: Diego Wyszynski, MD, MHS, PhD |
Principal Investigator: | Diego Wyszynski, MD, MHS, PhD | Pregistry |
Responsible Party: | Pregistry |
ClinicalTrials.gov Identifier: | NCT04705116 |
Other Study ID Numbers: |
PR004 |
First Posted: | January 12, 2021 Key Record Dates |
Last Update Posted: | April 19, 2022 |
Last Verified: | April 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Product Manufactured in and Exported from the U.S.: | Yes |
COVID-19 Pneumonia, Viral Pneumonia Respiratory Tract Infections Infections Virus Diseases |
Coronavirus Infections Coronaviridae Infections Nidovirales Infections RNA Virus Infections Lung Diseases Respiratory Tract Diseases |