Placental isoferritin patterns during normal first trimester and tubal gestations.

Placental isoferritin (PLF) has been shown to be involved in the down-regulation of the maternal immune system during pregnancy. In a prospective study, serum PLF concentrations were measured in 33 pregnant women with singleton, normal, ongoing first trimester gestations and compared with those of 22 women with tubal gestations. Diagnoses were based on endocrinological, sonographic, intra-operative and histopathological criteria. Venous blood was obtained from both groups for PLF determination before evacuation of the pregnancy products. beta-Human chorionic gonadotrophin (HCG), 17 beta-oestradiol and progesterone were determined at surgery for the tubal pregnancy patients. The mean +/- SD PLF concentrations were 18 +/- 14, 25.4 +/- 42.3 IU/ml among normal and tubal gestations respectively. Significant differences between normal and tubal pregnancies were found (P < 0.05). Based on PLF measurements, sensitivity (67%) and specificity (33%) values were found to be similar for the normal and ectopic pregnancies. No correlation was found between the other measured pregnancy hormones and PLF for the tubal pregnancy group. Low PLF concentrations among pathological gestations may reflect abnormal trophoblastic activity. The simultaneous assessment of PLF and beta-HCG concentrations which probably originate from different trophoblastic cells, is recommended for better diagnosis and monitoring of first trimester placental activity.