The Relationship Between HCG Levels In Serum And Follicular Fluid And Embryo Cultures And The Outcomes Of IVF-ET Cycles

Objectives: To analyze the relationships between hCG levels with clinicaloutcomes by detecting the hCG levels in serum and follicular fluid and embryocultures on the day of the retrieved oocytes for the patients undergoing in vitrofertilization embryo transfer (IVF-ET), and discussing whether it could becomea useful predictor for IVF outcome.Methods: A prospective study was conducted from October2013toJanuary2014in Reproductive Medicine Research Center of the First AffiliatedHospital of Guangxi Medical University and the infertility patients (a total of68cycles) were undergoing the first IVF treatment, GnRH-a long stimulateovulation was adopted. The patients were randomly divided into A, B groups，the hCG dose in hCG day of A group was6000IU(a total of36cycles), whereas10000IU hCG was in group B (a total of32cycles). Collected the serum ofpatients half an hour before the retrieval, the follicular fluid on the day of the retrieval and the embryo culture of D3embryo transplantation. The β-hCGlevels in serum and follicular fluid and embryo cultures were measured byenzyme-linked immunosorbent assay. The number of retrieved oocytes,fertilization, cleavage of oocytes for patients were tracked Divided the68patients into groups depend on the β-hCG levels in serum and follicular fluid tocompare， Meanwhile according to different embryo grades, pregnant andnon-pregnant group, different embryo implantation rate groups to compare thelevels of hCG in culture medium.and the relationship betweenβ-hCG levels andIVF-ET outcomes was analyzed.Results:1.The number of retrieved oocytes, normal fertilization rate,cleavage rate, high qualified embryo rate and pregnancy rate in A or B grouprespectively were14.50±5.37,70.7%,98.7%,64.0%,58.3%and12.81±5.16,71.7%,98.3%,65.3%,56.2%, and no statistical differences were detected in allgroups(P＞0.05).2. The β-hCG level in serum of group A (170.49±38.38)IU/L wassignificantly lower than of group B(296.77±32.92IU/L)(P＜0.01); the β-hCGlevel in follicular fluid was127.73±24.87IU/L for group A, and119.39±22.46IU/L for group B, no statistical differences were detected(P＞0.05).The β-hCG level in follicular fluid was lower than that in serum(P＜0.01). Thecorrelation analysis suggested that follicular fluid β-hCG level on the day of theretrieved oocytes and serum β-hCG level were significantly positive correlationin two groups(Group A:r=0.737,P＜0.001; Group B:r=0.538,P=0.001）。3. According to the serum β-hCG levels, three groups were separatelydivided in A or B groups(took the critical value by Percentile method,Criticalvalue of group A:155.14IU/L and176.21IU/L meanwhile280.27IU/L and 312.11IU/L of group B):With increasing the serum β-hCG level, the number ofretrieved oocytes, normal fertilization rate, high qualified embryo rate andpregnancy rate had no statistical difference in the three groups of group A or B(P＞0.05); Similarly divided A or B groups into three groups based on thefollicular fluid β-hCG levels(Critical value of group A:116.56IU/L and133.71IU/L； meanwhile106.38IU/Land122.57IU/L of group B):withincreasing the follicular fluid β-hCG level, an obvious growth trend of highqualified embryo rate was detected in group A(55.4%,62.5%,73.4%)withsignificant differences(P=0.011), the same growth trend was in the groupB(60.5%,63.6%,70.9%), but no significant differences(P＞0.05).4. The β-hCG levels of embryo culture for I/8(34cases) in group A andI/8(33cases) in group B were1.16±0.07IU/L,1.07±0.04IU/L;for II/8(15cases)in group A and II/8(14cases) in group B were1.04±0.10IU/L,1.05±0.12IU/L,no significant differences were detected (P＞0.05).5. In the68cases studied, a total of20patients received at D3embryoscontaining both I/8and II/8embryos,the β-hCG levels(IU/L)of their embryocultures were1.09±0.13,1.05±0.08; II/8and II/6were1.04±0.13,1.12±0.05for16samples;II/6and II/4were1.15±0.16,1.08±0.11for14samples, nosignificant differences were detected of the β-hCG levels in different grades’embryo cultures (P＞0.05).6. The β-hCG level of ET embryo culture was1.14±0.10IU/L in pregnancygroup,1.09±0.04IU/L in the non-pregnancy group, and there were significantdifferences compared with each other(P＜0.05). Embryo implantation rates were0%,50%,100%, and the corresponding β-hCG levels(IU/L) of ET embryo culture were1.09±0.04、1.11±0.07、1.29±0.05, significant differences weredetected(P＜0.01).Conclusions:1.There is no obvious effect on IVF-ET results in a range ofdoses of hCG (6000-10000IU), but for the patients at risk for OHSS, the dosageof hCG could be reduced appropriately.2. The hCG levels in embryo culture have no direct correlation with thedosage of hCG and embryo morphology.3.The hCG level in embryo culture is secreted by embryo, higher hCGlevels could be detected in pregnancy group and high embryo implantation rategroup, which suggests that the embryos with the high hCG levels of embryoculture may have a better development potential.