Routine investigations might be useful in pre-eclampsia, but not in gestational hypertension.
BACKGROUND
Women referred to secondary care with suspected pregnancy-induced hypertension (PIH) are commonly investigated with blood tests and cardiotocography (CTG), regardless of the clinical severity of their condition. Over-investigation might lead to inappropriate intervention.


OBJECTIVE
To investigate how often abnormal blood test and CTG results occur in women with pre-eclampsia and gestational hypertension and in women who do not have pregnancy-induced hypertension.


METHODS
Retrospective case note review of 526 consecutive women referred with suspected pregnancy-induced hypertension to a district hospital. The frequency of abnormal test results and the pregnancy outcomes were analysed according to clinical classification.


RESULTS
36% of women referred did not meet the clinical criteria for a diagnosis of pregnancy-induced hypertension. Abnormalities of platelet count and/or liver function were seen in 11% of women with pre-eclampsia and in less than 2% of women with gestational hypertension and in a similar proportion of women who did not have pregnancy-induced hypertension. Gestational hypertension was associated with increased induction and caesarean birth rates, but not with low birthweight or preterm delivery. Progression from gestational hypertension to pre-eclampsia was not predicted by blood test abnormalities. Support for the routine use of antenatal CTG was not found.


CONCLUSIONS
A clinical diagnosis of pregnancy-induced hypertension should be confirmed before blood tests are ordered. The incidence of test abnormalities was only increased in pre-eclampsia and in gestational hypertension before term. CTG might only be of use in selected cases.
Bailey
David J
DJ
Middlemore Hospital, Private Bag 93311, Otahuhu, Auckland, New Zealand. David.Bailey@middlemore.co.nz
Walton
Stuart M
SM
D015148:Cardiotocography; D003955:Diagnostic Tests, Routine; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000097:blood / Q000175:diagnosis; D011225:Pre-Eclampsia / Q000097:blood / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies