Impaired placentation in women with chronic hypertension who develop pre-eclampsia.

OBJECTIVE To compare the degree of impaired placentation in women with and those without chronic hypertension (CH) who develop pre-eclampsia (PE) in pregnancy. METHODS Data were derived from prospective screening for adverse pregnancy outcomes in women with singleton pregnancy attending their first routine hospital visit at 11 + 0 to 13 + 6 weeks' gestation. This visit included recording of maternal characteristics and medical history and measurement of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and serum pregnancy-associated plasma protein-A (PAPP-A). The measured biomarkers were converted to multiples of the median (MoM) after adjustment for pregnancy characteristics. MoM values in women with CH who developed PE (n = 283) were compared to those of women without CH who developed PE (n = 2236). RESULTS In both groups with and without CH, measurements of MAP and UtA-PI were increased, whereas those of PlGF and PAPP-A were decreased and the deviation from normal in all biomarkers decreased with advancing gestational age at delivery with PE. There was no significant difference between women with and those without CH in the slope of the regression line of log10 MoM biomarker values against gestational age at delivery with PE for any of the biomarkers. However, there was a significant difference in the intercepts and coefficients of biomarkers in the two groups; compared to those without CH, MAP MoM, PlGF MoM and PAPP-A MoM were higher and UtA-PI MoM was lower in the CH group (all P < 0.01). CONCLUSION In pregnancies that develop PE, the degree of impaired placentation, reflected in high UtA-PI and low PlGF and PAPP-A at 11-13 weeks' gestation, is less in women with CH than in those without CH. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.