The New Horizons Study
New mothers are at higher risk of blood clots in the legs or lungs for up to six weeks after birth. To prevent these, some women need blood-thinning medicines. Right now, the only proven options while breastfeeding are daily injections or a tablet called warfarin, which requires regular blood checks. Newer blood-thinning tablets called rivaroxaban and edoxaban are much easier to take, but doctors do not yet know how much of the medicine passes into breast milk. The New Horizons Study aims to find out. Women who gave birth in the last 12 weeks take one of these tablets for three days. Researchers collect milk and blood samples at home to measure drug levels. Because safety in breast milk is still being tested, mothers temporarily stop breastfeeding during the study. This research could help future mothers avoid uncomfortable daily injections.
At a glance
What is this study about?
Having a baby is an exciting time, but the first six weeks after giving birth carry an increased risk of developing blood clots in the veins of the legs or the lungs. For women who are at high risk, doctors recommend taking blood-thinning medication to prevent these clots from forming.
At the moment, choices for breastfeeding mothers are limited. The most common treatment is a daily injection, which can be sore and inconvenient. The other option is a tablet called warfarin, but this requires frequent trips to the clinic for blood tests. Modern blood-thinning tablets are widely used and much easier to take, but there is very little information about whether they pass into human breast milk.
The New Horizons Study is being run by King's College Hospital NHS Foundation Trust in London. Researchers are testing two modern blood thinners, called rivaroxaban and edoxaban, to see how much of the medicine gets into breast milk. By measuring this carefully over three days, doctors hope to discover whether these tablets might be safe and convenient options for breastfeeding mothers in the future.
Key takeaways
- Tests whether modern blood-thinning tablets pass into breast milk.
- Open to women aged 18 and over who gave birth within the last 12 weeks.
- Involves taking a tablet once a day for three consecutive days.
- Requires pausing breastfeeding for three days to keep your baby safe.
- Researchers visit your home to collect samples, avoiding hospital trips.
- Could help future mothers take tablets instead of daily injections.
Who may be eligible?
You may be able to join this study if you are a woman aged 18 or older who has given birth within the last 12 weeks. You need to be in generally good physical and mental health, with normal kidney and liver function, and not currently pregnant.
Because the study is testing whether the medicine passes into breast milk, you must be willing to pause breastfeeding your baby for the three days you are taking the tablets. You should also not be taking any other medicines that could interfere with the study drugs.
Finally, you must be happy for members of the research team to visit you at home to collect the blood and milk samples, so you do not need to travel to the hospital.
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 aged 18 or older.
- I gave birth within the last 12 weeks.
- I am willing to pause breastfeeding for three days during the study.
- I am in good general health with normal kidney and liver function.
- I am comfortable with researchers visiting my home to take blood and milk samples.
What does participation involve?
Taking part in the study lasts for three days in a row. You will be given one of two blood-thinning tablets (either rivaroxaban or edoxaban) to take once a day for three consecutive days.
During these three days, you will need to stop breastfeeding your baby so they do not drink the medicine. You can express and freeze your milk before the study starts to feed your baby during this time, or use formula.
A member of the research team will visit you at your home over the 72-hour period to collect small blood samples and samples of your breast milk. This means you do not have to worry about travelling to the hospital with a newborn. Once the study ends and the team gives you the all-clear, you can resume breastfeeding as normal.
Potential risks and benefits
Locations (1)
- King's College HospitalApproximateLondon, England
Common questions
Will my baby receive any of the study medicine?
No. You will pause breastfeeding while taking the medicine and during sample collection, ensuring your baby is not exposed to the drug.
How will I feed my baby during the study?
Most mothers express and store extra breast milk before the study begins, or choose to feed their baby infant formula during the three days.
Do I have to travel to the hospital?
No. To make things as easy as possible for you and your baby, the research team will visit you at home to collect all milk and blood samples.
Can I go back to breastfeeding after the study?
Yes. Once the three-day study period is finished and the team gives you the all-clear, you can restart breastfeeding normally.
What happens if I change my mind?
You are free to leave the study at any point. You do not have to give an explanation, and your normal healthcare will not be affected in any way.
How to find out more
Jignesh Patel
Always speak to your GP or specialist before deciding to take part in a study.
Discussion
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