What is it? Hypertension that develops after 20 weeks gestational age which is associated with proteinuria.
Breifly, what is the pathophysiology? The release of placental/fetal factors that alter maternal endothelial function. Ultimately there may be less vascular endothelial growth factor (VEGF) - possible from VEGF antagonists released by the placenta.
What are the diagnostic criteria?
- systolic BP >140 mmHg, or
- diastolic BP >90 mmHg, and
- proteinuria >0.3 grams in 24-hours, and
- gestational age >20 weeks
What are some of the other clinical manifestations of preeclampsia? this will relate to complications of endothelial damage and severe hypertension. Think about headaches, blurred vision, peripheral edema which may include the hands and face, pulmonary edema, and fetal compromise. Also think about end-organ damage from hypertension - you can read more at this link.
Are there risk factors? Yes, some of these include nulliparity, previous or family history of preeclampsia, preexisting hypertension, APLA syndrome or other connective tissue disease, multiple gestation, or 'extremes' of age (>40, <20). style="font-weight: bold;">Dreaded complications? Yep. Eclampsia (aka seizure), and the HELLP syndrome. HELLP stands for Hemolysis, Elevated Liver enzymes, and Low Platelets.
Okay, so what do I do? well, it's kind of complicated. First, remember that the only 'cure' is delivery. Also remember that cases can still present in the early post partum period. Get the obstetrical service involved early and ensure that the unborn child is well with a biophysical profile. Sometimes this is severe and an urgent delivery is necessary - so predelivery sterioids may be necessary to decrease fetal pulmonary complications. Otherwise, hypertension can be managed with a few drugs that are safe in pregnancy. Women with this condition should be watched very closely and there should be a very low threshold for admission to hospital.
Drugs commonly used in preeclampsia include labetolol, hydralazine, methyldopa, and nifedipine. The target blood pressure is debated, but many would agree on 130 to 150 mmHg systolic and 80 to 100 mmHg diastolic.
In severe preeclampsia, where eclampsia is a very real risk, Magnesium Sulfate is administered to reduce the seizure threshold. It is generally administered during labour and delivery, and is continued for 24-48 hours afterwards.
Here is a link on the utility of Magnesium in preventing eclampsia.
Here is a cool case of preeclampsia with a twist.