What is Hypertension In Pregnancy?
In pregnancy, there are various high blood pressure disorders, such as chronic high blood pressure, gestational hypertension, HELLP syndrome, and preeclampsia (with or without severe symptoms or eclampsia), that can pose a big health risk to both mom and baby. Even though regular prenatal check-ups can help catch early signs of preeclampsia and timely delivery can reduce or prevent harmful effects, these health risks still exist. High blood pressure on its own can cause problems, but the major concern is when it progresses into preeclampsia/eclampsia, which can lead to even more serious health problems.
What Causes Hypertension In Pregnancy?
Certain health issues can diminish the flow of blood in the uterus, increasing the risk for high blood pressure during pregnancy. Some of these conditions include high blood pressure before pregnancy, kidney disease, diabetes, sleep apnea, clotting disorders, and autoimmune diseases.
Further, women with a previous experience of preeclampsia, a condition causing high blood pressure during pregnancy, are at a greater risk. Similarly, women who previously had HELLP syndrome, a serious complication in pregnancy, multiple pregnancies like having twins, a Body Mass Index (BMI) over 30, or autoimmune disease also face higher chances of developing high blood pressure during pregnancy.
Women aged 35 or above, first-time moms, or women who have a mother or sister who had high blood pressure during their own pregnancies also stand at heightened risk of developing this condition. These women may also be more likely to develop a more severe form of high blood pressure known as pre-eclampsia during pregnancy.
Risk Factors and Frequency for Hypertension In Pregnancy
Hypertensive disorders are a concern for 5% to 10% of all pregnancies. Pre-eclampsia, a specific type of hypertension, affects between 2-8% of pregnancies worldwide. Interestingly, there has been a 25% increase in pre-eclampsia in the United States from 1987 to 2004. Factors like advanced maternal age and increased weight before pregnancy have contributed to the rise in cases of hypertension during pregnancy.
On the bright side, there has been a reduction in eclampsia incidences as a result of advanced prenatal care. Furthermore, antenatal therapies such as blood pressure control, the prevention of seizures with magnesium, and the induction of labor or cesarean section have proved to be beneficial. It’s worth noting that the latter options also serve as a cure for pre-eclampsia and eclampsia.
Signs and Symptoms of Hypertension In Pregnancy
Chronic and gestational hypertension are conditions that often present themselves with similar physical findings. These mainly include a systolic blood pressure over 140 mmHg and/or a diastolic blood pressure over 90 mmHg. If the blood pressure readings are extremely high, with systolic pressure over 160 mmHg and/or diastolic over 110 mmHg, it is considered severe. Women suffering from pre-eclampsia, a pregnancy complication characterized by high blood pressure, usually exhibit an increase in swelling, particularly in the legs, feet, or hands.
Those showing severe features may experience the following symptoms:
- Cerebral symptoms such as persisting severe headaches or changes in mental status
- Visual symptoms like blank areas in the field of vision, sensitivity to light, blurred vision, or temporary blindness
- Pulmonary edema resulting in shortness of breath or crackling sounds in the lungs upon examination
- Renal impairment leading to water retention and swelling in the extremities
- Hepatic impairment causing upper right abdominal pain
HELLP syndrome is a severe form of pre-eclampsia. Typical symptoms like a general feeling of discomfort and upper right abdominal pain are experienced by up to 90% of cases. It is also common for these patients to have episodes of vomiting.
Testing for Hypertension In Pregnancy
Chronic hypertension is identified when a patient’s systolic blood pressure is over 140mmHg or diastolic blood pressure is over 90mmHg. This needs to be confirmed by continuous blood pressure monitoring or several visits to the doctor’s office with high blood pressure readings at least 4 hours apart, and all before 20 weeks into the pregnancy.
Gestational hypertension is when a pregnant woman who previously had normal blood pressure, now shows blood pressure at or above 140mmHg systolic, or 90mmHg diastolic, after 20 weeks into her pregnancy. These readings should be registered twice, at least 4 hours apart. A patient’s systolic blood pressure higher than 160mmHg, or diastolic blood pressure higher than 110mmHg could also be signs of gestational hypertension if the similar pressure is recorded after a short while. These steps are necessary to start treatment for high blood pressure on time. Significant symptoms generally appear when blood pressure goes beyond 160/110, indicating possible damage to vital organs.
As per guidelines, pre-eclampsia is a condition that shows the above signs of hypertension along with more than or equal to 300mg protein excretion in urine in 24 hours, or a protein/creatinine ratio of more than or equal to 0.3. The criteria for pre-eclampsia can be met even without proteinuria if the patient has new-onset hypertension with low platelet count, kidney issues, fluid buildup in the lungs, impaired liver function, or persistent headaches with no other identifiable cause.
