Have you successfully undergone kidney transplantation and have a strong desire to have children? But are you unsure whether pregnancy is possible under these circumstances? This article will inform you about what you need to consider and what difficulties and complications can occur. You will also learn how you can positively influence the success of your pregnancy.
The good news right up front: pregnancy after kidney transplantation is not only possible, but has also been successful thousands of times, according to medical studies. After a successful kidney transplantation, your kidney function will normalize quite quickly. This is important because if the kidney function decreases, your fertility also decreases. This means that after the transplant it usually takes a little time for your cycle to return to normal or to start again. About 10% to 15% of kidney-transplanted women become pregnant at childbearing age.
At first glance, this may not sound like much, but compared to women who require dialysis, the probability is significantly higher. In addition, not every woman of childbearing age automatically wants to have children. So you can be quite optimistic.
However, pregnancy after kidney transplantation comes with some risks, which is why it is also considered a high-risk pregnancy. Again, this term is not meant to scare you. It only means that you have a higher risk of developing complications during pregnancy. The same applies, for example, to pregnant women with diabetes mellitus or multiple pregnancies (e.g. twins). In order to address possible challenges as quickly as possible, you will be called in for check-ups more often than other pregnant women. This way, your own health and that of your baby can be monitored optimally to enable a worry-free pregnancy.
To create optimal conditions for your pregnancy, you should plan it early. To do this, it is best to contact a prenatal center, where gynecologists, nephrologists and neonatologists work closely together and can give you the best possible advice. Your treating medical team can support you in the search for such a center.
What risks exist for pregnancy after kidney transplantation?
Your fertility usually improves significantly as a result of the transplant. This means that the basic prerequisite for a successful pregnancy has already been created.
Despite this, you should pay attention to a few things. After all, not only you and your baby are in the foreground, but also your donated kidney. As soon as you have the desire to have a child, you should contact your nephrologist and, if necessary, look together for a suitable prenatal center in your area.
Medications
It is particularly important to have your current medication checked at the beginning. To prevent your immune system from recognizing your new kidney as an intruder and rejecting it, you are taking medication known as immunosuppressants. Among them - but also among many other drugs - there are some that should never be taken during pregnancy. This is because they can be harmful to your growing baby. But again, there's no need to worry. There are alternatives that may be given during pregnancy. It is just best to change your medication before you become pregnant.
Risks to the baby
For pregnant women after kidney transplantation, the likelihood of an premature birth is 50% to 60%. On average, children are born at 36 weeks gestation. All babies born before the end of the 37th week of pregnancy are called “premature”. However, in 2021, six out of every hundred children were born prematurely, regardless of the mother's health situation. This means that there is always a certain risk of premature birth with every pregnancy. Thanks to ever-improving medical care, many premature babies are not impaired in the further course of their lives and develop in line with their age.
Another risk in pregnancy after kidney transplantation is low weight of the baby at birth. The World Health Organization (=WHO) defines low birth weight as less than 2,500 grams. Children who are born lighter may have a slightly harder time with further development. But again, low weight alone is not always a cause for concern.
Pregnancy disorders
As an expectant mother after kidney transplantation, the risk of illness during pregnancy is increased. This includes, for example, the so-called preeclampsia. Don't worry, no one pronounces this word correctly the first time. Colloquially, it is therefore also referred to as "pregnancy poisoning". The first signs are high blood pressure (=hypertension) and protein in the urine (=proteinuria).
Preeclampsia poses an additional risk for complication during pregnancy - both for the mother and the child. However, regardless of kidney function, two to three pregnant women out of 100 develop preeclampsia. As you can see, pregnancy itself carries certain risks that are completely independent of your kidney function. Nevertheless, the vast majority of children are born completely healthy. So don't be discouraged!
In addition, the risk of developing pregnancy-related diabetes (=gestational diabetes or gestational diabetes mellitus) is greater in a pregnancy after kidney transplantation than, for example, in kidney-healthy women. When you are pregnant, many different messenger substances (=hormones) are released. This also affects your metabolism and can therefore also change your utilization and absorption of sugar in your cells. This can lead to the development of diabetes during pregnancy, which can cause additional complications. Most of the time, however, your sugar metabolism returns to normal once your baby is born.
Increased risk of infection
The risk of infection is not increased by pregnancy per se. You take regular medication to lower your immune system so that it does not attack and reject your new kidney. As a result, your body can no longer defend itself so well against pathogens and you are more susceptible to infections. Any serious infection, whether you have a transplanted kidney or not, poses a risk to your pregnancy. So in your particular case, you need to be a little more careful so that you don't catch an infection during pregnancy.
Risks for your transplanted kidney
Not only will your transplanted kidney affect your pregnancy, but the other way around - pregnancy can also affect your new kidney. Especially in the first year after the transplant, the risk of worsening kidney function or even kidney rejection is higher than in women who do not become pregnant. However, the risk decreases the greater the time interval between the transplant and pregnancy.
How can I improve the likelihood of success in my pregnancy?
