The effect of gestational age and placental location on the prediction of pre-eclampsia by uterine artery Doppler velocimetry in low-risk nulliparous women.

OBJECTIVE: To assess how placental position and gestational age can influence the value of a diastolic notch of the uterine arteries as a screening test for pre-eclampsia, in a low-risk population of healthy nulliparous women. METHODS: Color Doppler ultrasound was used to examine both uterine arteries in 654 healthy nulliparas at 4-week intervals between 20 and 32 weeks. The only criterion for an abnormal result was the presence of an early diastolic notch. In each subject the placental position was also recorded. The major end points were pre-eclampsia and pre-eclampsia requiring delivery before the 34th week. RESULTS: Ninety-eight women (15%) had abnormal flow velocity waveforms at their first visit. Twenty-one out of 654 women developed pre-eclampsia (3.2%). The sensitivity of the test became lower as gestational age advanced and ranged from 81% at 20 weeks, to 71.4% at 32 weeks. In contrast, the specificity and positive predictive value increased significantly. Eleven out of 12 women who delivered before 34 weeks had abnormal waveforms at the 24th week. In women with a full lateral placenta, the predictive value of the test was extremely low, especially in cases with unilateral notches. CONCLUSION: Pre-eclampsia can be more accurately predicted if, along with the presence of a notch, both gestational age and placental position are taken into account. At week 24 the test maintains a high sensitivity (76.1%), but also has an improved specificity (95.1%) and positive predictive value (34%), which allow the clinician to intervene with a potential preventive treatment.     

Long-term effects of small doses of calcitriol in hemodialysis patients with moderate secondary hyperparathyroidism

Prevention of secondary hyperparathyroidism (SHPTH) and treatment of the moderate cases by small p.os doses of Vitamin D has not been thoroughly investigated on the long term, while large doses of Vitamin D have been successful in the short term treatment of this entity. We administered calcitriol p.os 0.5-1.0 microgram, according to iPTH levels, after each dialysis session, in 19 patients (group A) for 36 months. They were ten men and nine women, 63 years old (43-81), with iPTH levels > 4N (419 +/- 185 pg/mL). Seven adenomas were found in five of them (group A1). Serum Ca, phosphate (P) and alkaline phosphatase (AP) were measured every 15-30 days. Serum iPTH and aluminum as well as echogram or scanning of the parathyroid glands were checked every 6 months. Ten additional dialysis patients, seven men and three women, 54.5 years old (36-68), non-significantly different to group A in iPTH levels (290 +/- 225 pg/mL) with three adenomas in two of them (group B1) received no calcitriol and served as controls (group B). Calcitriol treatment significantly lowered serum iPTH levels in group A patients (from 419 +/- 185 to 173 +/- 142 pg/mL, p < 0.0001, delta iPTH: -246 +/- 161 pg/mL); iPTH remained stable in group B patients (delta iPTH: +7.9 +/- 116 pg/mL) with an intergroup significant difference at P < 0.0001. All other parameters measured did not show any significant change. No significant correlation of iPTH to Ca, P or AP was found in A. Initial iPTH levels were higher in A1 and B1 patients and decreased by calcitriol in A1 group. Adenomas in A1 patients did not change in number and size in contrast to B1 where new adenomas appeared (5 patients, 10 glands). Small doses of vitamin D lower high iPTH levels and prevent parathyroid gland hyperplasia. Existing hypertrophy is stabilized under calcitriol treatment both morphologically and biologically.