Background: The implantation process of the allo-antigenic fetus, is the most critical step in achieving a successful pregnancy.While a bidirectional TH1 and TH2/TREG interaction is reported in pregnancy, nitric oxide (by proxy of nitrite/nitrate concentration [NOx]) acts as a potent vasodilator to maintain fetal circulation efficiently. Currently, a high frequency of miscarriages remains a major problem in women pregnant via in-vitro fertilization –embryo transfer (IVF-ET) and the causes of miscarriages are not well understood among Sri Lankan women.
Objective: This study attempted to establish association of serum TH1(IFN-γ) and TH2/TREG(IL-10) cytokines and NOx levels with pregnancy outcomes of Sri Lankan women pregnant by means of IVF-ET.
Methods: Women in their first trimester of pregnancy via in vitro fertilization – embryo transfer (IVF-ET; n=44) and naturally conceived women with no history of miscarriages (T1,n=24) were recruited as test groups for the study. Non pregnant, fertile women served as controls (n=20). The women who were pregnant through IVF-ET were categorized into two groups according to their pregnancy outcome; successful (IVF-S,n=22) and miscarried (IVF-M,n=22). Serum cytokine (IL-10, IFN-γ) and NOx levels were assayed using sandwich ELISA kits and the Griess test, respectively.
Results: All pregnant groups manifested significantly higher levels of IL-10 than the non-pregnant control group (P<0.05). T1 and IVF-S groups did not differ in IL-10 levels (P>0.05); Conversely, IVF-M manifested significantly lower IL-10 levels than both these groups (P<0.05). IVF-M group manifested the highest IFN-γ level while T1 showed the lowest. NOx levels were significantly higher in T1 than those of IVF-S and IVF-M (P<0.05), with no deviation evidenced in the two IVF groups (Figure1).
Conclusion: High IL-10 and NOx levels were compatible with positive pregnancy outcomes, while high IFN-γ levels were associated with miscarriage in IVF-ET pregnant women.