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Endometrial waves in in vitro fertilization cycles: A validation study

2005; Elsevier BV; Volume: 83; Issue: 2 Linguagem: Inglês

10.1016/j.fertnstert.2004.07.959

1556-5653

Iris van Gestel, Marga M. IJland, H.J. Hoogland, J.L.H. Evers,

Endometriosis Research and Treatment

In a prospective validation study we could not confirm that the persistence of endometrial waves from fundus to cervix on the day of hCG administration is associated with a favorable pregnancy prognosis in patients undergoing IVF. In a prospective validation study we could not confirm that the persistence of endometrial waves from fundus to cervix on the day of hCG administration is associated with a favorable pregnancy prognosis in patients undergoing IVF. The nonpregnant uterus shows wave-like activity of the endometrium. These peristaltic movements are initiated in the subendometrial myometrium and can be easily visualized by transvaginal ultrasound. Observations in spontaneous (1IJland M.M. Evers J.L.H. Dunselman G.A.J. Hoogland H.J. Relation between endometrial wavelike activity and fecundability in spontaneous cycles.Fertil Steril. 1997; 67: 492-496Abstract Full Text PDF PubMed Scopus (112) Google Scholar) and stimulated (2IJland M.M. Evers J.L.H. Dunselman G.A.J. van Katwijk C. Lo C.R. Hoogland H.J. Endometrial movements during the menstrual cycle.Fertil Steril. 1996; 65: 746-749Abstract Full Text PDF PubMed Scopus (129) Google Scholar) cycles revealed specific endometrial wave-like activity patterns throughout the menstrual cycle. Waves from fundus to cervix (FC waves) are predominantly seen in the follicular phase and disappear after ovulation or hCG administration. Waves from cervix to fundus (CF waves) prevail in the periovulatory phase (2IJland M.M. Evers J.L.H. Dunselman G.A.J. van Katwijk C. Lo C.R. Hoogland H.J. Endometrial movements during the menstrual cycle.Fertil Steril. 1996; 65: 746-749Abstract Full Text PDF PubMed Scopus (129) Google Scholar).A previous study of 22 IVF cycles showed a relation between the direction of waves on the day of hCG administration and the pregnancy outcome (3IJland M.M. Hoogland H.J. Dunselman G.A.J. Lo C.R. Evers J.L.H. Endometrial wave direction switch and the outcome of in vitro fertilization.Fertil Steril. 1999; 71: 476-481Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar). The persisting presence of FC waves was called a late wave direction switch (WDS) and was associated with a favorable pregnancy prognosis. A premature WDS was associated with a comparatively reduced pregnancy rate (PR) in that particular cycle.We wanted to validate the results of this small study in an independent larger group of patients.From October 2001 to October 2003, during three separate periods in which the main investigator was available, ultrasound observations were performed in 90 cycles in 90 women undergoing IVF. There were no exclusion criteria to participate in the study. All cycles were stimulated with recombinant FSH (rFSH, Puregon; Organon, Oss, The Netherlands) in combination with intranasal administration of a GnRH analogue (GnRH-a) nafareline (Synarel 200 μg twice daily; Roche, Mijdrecht, The Netherlands) or IM triptoreline (Decapeptyl 0.1 mg once daily; Ferring, Hoofddorp, The Netherlands). Recombinant FSH was started after suppression of ovarian function with the GnRH-a. The patients in this study received 100 E–250 E of recombinant FSH as a single daily SC injection.Follicular growth was assessed by ultrasound. Human chorionic gonadotropin (5,000 IU; Pregnyl, Organon) was administered as soon as at least five follicles reached a mean diameter of ≥18 mm. The E2 determinations are not performed routinely in our clinic. On the day of hCG administration, recombinant FSH and GnRH-a were discontinued.Oocyte retrieval was performed under vaginal ultrasound guidance 34 hours after hCG administration. Embryos were transferred 2–3 days after insemination.Ultrasound measurement of wave direction was performed on the day of hCG administration. The examination was performed transvaginally (7.5-mHz transducer) with the use of a real-time scanner (Technos, Esaote-Pie Medical, Maastricht, The Netherlands). All ultrasound measurements were performed by a single observer (I.G.). Five to 15 minutes of video footage was recorded at the midsagittal display of the uterus. If no uterine activity was observed during 5 minutes, the recording was discontinued. Off-line analysis was performed at high-speed (four times) replay and focused on the presence (activity or no activity) and direction (wave type) of the endometrial wave-like activity. Endometrial wave-like activity was described by means of the wave classification system (2IJland M.M. Evers J.L.H. Dunselman G.A.J. van Katwijk C. Lo C.R. Hoogland H.J. Endometrial movements during the menstrual cycle.Fertil Steril. 