Routine Investigations Might be Useful in Preeclampsia, But Not in Gestational Hypertension

Abstract

Women diagnosed as having pregnancy-induced hypertension (PIH) frequently undergo blood testing and cardiotocography (CTG) without regard to the clinical severity of their condition. There always is a risk that excessive investigation will lead to inappropriate interventions. This retrospective observational study was an attempt to chronicle the management of 526 consecutive women referred with suspected PIH. A diagnosis of PIH required 2 or more blood pressure readings of 140/90 mm Hg or higher at an interval of at least 4 hours. High blood pressure was first recorded after 20 weeks gestation. Preeclampsia was diagnosed when PIH was accompanied by significant proteinuria. When there was no significant proteinuria, the diagnosis was gestational hypertension. Proteinuria itself was not sufficient reason to make a diagnosis of PIH. Preeclampsia was diagnosed in 21% of women, gestational hypertension in 43%, and lack of PIH in 36%. Preeclampsia correlated closely with preterm birth, low birth weight, induction of labor, and operative delivery. All 111 of these women had antenatal blood testing. Approximately 10% of those tested had a low platelet count and/or an elevated aspartame aminotransferase level. Gestational hypertension was associated with increased rates of induction and cesarean delivery. All but 3% of these women had blood tests antenatally. Four women had abnormal liver function, and one of them also had a low platelet count. One woman in this group delivered a growth-restricted infant at 28 weeks gestation when CTG was nonreassuring. Just over two thirds of women without PIH had antenatal blood testing. Two had abnormal liver function. One woman without PIH had labor induced because of nonreassuring antenatal CTG monitoring. These findings suggest that antenatal assessment should be used more selectively in women with PIH unless the diagnosis is made before term or proteinuria is present. There is little evidence endorsing the antenatal use of CTG monitoring in these women.