Proficiency in oocyte retrieval: plausible steps before perfection

22 08 2011

To the Editor:

We read with interest the retrospective analysis by Goldman et al (1). The authors attempt to determine the minimum number of procedures required for proficiency in oocyte retrieval (OR). Assessing and classifying the technical competence of a trainee objectively is quite difficult for two reasons: first, there is no clear definition of “competence,” as operative skill is a combination of knowledge, judgment, and technical ability (2). Second, the success of an OR depends on additional parameters, such as patient, nurse and embryologist compliance. We would like to share our thoughts on their work.

In cases of ORs, competence can be measured quantitatively. However, we are in agreement with the authors that there is a lack of structured assessments and limited acceptance of those which exist. In this study, the CUSUM methodology–reported by them (1)–could be used in their trial to accurately indicate when the trainee learning curve is complete, adding a qualitative element to their assessment.

The investigators adopted a proficiency score utilizing follicles ≥12 mm: we cannot be certain if, at that diameter, an oocyte exists for sure and that therefore its retrieval could be used to define trainees’ competence (3). For that reason, we feel it would be better to employ diameters of >14mm as a quantitative assessment tool. In addition, the score was calculated based on the ratio between oocytes retrieved to those expected. Parameters such as the suction pressure at recovery, the technique itself (use and number of flushings, type of puncturing the ovary, the operative time), the nurse’s and embryologists’ ability of locating and manipulating the oocyte and the operative room conditions are equally important and play a distinct role during an OR. We would thus suggest implantation, clinical pregnancy or, ultimately, live-birth rate as more significant primary outcomes.

Moreover, we would propose that supplementary data on complications during OR have to be taken into account. Although rare, during training they are a significant endpoint. Pain scores, vaginal or intraperitoneal bleeding, organs’ injuries, infections or pelvic abscesses and need for an extra surgery (4) are complications that could improve and solidify the assessment scheme credibility. The latter could be further improved upon with a larger number and especially the randomization of the trainees in a well-designed RCT, so that conclusions would be more robust.

Finally, we would like to comment on the operative conditions that the assessment took place. Exclusion of difficult cases constitutes an environment we feel is removed from clinical reality. The real meaning of training clinicians is to render them capable to handle the difficult situations independently. In many Assisted Reproduction Units the OR is performed under conscious sedation delivered by the provider, with the husband sitting next to the patient, a nurse and an embryologist participating in the procedure, while time is of the essence, creating a demanding and stressful environment.

We appreciate the effort made by authors to assess the competence in a data driven fashion. Nevertheless, perception, integration, and automatization are the three steps required to develop technical competence (5). Trainees’ development into competent specialists entails acquisition of both cognitive and motor skills (2), together with communicational properties.

Charalampos Siristatidis, M.D., Ph.D.
Antonis Lykakis, M.D.
Charalampos Chrelias, M.D., Ph.D.
University of Athens
Athens, Greece

1. Goldman KN, Moon KS, Yauger BJ, Payson MD, Segars JH, Stegmann BJ. Proficiency in oocyte retrieval: how many procedures are necessary for training? Fertil Steril 2011;95:2279-82.

2. Kenton K. How to Teach and Evaluate Learners in the Operating Room. Obstet Gynecol Clin North Am 2006;33:325-32.

3. Wittmaack FM, Kreger DO, Blasco L, Tureck RW, Mastroianni JL, Lessey BA. Effect of follicular size on oocyte retrieval, fertilization, cleavage, and embryo quality in in vitro fertilization cycles: a 6-year data collection. Fertil Steril 1994;62:1205-10.

4. Ludwig AK, Glawatz M, Griesinger G, Diedrich K, Ludwig M. Perioperative and post-operative complications of transvaginal ultrasound-guided oocyte retrieval: prospective study of >1000 oocyte retrievals. Hum Reprod 2006;21:3235-40.

5. Kopta JA. An approach to the evaluation of operative skills. Surgery 1971;70:297-303.

Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2011.08.030

The Authors Respond:

We thank the correspondents for their interest in our paper and appreciate the suggestion that the cumulative summation test for learning curve, or CUSUM, methodology could have been employed in our study to assess competence. However, we assert that this methodology mirrors the quantitative assessment that we employed.

