Predictive value of human chorionic gonadotrophin in the outcome of early pregnancy after in-vitro fertilization and spontaneous conception

This prospective study analyses the value of the -subunit ofhuman chorionic gonadotrophin (-HCG) in 120 pregnancies obtainedafter in-vitro fertilization (IVF)-embryo transfer. Spontaneousconception cycles (n = 16) were also analysed allowing a comparisonbetween these two forms of conception. Of the 120 clinical pregnancies,48 started as single gestations and 50 started with two or moresacs. There were 14 clinical abortions and eight ectopic pregnancies.All subjects had blood samples taken under a fixed protocolon days 11, 14, 17, 20 and 23 after follicular aspiration. Weeklysamples were obtained thereafter until day 60 from ovum retrieval.Transvaginal ultrasounds were performed at weekly intervals,starting on day 23 after follicular aspiration. In spontaneousconception cycles blood samples were obtained daily, startingon the day of follicular rupture. In spontaneous conceptioncycles and in IVF– embryo transfer conceptions, the doublingtime (DT) of ;-HCG was 1.4 ± 0.3 and 1.6 ± 0.4days respectively. This difference was not significant. In multigesta–tions,the DT was 1.5 ± 0.3 days. The absolute values of -HCGin early spontaneous gestations were significantly higher thanin IVF—embryo transfer cycles, suggesting that the blastocystimplants with less cellular mass when initiated in vitro ascompared with the in-vivo condition. The early prediction ofectopic pregnancy and spontaneous clinical abortion was analysedby the -HCG profile as well as the absolute values in comparisonto normal pregnancies. Both parameters showed significant differencesas early as the interval between days 11 and 23 from follicularaspiration. This study provides a comprehensive approach tothe evaluation of the outcome of early gestation in terms ofthe predictability of single and multigestation, ectopic pregnancyand early abortion.