Hypertensive Disorders Of Pregnancy

PRELUDE

Bimpe has been fit as a fiddle until two weeks ago, when she was told that her blood pressure was high. Her urine test also showed traces of protein. This is her sixth pregnancy overall, and the first one for her second husband. Her doctor requested for some lab tests and ultrasound on the same day. But instead of following the doctor’s instructions, she went to the prayer house where she spent three days praying and fasting.

After leaving the prayer house, she started having a headache and her vision became blurry. Her hands and feet were swollen, and she couldn’t perceive her baby’s movements like before. She thought the headache was due to stress, so she took some paracetamol and tried to rest.

Yesterday, she felt a sharp pain in her tummy, followed by a slight bleeding from her vag*na. On her way to the hospital, she experienced some jerking movements in her arms and legs which lasted for 3 minutes.

Bimpe lost her baby at 34 weeks and she is now lying unconscious at the Intensive Care Unit of the University Teaching Hospital, after an emergency caeserean section.

DEFINITIONS

Hypertensive disorders of pregnancy is a general terminology that includes chronic/preexisting hypertension, gestational hypertension, preeclampsia, and eclampsia. They occur in up to 10% of pregnancies and represent a significant cause of maternal and perinatal morbidity and mortality.

The definition of hypertension is constantly evolving. According to the American College of Obstetricians and Gynaecologists, the cut-off is considered as blood pressure of 140/90mmHg and above. This must be measured twice, at least 4 hours apart.

CHRONIC/PRE-EXISTING HYPERTENSION is hypertension discovered before conception or prior to 20 weeks’ gestation. Hypertension that does not go away after 12 weeks of childbirth is also considered to be chronic.

GESTATIONAL HYPERTENSION is hypertension discovered after 20 weeks of gestation and disappears by 6-12 weeks after childbirth.

PRE-ECLAMPSIA is gestational hypertension accompanied by any of the following:

• Proteinuria; presence of protein in the urine

• Other features of maternal organ dysfunction, including acute kidney injury, liver involvement, neurological complications (such as altered mental status, blindness, stroke, severe headaches, etc.), and hematological complications (such as coagulation problems and haemolysis)

• Uteroplacental dysfunction (such as fetal growth restriction or stillbirth)

Preeclampsia is further classified according to the severity of the above features : Preeclampsia with severe features and Preeclampsia without severe features.

ECLAMPSIA is pre-eclampsia associated with generalized seizures (convulsions).

CHRONIC/PRE-EXISTING HYPERTENSION WITH SUPERIMPOSED PRE-ECLAMPSIA/ECLAMPSIA is another entity which is defined as chronic hypertension (see above) with signs and symptoms of Preeclampsia/Eclampsia after 20 weeks’ gestation.

CAUSES

The hormonal changes of pregnancy induce significant adaptations in the cardiovascular physiology of the mother. Beginning early in the first trimester, there are surges of estrogen, progesterone, and relaxin. These hormones mediate the release of nitric oxide which triggers a cascade of events that leads to gestational hypertension.

The progression of hypertension to pre-eclampsia/eclampsia is thought to be related to a mechanism of reduced blood flow to the placenta, inducing vascular dysfunction throughout the body systems.

But why do some women develop hypertensive disorders while others don’t?

Research has shown that there are risk factors linked to the development of pre-eclampsia in some women:

  1. Being a teen or woman over 40
  2. Being a black woman or African American
  3. Being pregnant for the first time
  4. Being a smoker or illicit drug user
  5. Having babies less than 2 years apart or more than 10 years apart
  6. Pregnancy with a new partner instead of the father of your previous children
  7. High blood pressure before getting pregnant
  8. A history of preeclampsia
  9. A mother or sister who had preeclampsia
  10. A history of obesity
  11. Being malnourished
  12. Carrying more than one baby
  13. In-vitro fertilization
  14. A history of diabetes, kidney disease, lupus, or rheumatoid arthritis

SIGNS AND SYMPTOMS

A lot of patients may not know that they have this condition until later in pregnancy or few days after delivery. This is why it is important to have the blood pressure and urine checked at each antenatal appointment.

