Diuretics
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A diuretic can be used in pregnancy if prescribed by a doctor.
What are they?
Diuretics (sometimes called ‘water tablets’) increase urine production and help to get rid of excess fluid. They are used in the treatment of heart failure, high blood pressure, and some kidney conditions.
Diuretics commonly used in the UK include amiloride, chlorothiazide (Diuril®), hydrochlorothiazide, furosemide (Frusol®) and spironolactone (Aldactone®, Qaialdo®, Urospir®).
Benefits
What are the benefits of using a diuretic in pregnancy?
Diuretics can be used in pregnancy but are rarely needed. When they are needed, it is to prevent serious complications from the build-up of excess fluid in the body.
Risks
What are the risks of using a diuretic in pregnancy?
There is not much information on diuretics in pregnancy because hardly any pregnant women need to take them. However, there are a few issues that need to be considered:
Diuretics may reduce blood flow to the placenta. However, many of the medical conditions that you need diuretics for will also do this. Your baby will be monitored with extra growth scans.
Use of spironolactone specifically can potentially reduce levels of the male hormone testosterone in the baby. There are concerns that use in pregnancy could affect genital development in male babies. This has been shown in animal studies. There is a single human case report of a male baby with malformed genitals following spironolactone exposure, but also several case reports of male babies with normal genitals.
Use of a diuretic in pregnancy will only be recommended if the benefits of treating a potentially serious condition outweigh the possible risks.
Alternatives
Are there any alternatives to taking a diuretic in pregnancy?
Possibly. If you take a diuretic to treat high blood pressure, you will usually be offered a different medicine that is known to be safe during pregnancy.
However, if you are using a diuretic because you have heart failure, you may be advised to continue taking a diuretic, as this can get worse during pregnancy and other drugs are unlikely to be as effective.
Swapping to a diuretic in pregnancy may be advised if you are taking drugs called ACE-inhibitors or angiotensin receptor blockers because these can be dangerous for your baby if used in later pregnancy.
If you have a medical condition that affects your kidneys, you may also be advised to continue taking a diuretic to remain well.
If you are taking a diuretic and planning a pregnancy, speak to your doctor or specialist to make sure that this is right for you. Please do not make any changes to your medication unless your doctor has recommended this.
No treatment
What if I prefer not to take medicines in pregnancy?
It is important to take any medicines prescribed for high blood pressure, heart problems, or conditions affecting kidney function, as these can be serious for both you and your baby. A doctor will only prescribe medicines when necessary and will be happy to discuss any concerns.
Will I or my baby need extra monitoring?
As part of routine antenatal care, most women will be offered a detailed scan at around 20 weeks of pregnancy to check the baby’s development.
If you have high blood pressure, heart problems, or conditions affecting kidney function, you will be more closely monitored with additional fetal growth scans during pregnancy to make sure that you remain well throughout and that your baby is growing as expected.
Are there any risks to my baby if the father has taken a diuretic?
We do not expect any increased risk to your baby if the father takes a diuretic.
Who can I talk to if I have questions?
If you have any questions regarding the information in this leaflet, please discuss them with your health care provider. They can access more detailed medical and scientific information from www.uktis.org.