NCT07414511 · University of Washington
Hemophilia A Research Program
(HARP)
What this study is about
This study longitudinally observes the intergenerational (mother-child) continuum in hemophilia A from pregnancy through early childhood. Because the study follows mother-child pairs, the study includes both a maternal group of participants and a pediatric group of participants.
View original scientific description
This study longitudinally observes the intergenerational (mother-child) continuum in hemophilia A from pregnancy through early childhood. Because the study follows mother-child pairs, the study includes both a maternal cohort and a pediatric cohort. Each cohort has a primary goal: for the mother with a severe hemophilia genotype, the overarching primary goal is to understand the risks for pregnancy-associated bleeding and postpartum hemorrhage (PPH); for the child, the overarching primary goal is to understand the risks, timing, and circumstances of development of anti-FVIII antibodies. From a longitudinal perspective, risks for both bleeding in the mother and anti-FVIII antibody development in the child are expected to be influenced over time by genetic and environmental factors that begin early in (or before) pregnancy. Enrollment of blood relatives is offered to improve power to better understand inherited contributions to bleeding and inhibitor development in the mother-baby pairs.
Primary outcome measures
Primary Endpoint(s)/Outcome(s)
Time frame: For mother-child pairs, from enrollment until the child with severe hemophilia A is at least 2 years old*, or until a study discontinuation criteria is met. *This is the minimum duration, the mother-child pairs will be followed for as long as feasible.
The study primary endpoints/outcomes for the maternal and pediatric cohorts are as follows: • Maternal: Rates of primary PPH, defined as * estimated or quantified blood loss \> 1,000 mL in the first 24 hours PP, or * unplanned transfusion of blood products related to blood loss in the first 24 hours PP. As a subset of primary PPH, severe primary PPH is defined as * estimated or quantified blood loss \> 1,500 mL or requirement of \> 2 units packed red blood cells within 24 hours PP, or * primary PPH with estimated or quantified blood loss \> 1,000 mL and evidence of maternal hemodynamic instability (tachycardia, hypotension) or end organ damage with no other etiology (oliguria, creatinine \> 0.8, etc.). • Pediatric: Rate of development of humoral immune response to FVIII and proportion that progress to clinical inhibitors, defined as * clinical FVIII inhibitor, or * detection of an antibody specific to FVIII.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Pregnant individuals who meet the following criteria are eligible for enrollment as study participants:
- Currently pregnant and prior to 37 weeks gestation
- Known to have or at-risk of having a severe hemophilia A genotype
- Pregnant with at least one fetus at-risk of inheriting severe hemophilia A
- Ability to understand and willingness to provide informed consent
- 18 years of age or older Before the 38th week of pregnancy, enrolled participants must meet all the following criteria to continue to remain in the study:
- The pregnant mother has a severe hemophilia A genotype.
- A fetus is determined to have a \>/= 25% risk of inheriting severe hemophilia A, or prenatal testing indicates a fetus is affected by severe hemophilia A.
- No other discontinuation criteria have been identified. Pediatric Continuation / Inclusion Criteria: Eligibility of the child to continue is assessed by age 8 weeks. Mother-child pairs in which a child meets the following criteria will remain in the study:
- Severe hemophilia A defined by a baseline FVIII:C \< 0.01 IU/mL (or FVIII:C \< 1%) or a genotype predicted to cause severe hemophilia A
- Born to a mother participating in the study Thereafter, mothers and their children will continue in the study as long as no new discontinuation criteria occur. Inclusion Criteria for Blood Relatives: Blood relatives of the child may be offered participation if one of the following criteria are met:
- First-degree blood relatives (e.g., father, sibling) of the child
- Second-degree blood relatives (e.g., aunt, uncle, grandparent, half-sibling) of the child
- Any more distant male or female blood relative whose data or samples may be informative for the planned genetic studies of hemophilia and inhibitors
Exclusion criteria
- /Discontinuation Criteria: Maternal: For the pregnant person, exclusion or discontinuation criteria are as follows:
- Genetic testing is negative for a severe hemophilia A genotype
- Prenatal clinical diagnostic testing that indicates there is no fetus affected with severe hemophilia A
- Presence of another clinically significant bleeding disorder
- Participation in another study for which any blood collection total would exceed safety limits defined in this study
- Will deliver outside the United States or plans for regular pediatric care for the child to be delivered outside the United States
- Is a prisoner
- Any other reason that, in the opinion of the investigator, would render the individual unsuitable for participation in the study
- Inability for study team to obtain translated study documents in time for participation if participant is not fluent in English Pediatric: For the child, discontinuation criteria are as follows:
- Infant does not have severe hemophilia A defined by a baseline FVIII:C \< 0.01 IU/mL (or FVIII:C \< 1%) or does not have a genotype predicted to cause severe hemophilia A
- Mother or child did not have minimal required study samples or data collected before birth, around the time of delivery, or in the neonatal period
- Child has another clinically significant bleeding disorder
- Child has a clinically severe immune disorder
- Participation in another study for which any blood collection total would exceed safety limits defined in this study
- Any other reason that, in the opinion of the investigator, would render the individual unsuitable for participation in the study
Where
- Seattle, Washington
Collaborators
National Heart, Lung, and Blood Institute (NHLBI), RTI International, Emory University
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Feb 17, 2026 · Source of record for eligibility and locations