title: Ratio between inner cell mass diameter and blastocyst diameter is correlated with successful pregnancy outcomes of single blastocyst transfers.
abstract: OBJECTIVE
  To evaluate the ability to predict pregnancy outcomes of single-blastocyst transfers by measuring the ratio of inner cell mass (ICM) diameter to blastocyst diameter using time-lapse images.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  University-affiliated medical center.
  
  
  METHODS
  One hundred twenty-seven women undergoing a total of 129 blastocyst transfers with intracytoplasmic sperm injection.
  
  
  METHODS
  Embryo monitoring by time-lapse microscopy.
  
  
  METHODS
  The ratio of ICM diameter to blastocyst diameter in single-blastocyst transfers and clinical pregnancy rates.
  
  
  RESULTS
  In phase I of the study, 63 women underwent 65 single blastocyst transfers that resulted in 25 pregnancies (40% of the women). The successfully implanted blastocysts had an average ICM/blastocyst diameter ratio of 0.487 ± 0.086, whereas the average ICM/blastocyst ratio of nonimplanted blastocysts was significantly lower (0.337 ± 0.086). The live-birth rate was 29% (18/63). In phase II, 64 single-blastocyst transfers were performed in 64 women. The ICM/blastocyst diameter ratio was measured, and blastocysts with the highest ratios were chosen for transfer. Forty-three women (67%) with an average ICM/blastocyst diameter ratio of 0.46 achieved pregnancy, and 36 of the 43 pregnancies (84%) resulted in the delivery of a healthy baby. In the 21 women (33%) who failed to achieve pregnancy, the average ICM/blastocyst ratio was 0.45. The resultant positive predictive value was 74%, and the negative predictive value was 70%.
  
  
  CONCLUSIONS
  The ICM-to-blastocyst diameter ratio is a predictor of implantation and live birth in single-blastocyst transfers, offering a simple, noninterfering method to select blastocysts with high developmental capacity.
authors: Infertility and IVF Unit, Kaplan Medical Center, Rehovot, Israel, Hebrew University, Jerusalem, Israel. Electronic address: miriamal@clalit.org.il.
authors: Miriam
authors: M
authors: Almagor
authors: Infertility and IVF Unit, Kaplan Medical Center, Rehovot, Israel, Hebrew University, Jerusalem, Israel.
authors: Yael
authors: Y
authors: Harir
authors: Infertility and IVF Unit, Kaplan Medical Center, Rehovot, Israel, Hebrew University, Jerusalem, Israel.
authors: Sheila
authors: S
authors: Fieldust
authors: Infertility and IVF Unit, Kaplan Medical Center, Rehovot, Israel, Hebrew University, Jerusalem, Israel.
authors: Yuval
authors: Y
authors: Or
authors: Infertility and IVF Unit, Kaplan Medical Center, Rehovot, Israel, Hebrew University, Jerusalem, Israel.
authors: Zeev
authors: Z
authors: Shoham
mesh_terms: D000046:Academic Medical Centers; D000328:Adult; D001755:Blastocyst / Q000166:cytology*; D053624:Blastocyst Inner Cell Mass / Q000166:cytology*; D046149:Embryo Culture Techniques; D010064:Embryo Implantation; D005260:Female; D005298:Fertility; D006801:Humans; D007246:Infertility / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D050498:Live Birth; D011237:Predictive Value of Tests; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D056826:Single Embryo Transfer / Q000009:adverse effects; D020554:Sperm Injections, Intracytoplasmic / Q000009:adverse effects; D059008:Time-Lapse Imaging; D016896:Treatment Outcome
keywords: Blastocyst grading; inner cell mass; pregnancy; time-lapse