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. Transvaginal oocyte retrieval is more properly referred to as transvaginal ovum retrieval when the oocytes have matured into ova, as is normally the case in IVF.
Under ultrasound guidance, the operator inserts a needle through the vaginal wall and into an ovarian follicle, taking care not to injure organs located between the vaginal wall and the ovary. The other end of the needle is attached to a suction device. Once the follicle is entered, suction is gently applied to aspirate follicular fluid and with it, hopefully, cellular material including the oocyte. The follicular fluid is delivered to a technician in the IVF laboratory to identify and quantify the ova. 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 Once the ovarian follicles have been aspirated on one ovary, the needle is withdrawn, and the procedure repeated on the other ovary. It is not unusual to remove 20 oocytes as women are generally hyperstimulated in advance of this procedure. After completion, the needle is withdrawn, and hemostasis is achieved. The procedure usually lasts from 20–60 minutes.
Follicular flushing has not been found to increase pregnancy rates, nor result in an increase in oocyte yield. On the other hand, it requires a significantly longer operative time and more analgesia.
Initially performed using transabdominal ultrasonography, TVOR is currently performed with a transvaginal ultrasound transducer with an attached needle. TVOR is performed in an operating room or a physician's office, with the (female) subject in the lithotomy position. TVOR is usually performed under procedural sedation, general anesthesia, paracervical block, or sometimes spinal anesthesia. Local anesthesia is not typically used because local anesthetic agents interfere with follicular cleavage and the technique requires multiple needle punctures.
TVOR is typically performed after ovarian hyperstimulation, where oocytes are pharmacologically stimulated to mature. When the ovarian follicles have reached a certain degree of development, induction of final oocyte maturation is performed, generally by an intramuscular or subcutaneous injection of human chorionic gonadotropin (hCG). TVOR is typically performed 34–36 hours after hCG injection, when the eggs are fully mature but just prior to rupture of the follicles.
Injection of hCG as a trigger for ovulation confers a risk of ovarian hyperstimulation syndrome, especially in women with polycystic ovary syndrome who have been hyperstimulated during previous assisted reproduction cycles.
Complications of TVOR include injury to pelvic organs, hemorrhage, and infection. Occurring more often in lean patients with polycystic ovary syndrome, ovarian hemorrhage after TVOR is a potentially catastrophic and not so rare complication. Additional complications may result from the administration of intravenous sedation or general anesthesia. These include asphyxia caused by airway obstruction, apnea, hypotension, and pulmonary aspiration of stomach contents.
Propofol-based anesthetic techniques result in significant concentrations of propofol in follicular fluid. As propofol has been shown to have deleterious effects on oocyte fertilization (in a mouse model), some authors have suggested that the dose of propofol administered during anesthesia should be limited, and also that the retrieved oocytes should be washed free of propofol. 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.
This technique was first developed by Pierre Dellenbach and colleagues in Strasbourg, France, and reported in 1984. Steptoe and Edwards used laparoscopy to recover oocytes when IVF was introduced, and laparoscopy was the major method of oocyte recovery until TVOR was introduced.
- "Performing ultrasound-guided oocyte retrieval: RCN guidance for fertility nurses". London: Royal College of Nursing. 2004. Retrieved 2011-08-01.
- Farquhar, C.; Rishworth, J. R.; Brown, J.; Nelen, W. L. M.; Marjoribanks, J. (2013). Brown, Julie, ed. "Assisted reproductive technology: an overview of Cochrane Reviews". The Cochrane Library. doi:10.1002/14651858.CD010537.pub2. PMID 23970457.
- Killick, S (2006). "Ultrasound and fertility". In Bates, J. Practical gynaecological ultrasound (2nd ed.). Cambridge, England: Cambridge University Press. pp. 120–5. ISBN 9780521674508.
- Yasmin E, Dresner M, Balen A (2004). "Sedation and anaesthesia for transvaginal oocyte collection: an evaluation of practice in the UK". Human Reproduction 19 (12): 2942–5. doi:10.1093/humrep/deh526. PMID 15388681.
- Sequeira, PM (2011). "Anesthesia for in vitro fertilization". In Urman RD, Gross WL, Philip BK. Anesthesia outside of the operating room (1st ed.). Oxford, England: Oxford University Press. pp. 198–205. ISBN 9780195396676.
- Bumen S, Gunusen I, Firat V, Karaman S, Akdogan A, Tavmergen Goker EN (2011). "A comparison of intravenous general anesthesia and paracervical block for in vitro fertilization: effects on oocytes using the transvaginal technique". Turkish Journal of Medical Science 41 (5): 801–8. doi:10.3906/sag-1009-1101.
- Viscomi CM, Hill K, Johnson J, Sites C (1997). "Spinal anesthesia versus intravenous sedation for transvaginal oocyte retrieval: reproductive outcome, side-effects and recovery profiles". International Journal of Obstetric Anesthesia 6 (1): 49–51. doi:10.1016/S0959-289X(97)80052-0. PMID 15321311.
- Saxena R, Sood J, Kumra VP (2005). "Comparison of various sedation techniques for transvaginal oocyte retrieval in a daycare set up". Indian Journal of Anaesthesia 49 (2): 16–21.
- Stelling JR, Chapman ET, Frankfurter D, Harris DH, Oskowitz SP, Reindollar RH (2003). "Subcutaneous versus intramuscular administration of humanchorionicgonadotropin during an in vitro fertilization cycle". Fertility and Sterility 79 (4): 881–5. doi:10.1016/S0015-0282(02)04918-X. PMID 12749424.
- Kovacs, P (2004). "HCG injection after ovulation induction with clomiphene citrate". Medscape. Retrieved 2011-08-01.
- Oyawoye OA, Chander B, Hunter J, Gadir AA (2005). "Prevention of Ovarian Hyperstimulation Syndrome by Early Aspiration of Small Follicles in Hyper-responsive Patients With Polycystic Ovaries During Assisted Reproductive Treatment Cycles". Medscape General Medicine 7 (3): 60. PMC 1681679. PMID 16369286.
- 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". Fertility and Sterility 93 (3): 874–9. doi:10.1016/j.fertnstert.2008.10.028. PMID 19064264.
- Christiaens, F; Janssenswillen, C; Verborgh, C; Moerman, I; Devroey, P; Van Steirteghem, A; Camu, F (1999). "Propofol concentrations in follicular fluid during general anaesthesia for transvaginal oocyte retrieval". Human Reproduction 14 (2): 345–8. doi:10.1093/humrep/14.2.345. PMID 10099976.
- 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. doi:10.1093/humrep/12.8.1742. PMID 9308805.
- Cohen J, Gilligan A, Willadsen S (1998). "Culture and quality control of embryos". Human Reproduction 13 (Suppl 3): 137–44. doi:10.1093/humrep/13.suppl_3.137.
- Dellenbach P, Nisand I, Moreau L, Feger B, Plumere C, Gerlinger P, Brun B, Rumpler Y. "Transvaginal, sonographically controlled ovarian follicle puncture for egg retrieval.". Lancet. 1984 Jun 30;1(8392):1467. PMID 6145902.
- 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, 134–6.
- 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, 948–50.
- 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
- Tsen, LC (2002). From Darwin to desflurane: anesthesia for assisted reproductive technologies. IARS Review Course Lectures (San Francisco, California: International Anesthesia Research Society). pp. 109–13.