CompletedPhase IIIInterventional

HYPATIA: A prospective randomised controlled trial of hydroxychloroquine to improve pregnancy outcome in women with antiphospholipid antibodies

Antiphospholipid syndrome is an immune condition where the body makes antibodies that attack its own tissues. For women with these antibodies, pregnancy can carry higher risks of miscarriage, blood clots in the placenta, and high blood pressure. While standard treatments such as aspirin help many women have healthy babies, doctors want to find ways to make pregnancy even safer. The HYPATIA trial is looking at whether adding an existing medicine called hydroxychloroquine can improve pregnancy outcomes. Hydroxychloroquine is safe, low-cost, and commonly used for conditions like lupus. The study is for women aged 18 to 45 who have these antibodies and are planning a pregnancy. Participants take either one hydroxychloroquine tablet or a matching dummy tablet (placebo) once a day until their baby is born, alongside their normal NHS pregnancy care. Researchers will monitor both mother and baby to see if the medicine reduces complications.

At a glance

Status

Completed

Phase

Phase III

Sponsor

Guy's and St Thomas' NHS Foundation Trust

Enrolment target

400

Start

01 Jul 2017

Estimated completion

31 Jul 2026

Women with persistent antiphospholipid antibodies who are planning pregnancy

What is this study about?

Our immune system usually protects us from illness by making antibodies to fight off germs. Sometimes, however, the body mistakenly makes antibodies that attack its own healthy cells. When someone has persistent antiphospholipid antibodies, their blood is more likely to form unwanted clots. During pregnancy, these antibodies can cause problems with how the placenta attaches and grows, which may starve the baby of oxygen and nutrients. This can lead to slow growth, high blood pressure in the mother (pre-eclampsia), or miscarriage.

Doctors currently treat pregnant women who have these antibodies with blood-thinning medicines like low-dose aspirin and sometimes heparin injections. While these treatments have greatly improved the chances of having a healthy baby, some women still experience heartbreaking pregnancy losses or severe complications. Doctors are eager to find extra treatments that can give women the best possible chance of a safe pregnancy.

Hydroxychloroquine is an inexpensive tablet that has been used safely for decades to treat malaria, lupus, and arthritis. Past research found that pregnant women with lupus who took hydroxychloroquine had fewer miscarriages and healthier births. Because it calms the immune system and protects blood vessels, experts believe it could also help women who have antiphospholipid antibodies.

The HYPATIA study aims to find out for certain if hydroxychloroquine improves pregnancy success. By comparing women who take the medicine with women who take a dummy tablet, researchers can clearly see whether this simple daily tablet leads to more healthy, full-term births.

Key takeaways

The HYPATIA trial tests whether hydroxychloroquine can help prevent pregnancy complications in women with antiphospholipid antibodies.
Participants take either one study tablet or an inactive dummy tablet daily alongside their normal NHS care.
You must be aged 18 to 45 and planning a pregnancy to take part; you cannot join if you are already pregnant.
The medicine is inexpensive and has a long track record of safe use during pregnancy.
Taking part is voluntary, and you can stop at any time without affecting your routine maternity care.

Who may be eligible?

You may be able to join this study if you are a woman aged between 18 and 45, you have tested positive for antiphospholipid antibodies on at least two separate blood tests (at least 12 weeks apart, with the latest within the last year), and you are actively planning to get pregnant.

You cannot join if you are already pregnant when entering the study. You also cannot take part if you are already taking hydroxychloroquine, have had a bad reaction to it in the past, or have certain other medical conditions. These conditions include specific eye problems (retinopathy), uncontrolled epilepsy, psoriasis, or severe kidney and liver problems.

Your hospital care team will check your medical history and run standard blood tests to confirm whether this study is safe and suitable for you.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am a woman aged between 18 and 45.
I have been told I have persistent antiphospholipid antibodies or antiphospholipid syndrome (APS).
I am currently planning to get pregnant, but I am not pregnant yet.
I am not currently taking hydroxychloroquine.
I do not have a history of eye problems affecting my retina, uncontrolled epilepsy, or psoriasis.

Answer every question to see your result.

What does participation involve?

If you decide to take part, you will be randomly placed into one of two groups by a computer. One group will take a hydroxychloroquine tablet once a day, while the other group will take a dummy tablet (placebo) that looks identical. Neither you nor your doctor will choose or know which tablet you receive. You will take this tablet every day while trying to conceive and throughout your pregnancy until your baby is born.

You will continue to receive all your standard NHS pregnancy care, including any recommended blood-thinning medicines like aspirin or heparin. Throughout your pregnancy, you will have regular check-ups, scans, and blood tests so the research team can monitor your health and the growth of your baby. The study follows you through your pregnancy until delivery.

Potential risks and benefits

Taking part may not help your current pregnancy directly, as you might receive the dummy tablet. However, the results could help improve care and treatments for you in future pregnancies and for other women in the same situation. Hydroxychloroquine is widely used and generally considered safe during pregnancy and breastfeeding, but like all medicines, it can sometimes cause mild side effects like an upset stomach or skin rash. Serious side effects are rare. Taking part is completely voluntary, and you are free to leave the trial at any time without your regular NHS care being affected in any way.

Locations (10)

Guy's and St Thomas' NHS Foundation Trust
City only
London, England
University College London Hospital
City only
London, England
Imperial College London
Approximate
London, England
Oxford University Hospitals
City only
Oxford, England
Liverpool Women's Hospital
Approximate
Liverpool, England
Addenbrooke's Hospital
Unverified
Cambridge, England
Rigshospitalet Copenhagen University Hospital
Unverified
Copenhagen, Denmark
Odense University Hospital
Unverified
Odense, Denmark
Academic Medical Centre
Unverified
Amsterdam, Netherlands
Turin University Hospital
Unverified
Turin, Italy

Common questions

What is a placebo?

A placebo is a dummy tablet that looks and tastes exactly like the real medicine but contains no active ingredients. It allows researchers to see if the real drug works better than usual care alone.

Is hydroxychloroquine safe to take during pregnancy?

Yes. Hydroxychloroquine has been taken safely by many thousands of pregnant women with conditions like lupus and arthritis for decades, with no known increased risk of birth defects.

Will I still receive my normal pregnancy medicines?

Yes. The study tablet is taken in addition to your standard NHS care. You will still receive routine treatments, such as aspirin or heparin injections, as advised by your doctor.

Can I take part if I am already pregnant?

No. You must join the study while you are planning to become pregnant, before conception occurs.

What happens if I decide I no longer want to participate?

You can leave the study at any time without giving a reason. Your standard medical care and the support you receive from your doctors and midwives will continue as normal.

How to find out more

Beverley Hunt

beverley.hunt12@nhs.net +44 (0)20 7188 2736 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.