1996; 65: 746-749Abstract Full Text PDF PubMed Scopus (129) Google Scholar), which distinguishes five types of endometrial wave-like movements (CF waves, FC waves, opposing waves, random activity, and no activity). Cohen's Kappa statistics were calculated to assess agreement between observers and within observers. Kappa was 0.56 and 0.77, respectively, indicating good agreement between and within observers (2IJland M.M. Evers J.L.H. Dunselman G.A.J. van Katwijk C. Lo C.R. Hoogland H.J. Endometrial movements during the menstrual cycle.Fertil Steril. 1996; 65: 746-749Abstract Full Text PDF PubMed Scopus (129) Google Scholar).Endometrial wave-like activity on the day of hCG administration was related to IVF outcome. Patients were divided into two groups: those with and those without FC waves on the day of hCG administration. In the previous article we suggested that the presence of FC waves during the late follicular phase is beneficial for a good quality embryo to implant (3IJland M.M. Hoogland H.J. Dunselman G.A.J. Lo C.R. Evers J.L.H. Endometrial wave direction switch and the outcome of in vitro fertilization.Fertil Steril. 1999; 71: 476-481Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar). To exclude embryo factors as a cause of implantation failure as much as possible, cycles in which at least one top quality embryo was transferred were analyzed separately. Embryos were scored based on the number of pronuclei, the cleavage stage, and the morphology of the embryo (4Steer C.V. Mills C.L. Tan S.L. Campbell S. Edwards R.G. The cumulative embryo score: a predictive embryo scoring technique to select the optimal number of embryos to transfer in an in-vitro fertilization and embryo transfer programme.Hum Reprod. 1992; 7: 117-119PubMed Google Scholar). Those patients who did not have an embryo for transfer (n = 4) were excluded from further analysis, as this precluded relating the wave pattern to the occurrence of pregnancy.A power calculation, based on our previous results, showed that we would need to include at least 8 patients in the present study to confirm our previous findings with α = 0.05 and β = 0.20. Because of an expected drop out of about 10% we decided to include 90 patients.The age of the women ranged from 22–41 years (median 33 years). There were 64 (71%) cases of primary subfertility and 26 (29%) cases of secondary subfertility. Duration of subfertility varied from 1–14 years (median 4 years). Four different types of infertility were distinguished, namely, tubal pathology (n = 12), endometriosis (n = 2), male factor infertility (n = 53), and unexplained subfertility (n = 23). Duration of stimulation with recombinant FSH ranged from 8–23 days (median 13 days). The number of retrieved oocytes ranged from 1–26 (median 7). Transfer of either 1 or 2 embryos, but never more, was performed in 86 women. Fertilization failure occurred in 4 women. Thirty-one of the 86 women had a biochemical pregnancy, leading to 26 (30%) ongoing pregnancies (>12 weeks).Eighty-three of the 86 women showed endometrial wave-like activity. In two patients the wave direction was not identifiable and thereby they were excluded from further analysis. Waves from CF were the dominant wave type in 47 of 84 cycles. Waves from FC were seen in 27 of 84 cycles. Opposing and random waves were rarely seen. These findings are consistent with previous studies (3IJland M.M. Hoogland H.J. Dunselman G.A.J. Lo C.R. Evers J.L.H. Endometrial wave direction switch and the outcome of in vitro fertilization.Fertil Steril. 1999; 71: 476-481Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar, 5Kunz G. Beil D. Deininger H. Wildt L. Leyendecker G. The dynamics of rapid sperm transport through the female genital tract: evidence from vaginal sonography of uterine peristalsis and hysterosalpingography.Hum Reprod. 1996; 11: 627-632Crossref PubMed Scopus (331) Google Scholar, 6Bulletti C. DeZiegler D. Polli V. Diotallevi L. Del Ferro E. Flamingi C. Uterine contractility during the menstrual cycle.Hum Reprod. 