Chronic kidney disease (CKD) implies permanent damage to the kidneys. This may be due to abnormal kidney structure, or various disease processes. CKD is divided into stages 1 to 5 according to the level of kidney function. With mild CKD (stages 1-3) patients usually do not have any symptoms. Nevertheless, CKD can have an impact on the health of pregnant women and there are potential risks for the baby. The higher the stage of CKD the greater the risk for both mother and baby. The greatest risk is for mothers on dialysis. By contrast mothers who have had a successful kidney transplant can often have a successful pregnancy.
CKD is managed by GPs and kidney specialists. Their aims are to find out the cause of CKD, assess its severity, treat what is treatable and avoid any complications such as high blood pressure. High blood pressure in pregnancy is a risk both for the mother and her baby. Kidney specialists routinely work with the obstetric team, sometimes in a joint clinic, so that care is properly coordinated.
The combined impact of CKD and pregnancy on the mother’s health can be predicted by a blood test at the beginning of the pregnancy. This test measures creatinine which provides a general measure of kidney function. The higher the glomerular filtration rate (GFR), the better the kidney function and the greater the chance of a successful and uncomplicated pregnancy. This can be seen in the table below:
CKD stage (eGFR)
|Early delivery (<37 weeks)||Impaired growth of baby (SGA<10%)||Worsening kidney function due to pregnancy||
Dialysis within a year of pregnancy
1 (>90 ml/min)
|2 (60-90 ml/min)||50%||18%||13%||
3 (30-59 ml/min)
|4-5 (<30 ml/min)||88%||50%||20%||
There are a few exceptions to these rules and these will be explained in more detail on the Information for Clinicians page.
There are three main effects of CKD on pregnancy.
1. Developing high blood pressure. This can happen at any stage of the pregnancy and is a consequence of CKD.
2. Developing pre-eclampsia. This is an illness that happens in the second half of pregnancy. It causes high blood pressure, as well as protein in the urine. It is usually mild but can be severe. Once it has started it will usually worsen until the baby is delivered. CKD increases the risk of pre-eclampsia.
The symptoms may include bad headaches that do not go away, blurred vision or seeing flashing lights or spots before the eyes. There may be swelling of the hands, feet or face. Symptoms from liver swelling can cause a bad pain just below the ribs, especially on the right side .
In the antenatal clinic, blood pressure measurements and testing the urine for protein are done routinely. This helps pick up pre-eclampsia early. However, if a woman already has protein in the urine and high blood pressure because of kidney disease it is sometimes difficult to distinguish this from pre-eclampsia.
3. Deterioration of kidney function. This is rather unpredictable but in general the better the kidney function at the beginning of the pregnancy, the less likely it is to decline later. Women with more protein in their urine at the beginning of pregnancy are at increased risk of declining kidney function later.
Good antenatal care from the earliest stages of pregnancy improves outcomes generally. This is particularly true for women with CKD. Planning for pregnancy allows women with CKD to get pregnant at the right time, while on the right medications and in the best possible health. To achieve this all women with significant CKD should receive pre-pregnancy advice so that they can assess the potential risk and to ensure that everything is in place to minimise it.
These are the key things to think about before getting pregnant: When should a woman with CKD get pregnant?
This depends on the nature of the kidney disease. In general if a woman’s kidney function is likely to get worse over time it is better to plan the pregnancy sooner rather than later while function is still good. On the other hand, for a kidney disease that flares up and then settles down, such as Lupus nephritis, it is better to wait until the flare has settled for at least six months.
Other factors to take into account are a woman’s age and fertility. They may have had drugs in the past to treat a kidney condition that can impair fertility (e.g. cyclophosphamide). If so they may need to take advice on whether this is an additional problem.
Should she get pregnant at all?
There are very few women these days who are advised not to get pregnant. Even then it is always up to the woman (and her partner) whether to take the risk. It is much better to be forewarned of the possible problems and to discuss these in advance.
Will she need extra medicines when she’s pregnant?
