Association of early {beta}-human chorionic gonadotrophin values with pregnancy wastage and multiple implantation in a donor oocyte programme

An early marker predictive of a viable pregnancy would easethe anxiety associated with positive pregnancy tests after theuse of donor oocytes. We examined the predictive value of anearly serum quantitative human chorionic gonadotrophin (Q-HCG)concentration on pregnancy outcome following oocyte donation.Embryo transfers after oocyte donation resulting in a positiveserum -HCG were examined beginning 9 days after embryo transferfrom those samples assayed in our laboratory (n = 77). Q-HCGconcentrations were measured in our laboratory by an immunoradiometricassay utilizing the first International Reference Preparation.Implantations were defined as the number of gestational sacsvisualized by transvaginal ultrasound 21 days after embryo transfer.Biochemical pregnancies were those with transient elevationsin -HCG concentration but without implantation sites. Spontaneousabortions were characterized by an implantation site with theeventual arrest of development. Ongoing/delivered pregnanciesdeveloped appropriately and proceeded beyond the first trimester.Day 9 Q-HCG concentrations did not differentiate between biochemicalpregnancies/spontaneous abortions and ongoing/delivered pregnancies,although mean ± SD concentrations for biochemical pregnancieswere significantly lower than those for the other groups (P< 0.0001): biochemical pregnancies, n = 18, 5.8 ±8.9 mlU/ml, range 0–35; spontaneous abortions, n = 2,46.0 ± 10.0 mlU/ml, range 39–53; ongoing/deliveredpregnancies, n = 57, 41.5 ± 35.4 mlU/ml, range 0–214.In addition, day 9 Q-HCG concentrations did not differentiatebetween multiple implantations, although the implantation offour sacs had a significantly higher mean Q-HCG concentrationcompared with the implantation of fewer sacs (P > 0.0001):one sac, n = 22, 32.2 ± 21.5 mlU/ml, range 3–78;two sacs, n = 25, 35.8 ± 21.3, range 0–81; threesacs, n = 7, 47.1 ± 37.1 mlU/ml, range 22–126;four sacs, n = 4, 122.3 ± 62.4 mlU/ml, range 76–214.The positive predictive value of a Q-HCG >10 mlU/ml was 0.91(sensitivity 91%, specificity 75%). These initial data suggestthat early day 9 serum Q-HCG determinations do not accuratelyidentify viable pregnancies or multiple implantations. Evenan early negative pregnancy test should be repeated becauseit can be associated with a normal pregnancy.