Background In the non-pregnant population, national guidance recommends individualising the treatment of hypertension according to race. Ambulatory blood pressure monitoring (ABPM) provides a detailed blood pressure (BP) profile and provides information on nocturnal BP.

Aims

1. Determine the nocturnal BP dip in women with different ethnicity during pregnancy

2. Establish the BP variation over 24-hours for women taking calcium channel blockers (CCB) compared to those taking other antihypertensives (labetalol or methyldopa).

Method Women attending the Manchester Antenatal Vascular Service research clinic in the mid-trimester who were taking antihypertensive medication or whose BP was at the treatment threshold were offered 24-hour ABPM. The SpaceLabs 92506 ambulatory BP monitor was fitted.

Results Data was available for 17 patients. Six were of Afro-Caribbean origin. None of the Afro-Caribbean women had a nocturnal BP dip (≥10%) compared with 4/11 (36%) and 5/11 (45%) women from other ethnic origins for systolic and diastolic BP respectively (P = 0.07). The 24-hour variation in BP was not statistically different between ethnic groups. The systolic and diastolic load was significantly lower in Afro-Caribbean women, P = 0.004 and P = 0.003 respectively.

The 24-hour variation in MAP was similar for those on a CCB compared with those on other antihypertensives (CCB 7.9 vs other 9.1; P = 0.4).

Conclusion We have identified differences in 24-hour BP profiles and treatment effects between ethnic groups during pregnancy. Further research is necessary to determine the most effective antihypertensive for individual women during pregnancy.