Kidney diseases affect fertility (ease of becoming pregnant) and they affect pregancy itself. These are important questions for people with kidney diseases.
The answer is yes. Kidney disease makes women a bit less fertile, but as our management of kidney disease improves, so the numbers of women who become pregnant with kidney disease, with a kidney transplant or even when on dialysis are increasing.
Kidney disease interferes with the hormones that normally regulate periods, so many women with kidney disease find their periods become irregular or stop completely. It can become difficult to detect pregnancy. Some women only suspect that they are pregnant when they develop other unexplained symptoms like nausea and fatigue. Standard pregnancy tests including home kits are still reliable in kidney disease, unless your urine output is very low when a blood test can be done.
Having kidney disease can make pregnancy more complicated. The more severe your kidney disease, the greater the risk of having a difficult pregnancy. By 'risks', we mean risk to the baby and risk to the mother.
For most people with mild kidney disease, the risks may still be pretty low, even though they are higher than for someone with normal kidneys, but if no one has discussed this with you, you should ask your doctor. For some people, usually those with quite significant kidney disease, or with other health problems, the risks may occasionally be very high.
The worse your kidney function, the higher your blood pressure, and the more protein in your urine, the higher the risk.
The risks include the fact that pre-eclampsia is more likely (see next section), the risk that your kidneys may suffer further damage during pregnancy, and the risk to the baby.
Pre-eclampsia is a combination of high blood pressure, and a leak of protein from the kidneys into the urine. It only happens in pregnancy. Most cases are mild, but some are serious and require early delivery of the baby. Babies may be small as well as premature. High blood pressure is more common in people with kidney disease, and this makes pre-eclampsia more likely.
A lot of attention is paid to the blood
pressure in pregnancy. The higher and more difficult it is to
control a woman's blood pressure before pregnancy, the more likely
it is that pregnancy will be complicated. Starting pregnancy with
uncontrolled high blood pressure makes the chances of a miscarriage
high.
Having kidney disease itself does not harm the baby. However a few kidney diseases are inherited and may be passed onto a child. The table below lists the commoner of these; if you are not sure, ask your doctor if your kidney disease is inherited.
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|
|
|
|
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Autosomal Dominant Polycystic Kidney Disease (Polycystic kidneys) | 1/2 Risk |
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Alport's Syndrome | Variable |
|
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Reflux Nephropathy | Unknown |
Having kidney disease might result in slower growth of a baby
but this rarely causes any problems. More important is the fact
that some babies will be delivered earlier than at the normal
40 weeks; this may occur naturally, or might be "induced"
in order to protect the mother from pre-eclampsia.
The earlier a baby is born, the more likely it is to have problems with breathing, feeding and growth; babies who are born early often need special care in hospital for a while. If a baby is born before 22 weeks the outlook for survival is very bleak. From 22 weeks to 28 weeks the chances for survival improve with each extra week in the womb but still this prematurity carries a risk of complications. From 30 weeks on the overall outlook for the baby is good but the baby may still need a special care baby unit.
It is known that many drugs cross the placenta and could harm a baby. If you are on any medications, especially those used to control blood pressure, you may find that they are stopped and changed for others instead. You may be prescribed a small dose of aspirin as this may be helpful. You should remember that smoking, drinking alcohol and the use of non-prescription drugs could all harm a baby.
The best thing for a healthy baby is a healthy mother! It is important to balance the risks as best as possible, and not to stop important medicines that are keeping you well. SafeFetus.com lets you look up some information about risk of drugs in pregnancy, but remember they don't know anything about you - discuss with your obstetrics and renal team. The information they provide is quite complicated. Some drugs that are definitely harmful to babies are:
THESE ARE ONLY EXAMPLES. Others may need to be altered or stopped.
A kidney that is already diseased might suffer some further damage during pregnancy. This is more likely if the kidney disease is severe at the start. People with kidney failure who expect to need dialysis in the future may find that pregnancy hastens their progression to dialysis. Rarely it is necessary to start dialysis during pregnancy.
The risk of losing kidney function during pregnancy increases with increasing severity of kidney disease (lower GFR, higher creatinine) before pregnancy. The risk is probably low if your creatinine was below about 140 micromols/l; and moderate if it is 140-170. However there is a lot of variation. Having a lot of proteinuria and difficult blood pressure probably increase the risk.
Women on dialysis rarely become pregnant; those that do usually develop complications. Dialysis needs to be done more frequently, sometimes every day. Premature delivery usually happens, and unfortunately miscarriages are common.
Having a kidney transplant does not rule out pregnancy. A transplant that is functioning very well gives the best chance of a perfectly normal pregnancy. If the transplant is not absolutely normal, then all the possible complications noted above will apply, including the chances of a deterioration in the function of the transplant itself. It is essential to take anti-rejection therapy throughout pregnancy, and careful attention to drug doses will be needed.
Your GP and the team who normally look after your kidney disease will keep a close eye on you. You will also see specialist obstetricians who have a detailed knowledge of pregnancy and kidney disease; they will have a team including nurses and midwives. If you live a long way from a city, you may find that to get the best specialist care, your clinic visits are not at your local hospital, but in the city. Clinic visits can become very frequent, and sometimes admission to hospital is necessary during the pregnancy in order to monitor everything safely.
If at all possible, delivery will be by the normal vaginal route. If pregnancy is complicated, especially if an early delivery is needed, then a caesarean section may be needed. These options will be discussed with you.
Breast feeding is best. Some medication comes out in breast milk; your doctors will try to alter your medication to allow you to breast feed, but this may not always be safe.
If you have kidney disease, and if you wish to become pregnant, it is advisable to discuss this with your doctors. They will be able to say when or whether pregnancy is advisable, and they will be able to adjust your medicines appropriately. Folic acid supplements to reduce the chances of spina bifida should be started early if pregnancy is planned.
If you have kidney disease and wish to be sexually active, avoiding pregnancy by using contraception is advised, until your pregnancy plans are made. Many women with kidney disease have irregular periods, and therefore think that they are infertile; this is not the case, even if periods have disappeared completely. There are no problems in using barrier methods of contraception eg. condoms. Coils are not advised for women who are on immunosuppressive drugs. The pill is convenient but may interfere with blood pressure control. Your GP or kidney specialist will advise you on what may be best.
This
information is published from the Renal Unit at the Royal Infirmary
of Edinburgh, Scotland, UK, Renal@ed.ac.uk The author of this page was Paddy Gibson. It was written in September 2000 and reviewed
Please be aware that while we have made all efforts to ensure that this information is accurate, we cannot guarantee that there are no mistakes. Also that the best management for individual patients may differ from that outlined here. Only the doctors caring for the patient will be able to advise on this.
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