Maternal haemodynamics in placental implantation abnormalities: a pilot study

Objective. Low-lying and placenta previa are associated to risk for placenta accreta disorders (PAS). Maternal haemody­namic in patients with placental implantation abnormalities has not been yet investigated. During the two last decades some authors shifted the focus from placenta to maternal car­diovascular system to explain the development of growth re­striction. Mothers of FGR foetuses show low cardiac output and elevated systemic vascular resistance suggestive of a hy­povolemic circulation.
Our aim was to investigate if an altered maternal haemody­namic is associated to a foetal growth drop in pregnancies complicated by placental implantation abnormalities.
Materials and Methods. 33 normotensive patients with low lying placenta, placenta previa associated or not to PAS were submitted to an evaluation of maternal haemodynamics with USCOM. We then compared maternal cardiovascular profile between patients with a drop in foetal growth (> 1 quartile) from the second to the third trimester or within the third tri­mester, and patients with regular foetal growth.
Results. All patients showed haemodynamic values within in the normal range. There were no differences in mean arterial pressure (87 ± 8 mmHg vs 82 ± 9 mmHg), cardiac output (7.4 ± 1.1 L/min vs 7.0 ± 1.0 L/min), systemic vascular resistance (984 ± 139 vs 932 ± 173 dynes × s/cm5) between the two groups.
Conclusions. Maternal haemodynamic appears to be normal in pregnancies complicated by placental implantation abnor­malities. There were no haemodynamic differences between patients with normal and dropped foetal growth.