1 CECOS, Biologie de la Reproduction, Département de Gynécologie-Obstétrique et Reproduction Humaine, Centre Hospitalier Universitaire Bretonneau, 37044 Tours, and 2 Service d'Information Médicale et d'Hygiène, Centre Hospitalier Universitaire Bretonneau, 37044 Tours, France
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Abstract |
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Key words: artificial insemination/crude cumulative live-birth rate/drop-out/frozen donor semen/IVF
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Introduction |
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On initiating an assisted reproductive technology (ART) programme, patients need precise information on the chances of achieving successful pregnancy. This information is usually based on the ongoing clinical pregnancy or the live-birth rate per started cycle. However, the success rate of a single cycle does not answer the question of how high the cumulative chances of achieving successful pregnancy are after a given number of cycles. Various methods allow expression of cumulative pregnancy rate (CPR): (i) crude CPR without any assumption about patients discontinuing further treatment and (ii) CPR using life-table analysis. In the latter case, it is assumed that discontinuing patients have the same probability of a successful pregnancy as patients proceeding to a further cycle after previous failed treatments (Guzick et al., 1986; Haan et al., 1991
; Roest et al., 1998
; De Vries et al., 1999
). However, it should be kept in mind that, from a patient's point of view, the live-birth rate is the most important endpoint. Thus the probability of a live birth after a given number of insemination or IVF cycles remains the key issue that needs to be addressed for infertile couples. Although the use of donor semen is well established and widely used, it may be psychologically stressful for patients (Owens et al., 1993
). Physicians involved in AID need therefore to counsel their patients by providing them with a realistic prognosis in terms of the duration and outcome of treatment.
To our knowledge, the crude cumulative live-birth rate in a cohort of patients having embarked upon a frozen donor semen programme including AID and IVF-D cycles has not yet been reported. This monocentre cohort study (CECOS, Tours) was therefore designed to assess the crude cumulative live-birth rate in couples with primary infertility on initiating an ART programme with frozen donor semen. All patients were followed until the birth of a live baby or the end of treatment for medical or personal reasons.
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Materials and methods |
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Reasons for infertility in patients who initiated AID treatment comprized non-obstructive azoospermia (59.6%), severe (<1x106 sperm/ml) or moderate (110x106 sperm/ml) oligozoospermia (27.6%), obstructive azoospermia (7.3%), previous failure of ICSI (3.1%) and severe (total sperm motility <5%) asthenozoospermia (2.4%). It should be mentioned that from 1991 until 1997, there was a decrease in the percentage of patients with severe or moderate oligozoospermia or asthenozoospermia with the increasing use of ICSI. Only women who had never conceived before (delivery, abortion or ectopic pregnancy) were included in the cohort. Female infertility factors that could affect the outcome of treatment were detected before the initiation of AID cycles. This involved recording of medical history, current physical examination, basal body temperature charts, serum hormone assessment, transvaginal ultrasonographic examination and evaluation of cervical mucus. Tubal patency was confirmed by hysterosalpingography or laparoscopy. In addition, all couples attended an interview to discuss the psychological aspects of artificial procreation with donor semen prior to being included on the waiting list. The mean age (±) of the women in the cohort was 29.8 ± 3.4 years (range 2140 years). The duration of infertility of these couples ranged from 117 years (5.3 ± 2.7 years).
AID cycles
All AID cycles were performed using intracervical insemination with a cervical cap or cupule, depending on the opening of the cervix. One insemination was performed per cycle with at least 2.0x106 motile sperm per straw. For women with normal ovulatory cycles (46% of women), the appropriate time for insemination was estimated on the basis of basal body temperature charts, transvaginal ultrasonographic evaluation and examination of cervical mucus. The use of ovarian stimulation (54% of women) was indicated either for ovulatory disorder (including luteal defect and cervical mucus anomalies) or for irregular cycles in order to reduce the number of consultations. Ovarian stimulation used clomiphene citrate (Clomid®; Marion Merell SA, Puteaux, France) or HMG (Neopergonal®; Metrodine® Serono Laboratories, Paris, France; Humegon®; Organon Pharmaceuticals, Saint-Denis, France) or recombinant FSH (Follitropine alpha, Gonal F®; Serono Laboratories or Follitropine beta, Puregon®; Organon Pharmaceuticals). Except for cervical anomalies where low doses of gonadotrophins were preferred, antiestrogens were first used, then gonadotrophins, then possibly a combination of antiestrogens and gonadotrophins in severe ovulatory disorders. Monitoring involved serum estradiol assessment and transvaginal ultrasonographic evaluation of follicular growth. The criterion for timing the administration of HCG was the presence of one or two preovulatory follicles. The cancellation rate was 15%, with a similar distribution between multifollicular growth (3 preovulatory follicles) and insufficient follicular growth or cervical mucus quality. Intracervical insemination was performed on the day of HCG administration (5000 IU, i.m. Gonadotrophine Chorionique Endo®; Organon Pharmaceuticals). An average of 5.0 ± 3.4 AID cycles per couple was performed (range 114) in the cohort studied. After six and again after 12 AID cycles, previously failed AID cycles were assessed in order to decide whether to continue AID cycles, to proceed to IVF-D cycles or to stop all further treatment. Proceeding to IVF-D between the first and the sixth AID cycles was mainly decided when a poor or unsatisfactory response was observed in previous AID cycle(s). Poor response was defined by follicular growth defect despite increasing doses of gonadotrophins. Unsatisfactory response was mainly observed in patients with polycystic ovaries, when it was impossible to hinder multiple ovulations.
