Aim: Verifying the diagnosis of hypertension in pregnancy by home blood pressure (BP) or 24-h BP measurements is recommended (ACOG, 2013) to avoid over-treatment of white coat hypertension. In pregnancy a threshold of 140/90 mmHg measured by office BP is normally used, but in our center, we use a threshold of ≥135/85 mmHg for antihypertensive therapy in women with diabetes. The prevalence of white coat hypertension in pregnant women with diabetes is unknown. We explored the prevalence of white coat hypertension in early pregnancy in women with type 1 (T1DM) and type 2 (T2DM) diabetes.
Methods: Home BP was measured for 3 days (18 measurements in total) at median 67 gestational days (range 33-139), within a week of office BP measurement. The women were divided in groups: treated hypertension, white coat hypertension (office BP ≥135/85 mmHg and mean home BP <130/80 mmHg), true new-onset hypertension (office BP ≥135/85 mmHg and mean home BP ≥130/80 mmHg), masked hypertension (office BP <135/85 mmHg and home BP ≥130/80 mmHg) and normotension (office BP <135/85 mmHg and mean home BP <130/80 mmHg).
Results: In total 178 (72%) out of 244 consecutive pregnant women with diabetes were included: 107 women with T1DM and 71 women with T2DM with mean age 31±5 and 34±5 years and mean BMI 27±6 and 34±5 kg/m2, respectively. Treated hypertension was present in 11 (6%). In total 20/27 (74%) of the remaining women with hypertension measured by office BP ≥135/85 mmHg had white coat hypertension (85% (12/14) of women with T1DM and 62% (8/13) in women with T2DM). Among women with office BP ≥140/90 mmHg 8/9 (89%) had white coat hypertension (home BP <135/85 mmHg). True new onset hypertension was seen in 7 (4%). One women had masked hypertension and the remaining 139 (78%) were normotensive.
Conclusion: White coat hypertension in early pregnancy is prevalent in women with T1DM and T2DM. These data support routine home BP measurement before initiating antihypertensive therapy in this population.
M. Vestgaard: None. B. ásbjörnsdóttir: None. L. Ringholm: None. D.M. Jensen: None. L. Andersen: None. P. Damm: Advisory Panel; Self; Novo Nordisk A/S. Other Relationship; Self; Novo Nordisk A/S. E.R. Mathiesen: Speaker's Bureau; Self; Novo Nordisk A/S. Other Relationship; Self; Novo Nordisk A/S, Novo Nordisk Foundation, Novo Nordisk A/S.