High-frequency ultrasound imaging of the skin during normal and hypertensive pregnancies

Diagnosis of preeclampsia is currently made from blood pressure measurements taken at antenatal visits (either at the hospital or in the community). The aim of this work was to see whether the presence of underlying hypertensive diseases is accompanied by changes in the skin of pregnant women, which can be visualized using high-frequency diagnostic ultrasound.

This was a prospective study of pregnant and non-pregnant, hypertensive and non-hypertensive patients visiting the outpatient department of a central London Teaching Hospital. The study group consisted of 93 women, of which 30 were non-hypertensive in the second trimester of pregnancy, 26 were non-hypertensive in the third trimester of pregnancy, 9 were hypertensive in the second trimester of pregnancy, and 14 were hypertensive in the third trimester of pregnancy. Fourteen non-pregnant women of comparable age were recruited as controls. Changes in abdominal skin thickness and also skin structure, as analysed by fractal image analysis, was assessed in each patient.

In a normal pregnancy, abdominal skin gets thinner as pregnancy progresses. In hypertensive patients, the skin thickness did not appear to alter. Image analysis of abdominal skin scans showed that the skin of non-hypertensive pregnant women and non-pregnant women are different. Whereas the analysis of hypertensive pregnant women and non-pregnant women showed they were the same.

The data used to compare the groups indicates that if the abdominal skin of the patient does not get thinner as the pregnancy progresses there is an indication that the patient may be hypertensive. The fractal data comparing the groups indicates the following when comparing a patient's fractal signature with the non-pregnant control data: If the abdominal fractal for a pregnant woman is similar to the control group, there is an indication that the patient is hypertensive. It is difficult to predict hypertension in patients, and it is possible that a patient could develop severe preeclampsia between visits to the antenatal clinics. Therefore, if the high-frequency ultrasound scanner can pick up potential hypertensives early in pregnancy, these women could be identified as potentially high risk.