Especially important for your pregnancy to be successful is early planning. It is best to inform your nephrologist as soon as you think you want to have a child. Then you can create the best possible conditions together and thus increase the probability of a successful pregnancy. But what specifically should you pay attention to?
Time between kidney transplant and pregnancy
Even though your fertility usually improves or even normalizes after a short time, you should wait at least a year after the transplant to become pregnant. This gives your body enough time to recover from the kidney transplant procedure and get used to your new organ. One of the prerequisites for a successful pregnancy is also stable kidney function. And that takes time. So in this case, a little patience is the key to success.
Stable kidney function
Whether you've had a kidney transplant or have kidney disease, the risk of pregnancy complications decreases the better your kidney functions. To assess your kidney function, the creatinine level in your blood is often measured. Creatinine is a waste product that is produced when your muscles produce energy. Creatinine travels through the blood to the kidneys where it is then excreted in the urine. If your kidney no longer functions as it should, less creatinine is excreted in the urine. As you can probably guess, this means that the worse your kidney functions, the higher your creatinine level in the blood (=serum creatinine). Normally, this value is between 0.5 and 1 mg/dL in women. A rough guideline is that the likelihood of complications during pregnancy increases significantly from a blood creatinine level of 1.5 mg/dL. Therefore, your kidney function should be as optimal as possible in advance.
Another parameter that influences possible pregnancy complications is the amount of protein in the urine. This value also provides information about your kidney function and possible damage to your kidney. Increased amounts of protein in the urine (=proteinuria) (300 mg/24h) are also an indication of a higher risk of pregnancy complications.
So in summary, your creatinine level should be less than 1.5 mg/dL and there should be little to no protein in your urine. This will give you good conditions for a successful pregnancy. In addition, you will also be protecting your donated kidney. Studies have found that impaired kidney function (serum creatinine > 1.5 mg/dL, proteinuria > 300 mg/24h) and high blood pressure during pregnancy also increase the risk of rejection reactions - even kidney loss. So good kidney function during pregnancy not only protects your baby, but your new kidney as well.
Stable blood pressure
Another important aspect that affects the success of your pregnancy and your donated kidney is blood pressure. Optimally, your blood pressure should be in the normal range, meaning below 130/85 mmHg. Blood pressure values above 140/90 mmHg should always be discussed and treated with your medical team. To keep an eye on your values, you can buy a blood pressure monitor for your home. The devices are very easy to use and through regular measurement, you and your medical team get a good impression of your blood pressure situation.
If you measure your blood pressure exclusively with your doctor, you will often get higher values than in everyday life. However, this does not necessarily say anything about your actual blood pressure situation. This phenomenon is also known as white coat syndrome. This happens because your blood pressure can also increase as a result of situations that cause you to become agitated - such as a visit to the doctor. Regular measurement is therefore worthwhile.
Protect yourself from infections
By taking your immunosuppressants, you are at much higher risk for infectious diseases and also for more severe courses of disease. Any severe infection is a potential risk for pregnancy. To best counteract this, you should pay even more attention to ensuring that you have all the necessary vaccinations before you become pregnant. You can find out exactly what these are from your doctor.
Healthy lifestyle
You can also actively contribute to a successful pregnancy by following as healthy a lifestyle as possible. This includes regular exercise, healthy eating, sufficient sleep and, of course, abstaining from smoking and alcohol. All this has a positive effect on your blood pressure, which plays a major role in the development of pregnancy complications after kidney transplantation and rejection reactions.
What do I do if I don't get pregnant despite everything?
If you have already created optimal conditions and your desire to have a child still does not come true, it is by no means the end of the world. Artificial insemination is also possible after kidney transplantation. One example of this is "fertilization in a test tube" (=in vitro fertilization). For this purpose, several oocytes are usually retrieved from the woman at the same time. To ensure that there are enough "mature" eggs at the time of retrieval, the woman is often given certain hormones to stimulate them beforehand. This is also called hormone treatment.
If eggs were retrieved, they are combined with the man's sperm under laboratory conditions. If the eggs are fertilized, they are inserted into the uterus via the vagina using a flexible tube (= catheter). In Germany, a maximum of three fertilized eggs may be implanted to minimize the possibility of a multiple pregnancy (e.g. twins or triplets). Whether one or more eggs actually implant and result in a successful pregnancy is left to nature from then on. On average, the success rate is 25% to 30%.
Before the eggs are retrieved, the position of your transplanted kidney should be assessed. The removal is done with a needle that is inserted through the vagina to the ovaries, which are located in the abdomen. Even though the whole process is monitored by imaging, it is important to make sure that your kidney is not in the way.
In addition, only one fertilized egg should be implanted in you. This is because a multiple pregnancy is itself associated with an increased risk of pregnancy complications. In order to avoid an additional risk factor, the probability of a multiple pregnancy should be reduced by implanting only one fertilized egg.
As you can see, while there are a few things to consider if you want to get pregnant after kidney transplantation - it is possible! Despite all the preparations, try to give room to the anticipation of this new and exciting stage of your life. Having a baby is always a small miracle of nature.
