Population characteristics
The inclusion criteria for women with CH were met by 650 pregnancies and
were classified as group 1 (n=81), group 2 (n=199), group 3 (n=221) and
group 4 (n=149). The control group consisted of 142 normotensive women.
Maternal and pregnancy characteristics of the four groups of women with
CH and the control group are compared in Table 1. In the total cohort of
women with CH, compared with controls, maternal age, weight and systolic
and diastolic blood pressure at 11-13+6 weeks
gestation and the incidence of previous and/or family history of
preeclampsia were higher. Approximately 93% of women in groups 3 and 4
were taking one anti-hypertensive medication with 7% taking 2 or more.
In groups 3 and 4, compared to group 2, there was a significantly higher
weight, systolic blood pressure, incidence of Black racial origin and
previous PE. In groups 2 and 3, compared to group 1, systolic and
diastolic pressure were lower. Women of group 2 were more likely to be
younger and nulliparous when compared to group 3 and with a lower
diastolic blood pressure when compared to group 4. Those of group 1 were
also more likely to weigh more and be nulliparous when compared to
groups 2 and 3, respectively, and with a lower systolic blood pressure
compared to group 4. Groups 1 and 2 had a significantly lower rate of
preterm PE and higher gestation at delivery when compared to groups 3
and 4 and a significantly lower incidence of SGA neonate with higher
birth weight centile when compared to group 3, alone.