PLACENTAL LOCATION AND INCIDENCE OF PREEC LAMPSIA

In pregnancies with unilateral placental location, the uteroplacental Doppler flow measurements show significant side-to-side differences. H ighly divergent findings seem to be associated with an unfavourable ou tcome, particularly with preeclampsia. Therefore, we studied the relat ionship between placental location and subsequent development of preec lampsia prospectively. Method: 184 patients between 24 and 36 weeks of gestation were studied prospectively. Placental location was classifi ed as central or lateral by ultrasound. Preeclampsia was defined by bl ood pressure greater than or equal to 140/90 mmHg and proteinuria grea ter than or equal to 500 mg/24 h. Results: After consideration of excl usion criteria, 148 pregnancies could be evaluated: 115 had a laterall y and 33 a centrally located placenta. The incidence of preeclampsia i n these groups was 32/115 (28%) and 3/33 (9%) respectively. Conclusion : These data suggest that a laterally located placenta is associated w ith a significantly increased incidence of preeclampsia, with a risk r atio of 3.1 when compared to pregnancies with centrally located placen tas.