09 June, 2011

Predicting pre-eclampsia

Pre-eclampsia remains unpredictable, despite numerous biochemical and biophysical efforts to provide pointers. Working on history taking may prove of some value so North et al (BMJ 2011;342:d1875) embarked on an international study of over 3000 healthy nulliparous women which screened for pregnancy endpoints (the SCOPE study).

The women were interviewed at the start of the second trimester, routine biometry and Doppler studies were carried out around 20 weeks and the later development of pre-eclampsia tracked. It turned out that 5% did show signs and symptoms of pre-eclampsia with the following points on history indicating an increased risk: young maternal age, higher mean arterial blood pressure, raised BMI, family history of pre-eclampsia, family history of coronary heart disease, the woman having a low birth weight, vaginal bleeding for at least 5 days during early pregnancy or a duration of the sexual relationship of six months or less. The only protective predictor was a previous miscarriage of at least 10 weeks gestation with the same partner.

Adding the ultrasonic data did not improve the SCOPE prediction tool which raises the predictability of history taking to about 10%. Maybe adding the biochemical markers will increase the value of this interesting but inconclusive line of investigation.