[Transcranial Doppler velocimeter in pregnant and later normotensive puerperal women].
BACKGROUND
The physiological changes that take place in blood flow in the brain during pregnancy and the puerperium are still only poorly understood. The harmlessness of transcranial Doppler (TCD) makes it a suitable method of study.


OBJECTIVE
The purpose of this study was to determine the TCD velocimeter reading at the end of pregnancy and in the early puerperium of healthy expectant mothers.


METHODS
TCD was used to perform a bilateral study of the anterior (ACA), middle (MCA) and posterior cerebral arteries (PCA). Arterial blood pressure and haematocrit were also measured. Mean velocity (MV), the pulsatility index (PI), mean arterial blood pressure and haematocrit were employed as variables in the statistical analysis. Results from 44 normotensive pregnant women in the latter stages of gestation (week 33 to term) were compared with those of a control group made up of 58 women of a similar age, who were normotensive and not pregnant. The study was repeated in the group of pregnant women during the early puerperium (the first five days after labour) and the two different results were compared.


RESULTS
Age and MAP were similar in the gestating and non-gestating groups. Haematocrit was significantly lower in the former (p < 0.001) and MV were significantly lower in the pregnant women in all the arteries (p < 0.001), whereas the PI were also significantly lower in four of the six territories that were studied (p < 0.005). During the puerperium, a significant rise in MV was observed in all the arteries (p < 0.001) and the PI increased in three of them (p < 0.05). In this phase, the mean arterial pressure rose (p < 0.05), although haematocrit levels dropped (p < 0.001).


CONCLUSIONS
The low MV and PI seen at the end of pregnancy are compatible with cerebral vasodilatation. MV increase during the early puerperium and is probably linked to a relative hyperperfusion.
Franco-Macías
E
E
Servicio de Neurología, Hospitales Universitarios Virgen del Rocío, Sevilla, Spain. efranco@mixmail.com
Quesada
C M
CM
Miranda-Guisado
M L
ML
Cayuela-Domínguez
A
A
Gil-Peralta
A
A
D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology*; D002536:Cerebral Arteries / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006400:Hematocrit; D006801:Humans; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy; D012039:Regional Blood Flow; D017585:Ultrasonography, Doppler, Transcranial