In addition to blood pressure over 140/90, other signs and symptoms may include any combination of the following:

• Oedema: swelling due to accumulation of fluids in dependent areas of the body (especially feet, hands and face)
• Rapid weight gain over 1 or 2 days because of a large increase in body fluids
• Shoulder pain
• Tummy pain, especially in the upper right side
• Severe headaches
• Change in reflexes or mental state
• Peeing less or not at all
• Dizziness
• Trouble breathing
• Severe vomiting and nausea
• Vision changes like flashing lights, floaters, or blurry vision
• Reduction in fetal movement or sudden fetal death.

COMPLICATIONS

Hypertension and Preeclampsia affect the blood flow in the placenta. This may lead to fetal growth restriction (FGR) and a reduction in amniotic fluid. Babies born with FGR usually fare poorly during the neonatal period and subsequently, they stand a higher risk of developing co-morbid conditions in the future.

It’s also one of the most common causes of premature births and the complications that can follow, including learning disabilities, epilepsy, cerebral palsy, and hearing and vision problems.

Preeclampsia can also cause the placenta to suddenly separate from the uterus, which is called placental abruption. This can lead to stillbirth.

For the mother, Preeclampsia can cause rare but serious complications that include:

• Stroke
• Seizures
• Fluid buildup in the chest (pulmonary oedema)
• Heart failure, Kidney failure and multi-organ dysfunction
• Reversible blindness
• Excessive bleeding after childbirth
• Disseminated Intravascular Coagulation (DIC): A severe case of bleeding due to failure of the clotting system. It manifests as bleeding from the gums, nose, vagina, stomach and injection sites.
• HELLP syndrome: This stands for:
Hemolysis: Excessive breaking down of red blood cells.
Elevated Liver enzymes.
Low platelet counts: This results in the failure of blood to clot the way it should.

HELLP syndrome is a medical emergency. Call the ambulance or go to the emergency room immediately!

MANAGEMENT

Since these disorders are associated with the hormones of pregnancy and the placenta, the only cure is to deliver the baby and the placenta.

When and how to deliver the baby will depend on the severity of the condition and the gestational age of the baby.

If the baby is already term or near term, the best bet is to deliver immediately. But if the baby is preterm, the doctors will discuss with the woman and weigh the pros and cons of preterm delivery versus potential complications of the disease.

If the baby is not close to term, the doctors will try to manage the blood pressure and monitor the baby’s condition closely. The woman will be given injections to help speeed up the maturity of the baby’s lungs, so that he can breathe comfortably in case he needs to be delivered prematurely.

For pre-eclampsia without severe features, the doctors may advise:
•Bed rest, either at home or in the hospital; resting mostly on your left side
•Careful monitoring of the fetal heart rate and frequent ultrasound scans
•Medicines like labetalol and nifedipine to lower the blood pressure
•Blood and urine tests to monitor the woman’s health

Once a woman develops Eclampsia or any other severe features, she will be admitted to the hospital and immediately delivered of the baby because her life matters first!

Before and after delivery, she will be given an infusion of magnesium sulphate, which will prevent further seizures. Other medicines may also be given as required.

Some women may develop Eclampsia few days after delivery. Therefore, the doctors will not discharge them from the hospital until they are satisfied with the woman’s condition. They may also ask her to monitor her blood pressure at home or visit the hospital every week until 6 to 12 weeks post-partum, to be sure that she does not progress into chronic hypertension.

PREVENTION

To prevent preeclampsia in particular, pregnant women who have any of the risk factors mentioned earlier should talk to their doctors about making lifestyle changes that can help keep them healthy.

Such women are advised to:

•Lose some weight if overweight
•Stop smoking
•Exercise regularly
•Get their blood pressure or blood sugar under control
•Take a low-dose (81 milligram) aspirin daily
•Take vitamin D supplements daily
•Register for antenatal very early and follow up with an experienced Obstetrician

CONCLUSION

Hypertensive disorders of pregnancy are quite common and they cause significant morbidity and mortality for both mothers and children. Prevention, early detection and prompt treatment can help to reduce the burden of the condition on maternity services.

Acknowledgement:
Some parts of this article were adapted from WebMD and NCBI journals.

©Doctor KT
2022

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