Hypertension or high blood pressure poses a threat to both mother and unborn child. According to the National Institutes of Health, hypertension can lead to low birth weight and premature delivery of the baby. More severe forms of hypertension in pregnancy called preeclampsia, according to the American Heart Association (AHA), can lead to liver failure, kidney failure, bleeding tendencies and convulsions.
Treatment of hypertension in pregnancy is important to avoid major complications for both mother and child. The treatment modalities vary widely depending on the type and severity of hypertension.
Lifestyle Changes
In uncomplicated cases, according to the American Congress of Obstetricians and Gynecologists, bed rest appears to help. Bed rest may be accomplished at home or in a medical facility according to the care giver's appraisal. Other useful adjustments, according to the Mayo clinic, include avoiding alcohol, illicit drugs and tobacco, some salt restriction and keeping to the caregiver's advice on physical activity.
Drug Treatment
Antihypertensives that lower blood pressure are used in essential or chronic hypertension. Every woman who is pregnant or plans to get pregnant should consult her caregiver over the medication she is taking. Some dosage adjustments may be required in some cases. In some other cases, the drugs may be stopped or switched to those judged to be safe in pregnancy.
One such drug, judged safe in pregnancy, is alpha methyl-dopa (Aldomet). It acts on the central nervous system to reduce its influence on peripheral nerves, leading to relaxation of the muscles in the walls of the arteries. The national heart, lung and blood institute recommends substituting this for other drugs not cleared for use in pregnancy, particularly in patients with chronic hypertension.
Another drug used in treating hypertension in pregnancy is labetalol. It acts on certain peripheral receptors of the nervous system to bring about a general dilatation of the blood vessels. Again, even though it can get to the baby, it has not been proven to be of harm.
Other drugs generally used for treatment of hypertension during pregnancy include the clonidine, Beta Blockers like metoprolol, calcium channel blockers like nifedipine and diuretics. Certain antihypertensives are particularly to be avoided in pregnancy because of proven risks to the fetus like Angiotensin Converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs).
Delivery of the Baby
Cases of gestational hypertension return to normal after the delivery of the baby, according to the ACOG. Chronic hypertension is also much easier to treat in the absence of the unborn child and issues of drug safety. More aggressive treatment and higher dosages can be employed after the birth of the child to lower the blood pressure. Water and salt retention seen in pregnancy and contributory to the blood pressure also begins to resolve with the end of the pregnancy and the return of the body's hormonal balance.
The aim of all treatment is to guide the uncomplicated cases of hypertension in pregnancy to within two weeks of their expected date to ensure full maturity of the fetus. Favorable cases may still have a normal vaginal birth, though an induction of labor might be indicated in some cases. But, whenever there is a progression to preeclampsia, there is an urgent need to end the pregnancy as soon as possible for both the baby and the mother. If the woman is not yet in labor, then a cesarean section is done to surgically deliver the baby and end the pregnancy.
References
- National Institutes of Health: High Blood Pressure in Pregnancy
- The American Heart Association: Chronic hypertension in Pregnancy
- The American Congress of Obstetricians and Gynecologists: High Blood Pressure During Pregnancy
- The Mayo Clinic: High Blood Pressure in Pregnancy
- The National Heart, Lung and Blood Institute: Research on Hypertension During Pregnancy
