P-58 Dynamic Analysis of the Relationship Between the Collapse of Blastulation and Hatching in Human Blastocysts Using Time-Lapse Cinematography. K. Yumoto,a K. Iwata,a C.H. Sargent,a Y. Kai,a A. Imajyo,a Y. Iba,a Y. Mio.a a Mio Fertility Clinic, Reproductive Centre. OBJECTIVE(S): Blastocyst hatching is the final stage of human embryonic development before implantation, although the mechanisms underlying this process remain unknown. We previously demonstrated that human blastocysts developed in vitro show repeated expansion and collapse of blastulation, and that the blastula collapse might be associated with disturbance of the trophectoderm (TE). In addition, analysis of the hatching process by time-lapse cinematography (TLC) showed the collapse of blastulation in some fully expanded human blastocysts resulting in formation of a hatching site in the ZP. This study further investigated the relationship between the collapse of blastulation and the outcome of hatching in human blastocysts using TLC. MATERIALS AND METHOD(S): Surplus frozen/thawed early-stage embryos (n¼131) were used in this study. Embryos were maintained at optimal culturing conditions for up to 5 days and images were recorded digitally every 1 to 5 minutes with an exposure time of 1/20 second. Out of those embryos, 44 that had developed into fully expanded blastocysts with formation of a hatching site in the ZP were further analyzed. RESULT(S): Of the 44 fully expanded blastocysts, 36 (81.8%) completely escaped from the ZP [hatching (+)] and the remaining blastocysts degenerated without hatching [hatching (-)]. The difference in collapse frequencies between hatching (+) and (-) was significant (P<0.05). In the hatching (+) blastocysts from the formation of the hatching site to the completion of escape, 9 (27.3%) showed no blastula collapse, while 17 (51.5%) showed partial collapse, and 7 (21.2%) showed general collapse. The time difference was significant between the no-collapse and general-collapse groups (P<0.05). In contrast, out of 44 fully expanded blastocysts with hatching site, 27 (61.3%) formed the hatching site by retracting the ZP followed by the blastula collapse (inward pattern), while the remaining blastocysts formed the hatching site outwardly by constant expansion of the blastula (outward pattern). CONCLUSION(S): This study demonstrated that blastula collapse had a detrimental effect on the viability of fully expanded blastocysts during the hatching process. That the blastula collapse was caused by a disturbance of the TE strongly suggests that this phenomenon is a negative impact of extended culture in vitro. In addition, the time required for completion of the blastocyst escape was shortest in those showing no collapse. Further investigations using TLC are necessary to elucidate the physiological impact of blastula collapse during hatching with respect to different culturing conditions in vitro and in vivo.
P-59 Characteristics of Menstrual Cycle Manipulation With Combined Hormonal Contraception in a University Student Population. Hannah Lakehomer,a Paul Kaplan,a David Wozniak,b Chris Minson.a a University of Oregon; b Eastern Michigan University. BACKGROUND: We have observed an increasing number of young women manipulating their monthly menstrual cycles with the use of combined hormonal contraception methods. OBJECTIVE(S): To assess the frequency and characteristics of menstrual cycle manipulation with combined hormonal contraception among a population of college-age women. MATERIALS AND METHOD(S): From April to May 2011, a self-administered email survey of menstrual cycle practices and beliefs was distributed to all female students at the University of Oregon. Assessment of survey participant characteristics, menstrual cycle manipulation features, and attitudes and knowledge toward hormonal contraception was analyzed using standard statistical methods as well as probit models to measure frequencies and associations. RESULT(S): An estimated 11,900 email surveys were distributed with 1719 (14.4%) initial responses. Of respondents, 1374 (79.9%) reported using combined hormonal contraception currently or recently and 275 (20%) of these women reported altering their menstrual cycle pattern or using extended cycle regimens to delay or skip their menstrual periods. Of cycle ma-
