Stroke and birth control pills
Posted by on December 18, 2012 - 10:30am

The relative risks of thrombotic stroke and myocardial infarction (MI) are higher among users of hormonal contraception, although absolute risks remain low, a Danish study conducted at Copenhagen University  showed.

Use of oral contraceptives combining low-to-moderate doses of ethinyl estradiol and various progestins was associated with up to 2.3 times the risks of thrombotic stroke or MI compared with non-use.The type of progestin in the pill had little effect on the risks, the researchers reported in the June 14 issue of the New England Journal of Medicine.

To put the risk in perspective, they estimated that among 10,000 women taking a pill combining desogestrel with ethinyl estradiol at a dose of 20 μg for 1 year, two will have arterial thrombosis and seven will have venous thrombosis.

"Although venous thrombosis is three to four times as frequent as arterial thrombosis among young women, the latter is associated with higher mortality and more serious consequences for the survivors," they wrote. "Therefore, these figures should be taken into account when prescribing hormonal contraception."

Several previous studies have examined the relationship between hormonal contraceptive use and the risk of venous thromboembolism. But fewer have looked at arterial complications like thrombotic stroke and MI, and the results have been mixed.

In an accompanying editorial, Diana Petitti, MD, MPH, of Arizona State University in Tempe, said that the absolute increases in the risks of thrombotic stroke and MI observed in the study were small."None of the hormonal contraceptives studied ... were associated with an excess risk of stroke that was unacceptable, considering their contraceptive and noncontraceptive benefits," she wrote.

And, she added, evidence from previous studies "shows that the small risk could be minimized and perhaps eliminated by abstinence from smoking and by checking blood pressure, with avoidance of hormonal contraceptive use if blood pressure is raised."

The researchers acknowledged the study was limited by possible diagnostic misclassification, the potential for a time lag between the date of prescription and when the contraceptives were started, the lack of information on body mass index, and the incomplete information on smoking status.

Source reference:
Lidegaard Ø, et al "Thrombotic stroke and myocardial infarction with hormonal contraception" N Engl J Med 2012; 366: 2257-2566.

 

 

The Pill, HRT and Pregnancy may Increase Risk for High Blood Pressure
Posted by on March 31, 2011 - 3:32pm

Women who tend to have high blood pressure (HBP) should be particularly vigilant if they are on oral contraceptives, are pregnant, or on hormone replacement therapy.

Women on oral contraceptives (OC) experience small but detectable increase in both systolic and diastolic blood pressure, usually in the normal range.  If it runs higher than normal make sure you talk to your doctor about it.   Women taking OCs who are 35 years and older and who smoke cigarettes are at even greater risk for heart disease and stroke and are encouraged to quit smoking.   If they are unable to quit smoking, they should talk to their doctor about using other forms of contraception.

Most studies show that blood pressure does not increase significantly with hormone replacement therapy in most women with and without high blood pressure.   However, a few women may experience a rise in blood pressure attributable to estrogen therapy.   It is recommended that women on HRT have their blood pressure monitored more often.

Many woman with HBP can have healthy babies but HBP during pregnancy can be dangerous for both mother and fetus.  Women with pre-existing, or chronic, high blood pressure are more likely to have certain complications during pregnancy than those with normal blood pressure.   Some women who have normal blood pressure before pregnancy may develop high blood pressure during pregnancy, called gestational hypertension.   The effects of high blood pressure range from mild to severe.   High PB can harm the mother's kidneys and other organs, and it can cause low birth weight and early delivery.  In the most serious cases, the mother develops pre-eclampsia or "toxemia of pregnancy" which can be life threatening.  More guidance for handling HPB during pregnancy can be found HERE.

Below is a chart for average normal blood pressure ranges.   However, age can effect the range, with slightly higher normal ranges as one ages.

Systolic pressure (mm Hg) Diastolic pressure (mm Hg) Pressure Range
130 85 High Normal Blood  Pressure
120 80 Normal Blood Pressure
110 75 Low Normal Blood  Pressure

Source:   National Heart, Lung and Blood Institute