by email@example.com (322 Posts), Sun Sep 16, 2007 06:28 pm
I will pass as a placental pathologist, except to say clots and infarcts are seen more frequently in hypertensive disorders, primarily preeclampsia, and may be related to relative hypoxia.. I doubt if there is any specificity here.
Concerning the case description: As usual one would like considerably more information, and thus again, as usual, my remarks are hypothetical and not related to this case specifically. First, sudden fetal loss, often unexplained, is an unfortunate occurrence and is associated with both diabetic and hypertensive gestations, one reason close monitoring, (including electronic evaluation of fetal heart rate patterns) is often commenced earlier in the pregnancy of these patients (though, metanalyses have not given good score cards to the use of fetal monitoring). The patient is correct that fetal growth here seems appropriate, especially since beta receptor blocking agents (lopressor here) are associated with smaller babies (labetalol is a combined alpha, beta blocker, thus less so), and one might have expected the extensive placental infarction also to be associated with growth restriction.
Now for the primary question: Non pregnant hypertensives are often classified as having volume dependent or independent hypertension, the former obviously better controlled with sodium restriction and diuretics. For this reason the NHBP working group gave physicians the option of continuing the use of a diuretic in chronic hypertensives who conceive when such therapy had been an important constituent of nonpregnant control. This patientÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s statement of how good her control is now is an obvious hint that she has a volume component to her high blood pressure. Also, when chronic hypertensives loose control during pregnancy, adding a diuretic (carefully) is often more successful than other second line drugs, especially in diabetics, and personal experience has seen this approach prolong pregnancy to viability, especially in these diabetics with both high blood pressure and some edema. The thiazide diuretics are perhaps those with the largest history of pregnancy use as they were at one time prescribed in normal gestation to prevent preeclampsia, and thus their relative safety established.
I personally stop diuretics when the pregnancy starts given the normal decrease in blood pressure during both normal and most hypertensive pregnancies. However, if her physician chose to continue this, it would be a reasonable choice.