ABSTRACT
OBJECTIVE: To compare the midtrimester triple marker levels for down syndrome screening between natural and IVF twin pregnancies and to evaluate the difference triple marker in IVF twin pregnancies according to the fertilization method and number of transferred embryos. METHODS: The study population consisted of conventional IVF twin (n=106), ICSI twin (n=142), and natural (n=436) twin pregnancies as controls between 2001 and 2004. All pregnancies in this study were known to have normal outcome. Maternal serum samples were collected between 14-18 gestational weeks. Levels of AFP, total hCG, and uE3 were measured and were expressed as multiples of the median (MoM) based on reference medians established at Cheil Hospital. RESULTS: The mean maternal age (31.6+/-2.8 vs. 31.6+/-3.0 vs. 32.1+/-2.1: conventional IVF group vs. ICSI group vs. control, respectively) and gestational weeks (16.0+/-0.5 vs. 16.0+/-0.7 vs. 16.1+/-0.2) for triple test were similar. There was no difference in levels of all serum markers between conventional IVF and ICSI group. The median AFP MoM for conventional IVF and ICSI group were significantly higher than that of the control group (2.40 vs. 2.22 vs. 1.98; p0.05). Also, the median hCG MoM was not different from that of the control group (2.04 vs. 2.06 vs. 2.02; p>0.05). There was no correlation in triple marker levels according to the number of transferred embryos in conventional IVF and ICSI groups. CONCLUSION: Midtrimester triple marker levels of IVF twin pregnancy for down syndrome screening are similar with those of natural twin pregnancy regardless of fertilization method and number of transferred embryos.