II-200 ZDRAV VESTN 2003; 72: SUPPL II ZGODNJI PRESEJALNI TESTI ZA TRISOMIJO 21 PRI NOSEČNICAH PO OPLODITVI Z BIOMEDICINSKO POMOČJO SCREENING FOR TRISOMY 21 IN THE FIRST TRIMESTER IN PREGNANCIES AFTER ASSISTED REPRODUCTION Nataša Tul, Živa Novak-Antolič Klinični oddelek za za perinatologijo, Ginekološka klinika, Klinični center, Šlajmerjeva 3, 1525 Ljubljana Ključne besede: oploditev z biomedicinsko pomočjo; presejal- ni testi; trisomija 21; nuhalna svetlina; prosti β hCG; PAPP-A Izvleček – Izhodišča. Nosečnice, ki zanosijo po oploditvi z bio- medicinsko pomočjo (OBMP), imajo pri trojnem presejalnem testu v drugem trimesečju večji delež lažno pozitivnih rezul- tatov (LPR), zato smo želeli ugotoviti, ali imajo te nosečnice tudi pri presejalnih testih za trisomijo 21 (T21) v prvem tri- mesečju več LPR. Metode. Vključili smo 1122 nosečnic, za katere smo imeli po- datek o načinu zanositve. Razdelili smo jih v skupine glede na način zanositve (130 jih je zanosilo po IVF, 54 po ICSI, 24 po indukciji ovulacije in 914 spontano) ter med njimi pri- merjali vrednosti nuhalne svetline (NS) pri plodu, ter serum- ske vrednosti prostega β humanega horionskega gonadotro- pina (fβ hCG) in PAPP-A (Pregnancy Associated Plasma Pro- tein A) pri nosečnicah med 10. in 14. tednom nosečnosti. Iz- računali smo tveganja za T21 na podlagi starosti nosečnice ter v kombinaciji z NS, fβ hCG in PAPP-A. Izračunali smo de- leže LPR za posamezne skupine. Rezultati. Metode OBMP niso vplivale na vrednosti NS. Vre- dnosti fβ hCG pri nosečnicah po OBMP niso bile statistično pomembno različne od vrednosti pri nosečnicah, ki so zano- sile spontano; vrednosti PAPP-A so bile nižje, še zlasti pri no- sečnicah po ICSI. Pri izračunavanju tveganja za T21 na pod- lagi starosti nosečnice in NS je imelo po spontani zanostivi 4,6% nosečnic LPR, po IVF 8,5%, po ICSI 7,4%. Po dvojnem presejalnem testu (starost nosečnice, fβ hCG, PAPP-A) je imelo LPR po spontani zanostivi 8,3% nosečnic, po IVF 21,5%, po ICSI 22,2% nosečnic. Sestavljeno presejanje (starost nosečni- ce, NS, fβ hCG, PAPP-A) je dalo LPR pri 3,1% nosečnic po spon- tani zanostivi, pri 9,2% nosečnic po IVF in pri 13% nosečnic po ICSI. Statistično najbolj pomembna odstopanja od normal- nih vrednosti so imele nosečnice, kjer je bila za IVF ali ICSI vzrok moška neplodnost. Zaključki. Presejanje z NS je enako primerno za vse nosečni- ce ne glede na način zanositve. Pri sestavljenem presejanju na podlagi starosti nosečnice, NS, fβ hCG in PAPP-A je bil med nosečnicami po IVF delež LPR nekoliko večji kot pri istih no- sečnicah ob presejanju le z NS, zato je tudi sestavljeni prese- jalni test primeren za nosečnice po IVF, zlasti, ker je delež odkritih plodov s T21 s sestavljenim presejalnim testom večji. Spremenjene vrednosti označevalcev so najbrž povezane s sa- mimi postopki OBMP ali s še neprepoznanimi lastnostmi pri neplodnih parih. Key words: assisted reproduction; screening test; trisomy 21; nuchal translucency; free β hCG; PAPP-A Abstract – Background. At the second trimester screening for trisomy 21 (T21), the false positive results (FPR) are higher in pregnancies achieved after assisted reproduction techni- ques (ART). The aim of this study was therefore to examine the effects of ART on the FPR at the first trimester screening for T21. Methods. Of the 1122 pregnant women enrolled, 130 achi- eved pregnancy after IVF, 54 after ICSI, 24 after induction of ovulation and 914 spontaneously. Fetal nuchal translucency (NT), maternal serum free b human chorionic gonadotrophin (fβ hCG) and pregnancy associated plasma protein A (PAPP-A) levels were measured at the 10–14 week of gesta- tion. Calculation of the risk for T21 was based on maternal age and in combination with NT, fβ hCG and PAPP-A; FPR rates were calculated for each subgroup. Results. Fetal NT was not affected by ART. In pregnancies af- ter ART fβ hCG levels were not statistically significantly diffe- rent form those in spontaneous pregnancies; PAPP-A levels were lower, particularly in pregnancies after ICSI. In risk cal- culation based on maternal age and NT, FPR were found pre- sent in 4.6% of spontaneous pregnancies, in 8.5% of IVF and in 7.4% of ICSI-derived pregnancies. At the double test (ma- ternal age, fβ hCG, PAPP-A) FPR were found in 8.3% in spon- taneous pregnancies, in 21.5% of IVF and in 22.2% of ICSI pregnancies. At screening by maternal age, NT, fβ hCG and PAPP-A, FPR was 3.1% after spontaneous conception, 9.2% after IVF and 13% after ICSI. If male factor infertility was the indication for IVF or ICSI, the marker levels were most abnor- mal. Conclusions. Screening by NT is equally appropriate for all pregnant women, regardless of the way of conception. In IVF pregnancies, FPR was somewhat higher after combined scre- ening based on maternal age, NT, fβ hCG and PAPP-A levels than after screening based only on maternal age and NT. Different levels of markers in pregnancies after ART can be associated with ART procedures, or with yet unrecognised pro- perties of the unfertile couple.