nipulators, 50% indicated that they delayed or skipped their menstrual cycle for convenience or scheduling purposes. In this same group, 50% of women indicated that they learned to manipulate their menstrual cycle from healthcare professionals, while about 30% indicated their source of information was from family or friends. Women who were taking hormonal contraceptives for period regulation, of Asian race, on a regular exercise program, and who preferred to menstruate monthly were all less likely to manipulate their menstrual cycle. The likelihood of females manipulating their menstrual cycle increased as their age increased. Menstrual cycle manipulation was also more likely to be practiced by pill users, females that preferred to menstruate less than monthly, and females who felt fairly knowledgeable about their birth control. CONCLUSION(S): A significant percentage of university-aged women who use combined hormonal contraceptives choose to manipulate their menstrual cycle and the characteristics of these women may predict probability of this choice. The majority of these women are manipulating their menstrual cycle because of convenience rather than to avoid menstrual symptoms and a significant number of women who do manipulate their cycles through are learning to do so from friends or other nonmedical sources. FINANCIAL SUPPORT: NIH Grant HL081671
P-60 Analysis of Compaction Initiation in Human Embryos Using TimeLapse Cinematography. C.H Sargent, K. Iwata, Y. Kai, A. Imajo, K. Yumoto, Y. Iba, Y. Mio. Mio Fertility Clinic Reproductive Centre. OBJECTIVE(S): Compaction, the first morphologically evident differentiation event in embryonic development, occurs at the late eight-cell stage in mouse embryos. We used time-lapse cinematography to examine the timing of initiation of this event in cultured human embryos. MATERIALS AND METHOD(S): We developed a new system for timelapse cinematography (TLC), which uses an inverted microscope with differential interference contrast (DIC) optics and a micromanipulator covered with a handcrafted chamber of acrylic resin. The temperature was maintained at 37 0.2 C and pH at 7.37 0.05 by controlling CO2 flow. Digital images of the cultured embryos were acquired for 5 days with an exposure time of 1/ 20seconds. Of 96 donated embryos frozen at early stage (pronuclear stage to 4 cell stage), 78 successfully developed to blastocyst stage and could be analyzed. RESULT(S): The mean cell number at initiation of compaction was 10.2 2.9 (range, 4-16 cells). Despite some variability in the timing, the 8-cell stage was the most common cell stage at which compaction started (24.4%, 19/78), and 91% (n¼71) of the embryos started compaction at or after the 8-cell stage. Embryos in which compaction was initiated before the 8-cell stage (n¼7) did not continue to develop normally; 6 of these embryos had multinuclear blastomeres. CONCLUSION(S): Despite variability in timing, compaction is initiated at the 8-cell stage or later in more than 90% of human embryos. Initiation earlier than the 8-cell stage was associated with increased incidence of abnormal aneuploid blastomeres, suggesting that early initiation of compaction may affect cytokinesis after karyokinesis.
P-61 Uterine Didelphys With Obstructed Hemivagina and Ipsilateral Renal Agenesis Presenting With Hydronephrosis. Nina Resetkova, Mindy Christianson, Lisa Kolp. BACKGROUND: Mullerian anomalies are present in 7% of the female population with a multifactorial pathogenesis thought to be associated with a midline fusion defect. OHVIRA (Obstructed Hemivagina and Ipsilateral Renal Anomaly) Syndrome comprises about 2-3% of Mullerian abnormalities. Case reports and small series have reported on this syndrome, which most commonly presents in young females with abdominal pain and a pelvic mass. OBJECTIVE(S): To report a case of OVIRA presenting with hydronephrosis. MATERIALS AND METHOD(S): Case Report RESULT(S): A 12 year-old, nulligravid African-American female presented to the emergency department complaining of abdominal pain, flank pain and inability to urinate. Her past medical history was significant for right renal agenesis. She had menarche at 11 years old with significant
Vol. 97, No. 3, Supplement, March 2012