Maternal cardiovascular and endothelial function from first trimester to postpartum

<div><p>Objective</p><p>To explore noninvasively the complex interactions of the maternal hemodynamic system throughout pregnancy and the resulting after-effect six weeks postpartum.</p><p>Methods</p><p>Eighteen women were tested beginning at the 12^th week of gestation at six time-points throughout pregnancy and six weeks postpartum. Heart rate, heart rate variability, blood pressure, pulse transit time (PTT), respiration, and baroreceptor sensitivity were analyzed in resting conditions. Additionally, hemoglobin, asymmetric and symmetric dimethylarginine and Endothelin (ET-1) were obtained.</p><p>Results</p><p>Heart rate and sympathovagal balance favoring sympathetic drive increased, the vagal tone and the baroreflex sensitivity decreased during pregnancy. Relative sympathetic drive (sympathovagal balance) reached a maximum at 6 weeks postpartum whereas the other variables did not differ compared to first trimester levels. Postpartum diastolic blood pressure was higher compared to first and second trimester. Pulse transit time and endothelial markers showed no difference throughout gestation. However, opposing variables PTT and asymmetric dimethylarginine (ADMA) were both higher six weeks postpartum.</p><p>Conclusions</p><p>The sympathetic up regulation throughout pregnancy goes hand in hand with a decreased baroreflex sensitivity. In the postpartum period, the autonomic nervous system, biochemical endothelial reactions and PTT show significant and opposing changes compared to pregnancy findings, indicating the complex aftermath of the increase of blood volume, the changes in perfusion strategies and blood pressure regulation that occur in pregnancy.</p></div

Blood pressure and pulse transit time variables (mean ± SD) of participants.

<p>Blood pressure and pulse transit time variables (mean ± SD) of participants.</p

Thoracic impedance variables and baroreflex sensitivity (mean ± SD) of participants.

<p>Thoracic impedance variables and baroreflex sensitivity (mean ± SD) of participants.</p

Laboratory values (mean ± SD) of participants.

<p>Laboratory values (mean ± SD) of participants.</p

Biometric data of the participants.

<p>Biometric data of the participants.</p

Test design – Graz, cable car and Dachstein.

<p>Test design – Graz, cable car and Dachstein.</p

Analysis of differences between study locations, kind of stress and the interaction of study location*kind of stress (two factor repeated measurement ANOVA).

<p>Analysis of differences between study locations, kind of stress and the interaction of study location*kind of stress (two factor repeated measurement ANOVA).</p

Absolute values of pulse oximetry (Graz vs. Dachstein).

<p>Absolute values of pulse oximetry (Graz vs. Dachstein).</p

Differences of biometrical data (HR, sBP, dBP and BRS) measured during the first period of rest R1.

<p>Differences of biometrical data (HR, sBP, dBP and BRS) measured during the first period of rest R1.</p