High blood pressure during pregnancy
If you have high blood pressure and are planning to have a baby
or if you are already pregnant and have high blood pressure here
is information about prevention and treatment, along with antenatal
care and pre-eclampsia.
What do I need to know if I already have high blood
pressure and plan to become pregnant?
If you already have high blood pressure and you are planning to
have a baby you should talk to your doctor about preparing to conceive.
You can, like any other woman, have a successful and healthy pregnancy
but you have a slightly greater chance of complications than other
women do if you have high blood pressure. For this reason you will
need to be more closely monitored than women without high blood
pressure.
It is important to plan your pregnancy if you can
If at all possible your doctor will stop any medicines that you
take for high blood pressure before you become pregnant. You should
not become pregnant whilst you are taking atenolol (beta-blocker),
ACE Inhibitors or Angiotensin Receptor Blockers as these medications
can affect the development of your baby. Therefore it is important
that you plan your pregnancy if you can.
Examples of ACE inhibitors and Angiotensin Receptor Blockers:-
ACE Inhibitors: Captopril, Cilazapril, Enalapril, Fosinopril, Lisinopril,
Perindopril, Ramipril, Trandolapril
Angiotensin Receptor Blockers: Candesartan, Eprosartan, Irbesartan,
Losartan, Telmisartan, Valsartan
However, some women will have to continue to take tablets for high
blood pressure. If this is the case then you may find that your
blood pressure falls in the middle of your pregnancy. If this happens,
the tablets might be stopped. There are certain medicines that can
safely be taken during pregnancy, so if you need to continue to
take medications, there are choices available.
Throughout your pregnancy you will need to have your blood pressure
checked regularly, at least once a month. Some women find it useful
to buy a monitor to use at home, so that they can check their blood
pressure levels in between the times when they see their doctor
or midwife. Check with your midwife or doctor before you decide
to buy a monitor, as home measurement may not be appropriate for
everyone. Make sure that you use an accurate, properly validated
machine. See the information about measuring
your blood pressure, which explains how to take your blood pressure
readings properly and identifies details of accurate
blood pressure monitors
The Microlife 3BTO-A (2) is supplied with two different sized cuffs
provided and is ideal for use during pregnancy and other validated
machines with different cuff size are available from
Medisave
What do I need to know if I have developed high
blood pressure during my pregnancy?
5% or one in every twenty women will develop high blood pressure
whilst they are pregnant. If your blood pressure rises by a small
amount and your urine contains no protein, then this is called gestational
hypertension. If your blood pressure rises by a large amount, and
your urine contains protein then this is called pre-eclampsia. It
is now thought that gestational hypertension may be a milder form
of pre-eclampsia so careful monitoring is essential.
Pre-eclampsia is caused by a problem with the placenta, which joins
mother and baby and supplies the baby with nutrients and oxygen
from the mother's blood. It is potentially very dangerous for both
mother and baby if it is undetected. The signs and symptoms are
a rise in blood pressure and protein in the urine. Sometimes the
baby may be slow to grow and the mother may have swollen hands and
feet, though there are other things that can cause these symptoms.
It is very important that all pregnant women have regular checks
by their midwife throughout their pregnancy, so that any problems
can be spotted early and dealt with.
If you are found to have pre-eclampsia then you and your baby will
be closely monitored. The only way to stop pre-eclampsia is for
the baby to be delivered, which can sometimes mean a premature birth.
Action on Pre-Eclampsia
is an organisation that provides information on pre-eclampsia.
High blood pressure can be treated during pregnancy. Your doctor
may ask you to make some changes to your diet, or change your lifestyle
and if your blood pressure is very high, may ask you to take medications
to lower it. There are medicines that are safe for you and your
baby, but you will need to be monitored closely. Your doctor will
avoid medications unless there is no alternative.
Methyldopa is the medicine most commonly used to manage high blood
pressure during pregnancy. Diuretics, ACE inhibitors, Angiotensin
Receptor Blockers and atenolol (a beta-blocker) should not be used
during pregnancy. Other beta-blockers, such as labetolol are occasionally
used, though there is very little evidence about their effects during
pregnancy. Likewise, there is very little information on the use
of calcium channel-blockers in pregnancy. If your blood pressure
is sufficiently high, then these latter drugs will be used to reduce
it.
If you develop high blood pressure during your pregnancy then it
is very important that once the baby is born that you make sure
your blood pressure is regularly checked until it returns to its
usual level. Blood pressure levels can rise sharply in the days
following the delivery of a baby and can continue at high levels
for a few weeks. In most women it returns to the same levels as
prior to the pregnancy, but it is important to check that this has
happened.
If I already have high blood pressure prior to
becoming pregnant am I more likely to develop pre-eclampsia?
If you already have high blood pressure then you do have a slightly
greater chance of developing pre-eclampsia in pregnancy. Your doctor
and midwife will closely monitor your blood pressure and then decide
to use treatment if it starts to rise.
There is no way of preventing pre-eclampsia, though you should
eat a healthy diet (low in salt and saturated fats and high in fruit
and vegetables) throughout your pregnancy, to ensure that you and
your baby are healthy.
What do I need to know if I had high blood pressure
during a previous pregnancy?
High blood pressure in a previous pregnancy does not necessarily
mean that you will have it again during further pregnancy, though
you do have a slightly greater chance of having it than a woman
who has never had a raised blood pressure. Many women who have high
blood pressure during pregnancy have a normal blood pressure in
later pregnancies.
There has been some research which suggests that women who have
high blood pressure or pre-eclampsia during pregnancy may be more
likely to have a stroke or heart disease much later in life. It
is important for everyone to know what their blood pressure is and
to make sure that it is checked regularly so that any rise in your
blood pressure can be picked up and treated when necessary. If you
have had pre-eclampsia or high blood pressure during a pregnancy,
it is even more important that you have your blood pressure checked
as you grow older, ideally every year.
Can I breast feed my baby if I am taking medicines
for high blood pressure?
There is some evidence that atenolol gets into breast milk, although
this has affected the baby in just two cases. All other medicines
for high blood pressure are safe in breast-feeding, but in general
doctors are keen to avoid using medicines in women who breast-feeding.
You should make sure that your GP knows if you intend to breast-feed.
Need to know more?
Your midwife, obstetrician or doctor can help with more information.
You may also find the following organisation useful:
APEC (Action on Pre-eclampsia)
84-88 Pinner Road
Harrow
Middlesex HA1 4HZ
Telephone: 020 8863 3271
References:
Article: Hypertensive diseases of pregnancy and risk of hypertension
and stroke in later life: results from cohort study
Publication: British Medical Journal, April 2003, Volume 326 Page
845
Authors: B Wilson, M Stuart Watson, G Prescott and others
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