Controversy exists regarding the effects of anesthetic
drugs administered during transvaginal
puncture procedures for oocyte retrieval on ART
outcome. Anesthetics have been detected in follicular
fluid, (1–3); both animal (
Concerns regarding the potentially deleterious
effects of anesthetic drugs have led to the use of
anesthetic techniques that minimize exposure. Increasingly,
these procedures are performed with
sedative and/or analgesic drugs as part of a monitored
anesthesia care (MAC) technique, particularly
in oocyte retrieval (
Remifentanil, which is a rapid and ultra-short
acting opioid analgesic, has been successfully
used for ultrasonic-guided oocyte retrieval procedures
as part of an MAC technique.(
This double-blind, randomized clinical trial was carried out in the Yazd Research and Clinical Center for Infertility, Yazd, Iran. A total of 145 American Society of Anesthesiologists (ASA) physical status I women who were participating in an intracytoplasmic sperm injection (ICSI) program were studied. The study was approved by the Institutional Review Board at the Yazd Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Science and Health Services. Written informed consent was obtained from all participants. All patients were scheduled for identical ovarian stimulation and ultrasonically guided transvaginal follicular aspiration protocols. Women underwent microinjection cycles with a long protocol.
During the study (March 2006 to January 2007), all patients received standardized monitored anesthesia care with remifentanil (1μg/kg IV) or fentanyl (2μg/kg IV) and thiopental (5 mg/kg IV) after 2 minutes. In the first phase of the study, we compared the mean systolic and diastolic blood pressure (millimeter Hg) in addition to the mean pulse rate (beats/minute).
If serum β human chorionic gonadotropin (HCG) level was greater than 10 after the 12th week of gestation, the procedure was considered a success. The primary endpoint was pregnancy rate per transfer. The numbers of oocytes collected, fertilized and cleaved were recorded, as was the number of oocytes transferred and recovery profile. In the second phase of the study, all patients were followed for outcome of ART cycle.
Statistical analysis consisted of the chi-square test for nominal and student’s t test for numerical data using SPSS computer software (version 11.5), with p values <0.05 statistically significant.
Only mature MII oocytes were included in the ICSI program. After 16 to 18 post-oocyte microinjections, all oocytes were microscopically observed for signs of fertilization. Fertilization was confirmed when two pronuclei were present within the ooplasm. The rate of fertilization was calculated as the percentage of the fertilized oocytes per MII oocytes. Exactly 24 hours after fertilization, cleaved embryos were assessed and graded according to the degree of fragmentation and size of blastomeres. These were categorized into four groups: A (score 18-20), B (score 16-17), C (score 14-15) and D (score 12-13). In general, grade D embryos were discarded.
Patient characteristics in the two study groups
|Characteristics||Remifentanil (n=70)||Fentanyl (n=75)||P-value|
|3.68 ± 3.44||3.04 ± 2.86||0.231|
|5.11 ± 3.48||3.58 ± 2.99||0.006|
|17.62 ± 2.16||16.8 ± 2.29||0.032|
|2.33 ± 1.21||2.26 ± 1.01||0.699|
Patient recovery profile in the two study groups
|12.84 ± 1.29||12.84 ± 1.67||0.423|
|7.55 ± 0.79||7.59 ± 0.81||0.723|
|80.59 ± 7.49||84.56 ± 9.47||0.006|
Although the numbers of oocytes harvested, fertilized and transferred in both study groups were similar, the pregnancy rate was significantly higher after remifentanil than after fentanyl (21.43% vs. 16%) (p<0.05). However, the recovery times were significantly shorter with the remifentanil group versus the fentanyl group (p< 0.05; Table 2).
This prospective study suggests that in women undergoing transvaginal ultrasound-guided oocyte retrieval procedures, the likelihood of a successful pregnancy is higher with a remifentanil-based MAC technique than with a fentanyl-based MAC technique.
Anesthetic drugs have been detected in follicular
These findings are supported by a recent preliminary
report by Toon et al. (
Interestingly, the use of electroacupuncture in
combination with a paracervical block for oocyte
aspiration has been judged a good alternative to an
opioid-based MAC technique, with an even higher
pregnancy rate (
It is difficult to identify precisely which anesthetic
drug was responsible for the difference in pregnancy
outcome observed between the MAC and general
anesthesia groups. Of interest, Stapleton et al.
were unable to demonstrate a difference in outcome
The duration of anesthesia or analgesia, as well
as the procedural times, was significantly shorter
with MAC than with general anesthesia. Interestingly,
a similar finding has been reported recently
in outpatients undergoing anorectal surgery procedures
with MAC versus general anesthesia (
Pregnancy rates in women undergoing transvaginal oocyte retrieval for ART were higher with a remifentanil-based MAC technique than with a fentanyl-based MAC.