2000; 15: 81-89Crossref PubMed Scopus (147) Google Scholar).Twenty-seven of the 84 patients showed FC waves. Of these, 11 achieved a pregnancy (41%), compared with 19 of the 57 (33%) patients not showing FC waves on the day of hCG administration (Table 1). Although more patients became pregnant in the group showing FC waves, the difference is not statistically significant. Transfer of a top quality embryo was performed in 19 of the 84 patients. Six of the 19 patients showed FC waves. Of these, 4 patients achieved pregnancy (67%), compared with 3 of the 13 (23%) patients not showing FC waves (P = not significant; Table 1).TABLE 1Recording of the wave direction on the day of hCG administration in relation to pregnancy.Waves from fundus to cervixPatient groupNumber of patients who did not become pregnantNumber of patients who became pregnantAbsent38 (10)19 (3)Present16 (2)11 (4)Note: RR 1.1 (95% CI 0.8–1.6), P=.63. Between parentheses the top-quality embryo group. RR 1.9 (95% CI 1.0–5.4), P (one-sided) = .09. Open table in a new tab Endometrial wave-like activity is conceivably an important uterine factor in fertility. In a previous study we have shown that the persistence of FC waves until the day of hCG administration predicted a favorable pregnancy outcome. The wave direction recording seemed a fair predictor of failure of pregnancy (NPV, negative predictive value), but only a moderate predictor of pregnancy (PPV, positive predictive value). Our suggestion then was that the persistence of FC waves until the day of hCG administration is beneficial for a good quality embryo to implant. In the present study, however, we could not confirm the results in a larger study group. Although the IVF outcome was better in the group with FC waves, this was not statistically significant (P=.63). Patients in whom at least one top quality embryo was transferred had a better pregnancy chance (67%) if FC waves were detected, compared to those without FC waves (23%). Although this is in accordance with our theory about good quality embryos in relation to endometrial wave-like activity, the group is obviously too small to allow for drawing meaningful conclusions. Furthermore, embryo quality is a poorly defined entity that is subject to much controversy. It is tempting to suggest that if embryo quality can be defined better, the independent contribution of endometrial wave-like activity to conceiving by way of IVF may be investigated more reliably. The first figures from the present study of top quality embryos suggest that in IVF, if corrected for embryo quality, the pattern of endometrial wave-like activity may be another determinant of successful implantation.In an unselected group of IVF patients we could, however, not confirm the findings of our previous study. The present investigation shows the importance of validation studies. Exceptional incidental findings in a small study group, leading to a type 1 error, should always be validated prospectively in an independent larger sample. The nonpregnant uterus shows wave-like activity of the endometrium. These peristaltic movements are initiated in the subendometrial myometrium and can be easily visualized by transvaginal ultrasound. Observations in spontaneous (1IJland M.M. Evers J.L.H. Dunselman G.A.J. Hoogland H.J. Relation between endometrial wavelike activity and fecundability in spontaneous cycles.Fertil Steril. 1997; 67: 492-496Abstract Full Text PDF PubMed Scopus (112) Google Scholar) and stimulated (2IJland M.M. Evers J.L.H. Dunselman G.A.J. van Katwijk C. Lo C.R. Hoogland H.J. Endometrial movements during the menstrual cycle.Fertil Steril. 1996; 65: 746-749Abstract Full Text PDF PubMed Scopus (129) Google Scholar) cycles revealed specific endometrial wave-like activity patterns throughout the menstrual cycle. Waves from fundus to cervix (FC waves) are predominantly seen in the follicular phase and disappear after ovulation or hCG administration. Waves from cervix to fundus (CF waves) prevail in the periovulatory phase (2IJland M.M. Evers J.L.H. Dunselman G.A.J. van Katwijk C. Lo C.R. Hoogland H.J. Endometrial movements during the menstrual cycle.Fertil Steril. 1996; 65: 746-749Abstract Full Text PDF PubMed Scopus (129) Google Scholar). A previous study of 22 IVF cycles showed a relation between the direction of waves on the day of hCG administration and the pregnancy outcome (3IJland M.M. Hoogland H.J. Dunselman G.A.J. Lo C.R. Evers J.L.H. Endometrial wave direction switch and the outcome of in vitro fertilization.Fertil Steril. 