Transvaginal oocyte retrieval

Transvaginal oocyte retrieval (TVOR), also referred to as oocyte retrieval (OCR) or even simply egg collection, is a technique used in in vitro fertilization (IVF) in order to remove oocytes from the ovary of the female, enabling fertilization outside the body.^[1] Transvaginal oocyte retrieval can be called transvaginal ovum retrieval if the oocytes have matured into ova, as is normally the case in IVF.

Procedure

TVOR is performed in an operating room with the (female) patient in the lithotomy position. Initially performed using a transvaginal needle guided by transabdominal ultrasonography, TVOR is currently performed with a transvaginal ultrasound transducer with an attached needle.^[2] Once the follicle of the ovary is lined up with the guiding line of the transducer, the needle is advanced through the vaginal wall into the follicle of the ovary. Care is taken not to injure organs located between the vaginal wall and the ovary. Once the follicle is entered, suction is gently applied to aspirate follicular fluid and with it, hopefully, cellular material including the oocyte. Next, other follicles are aspirated. Once the ovarian follicles have been aspirated on one ovary, the needle is withdrawn, and the procedure repeated on the contralateral ovary. After completion, the needle is withdrawn, and hemostasis is achieved. The process takes about 20 minutes and is usually done under procedural sedation or general anesthesia.

The technique mostly succeeds after ovarian hyperstimulation, where oocytes are pharmacologically stimulated to mature. In addition, oocyte release triggering is usually performed to induce final maturation of oocytes. An agent used for this purpose is human chorionic gonadotropin (hCG). It would cause ovulation to occur between 38 and 40 hours after injection,^[3] but TVOR is typically performed at a time usually between 34 and 36 hours after hCG injection, that is, just prior to the expected rupture of the follicles. hCG injection confers a risk of ovarian hyperstimulation syndrome.

Complications

The retrieval can lead to complication resulting in injury to organs, bleeding, and infection. The aspirates are handed to the laboratory to examine it for oocytes. Among lean patients with polycystic ovary syndrome, ovarian hemorrhage after ultrasonographically guided transvaginal oocyte retrieval is a potentially catastrophic and not so rare complication.^[2]

Anecdotal evidence suggests that certain airborne chemical contaminants and particles, especially volatile organic compounds (VOC), may be toxic to and impair the growth and development of embryos if present in sufficient concentrations in the ambient atmosphere of an IVF incubator.^[4][5]

History

This technique was first developed by Pierre Dellenbach and colleagues in Strasbourg, France, in 1984 and introduced into the United States at the Genetics and IVF Institute in Virginia in 1985 with the help of Deborah Costakos.^[6]

References

1. ^ "Performing ultrasound-guided oocyte retrieval: RCN guidance for fertility nurses". London: Royal College of Nursing. 2004. http://www.rcn.org.uk/publications/pdf/ultrasound-guided-oocyte-retrieval.pdf. Retrieved 2011-08-01. 
2. ^ ^{a b} Liberty G, Hyman JH, Eldar-Geva T, Latinsky B, Gal M, Margalioth EJ (2008). "Ovarian hemorrhage after transvaginal ultrasonographically guided oocyte aspiration: a potentially catastrophic and not so rare complication among lean patients with polycystic ovary syndrome". Fertil Steril 93 (3): 874–9. doi:10.1016/j.fertnstert.2008.10.028. PMID 19064264. 
3. ^ Kovacs P (2004). "HCG Injection After Ovulation Induction With Clomiphene Citrate". Medscape. http://www.medscape.com/viewarticle/473515. Retrieved 2011-08-01. 
4. ^ Cohen J, Gilligan A, Esposito W, Schimmel T, Dale B (1997). "Ambient air and its potential effects on conception in vitro". Human Reproduction 12 (8): 1742–9. PMID 9308805. http://www.humrep.oxfordjournals.org/content/12/8/1742.full.pdf. 
5. ^ Cohen J, Gilligan A, Willadsen S (1998). "Culture and quality control of embryos". Hum Reprod 1998 13 (Suppl 3): 137–44. http://www.humrep.oxfordjournals.org/content/13/suppl_3/137.full.pdf. 
6. ^ Schulman JD, Dorfmann AD, Jones SL, Pitt CC, Joyce B, Patton LA (1987). "Outpatient in vitro fertilization using transvaginal ultrasound-guided oocyte retrieval". Obstetrics and Gynecology 69 (4): 665–8. PMID 3103035. 

Further reading

• Bracha, J., Lotan, M. and Zakut, H. (1988) Ovarian abscess following cesarean section. A case report and review of the literature. Clin. Exp. Obstet. Gynecol., 15, 134–136.
• Coroleu, B., Lopez-Mourelle, F., Hereter, L. et al. (1997). Ureteral lesion secondary to vaginal ultrasound follicular puncture for oocyte recovery in in-vitro fertilization. Hum. Reprod., 12, 948–950.
• Dicker, D., Ashkenazi, J., Feldberg, D. et al. (1993) Severe abdominal complications after transvaginal ultrasonographically guided retrieval of oocytes for in vitro fertilization and embryo transfer. Fertil. Steril., 59