Objective: To compare first trimester maternal serum levels of Placental Protein 13 (PP13) among singleton and twins pregnancy with and without severe pre-eclampsia (PE).

Methods: Fresh serum samples collected from pregnant women attending first trimester pregnancy evaluation were prospectively tested for PP13. An in-house ELISA assay was used. Information on demographic, medical and pregnancy history factors was collected at the first visit. Outcome of pregnancy was subsequently determined. The series of samples tested was enriched to include additional twins who were enrolled elsewhere but tested in parallel.

Results: Among singleton pregnancies (n=676) there was no association between PP13 and gestation or smoking status but there was a significant decline in concentration with maternal weight and levels were lower in pregnancies conceived by IVF. The latter two factors were used to express results in MoMs. The median PP13 level in twins (n=76) was 1.82 MoM, compared with 1.02 MoM in singletons, P<0.0001. In singletons the median for pregnancies with severe PE (n=26) was 0.44 MoM and 1.04 MoM in the remainder, P<0.0001. In twins with severe PE (n=10) it was 1.61 MoM, compared with 1.89 MoM, P=0.07 (1-tail test).

Conclusion: Twins PP13 values are higher than in singleton reflecting the placental origin of PP13 and a larger placental mass. PP13 is reduced in singletons that subsequently developed severe PE. This appears to also hold for twins although confirmatory studies will be needed.

Authors:

R. Svirski 1, H. Meiri 2, A. Herzog2, H.S. Cuckle 3 and R. Maymon 1
1. Asaf Ha’Ropeh Med. Cntr., Tel Aviv U, Israel

2. Hylab. Rehovot and TeleMarpeh, Tel Aviv

3.ObGyn Dep, Columbia U, New York