1999; 71: 476-481Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar). The persisting presence of FC waves was called a late wave direction switch (WDS) and was associated with a favorable pregnancy prognosis. A premature WDS was associated with a comparatively reduced pregnancy rate (PR) in that particular cycle. We wanted to validate the results of this small study in an independent larger group of patients. From October 2001 to October 2003, during three separate periods in which the main investigator was available, ultrasound observations were performed in 90 cycles in 90 women undergoing IVF. There were no exclusion criteria to participate in the study. All cycles were stimulated with recombinant FSH (rFSH, Puregon; Organon, Oss, The Netherlands) in combination with intranasal administration of a GnRH analogue (GnRH-a) nafareline (Synarel 200 μg twice daily; Roche, Mijdrecht, The Netherlands) or IM triptoreline (Decapeptyl 0.1 mg once daily; Ferring, Hoofddorp, The Netherlands). Recombinant FSH was started after suppression of ovarian function with the GnRH-a. The patients in this study received 100 E–250 E of recombinant FSH as a single daily SC injection. Follicular growth was assessed by ultrasound. Human chorionic gonadotropin (5,000 IU; Pregnyl, Organon) was administered as soon as at least five follicles reached a mean diameter of ≥18 mm. The E2 determinations are not performed routinely in our clinic. On the day of hCG administration, recombinant FSH and GnRH-a were discontinued. Oocyte retrieval was performed under vaginal ultrasound guidance 34 hours after hCG administration. Embryos were transferred 2–3 days after insemination. Ultrasound measurement of wave direction was performed on the day of hCG administration. The examination was performed transvaginally (7.5-mHz transducer) with the use of a real-time scanner (Technos, Esaote-Pie Medical, Maastricht, The Netherlands). All ultrasound measurements were performed by a single observer (I.G.). Five to 15 minutes of video footage was recorded at the midsagittal display of the uterus. If no uterine activity was observed during 5 minutes, the recording was discontinued. Off-line analysis was performed at high-speed (four times) replay and focused on the presence (activity or no activity) and direction (wave type) of the endometrial wave-like activity. Endometrial wave-like activity was described by means of the wave classification system (2IJland M.M. Evers J.L.H. Dunselman G.A.J. van Katwijk C. Lo C.R. Hoogland H.J. Endometrial movements during the menstrual cycle.Fertil Steril. 1996; 65: 746-749Abstract Full Text PDF PubMed Scopus (129) Google Scholar), which distinguishes five types of endometrial wave-like movements (CF waves, FC waves, opposing waves, random activity, and no activity). Cohen's Kappa statistics were calculated to assess agreement between observers and within observers. Kappa was 0.56 and 0.77, respectively, indicating good agreement between and within observers (2IJland M.M. Evers J.L.H. Dunselman G.A.J. van Katwijk C. Lo C.R. Hoogland H.J. Endometrial movements during the menstrual cycle.Fertil Steril. 1996; 65: 746-749Abstract Full Text PDF PubMed Scopus (129) Google Scholar). Endometrial wave-like activity on the day of hCG administration was related to IVF outcome. Patients were divided into two groups: those with and those without FC waves on the day of hCG administration. In the previous article we suggested that the presence of FC waves during the late follicular phase is beneficial for a good quality embryo to implant (3IJland M.M. Hoogland H.J. Dunselman G.A.J. Lo C.R. Evers J.L.H. Endometrial wave direction switch and the outcome of in vitro fertilization.Fertil Steril. 1999; 71: 476-481Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar). To exclude embryo factors as a cause of implantation failure as much as possible, cycles in which at least one top quality embryo was transferred were analyzed separately. Embryos were scored based on the number of pronuclei, the cleavage stage, and the morphology of the embryo (4Steer C.V. Mills C.L. Tan S.L. Campbell S. Edwards R.G. The cumulative embryo score: a predictive embryo scoring technique to select the optimal number of embryos to transfer in an in-vitro fertilization and embryo transfer programme.Hum Reprod. 