(RxWiki News) It's normal to have a slightly higher blood pressure after giving birth. However, some women are at higher risk than others for longer term blood pressure issues from pregnancy.
A recent study reviewed the current research related to blood pressure and pregnancy.
The researchers concluded that women with high blood pressure during or after pregnancy should continue to be monitored for several days after delivery.
They should also schedule follow-up appointments with their doctor. Some women may require blood pressure medications after pregnancy, but there are ones available that are safe during breastfeeding.
"Pregnant? Ask about your blood pressure."
The study, led by Marie Smith, MRCOG, an obstetrician at the Royal Victoria Infirmary in the United Kingdom, looked at what researchers have found out about long-term blood pressure risks from pregnancy.
Women who were forced to give birth early due to high blood pressure are more than 75 percent more likely than an average woman without high blood pressure to experience longer-term high blood pressure after giving birth.
The risk among those who had pre-eclampsia, but did not have to give birth early, was about 33 percent higher for continued high blood pressure.
Pre-eclampsia is a pregnancy complication in which a woman has high blood pressure from the pregnancy itself along with protein in her urine.
Even women who did not have pre-eclampsia or other high blood pressure conditions during pregnancy, however, could experience longer-term high blood pressure. Symptoms of this could include headaches, difficulty with vision, nausea and vomiting.
The researchers determined that any woman who had pre-eclampsia or another blood pressure condition are still at risk for serious complications after they give birth, so they should be monitored in the hospital for three days after delivery.
After being discharged, women's blood pressure should continue to be monitored for two weeks. She should see a doctor if there are two measurements exceeding 150/100 mmHg more than 20 minutes apart.
Sarah Samaan, MD, a cardiologist with Legacy Heart Center in Dallas-Fort Worth and a dailyRx Contributing Expert, said she commonly treats women with high blood pressure following pregnancy.
"In some cases, high blood pressure may lead to congestive heart failure," Dr. Samaan said. "It is not unusual for me to see a woman with very high blood pressure two to three days after leaving the hospital following a normal delivery."
She said high blood pressure after pregnancy is more common in women over age 35 or in obese women of any age, much as the researchers in this study found.
Dr. Samaan explained that the blood pressure changes can occur due to fluid shifting in the body.
"Pregnancy increases blood volume by about 50 percent, and much of that volume goes to the fetus and placenta," Dr. Samaan explained. "Typically, a woman will simply lose the fluid through the urine over the course of several days or weeks, but for some women, the rather abrupt changes that occur after pregnancy can overwhelm the body's ability to cope. This can lead to swelling and high blood pressure."
She said this can be managed without complications in most women, but some may need further treatment.
"As long as the heart is functioning normally, a few doses of a diuretic may resolve the problem, but some women will need blood pressure medications for weeks to months, and occasionally for the long term," she said. "It may take as long as six months for all the hormonal changes that happen with a normal pregnancy to subside."
The researchers in this study noted that women have more options for medications to help control their blood pressure after they give birth than they have available while still pregnant.
For women who are breastfeeding, the following medications for blood pressure control have not been shown to cause side effects in nursing babies: labetalol, nifedipine, enalapril, captopril, atenolol and metoprolol.
There is not enough evidence to determine whether the following medications, taken by a nursing mother, could cause problems for her breastfeeding baby: angiotensin receptor blocking agents (ARBs), amlodipine, angiotensin converting enzyme inhibitors (ACE inhibitors) other than enalapril or captopril.
Yet Dr. Samaan said she generally discourages use of ACE inhibitors, including enalapril and captopril, because they can cause serious complications to a developing baby if a woman becomes pregnant while taking them.
"As many women will attest, it is possible to become pregnant while breast feeding. Unless the woman has had a tubal ligation or is using highly effective birth control, I just don't think it's worth the risk," Dr. Samaan said. "I also always advise nursing women to let their pediatricians know what medications they are taking."
The researchers note that most women who may need to take medication for blood pressure after giving birth should be able to discontinue the medication in two to six weeks, or when the blood pressure is 130-140/80-90 mmHg.
If there is a continued need for medication, then she should see a doctor to find out whether there is another underlying cause of the high blood pressure aside from pregnancy.
Either way, women who had high blood pressure in pregnancy should schedule a follow-up appointment with their doctor six weeks after delivery to talk about their heart disease risks and future pregnancies.
Women who continue to have a slightly higher risk for high blood pressure should consider taking low-dose aspirin during a future pregnancy, the researchers suggested. However, Dr. Samaan said it's always important for women to check with their OBs regarding the use of aspirin during pregnancy.
In addition, women who have pre-eclampsia have been found to have a higher risk of cardiovascular disease. The researchers noted, "Patients should be made aware of this so that they have the opportunity to make lifestyle choices to minimize their risk."
"If a woman has pre-existing high blood pressure prior to pregnancy, it's especially important that she is monitored closely, and that she is switched to blood pressure medications that can be safely used while pregnant," Dr. Samaan said. "Generally I like to work with my patients to make these medication changes prior to pregnancy."
The study was published January 11 in the journal The Obstetrician and Gynaecologist. The researchers did not note any external funding and had no disclosures to declare.