Dee C Harris

Quantitative grading of a human blastocyst: optimal inner cell mass size and shape

OBJECTIVE To investigate the predictive value of quantitative measurements of blastocyst morphology on subsequent implantation rates after transfer. DESIGN Prospective observational study. SETTING Private assisted reproductive technology center. PATIENT(S) One hundred seventy-four IVF patients receiving transfers of expanded blastocyst-stage embryos on day 5 (n = 112) or day 6 (n = 62) after oocyte retrieval. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Blastocyst diameter, number of trophectoderm cells, inner cell mass (ICM) size, ICM shape, and implantation and pregnancy rates. RESULT(S) Blastocyst diameter and trophectoderm cell numbers were unrelated to implantation rates. Day 5 expanded blastocysts with ICMs of >4,500 microm(2) implanted at a higher rate than did those with smaller ICMs (55% vs. 31%). Day 5 expanded blastocysts with slightly oval ICMs implanted at a higher rate (58%) compared with those with either rounder ICMs (7%) or more elongated ICMs (33%). Implantation rates were highest (71%) for embryos with both optimal ICM size and shape. Pregnancy rates were higher for day 5 transfers of optimally shaped ICMs compared with day 5 transfers of optimally sized ICMs. CONCLUSION(S) Quantitative measurements of the inner cell mass are highly indicative of blastocyst implantation potential. Blastocysts with relatively large and/or slightly oval ICMs are more likely to implant than other blastocysts.

A comparison of day 5 and day 6 blastocyst transfers

OBJECTIVE To compare implantation and pregnancy rates according to the day of embryo transfer (day 5 or 6 after oocyte retrieval) when transfer was postponed until expanded blastocysts developed. DESIGN Retrospective clinical study. SETTING Private ART center. PATIENT(S) One-hundred and eighty-three women undergoing blastocyst-stage embryo transfer following in vitro fertilization. INTERVENTION(S) Bipronucleate oocytes were grown for up to 144 hours and subsequently transferred only when at least one embryo attained the expanded blastocyst stage. MAIN OUTCOME MEASURE(S) Implantation and pregnancy rates. RESULT(S) Blastocysts transferred on day 5 implanted at nearly twice the rate of blastocysts transferred on day 6 (36.3% vs. 19.0%). Pregnancy rates were also almost twice as high among the day 5 transfer patients (59.3% vs. 32.3%). In addition, more blastocysts developed (3.6 vs. 2.4), and more were transferred (2.7 vs. 2.3) to the day 5 transfer patients, although the proportion of expanded blastocysts among the blastocysts that were transferred was the same for the two groups (91.7% vs. 93.6%). CONCLUSION(S) Embryos that develop to the expanded blastocyst stage and are transferred on day 5 after retrieval are approximately twice as likely to implant compared to those for which expansion and transfer are delayed until day 6.

Predictive value of 72-hour blastomere cell number on blastocyst development and success of subsequent transfer based on the degree of blastocyst development

OBJECTIVE To determine the predictive value of 72-hour blastomere cell number on blastocyst development and to compare success rates of subsequent transfer based on the degree of blastocyst development. DESIGN Retrospective clinical study. SETTING Private assisted reproductive technology center. PATIENT(S) Ninety-three women aged 32.0 +/- 5.1 years undergoing oocyte retrieval for IVF. INTERVENTION(S) Bipronucleate oocytes obtained from IVF were grown for up to 168 hours after fertilization and subsequently transferred at the blastocyst stage. MAIN OUTCOME MEASURE(S) Percentages of embryos developing to blastocyst from 72-hour embryos by blastomere cell number and subsequent implantation and pregnancy rates of transferred blastocysts. RESULT(S) Rates of blastocyst formation and expansion increased as cell numbers at 72 hours increased. Implantation rates were 43% for embryos transferred to women receiving only expanded blastocysts and 17% for embryos transferred to women receiving one or more less developed blastocysts. Pregnancy rates were higher for women receiving only expanded blastocysts than for women receiving one or more less developed blastocysts, although the difference was not significant. CONCLUSION(S) More developed 72-hour embryos are more likely to become blastocysts and expand. Implantation rates are greater for the transfer of expanded rather than unexpanded blastocysts.

Dramatic declines in implantation and pregnancy rates in patients who undergo repeated cycles of in vitro fertilization with blastocyst transfer after one or more failed attempts

OBJECTIVE To compare the outcome of second and third cycles of in vitro fertilization with blastocyst transfer to the outcome of first attempts at IVF with blastocyst transfer. DESIGN Retrospective study. SETTING Private ART center. PATIENT(S) Three hundred and four patients undergoing treatment with in vitro fertilization with blastocyst transfer, 87 of which underwent at least one cycle of re-treatment after failing to achieve pregnancy in their first cycle. INTERVENTION(S) Bipronucleate oocytes were grown for up to 144 hours and subsequently transferred when at least one embryo attained the expanded blastocyst stage. MAIN OUTCOME MEASURE(S) Pregnancy and implantation rates. RESULT(S) Pregnancy rates per retrieval were significantly higher for patients undergoing their first cycle of in vitro fertilization with blastocyst transfer (36%) compared to those undergoing their second (19%) or their third (9%) cycles of treatment. Implantation rates per embryo were also higher for first cycles of in vitro fertilization with blastocyst transfer (30%) compared to second (18%) or third cycles (8%). CONCLUSION(S) Pregnancy and implantation rates decline dramatically in repeated cycles of in vitro fertilization with blastocyst transfer following one or more unsuccessful cycles of in vitro fertilization with blastocyst transfer.

Influence of patient age on the growth and transfer of blastocyst-stage embryos

OBJECTIVE To examine the effects of patient age on the growth and transfer of blastocyst-stage embryos. DESIGN Retrospective clinical study. SETTING Private assisted reproductive technologies center. PATIENT(S) Three hundred patients between the ages of 18 and 45 undergoing in vitro fertilization. INTERVENTION(S) Bipronucleate oocytes were grown for up to 144 hours and subsequently transferred when at least one embryo attained the expanded blastocyst stage. MAIN OUTCOME MEASURE(S) Oocytes retrieved and fertilized, blastocyst formation rates, implantation rates, and pregnancy rates per retrieval and transfer. RESULT(S) The rate of cycle cancellation before oocyte retrieval increased significantly with age, and the average number of oocytes per retrieval declined significantly with age. Fertilization rates were unrelated to patient age. The proportion of cycles with expanded blastocysts declined significantly with age. Pregnancy rates per stimulation declined with age, but pregnancy rates per transfer were approximately 50% across the entire age range studied. CONCLUSION(S) The decline in female fertility with age appears to be the result of reduced numbers of oocytes and the inability of fertilized oocytes to develop to the blastocyst stage. Implantation and pregnancy rates appear to be unaffected by age when blastocysts do form.