Pre-eclampsia can worsen chronic hypertension or be part of gestational hypertensive disease progression. In severe cases, systolic blood pressure may rise to over 160mmHg, or diastolic blood pressure over 110mmHg, prompting the initiation of specialised medication.
Eclampsia refers to a patient with pre-eclampsia experiencing generalized seizures. This condition tends to appear during childbirth and up to 72 hours after delivery due to untreated or inadequately treated pre-eclampsia. Approximately 2-3% of women not receiving anti-seizure prophylaxis could develop eclampsia, and maternal complications can occur in nearly 70% of these cases.
HELLP syndrome, a severe form of pre-eclampsia, is characterized by hemolysis (breaking down of red blood cells), elevated liver enzymes, and low platelet count. The specific criteria include signs of hemolysis, liver damage, and low platelet count, as mentioned above.
Treatment Options for Hypertension In Pregnancy
If a pregnant woman has one high-risk factor or two moderate risk factors, taking a low-dose (81mg) aspirin daily can help prevent complications. High-risk factors include a history of conditions like pre-eclampsia, chronic high blood pressure, diabetes, kidney disease, autoimmune diseases like lupus, and carrying multiple babies at once. Moderate risk factors include being a first-time mom, having a 10-year gap or more between pregnancies, being overweight, living in poverty, being African American, having a close relative who had preeclampsia, being over 35 years old at the time of delivery, having a baby who isn’t growing properly, or having a previous unhealthy pregnancy.
High blood pressure during pregnancy (either gestational hypertension or chronic hypertension) is always something that needs to be managed when the blood pressure readings are very high (above 160/110) and last for at least 15 minutes. Doctors usually don’t recommend medication for mildly high blood pressure readings, unless the mom-to-be was already on high blood pressure medication before getting pregnant. For chronic high blood pressure, treatment typically starts when the readings hit 140/90. Medications that can be used include labetalol, hydralazine, or nifedipine. Nifedipine is often given as a pill for fast-acting relief, and nifedipine or labetalol can be used at home. Certain medications are not safe to use during pregnancy because they can harm the developing baby, so they should not be used unless absolutely necessary
If a pregnant woman has a severe form of pre-eclampsia, she may need to be given magnesium to prevent seizures. This is typically given until after delivery or until the body has been able to get rid of excess fluids properly. If delivery is likely to occur too early due to pre-eclampsia, eclampsia, or other factors, a pregnant woman may be given steroid medication to help the baby’s lungs mature faster.
Pregnant women who have high blood pressure or pre-eclampsia need more careful monitoring because of the risk of the baby not growing properly, premature separation of the placenta, and poor blood flow to the placenta and baby. These women may need checkups for their blood pressure as often as twice a week. These appointments could also include checking the baby’s heart rate, examining the amount of amniotic fluid, and performing blood tests. If these tests show anything abnormal, it could signal that delivery needs to happen sooner than expected.
Ultimately, the final treatment for high blood pressure, pre-eclampsia, or eclampsia during pregnancy is to deliver the baby. Many times, the health issues the mom is facing rapidly go away after the baby is born. However, deciding when to induce delivery early can be a hard balance between letting the baby develop more and wanting to lessen the health risks for the mom. The timing will vary depending on the specifics of each case.
What else can Hypertension In Pregnancy be?
When a pregnant woman has high blood pressure, doctors need to consider a number of possibilities. These can include:
- Antiphospholipid syndrome, a disorder of the immune system
- Aortic coarctation, a narrowing of part of the aorta (the large blood vessel that delivers oxygen-rich blood from the heart to the body)
- Cushing syndrome, a condition caused by high cortisol levels
- Eclampsia, a rare but serious condition where high blood pressure results in seizures during pregnancy
- Glomerulonephritis, a type of kidney disease
- Hydatiform mole, a rare mass or growth that forms inside the womb at the beginning of a pregnancy
- Conn syndrome, a disease of the adrenal glands causing them to make too much aldosterone hormone
- Hyperthyroidism, a condition where the thyroid gland produces too much thyroid hormone
- Malignant hypertension, a dangerous form of very high blood pressure
Doctors need to carefully check for these conditions when pregnant women experience high blood pressure to ensure proper treatment and care.
Possible Complications When Diagnosed with Hypertension In Pregnancy
Hypertension during pregnancy can lead to several complications, including:
- Seizures related to high blood pressure (eclampsia)
- Bleeding in the brain (intracranial hemorrhage)
- Fluid in the lungs (pulmonary edema)
- Kidney failure
- Blood clotting disorders (coagulopathy)
- Blood cell destruction (hemolysis)
- Liver injury
- Low platelet count in blood (thrombocytopenia)
- Slowed or stopped growth of the baby in the womb (intra-uterine growth restriction)
- Low levels of amniotic fluid around the unborn baby (oligohydramnios)
- Premature detachment of the placenta from the uterus (placental abruption)
- Signs that the baby is not well (nonreassuring fetal status)