We ask the experts to settle common questions we've all wondered about.
QUESTION: How do I know if I'm at risk for pre-eclampsia, a form of high blood pressure experienced during pregnancy? Can it be prevented and how is it treated?
ANSWER: Pre-eclampsia is on the rise in Canada and worldwide. In fact, every year at least three million mothers globally are afflicted.
First, let's put at ease a large group of pregnant women with a minimal risk of developing pre-eclampsia. These are women under 35 years of age, who have had a healthy full-term baby in the past three years, have remained healthy since then, are not overweight and are pregnant again through natural conception with the same partner.
The unfortunate fact is that women in their first pregnancy are at risk of pre-eclampsia, regardless of their age or health status. Education about pre-eclampsia and focused prenatal care for this group is imperative because as many as 1 in 20 women are at risk.
Apart from first pregnancy, several Western lifestyle factors increase an individual's risk. These include: obesity; a diet heavy in processed food; advanced maternal age (35 or older at first pregnancy); teenage pregnancy; age-related underlying health conditions such as chronic hypertension, insulin-dependent diabetes and auto immune diseases; use of assisted fertility treatments - especially with donor sperm or eggs; and a family history of early cardiovascular disease (stroke, heart attack or high blood pressure under age 50 in a parent or sibling).
Signs of pre-eclampsia can vary. The disease causes elevated blood pressure after 20 weeks, and can be accompanied by feeling unwell - headaches, nausea or vomiting, leg swelling, excess protein in the urine detectable by a dipstick test, or blood test abnormalities. Some women may recognize the symptoms of pre-eclampsia between their appointments and seek help. But the disease may initially have no obvious symptoms. So, it is important to have regular checks of blood pressure and a urine dip every two weeks, unless the woman is in the lowest-risk group - healthy moms under 35 who have already had a relatively problem-free pregnancy.
Most of the time the disease occurs at the end of pregnancy, is mild, and is managed simply by inducing labour. The disease may become worse after delivery, and require the mother to take blood pressure pills for a few weeks, but her health will be restored by the time the baby is six weeks.
Almost 20 per cent of affected women have a more severe form of pre-eclampsia that occurs earlier in the pregnancy. This type of pre-eclampsia is usually caused by an unhealthy placenta - the organ that connects the developing baby to the wall of the womb. In this situation the developing baby appears small on the ultrasound, and the mother may need to be admitted to hospital for blood pressure control and monitoring of the baby's health. Early delivery, often by Caesarean section, is needed because the disease will get worse until the placenta is delivered with the baby.
Unfortunately, once a woman is pregnant, most of the risk factors for pre-eclampsia are not preventable or reversible. At present, the only medication clearly established to somewhat reduce the risk is low-dose - 81 milligrams per day - Aspirin. Calcium supplements, antioxidant vitamins, pills that relax blood vessels, and exercise, have shown promise, but have not proven to be effective in large high-quality research studies.
For 2010, the focus is therefore on primary prevention. That means educating young women, and their partners, about the importance of preparing for pregnancy by addressing dietary health, exercise and weight loss. And keep in mind that the safest period for women to have children is when they are in their 20s and early 30s.
For more information about pre-eclampsia, visit www.mountsinai.on.ca/care/placenta-clinic
Dr. John Kingdom is a maternal-fetal medicine specialist at Mount Sinai Hospital in Toronto and head of its placenta clinic.