During pregnancy marked physiological changes occurs and for successful and happy outcome of pregnancy the female body has to undergo successful physiological adaptation. If the adaptation process is not perfect or appropriate medical disorders may occur during pregnancy. Some of the medical disorders are fairly common during pregnancy and increase in blood pressure is one such common medical problem during pregnancy.
During pregnancy the cardiac output (which the quantity of blood heart has to pump every minute) increases by approximately 40% and the heart rate or pulse rate increases by approximately 10 beats per minute mainly during the last three months of pregnancy. But despite the increase in heart rate the increase in cardiac output is mainly due to increase in stroke volume, which is the amount of blood heart pumps out in every heart beat.
During second trimester of pregnancy there is reduction in the vascular resistance and there is reduction in blood pressure in normal pregnant women. Blood pressure is the result of cardiac output and degree of vascular resistance and if there is reduction in the vascular resistance, blood pressure falls. That is the reason blood pressure of 140/90 mm of Hg is considered very high during pregnancy (mainly during second trimester), whereas the same pressure is considered only the beginning of high blood pressure in general population. High perinatal (4 weeks before delivery to 4 weeks after delivery is the perinatal period) mortality and morbidity is associated even at blood pressure of 140/90 mm of Hg.
The diagnosis of hypertension (high blood pressure) is different in pregnant women in compare to general population. Blood pressure in a pregnant woman should be checked in sitting position, because if blood pressure is taken in lateral recumbent position, as is the practice in general, blood pressure may be lower than in sitting position. The diagnosis of high blood pressure in pregnant woman requires measurement of at least two elevated blood pressure of at least 6 hours apart. Blood pressure of 140/90 mm of Hg is considered very high blood pressure during pregnancy as generally blood pressure is low during pregnancy due to reduction in vascular resistance. 140/90 mm of Hg is considered only mild hypertension in a normal subject, but in pregnant women the same pressure is considered very high blood pressure.
High blood pressure in pregnancy may cause intrauterine growth retardation, increased perinatal mortality etc. Pregnant women with hypertension are also at risk of development of medical problems like preeclampsia and abruptio placenta. To prevent the complications of hypertension, women with chronic hypertension should be thoroughly evaluated for to identify the remediable causes of hypertension and also to prevent adverse effects of anti hypertensive drugs during pregnancy. Read more…
Millions of women become pregnant every year and a significant proportion of these pregnancies are complicated by one or more of the medical disorders that can occur during pregnancy. Some of the medical disorders during pregnancy are common and some are less common and some of the medical disorders during pregnancy are rare. The pattern of medical disorders during is also changing. Medical science is advancing rapidly and many medical disorders which were considered contraindications of pregnancy few decades ago are no more considered contraindication of pregnancy. Due to advancement of obstetrics, neonatology, obstetric anesthesiology, and medicine, the expectation of happy outcome of pregnancy for the mother as well as the fetus has also increased to a great extent.
Marked physiological changes occur during pregnancy (e.g. marked increase in cardiac output and workload of heart, which is as much as 40% increase) and the mother’s body need to adapt to these physiological changes appropriately to have a good outcome of pregnancy. Medical disorders which interfere with physiological adaptations of pregnancy can increase the risk of a poor outcome of pregnancy and pregnancy may sometimes aggravate the preexisting medical disorder in a woman.
The medical disorders which can occur during pregnancy are preeclampsia (development of hypertension and presence of protein in urine after 20 weeks of pregnancy or gestation) which occurs in approximately 5-7% of all pregnancies, eclampsia, gestational hypertension, aggravation of existing essential hypertension, cardiovascular disorders (like mitral stenosis, mitral and aortic regurgitation etc.), renal disorders, pulmonary hypertension, pulmonary embolism, deep vein thrombosis, hormonal disorders (like diabetes, gestational diabetes, hypothyroidism or hyperthyroidism), blood disorders, neurological disorders, gastrointestinal disorders and liver diseases. The pregnant women are also prone to develop certain bacterial (urinary tract infection, which is very common medical problem during pregnancy) and viral infections (cytomegalovirus infection, rubella, herpes, HIV infection etc.).