1992; 7: 117-119PubMed Google Scholar). Those patients who did not have an embryo for transfer (n = 4) were excluded from further analysis, as this precluded relating the wave pattern to the occurrence of pregnancy. A power calculation, based on our previous results, showed that we would need to include at least 8 patients in the present study to confirm our previous findings with α = 0.05 and β = 0.20. Because of an expected drop out of about 10% we decided to include 90 patients. The age of the women ranged from 22–41 years (median 33 years). There were 64 (71%) cases of primary subfertility and 26 (29%) cases of secondary subfertility. Duration of subfertility varied from 1–14 years (median 4 years). Four different types of infertility were distinguished, namely, tubal pathology (n = 12), endometriosis (n = 2), male factor infertility (n = 53), and unexplained subfertility (n = 23). Duration of stimulation with recombinant FSH ranged from 8–23 days (median 13 days). The number of retrieved oocytes ranged from 1–26 (median 7). Transfer of either 1 or 2 embryos, but never more, was performed in 86 women. Fertilization failure occurred in 4 women. Thirty-one of the 86 women had a biochemical pregnancy, leading to 26 (30%) ongoing pregnancies (>12 weeks). Eighty-three of the 86 women showed endometrial wave-like activity. In two patients the wave direction was not identifiable and thereby they were excluded from further analysis. Waves from CF were the dominant wave type in 47 of 84 cycles. Waves from FC were seen in 27 of 84 cycles. Opposing and random waves were rarely seen. These findings are consistent with previous studies (3IJland M.M. Hoogland H.J. Dunselman G.A.J. Lo C.R. Evers J.L.H. Endometrial wave direction switch and the outcome of in vitro fertilization.Fertil Steril. 1999; 71: 476-481Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar, 5Kunz G. Beil D. Deininger H. Wildt L. Leyendecker G. The dynamics of rapid sperm transport through the female genital tract: evidence from vaginal sonography of uterine peristalsis and hysterosalpingography.Hum Reprod. 1996; 11: 627-632Crossref PubMed Scopus (331) Google Scholar, 6Bulletti C. DeZiegler D. Polli V. Diotallevi L. Del Ferro E. Flamingi C. Uterine contractility during the menstrual cycle.Hum Reprod. 2000; 15: 81-89Crossref PubMed Scopus (147) Google Scholar). Twenty-seven of the 84 patients showed FC waves. Of these, 11 achieved a pregnancy (41%), compared with 19 of the 57 (33%) patients not showing FC waves on the day of hCG administration (Table 1). Although more patients became pregnant in the group showing FC waves, the difference is not statistically significant. Transfer of a top quality embryo was performed in 19 of the 84 patients. Six of the 19 patients showed FC waves. Of these, 4 patients achieved pregnancy (67%), compared with 3 of the 13 (23%) patients not showing FC waves (P = not significant; Table 1). Note: RR 1.1 (95% CI 0.8–1.6), P=.63. Between parentheses the top-quality embryo group. RR 1.9 (95% CI 1.0–5.4), P (one-sided) = .09. Endometrial wave-like activity is conceivably an important uterine factor in fertility. In a previous study we have shown that the persistence of FC waves until the day of hCG administration predicted a favorable pregnancy outcome. The wave direction recording seemed a fair predictor of failure of pregnancy (NPV, negative predictive value), but only a moderate predictor of pregnancy (PPV, positive predictive value). Our suggestion then was that the persistence of FC waves until the day of hCG administration is beneficial for a good quality embryo to implant. In the present study, however, we could not confirm the results in a larger study group. Although the IVF outcome was better in the group with FC waves, this was not statistically significant (P=.63). Patients in whom at least one top quality embryo was transferred had a better pregnancy chance (67%) if FC waves were detected, compared to those without FC waves (23%). Although this is in accordance with our theory about good quality embryos in relation to endometrial wave-like activity, the group is obviously too small to allow for drawing meaningful conclusions. Furthermore, embryo quality is a poorly defined entity that is subject to much controversy. It is tempting to suggest that if embryo quality can be defined better, the independent contribution of endometrial wave-like activity to conceiving by way of IVF may be investigated more reliably. The first figures from the present study of top quality embryos suggest that in IVF, if corrected for embryo quality, the pattern of endometrial wave-like activity may be another determinant of successful implantation. In an unselected group of IVF patients we could, however, not confirm the findings of our previous study. The present investigation shows the importance of validation studies. Exceptional incidental findings in a small study group, leading to a type 1 error, should always be validated prospectively in an independent larger sample.