What is diabetes insipidus?
Diabetes insipidus (DI) is a disorder of body fluids in which a person urinates excessively, releasing very dilute urine and feels extremely thirsty. It is very different from the more commonly known type of diabetes, diabetes mellitus (DM), in which a person urinates excessively due to her blood sugar level being too high. In contrast, DI results from problems occurring either in a region of the brain called the hypothalamus a condition called central DI or from problems in the kidney a condition called nephrogenic DI.
Alongside central DI and nephrogenic DI is a type of DI that develops specifically during pregnancy, which is called gestational DI. It is distinguished from other types of DI in that it resolves after you deliver your baby (just as gestational DM tends to resolve with delivery). On the other hand, occasionally, DI that appears during pregnancy is not a case of gestational DI, but of pregnancy unmasking either central or nephrogenic DI. Finally, there is another class of DI called primary polydipsia, where the underlying problem is an urge to drink an excessive amount of water, rather than the thirst being an effect of dilution happening for other reasons. Primary polydipsia can be either dipsogenic (caused by a problem in the control of thirst) or psychogenic (caused by a mental problem).
When DI is indeed the gestational type, the reason is that the woman has activity of vasopressinase, an enzyme that is produced by cells of the placenta, and which breaks down arginine vasopressin (AVP), a hormone that enables your kidneys to retain water in your body and keep from eliminating it in the urine. Since you get rid of the placenta during delivery, the condition is temporary.
How common is diabetes insipidus during pregnancy?
Gestational DI develops in roughly 2-4 per 100,000 pregnancies.
How is diabetes insipidus diagnosed?
The main symptoms that act as clues that you may have DI are an excessive amount of urination, including urination at night (frequent waking from sleep to urinate, or urination during sleep), dry skin and dry mouth, and excessive thirst and consumption of water. Physical examination may or may not provide additional hints, such as dry skin, dry eyes, and dry mucous membranes, and a stretched bladder. Once DI is suspected, the next step is to measure the volume of urine that you excrete over a 24-hour period. If you put out less than 3 liters, DI then can be eliminated from the list of possible diagnoses, but otherwise, there are a variety of tests that doctors will perform. These include measuring the levels of AVP in your blood, and measuring whats called the osmolality of your urine, and measuring urine osmolality again after you are given a hormone similar to AVP. Normally an evaluation for DI also includes depriving the patient of liquid before testing urine osmolality, but this is avoided during pregnancy as it can cause dehydration severe enough to harm the developing baby. Based on the combination of findings of these tests, doctors can distinguish between central nephrogenic and gestational DI.
Doctors also will check your levels of certain enzymes from the liver called transaminases to help determine whether you have a pregnancy complication called HELLP syndrome, which can cause DI.
Does diabetes insipidus cause problems during pregnancy?
Usually, gestational DI develops around the end of the second trimester, or early in the third as the placenta grows larger. During this time, you would experience excessive urination and high frequency of urination much worse than the usual increase in urinary frequency that is common in pregnancy. Whereas in normal pregnancy, a mother-to-be will urinate often because the pressure on the bladder from the growing womb simply decreases the amount of volume available in the bladder for urine, in gestational DI, there is urinary frequency, but excessive quantities of urine come out during each urination episode. As noted early, excessive quantities mean more than 3 liters of urine excreted per day.
DI in pregnancy increases the risk that youll develop preeclampsia, a pregnancy complication that includes increased blood pressure and proteins in the urine.
Generally, gestational DI resolves within 4 to 6 weeks of delivery.
Does diabetes insipidus during pregnancy cause problems for the baby?
If DI leads to extreme dehydration, this can decrease the quantity of amniotic fluid, which can interfere with the growth of the baby, plus it can trigger premature labor and delivery. If DI leads to preeclampsia, this potentially can cut off circulation through the placenta, putting the baby’s life at risk.
What to consider about taking medications when you are pregnant or breastfeeding:
- The risks to yourself and your baby if you do not treat the DI
- The risks and benefits of each medication you use when you are pregnant
- The risks and benefits of each medication you use when you are breastfeeding
What should I know about using medication to treat DI during pregnancy?
The medication used to treat DI, including during pregnancy, is desmopressin (DDAVP), which is a synthetic hormone that works similarly to AVP. Desmopressin is taken as a mist through your nose and is safe for the developing baby, plus it does not raise blood pressure, even in cases when the woman has developed preeclampsia, which as noted earlier includes high blood pressure. Another advantage of desmopressin is that it is not easily broken down by the placenta.
Who should NOT stop taking medication for diabetes insipidus during pregnancy?
No pregnant woman who is taking desmopressin for DI should stop taking it during pregnancy, as it is safe and effective, whereas an increase in the symptoms of DI would be harmful.
What should I know about choosing a medication for diabetes insipidus during pregnancy?
You may find Pregistrys expert reports about the individual medications used to treat DI here. Additional information can also be found in the sources listed at the end of this report.
What should I know about taking a medication for my diabetes insipidus when I am breastfeeding?
Desmopressin is considered safe during breastfeeding.
What alternative therapies besides medications can I use to treat my diabetes insipidus during pregnancy?
There is no alternative to medication, but certain diuretic drugs (medications that INCREASE elimination of water) are used along with desmopressin, as is another group of drugs called sulfonylureas, in cases when desmopressin is not working adequately.
What can I do for myself and my baby when I have diabetes insipidus during pregnancy?
Use the medication that your doctor prescribes, and stay hydrated.
Resources for diabetes insipidus during pregnancy:
For more information about diabetes insipidus during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or check the following links: