INFORMATION FOR WOMEN WHO HAVE HYPOTENSION DURING PREGNANCY OR BREASTFEEDING
What is hypotension during pregnancy?
Hypotension is abnormally low blood pressure. For a pregnant woman, this means a systolic pressure below 90 mm Hg or a diastolic pressure below 60 mm Hg, which is to say that you are hypotensive if your blood pressure is less than 90/60 mmHg. Some experts believe that the diastolic cutoff for hypotension should be 100 mmHg rather than 90 mmHg. A person could have hypotension overall, or she could have whats called orthostatic hypotension, meaning that your blood pressure drops soon after you stand up, either from a sitting or a lying down (supine) position. Common reasons why you may become hypotensive include loss of water (dehydration), various medications because they make you excrete water, or they cause blood vessels to dilate (widen), which means that a larger volume is available to your blood. Spending more than a few minutes in a hot tub also can cause hypotension, since the heat causes dilation of many blood vessels in the skin. This is particularly likely if you have consumed a big meal, which further diverts blood flow to the gastrointestinal tract, or if you have consumed alcohol, which also causes blood vessels to dilate.
Also, due to blood vessel dilation, hypotension occurs as part of anaphylactic shock, a severe type of allergic reaction. A decrease in the rate and force of heart contractions also lowers blood pressure. Stimulation of whats called the parasympathetic nervous system, which includes stimulation of the vagus nerve, slows and reduces the force of the heartbeat and dilates blood vessels. This can happen as part of an extreme emotional event and also from medications. Loss of blood, from an injury or even if you donate a unit of blood, also lowers blood pressure. If blood loss is severe, it causes hypovolemic shock. Finally, blood vessel dilation occurs as pregnancy advances on account of hormonal changes. This is to compensate for an increase in the blood volume, which normally keeps blood pressure from getting too low, but you can become hypotensive if there is some other factor pulling your blood pressure down, even something as simple as not drinking enough water, causing you to dehydrate. Additionally, you can become hypotensive as a result of epidural or spinal anesthesia administered for your delivery.
How common is hypotension during pregnancy?
Hypotension is overall fairly common among pregnant women, but its prevalence varies widely between different reports. The chances that you will suffer an episode of hypotension rise substantially if you have a cesarean delivery with spinal anesthesia.
How is hypotension during pregnancy diagnosed?
Your blood pressure is taken with a blood pressure cuff, which measures systolic pressure (pressure at the peak of ventricular contraction) and diastolic pressure (lowest pressure during the period between ventricular contractions) in your arm. Hypotension is diagnosed if systolic pressure is below 90 mm Hg (some experts say 100mmHg) or diastolic pressure is below 60 mm Hg, which is to say that you are hypotensive if your blood pressure is less than 90/60 mmHg. Your blood pressure also may be measured lying down, sitting, and standing to see if you have orthostatic hypotension, which can result from certain medications.
Does hypotension cause problems during pregnancy?
Hypotension can make you feel dizzy, lightheaded, nauseous, tired, and confused. It reduces your ability to concentrate, blurs your vision, and can cause you to faint. If severe, hypotension can lead to shock, a potentially fatal condition that is characterized by pale, cold, clammy, skin, a rapid, weak pulse, and rapid, shallow breathing.
Does hypotension cause problems for the baby?
A hypotensive pregnant woman may have inadequate blood flow through the uterus and placenta. This, in turn, can cause intrauterine growth retardation (IUGR), which can result in low birth weight and developmental problems. Maternal hypotension also might increase the risk of stillbirth.
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 hypotension
- 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 hypotension during pregnancy?
Hypotension can be treated with a medication called fludrocortisone, whose effects on the fetus are not well understood. Fludrocortisone is what doctors call a mineralocorticoid, which promotes retention of fluid by the kidneys. The drug can be given along with dietary salt. Other medications, such as midodrine, are given specifically in cases of orthostatic hypotension as they help to keep blood pressure from dropping when you stand. It is to be used with extreme caution during pregnancy. In cases of shock, various medications are available that increase the force of the heart contraction (called inotropes) and also that contract blood vessels (called vasopressors). These include norepinephrine, epinephrine, dopamine, dobutamine, milrinone, ephedrine, and pseudoephedrine. These drugs must be given only with extreme caution if needed – in pregnant women, there is a possibility of reducing blood flow through the placenta, but if you’re dealing with shock, then the goal of saving the mothers life dominates the therapy.
Who should NOT stop taking medication for hypotension during pregnancy?
With all of the medications available to raise blood pressure, there are possible risks to the fetus, but these must be weighed against the risks, both maternal and fetal, of the mothers condition.
What should I know about choosing a medication for my hypotension during pregnancy?
It is important to stay in communication with your health care provider as the release of new studies over time can change the outlook on the role of specific medications during pregnancy.
You may find Pregistrys expert reports about the medications to treat this condition here. Additional information can also be found in the sources listed below.
What should I know about taking a medication for my hypotension when I am breastfeeding?
Many unknowns are surrounding the possibility of risks of anti-hypotension medications to nursing neonates. However, there is evidence that blood pressure drops during breastfeeding. Consequently, you should discuss with your doctor whether or not you should breastfeed at all.
What alternative therapies besides medications can I use to treat my hypotension during pregnancy?
If your hypotension is mild, then it may be manageable with oral hydration (drinking adequate liquids), salt supplementation, and possibly pressure stockings.
What can I do for myself and my baby when I have hypotension during pregnancy?
Follow the instructions of your physician. Hypotension is a manageable condition. In pregnant women, it is often mild and resolves after you deliver.
Resources for hypotension in pregnancy:
For more information about hypotension during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or contact the following organizations:
- < a href="http://https://www.mayoclinic.org/diseases-conditions/low-blood-pressure/symptoms-causes/syc-20355465">Mayo Clinic. Low Blood Pressure (Hypotension)
- Healthline. Everything You Need to Know About Low Blood Pressure.