Maternal Hyperoxygenation for Left Heart Hypoplasia

(MHO Trial)

Age: 18+

Sex: Female

Trial Phase: Academic

Sponsor: Baylor College of Medicine

Disqualifiers: Multiple gestations, Arrhythmia, Poor ultrasound, others

Compensation: Varies

Number of Visits: Unknown

Duration: Duration of pregnancy

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether providing extra oxygen to pregnant mothers (maternal hyperoxygenation) can benefit babies with left heart hypoplasia (LHH), a condition where the left side of the heart is too small. The researchers aim to determine if this approach can improve outcomes for these babies. The trial includes different groups: some mothers will receive daily oxygen therapy, others will undergo testing, and there are groups of healthy pregnancies for comparison. The trial seeks pregnant women whose babies have been diagnosed with LHH or are at risk for certain heart problems. As an unphased trial, this study offers a unique opportunity to contribute to groundbreaking research that could enhance care for future pregnancies.

Do I need to stop my current medications for the trial?

The trial protocol does not specify if you need to stop taking your current medications. However, if you have moderate to severe hypertension requiring medication, you may not be eligible to participate.

What prior data suggests that maternal hyperoxygenation is safe for treating left heart hypoplasia?

Research shows that providing extra oxygen to pregnant women, either long-term or short-term, has been studied for safety in cases where the unborn baby has a heart condition. Long-term extra oxygen for the mother has proven safe and feasible for pregnancies with these heart issues. Studies suggest that small amounts are well-tolerated by expectant mothers.

For short-term extra oxygen, research has shown it can help assess the baby's heart condition without causing major side effects. This approach appears safe for both the mother and the baby during testing.

These findings suggest that both long-term and short-term extra oxygen are generally safe and well-tolerated for pregnancies with fetal heart conditions. However, discussing potential risks and benefits with a healthcare provider remains important. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about maternal hyperoxygenation for left heart hypoplasia (LHH) because it offers a unique, non-invasive approach to potentially improve fetal heart development. Unlike traditional treatments for LHH, which often involve surgical interventions after birth, maternal hyperoxygenation aims to enhance fetal oxygen delivery and support heart growth while still in the womb. By providing either chronic or acute oxygen therapy to the mother, this treatment could help develop the fetal heart more effectively and reduce the need for complex surgeries post-birth. This approach is particularly promising because it targets the condition earlier and less invasively than current standards, potentially leading to better outcomes for both mothers and their babies.

What evidence suggests that maternal hyperoxygenation might be an effective treatment for left heart hypoplasia?

Research has shown that when a mother breathes in extra oxygen, it may help babies with left heart hypoplasia (LHH), a condition where part of the heart is underdeveloped. In this trial, some mothers will undergo chronic maternal hyperoxygenation therapy, while others will participate in acute maternal hyperoxygenation challenge testing. Studies suggest that providing the mother with oxygen can aid the baby's heart growth. Specifically, one study found that oxygen therapy for mothers predicted a 92% survival rate for the babies. This treatment is safe and is now commonly used to monitor heart development. It offers a promising and non-invasive way to assist babies with this serious heart condition. ^{1 2 6 7 8}

Who Is on the Research Team?

Shaine A Morris, MD

Principal Investigator

Baylor College of Medicine

Are You a Good Fit for This Trial?

This trial is for pregnant women with normal ultrasounds or those whose fetuses have specific heart issues like left heart hypoplasia, at risk of aortic coarctation, or related conditions. It's not for mothers with multiple pregnancies, certain health problems (like severe hypertension), or poor ultrasound images.

Inclusion Criteria

My fetus has a heart condition affecting the left side or aorta.

Group B: Healthy Fetal controls - Mothers undergoing screening fetal echo for family history of CHD with a normal echo; Mothers undergoing fetal echocardiography for suspected heart disease with a normal echo; Mothers evaluated in the fetal center with normal ultrasound

My fetus has a heart condition with specific measurements and blood flow issues.

Exclusion Criteria

Multiple gestations

I have a health condition during pregnancy that could affect my baby's heart and blood flow.

Major extra cardiac anomalies

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Mothers receive daily maternal hyperoxygenation therapy for the rest of the pregnancy

Duration of pregnancy

Continuous daily treatment

Follow-up

Participants are monitored for safety and effectiveness after treatment

2 years

What Are the Treatments Tested in This Trial?

Interventions

• Maternal Hyperoxygenation

Trial Overview The study tests if giving extra oxygen to the mother can help babies who might be born with small left-sided heart structures. Mothers breathe in more oxygen and doctors check if it improves the baby's heart condition before birth.

How Is the Trial Designed?

Group I: Chonic Maternal Hyperoxygenation w/ LHH Experimental Treatment 1 Intervention

Mothers who have a fetus diagnosed with LHH and elect daily maternal hyperoxygenation therapy.

Group II: Acute Maternal Hyperoxygenation with LHH Experimental Treatment 1 Intervention

Mothers who have a fetus diagnosed with LHH and elect acute maternal hyperoxygenation challenge testing.

Group III: Historical LHH Controls Active Control 1 Intervention

Previous women with a dx of fetal LHH and whose care was continued at Texas Children's Hospital.

Group IV: Healthy Fetal Controls Placebo Group 1 Intervention

Healthy mothers with healthy fetuses that will come in monthly for fetal echcos starting at 20 wks.

Who Is Running the Clinical Trial?

Baylor College of Medicine

Lead Sponsor

Trials

1,044

Recruited

6,031,000+

Published Research Related to This Trial

Chronic maternal hyperoxygenation (CMH) therapy has shown promise in improving fetal pulmonary blood flow and enhancing the growth of the left heart in fetuses with left-sided cardiac defects, potentially leading to better heart structure development as gestation progresses.

Despite its benefits, there are concerns regarding potential fetal complications, such as growth restriction and impacts on brain development, which need to be carefully considered when using CMH therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Successful prenatal treatment with continuous chronic maternal hyperoxygenation therapy in hypoplastic left heart in two pregnancies: Case report. Bolluk, G., Oztarhan, A., Vural, C., et al.[2023]

Maternal hyperoxygenation has been explored since the 1960s as a potential treatment for various obstetric conditions, but there is still no clear evidence supporting its benefits, particularly for fetal growth restriction.

Research on maternal oxygen therapy for fetal congenital cardiac disease has shown mixed results and raised concerns about possible adverse effects, highlighting the need for careful consideration before conducting further clinical trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Calling into question the future of hyperoxygenation in pregnancy. McHugh, A., El-Khuffash, A., Franklin, O., et al.[2021]

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT02965638

Trial of Maternal Oxygen for Fetal Left Heart Hypoplasia The purpose of this study is to determine if maternal hyperoxygenation is an effective treatment for fetal left heart hypoplasia versus room air (placebo).

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8429855/

Maternal hyperoxygenation in congenital heart disease - PMC Based on the current studies, it appears CMH therapy administered early in the third trimester at ~50% FiO2 for at least 9 hours per day may be beneficial for ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S0301211520308484#!

Calling into question the future of hyperoxygenation in ... They found that short term administration of MH was safe and reported no negative effects. Maternal hyperoxygenation has now become a standard diagnostic tool ...

4. onlinelibrary.wiley.com onlinelibrary.wiley.com/doi/10.1002/jcu.23347

Maternal hyperoxygenation during pregnancy as a tool in ... A reactive test predicted a 92% survival rate for infants, while a nonreactive test predicted a 79% mortality rate from pulmonary hypoplasia.

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9304816/

Hypoplastic Left Heart Syndrome: Is There a Role for Fetal ... Chronic maternal hyperoxygenation may be a non-invasive treatment-alternative to promote left heart growth in fetuses with left heart hypoplasia, but the ...

6. onlinelibrary.wiley.com onlinelibrary.wiley.com/doi/10.1111/echo.13722

Maternal hyperoxygenation: A potential therapy for ... 5 studied acute MH to risk stratify fetuses with left ventricular hypoplasia, and showed an increase in LV filling with patients with atrial ...

7. frontiersin.org frontiersin.org/journals/pediatrics/articles/10.3389/fped.2022.944813/full

Hypoplastic Left Heart Syndrome: Is There a Role for Fetal ... The aim of this review is to cover patient selection and possible hemodynamic effects of fetal cardiac procedures and maternal hyperoxygenation in fetuses with ...

8. ahajournals.org ahajournals.org/doi/10.1161/circimaging.109.848432

Vasoreactive Response to Maternal Hyperoxygenation in ... PA vasoreactivity to MH occurs in the fetus with HLHS. MH testing accurately identifies fetuses requiring urgent postnatal intervention at birth.