BackgroundTo preclude transfer of aneuploid embryos, current preimplantation genetic screening (PGS) usually involves one trophectoderm biopsy at blastocyst stage, assumed to represent embryo ploidy. Whether one such biopsy can correctly assess embryo ploidy has recently, however, been questioned.MethodsThis descriptive study investigated accuracy of PGS in two ways. Part I: Two infertile couples donated 11 embryos, previously diagnosed as aneuploid and, therefore, destined to be discarded. They were dissected into 37 anonymized specimens, and sent to another national laboratory for repeat analyses to assess (i) inter-laboratory congruity and (ii) intra-embryo congruity of multiple embryo biopsies in a single laboratory. Part II: Reports on human IVF cycle outcomes after transfer of allegedly aneuploid embryos into 8 infertile patients.ResultsOnly 2/11 (18.2 %) embryos were identically assessed at two PGS laboratories; 4/11 (36.4 %), on repeat analysis were chromosomally normal, 2 mosaic normal/abnormal, and 5/11 (45.5 %) completely differed in reported aneuploidies. In intra-embryo analyses, 5/10 (50 %) differed between biopsy sites. Eight transfers of previously reported aneuploid embryos resulted in 5 chromosomally normal pregnancies, 4 delivered and 1 ongoing. Three patients did not conceive, though 1 among them experienced a chemical pregnancy.ConclusionsThough populations of both study parts are too small to draw statistically adequately powered conclusions on specific degrees of inaccuracy of PGS, here presented results do raise concerns especially about false-positive diagnoses. While inter-laboratory variations may at least partially be explained by different diagnostic platforms utilized, they cannot explain observed intra-embryo variations, suggesting more frequent trophectoderm mosiaicsm than previously reported. Together with recentl published mouse studies of lineages-specific degrees of survival of aneuploid cells in early stage embryos, these results call into question the biological basis of PGS, based on the assumption that a single trophectoderm biopsy can reliably determine embryo ploidy.

Groups presented similar pregnancy (36.2% x 31.2%; p¼0.385) and multiple pregnancy rates (31.1% x 25.0%; p¼0.541).CONCLUSIONS: Limiting the number of embryos transferred can benefit the bottom line by decreasing the incidence of multiple pregnancy. We hypothesized that patients who failed in fresh eSET could present worst prognosis and hence had lower multiple pregnancy rates in a second attempt with two embryos transferred. However, in this sample, the second transfer with two elective embryos, after a failed elective transfer of one embryo, was not effective to protect this population of multiple gestation, suggesting that for this purpose the appointment of new elective transfer of an embryo would be the most appropriate for good prognosis patients, even after a failure Supported by: Not applicable.

The efficacy of different methods of fetal weight estimation using sonographic measurements of the abdominal circumference (AC), biparietal diameter (BPD), and femur length (FL), either alone or in combination, was evaluated in the fetus with intrauterine growth retardation (IUGR). Eighty-one patients, referred with a clinical suspicion of IUGR, were studied. All patients had sonographic measurements within 7 days of delivery. Four regression equations were used to estimate fetal weight: AC (Hadlock), BPD-AC (Shepard), AC-FL (Hadlock), BPD-AC-FL (Hadlock). For the total study group, as well as for the infants who were found to be IUGR at birth, 75% of the estimates of fetal weight using the BPD-AC-FL method were within 10% of the actual birthweight. Nearly comparable results were obtained using the AC-FL method. In the fetus with IUGR, estimates of fetal weight that incorporated the FL correlated best with the actual birthweight.

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