Women trying to get pregnant should start taking the vitamin folic acid to reduce the chance of their baby having spina bifida, an abnormality of the spinal cord. The normal dose of folic acid is 400ug per day and can be bought over the counter. However, if the folate level is low or a patient is on the drug azathioprine which affects the way folic acid works, the dose of 5mg daily may be prescribed. No other over the counter vitamins are required unless specifically advised by a doctor or midwife. All pregnant patients should avoid additional supplements of vitamin A. If vitamin D levels are low GPs will advise correction with high dose prescribed vitamin D (also known as cholecalciferol).
Women with kidney diseases are at higher risk of pre-eclampsia. Aspirin lowers the risk of pre eclampsia, and women with CKD are usually offered a low dose aspirin (75mg once daily) throughout pregnancy unless there are specific reasons not to take it e.g. they are allergic to aspirin.
Pregnant women with a high level of protein in their urine have an increased risk of developing blood clots (thrombosis). This can be reduced by small daily injections of low molecular weight heparin. Heparin reduces the way the blood clots.
Both pregnancy and CKD can cause a low blood count (anaemia). When combined, anaemia can be more of a problem. Iron tablets or injections may be used and some women need to take the hormone erythropoietin (EPO) as a weekly or monthly injection to overcome the anaemia. Blood transfusions are usually avoided in pregnancy.
Pregnancy alters the control of sugar (glucose) in the body. This may be worse for patients on steroids (e.g. prednisolone), those from an Asian or African background, or who are overweight. Patients may develop a condition called gestational diabetes (diabetes caused by pregnancy) and require treatment with insulin.
Angela’s Story ES’s story
My story began over 7 years ago when I found out I was pregnant with my daughter. I was over the moon. My happiness didn’t last long though as tests showed that I had kidney disease. My pregnancy was hell on earth with the constant worry that my daughter wouldn’t be healthy when she was born. There were weekly tests and I had severe swelling of my legs and feet. My due date couldn’t come soon enough.
Thankfully my little girl arrived weighing in at a healthy 7lb 5oz.
When I had my biopsy I was told I had IgA nephropathy. In laymen’s terms, my immune system was attacking my kidneys. My biggest upset was being told it would be too dangerous to have any more children.
I felt scared then angry that I might not live to see my daughter grow up. I resented anyone that was healthy who in my eyes were wasting their lives. After a while I realised how lucky I was. My tests showed very good improvements at each visit to the clinic. I decided that it was pointless feeling sorry for myself and that positive thinking and a change in lifestyle would go a long way in getting through life. Proof is in the pudding, as they say. My kidney disease improved so much I was able to go on to have a second child. My son arrived just in time for Christmas and is now a chunky monkey at 3 months old. I feel overwhelmed with happiness to be given the chance to watch them grow up.
The team at the clinic were a big help too. If I felt that if I couldn’t cope all I had to do was talk to someone. They were always willing to listen. My thanks and gratitude go to them.
Last year I gave birth to my 4th child, Lois. I have renal disease which means I had to be monitored very closely during and after the pregnancy to ensure the best outcome for myself and my baby.
My renal function deteriorated considerably as the pregnancy progressed, so much so that Lois was delivered at 28 weeks gestation. Lois was 2lb 1oz (940g) when born and had to stay in the neonatal unit for 9 weeks. She did amazingly well and is now thriving. However, my renal function did not improve after the pregnancy and I have since started peritoneal dialysis.
Thankfully I have felt quite well throughout, not experiencing many of the symptoms associated with kidney failure. I think this has made the whole experience feel quite surreal, as I don’t really feel like there’s anything wrong with me!
I am about to begin the process of going on the transplant list, which is the next step of our journey through what has been an incredibly challenging time in our lives. Every time I look at Lois I am reminded that she is worth it and am so grateful for all the fantastic medical expertise and care along the way that meant we got the outcome we did, both for myself and Lois.
The lower the kidney function in the mother, the greater is the risk for the baby, as shown in the table above.
There are two main problems that can affect the baby. Firstly, the growth of the baby while in the womb can be reduced (intrauterine growth retardation) by poor kidney function, pre-eclampsia and some of the underlying causes of CKD. This happens if the supply of food and oxygen to the baby through the placenta (afterbirth) is reduced. It can lead to long term health problems for the baby, difficulties in the newborn period, and in extreme cases the baby may not survive.
