Anesthesia for In Vitro Fertilization
In vitro fertilization (IVF) is a complex series of procedures used to help with fertility, prevent genetic problems and assist with childbearing.1 In IVF, mature eggs (oocytes) are collected from the ovaries and fertilized by sperm in a lab; then, the fertilized egg or eggs are transferred to a uterus.1 One cycle of IVF takes about three weeks, though it may take multiple cycles for a patient to become pregnant.1 The success of IVF depends on factors such as age and the cause of infertility, and IVF can be time-consuming, expensive and invasive.1 The initial oocyte retrieval is painful and must be conducted under ultrasound guidance.2 Thus, an anesthesiology practitioner needs to be present to provide anesthesia or sedation.2 Because of the complex and delicate nature of IVF procedures, anesthesia providers must have in-depth knowledge about the IVF process and their own role in oocyte retrieval.
IVF began to rise in popularity in 1978 with Louise Brown, the first live birth from fertilization outside the human body.3 It is used for patients who have ovaries, but whose uterine tubes are damaged or occluded, thus not allowing eggs and sperm to meet inside the body.3 IVF is an intensive process, including blood tests, pelvic exams and transvaginal ultrasounds.4 Contemporary IVF also includes ovarian stimulation, which is used to generate as many mature eggs as possible and increase the odds of conception.3 Stimulation is produced by medications, including follicle stimulating hormone (FSH) and luteinizing hormone (LH) derivatives and human chorionic gonadotropin (hCG), which are injected for eight to 14 days to produce ovulation.4 After the final shot of hCG, the clinician will retrieve oocytes from the patient’s ovary. This entails using ultrasound to examine the ovaries and then guiding a needle into each ovary, which will puncture the ovaries and capture the eggs.4 The next steps involve fertilizing the eggs in vitro (i.e., in the laboratory) and transferring them back to a uterus (belonging either to the patient or a surrogate).3 Clearly, the IVF process is complicated and invasive, and some procedures can be painful.2
The anesthesia provider plays a crucial part in the most painful steps of IVF, such as oocyte retrieval.5 Due to ethical reasons, it can be difficult to study best anesthetic practices in IVF with randomized controlled trials.2 Thus, though many anesthetic modalities and procedures have been tested in various studies, there are no definite conclusions about the best types of anesthesia for IVF.6 However, according to a review by Sharma et al., research shows that anesthetic drugs have been detected in the oocyte follicular fluid and could potentially influence oocyte fertilization and implantation.6 A retrospective study by Tola found that ketamine use during oocyte retrieval can decrease fertilization rate compared to propofol and a propofol and ketamine combination.7 Additionally, long durations of anesthesia also seemed to decrease implantation and pregnancy rates.7 Guasch et al. state that though more research is needed for the ideal drug combination or modality, anesthesia providers may want to consider spinal anesthesia and nerve blockades for oocyte retrieval.8 Indeed, Rolland et al. found that paracervical block and general anesthesia for oocyte retrieval produced similar live birth rates later on, suggesting that the type of anesthesia should be the patient’s choice.9 Given these data, researchers suggest that anesthetic techniques for oocyte retrieval should be individualized,6 should aim to reduce anxiety10 and should cause minimal harm to the oocyte and embryo.2
IVF is a psychologically and physically taxing process. Thus, an anesthesia provider is vital in reducing the patient’s anxiety and pain. Anesthetic techniques for oocyte retrieval in IVF should be based on the patient’s preferences and minimize any harmful pregnancy-related outcomes. Future research is needed to determine the exact effects of various anesthetic drugs and processes on oocytes, embryos and pregnancies, as well as the best anesthetic technique for pain and anxiety reduction in the patient.
1. Mayo Clinic. In vitro fertilization (IVF). Tests & Procedures June 22, 2019; https://www.mayoclinic.org/tests-procedures/in-vitro-fertilization/about/pac-20384716.
2. Fitzgerald J, Higgins N, Loughrey JPR. Infertility Treatment: The Role of Anesthesia Techniques. In: Goudra BG, Singh PM, eds. Out of Operating Room Anesthesia: A Comprehensive Review. Cham: Springer International Publishing; 2017:357–367.
3. Wang J, Sauer MV. In vitro fertilization (IVF): A review of 3 decades of clinical innovation and technological advancement. Therapeutics and Clinical Risk Management. 2006;2(4):355–364.
4. Aspire Fertility. IVF Process. In Vitro Fertilization (IVF) 2020; https://www.aspirefertility.com/fertility-treatment/ivf/ivf-process.
5. Nagarajan S, Lew E. Practical Problems in Assisted Conception. In: Cheong Y, Tulandi T, Li T-C, eds. Anesthetic Choices in IVF Practice. Cambridge, UK: Cambridge University Press; September 20, 2018.
6. Sharma A, Borle A, Trikha A. Anesthesia for in vitro fertilization. Journal of Obstetric Anaesthesia and Critical Care. 2015;5(2):62–72.
7. Tola EN. The effect of anesthetic agents for oocyte pick-up on in vitro fertilization outcome: A retrospective study in a tertiary center. Taiwanese Journal of Obstetrics and Gynecology. 2019;58(5):673–679.
8. Guasch E, Gómez R, Brogly N, Gilsanz F. Anesthesia and analgesia for transvaginal oocyte retrieval. Should we recommend or avoid any anesthetic drug or technique? Current Opinion in Anesthesiology. 2019;32(3):285–290.
9. Rolland L, Perrin J, Villes V, Pellegrin V, Boubli L, Courbiere B. IVF oocyte retrieval: Prospective evaluation of the type of anesthesia on live birth rate, pain, and patient satisfaction. Journal of Assisted Reproduction and Genetics. 2017;34(11):1523–1528.
10. Vlahos NF, Giannakikou I, Vlachos A, Vitoratos N. Analgesia and anesthesia for assisted reproductive technologies. International Journal of Gynaecology and Obstetrics. 2009;105(3):201–205.