Is high normotension a norm or a risk factor for perinatal complications: prospective cohort study

Aim. Comparative assessment of the effect of high normotension and hypertension 1–2nd stage on the risk of gestational and perinatal complications.

Materials and methods. A prospective cohort study (n=110) assessing the effect of high normotension on the risk of gestational complications and pregnancy outcomes was conducted. The main group (n=70) included 30 patients with high normotension – subgroup A, and 40 patients with hypertension 1–2nd stage – subgroup B. The comparison group included 40 patients with "white coat hypertension".

Results. The most frequent complications in the 2nd and 3rd trimesters of pregnancy were toxaemia, threatened miscarriage, edema (detected in more than half of patients with high normotension and hypertension 1–2nd stage) and well as threatened preterm labor (p<0.05). The frequency of pre-eclampsia development in subgroups A and B did not differ significantly, however, in patients with high normotension in the 3rd trimester during a test of endothelium-dependent vasodilation were detected signs of endothelial dysfunction, which may be one of the mechanisms for the subsequent formation of hypertension in these patients. Placental insufficiency of varying severity was detected only in subgroups A and B. Placental insufficiency, along with intrauterine fetal hypoxia of different etiologies, were the most frequent causes of emergency caesarean section, occurring only in the main group – 3 (75.0%) in subgroup A and 6 (66.67%) in subgroup B – and associated with blood pressure above 130/85 mm Hg.

Conclusion. The importance of preventing blood pressure increase to high normal rate is explained by the development of endothelial dysfunction at late gestation, which can serve as the mechanisms of hypertension formation in this category of pregnant women.