1. Human chorionic gonadotropin levels after blastocyst transfer are highly predictive of pregnancy outcome1 
Theocharis C Papageorgiou, M.D., Mark P Leondires, M.D., Bradley T Miller, M.D., Audrey S Chang, Ph.D., Alicia B Armstrong, M.D., Lynette A Scott, Ph.D., James H Segars, M.D. 
Fertility and Sterility 
Volume 76, Issue 5, Pages (November 2001)
DOI: /S (01)

2. Figure 1
Receiver operating characteristic curve for day 3 and day 5 embryo transfers based on β–hCG serum values (mIU/mL) 16 days after ovum retrieval. Solid line = day 5 values. Dashed line = day 3 samples. The value of 232 mIU/mL for the day 5 group is circled. The value of 173 mIU/mL for the day 3 group is circled. These two circles represent the optimal sensitivity and specificity for the assay.
Papageorgiou. β-hCG levels after blastocyst transfer. Fertil Steril 2001.
Fertility and Sterility  , DOI: ( /S (01) )

3. Figure 2
Percentages of a multiple pregnancies for day 3 and day 5 embryo transfers based on day 16 β–hCG serum values (mIU/mL). Pregnancies = clinical pregnancies. Multiple pregnancies = twin gestation and higher on ultrasound at 12 weeks gestation. Error bars = mean ± SEM.
Papageorgiou. β-hCG levels after blastocyst transfer. Fertil Steril 2001.
Fertility and Sterility  , DOI: ( /S (01) )