Babies with intrauterine growth retardation weigh less than expected for their gestational age. At birth they are thin and look malnourished. Generally the growth and development of the baby’s brain is protected so that head size is less affected than the rest of the body. Their growth usually catches up when feeding is fully established. Nevertheless adult survivors of intrauterine growth retardation may have long term side effects from their period of malnutrition. Higher rates of cardiovascular disease in middle and old age have been reported for example.
The second problem is that babies of women with CKD are more likely to be born prematurely, that is to say before the normal 40 weeks of gestation. The more premature the birth, the more likely that specialist neonatal care will be needed. Babies born before 32 weeks often have breathing problems and require close monitoring, extra oxygen, a specific treatment to help expand their lungs (surfactant), and sometimes artificial ventilation. Very premature babies are at risk of serious infections, feeding difficulties, intestinal problems (necrotising enterocolitis), brain damage and visual problems. These can leave the child with long term disabilities.
For mothers with advanced kidney disease the outcome for the baby can be improved by dialysis. Dialysis may be started sooner if the mother is close to needing it anyway, or the amount of dialysis increased in those already on it regularly.
Fetal growth is monitored by ultrasound scans. Scans are repeated to see if the baby is growing normally. If growth slows down it becomes important to decide whether the baby is better off continuing to grow in the womb or being delivered early. In high risk cases or if the mother’s kidney function is getting worse, it is often safer both for mother and child for labour to be induced (started medically), particularly if gestation is around 38 weeks. This might need to be done earlier and the issues of prematurity taken into consideration. Earlier on in pregnancy medical induction of labour is less reliable and a caesarean section will then be needed.
Where there is a risk of early delivery the mother should be under the care of an obstetric unit with a neonatal intensive care to ensure rapid support for the newborn is available.
Some women with CKD can carry a pregnancy to term, and for them a normal delivery is often possible and to be encouraged.
Will medication harm the baby?
There are some medicines used in CKD which have to be stopped before getting pregnant. This is because they can cause abnormalities to the fetus. The most common drugs of concern to kidney patients are those used to suppress the immune system. Cyclophosphamide, Mycophenolate mofetil and Sirolimus should not be taken during or for some months before pregnancy. Patients would need to switch to safer medications such as azathioprine, cyclosporine, tacrolimus and prednisolone.
Some medicines used for the treatment of high blood pressure also need to be stopped in early pregnancy or before pregnancy. These include Angiotensin Converting Enzyme (ACE) inhibitors such as enalapril, ramipril, lisinopril; and Angiotensin Receptor Blockers (ARB) such as irbesartan, valsartan and losartan.
It is important that patients do not simply stop their medication on learning that they are pregnant. Many medicines are either safe or there are safe alternatives. Medicines that are safe and must not be stopped without medical advice include prednisolone, azathioprine, cyclosporine, tacrolimus, hydroxychloroquine, nifedipine, labetalol and methyl dopa.
Will the baby get kidney disease?
This depends on the nature of the mother’s kidney disease. Some conditions are directly inherited. If that is the case, parents can be told of the risks and whether there is a way to confirm or exclude the possibility of the baby being affected. Some conditions are partially inherited. For example, for women with vesico ureteric reflux or congential abnormalities of the urinary tract, there is a small increased chance overall that the child will have a similar problem, but it cannot be predicted accurately. Babies of these mothers should have their kidneys and bladders scanned in infancy to identify any abnormalities early.
Where should the birth take place?
It is perfectly reasonable for a woman with mild CKD, in generally good health and with well controlled blood pressure to remain under the care of her usual kidney specialists and local obstetric unit.
For those with more severe CKD, a kidney transplant, lupus nephritis, or other rare conditions, it is wise to be under a specialist unit. This will provide access to nephrologists experienced in managing advanced kidney disease in pregnancy, obstetricians and midwives trained in managing high risk pregnancies and paediatric neonatal support.
Is breast feeding safe?
In general yes! Some drugs are excreted into breast milk so that the baby is exposed to them. However, for several commonly used drugs it seems not to be a problem. Specific advice should be obtained from your obstetric team. A full list of drugs that should be avoided in breast feeding will shortly be provided on the Information for Clinicians page.