The CUSUM methodology utilizes objective data to compile a graphical representation indicating when a learner has reached a predefined level of performance (1). But as we explained in our previous response, this model is simply not appropriate to this training situation ( Oocyte retrieval is a skill that can be measured quantitatively, and therefore we used quantitative data as a surrogate for proficiency. However, we do not dispute that an ideal assessment tool would synthesize both quantitative and qualitative measures to discern competence in a trainee.

We acknowledge the suggestion that follicles ≥14mm could have been used as an alternative to follicles >12mm. Our decision was based on a study by Wittmaack et al, in which follicular fluid volume of >1 mL (follicular size ≥12mm) corresponded with optimal oocyte recovery, fertilization, and cleavage in IVF cycles (2). Our data ultimately supported this assumption given that a greater number of oocytes were retrieved than were expected based on the number of 12 mm follicles.

We agree that multiple parameters influence the success of oocyte retrieval, and to minimize the influence of these parameters, all oocyte retrievals were performed at the Walter Reed Army Medical Center with the same experienced staff and embryologists. While implantation, clinical pregnancy, or live birth are also acceptable outcomes, given the many steps following oocyte retrieval that are often performed by other providers, it would be difficult to adequately attribute those outcomes to the trainee performing the retrieval.

We also know that provider plays a role in the success of embryo transfer (3), and therefore clinical pregnancy outcomes would only be attributable to the trainee if he or she performed both the oocyte retrieval and the embryo transfer and if the embryo quality was identical. And while complications during oocyte retrieval are rare, they are an important endpoint. However, our database did not contain information on complications and we were, therefore, unable to adequately assess the rate of complications in relation to a trainee’s proficiency.

Finally, we agree that a clinician must be capable of handling challenging situations independently. However, training is precisely the time when a clinician should be supervised in order to gain these skills. As clinicians, our ultimate responsibility is to the patient and it is in the patient’s best interest that difficult and high risk procedures are performed by experienced clinicians. Oocyte retrievals can certainly become stressful, particularly when a patient’s family member is present and observing, but this is precisely why it is crucial to learn the procedure in a supervised fashion in order to strengthen one’s skills in a controlled environment.

Kara N. Goldman, M.D. a,b
Kimberly S. Moon, M.D.a
Belinda J. Yauger, M.D.a
Mark D. Payson, M.D.a,c
James H. Segars, M.D.a
Barbara J. Stegmann, M.D., M.P.H.d

aProgram of Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
bDepartment of Obstetrics and Gynecology, Northwestern University, Prentice Women’s Hospital, Chicago, Illinois
cAssisted Reproductive Technologies Program, Division of Reproductive Endocrinology and Infertility, Walter Reed Army Medical Center, Washington, D.C.
dDepartment of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, University of Iowa Hospitals and Clinics, Iowa City, Iowa

1. Dessolle L, Fréour T, Barrière P, Jean M, Ravel C, Daraï E, et al. How soon can I be proficient in embryo transfer? Lessons from the cumulative summation test for learning curve (LC-CUSUM). Hum Reprod 2010;25:380-386.

2. Wittmaack FM, Kreger DO, Blaso L, Tureck RW, Mastroianni JL, Lessey BA. Effect of follicular size on oocyte retrieval, fertilization, cleavage, and embryo quality in in vitro fertilization cycles: a 6-year data collection. Fertil Steril 1994;62:1205-10.

3. Hearns-Stokes RM, Miller BT, Scott L, Creuss D, Chakraborty PK, Segars JH. Pregnancy rates after embryo transfer depend on the provider at embryo transfer. Fertil Steril 2000;74(1):80-6.

Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2011.08.031




One response

20 12 2011
Hans-Peter Steiner

One of the most important parameters is a proper technique in egg collection. As you can read in my book chapter (link at, with STEINER-TAN needle 17-gauge or even 21-gauge quasi-double lumen 7 cm prox. of needle tip it is possible to flush follicles without narrowing the inner lumen. This happens in conventional 17-gauge double-lumen needles, creating minimal flushing effect.

50% of our colleagues are non-flushing at the moment. With this new needle, they will have no argument against flushing in the future.

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