IVF-D cycles
The ovarian stimulation protocol in IVF-D cycles involved desensitization with GnRH agonist (0.1 mg triptorelin, Decapeptyl®; Ipsen-Biotech Laboratories, Paris, France; 0.3 mg buserelin, Suprefact®; Hoechst-Aventis Laboratories, Paris, France). Once desensitization was confirmed by serum estradiol assessment (<50 pg/ml) and transvaginal ultrasonography (absence of follicle with a diameter >10 mm), treatment with HMG or recombinant FSH was initiated. Monitoring involved serum estradiol assessment and transvaginal ultrasonographic evaluation of follicular growth. HCG (10 000 IU, i.m.) was administered when at least three follicles reached a mean diameter of 18 mm with adequate estradiol concentrations (>300 pg/ml per mature follicle). Transvaginal oocyte retrieval was performed 3436 h following HCG injection. Fertilization was checked 1618 h post-insemination. At day 2, one to three embryos were transferred. All single embryo transfers in this series were compulsory. Two embryos were transferred more often than three embryos depending on the female age, the quality of the embryos and the rank of the IVF-D cycle (e.g. 67 versus 23% during the first cycle, 50 versus 50% during the fourth cycle for two and three embryos, respectively). An average of 1.9 ± 0.9 IVF-D cycles per couple was performed (range 14) in the cohort.
Only live births were taken into account. Spontaneous abortions, ectopic pregnancies and pregnancies lost beyond 12 weeks were considered as failed cycles. The end-point of patients' follow-up was either live birth or withdrawal from the programme. Discontinuing patients were divided into two groups: medical or personal reasons. Some patients were denied further treatment for medical reasons involving poor prognosis [poor response to hormonal stimulation and/or age >40 years and/or failure and/or weak (<20%) fertilization rate in IVF-D]. Other patients discontinued further treatment for personal reasons (lost to follow-up, decision to postpone further treatment, move, adoption, divorce, changing to ICSI). Patients were considered as lost to follow-up when they failed to return to follow-up appointments for >12 months. For each couple, live-birth rate, changing to IVF-D and drop-out for medical or personal reasons were recorded. When IVF-D cycles were subsequently performed for some couples, live-birth rate (including results of frozenthawed embryo transfers) and reasons for drop-out were also recorded.
Statistical methods
The results are given as mean values ± SD and were analysed using Staview 4.1 (Abacus Concepts, Berkeley, USA). ANOVA followed by post hoc comparisons or contingency tables were used, depending on the parameter being evaluated, with P < 0.05 as the threshold of statistical significance.
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Results |
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Outcome of AID cycles
The outcome of 3119 AID cycles is shown in Table I. The mean live-birth rate per AID cycle in this cohort was 10.9%, with the highest rate during the first AID cycle (14.3%). From the second to the seventh AID cycle, the live-birth rate per cycle was similar (range 10.112.1%) and decreased progressively thereafter (from 8.1 to 5.4%). Finally, the crude cumulative live-birth rate reached 49 and 58% after six and twelve or more AID cycles respectively. Among the couples who did not achieve a pregnancy with live birth, 21.1% turned to IVF-D and 20.9% dropped out. Couples stopped further treatment mainly for personal reasons and rarely for medical reasons (83.7 versus 16.3% respectively; P < 0.05). The frequency of couples who dropped out or turned to IVF-D was higher after the sixth and twelfth AID cycles. Beyond six AID cycles, the proportion of couples who stopped any further treatment or turned to IVF-D was similar (11.2 and 12.3% respectively). In contrast, after twelve or more AID cycles, a higher proportion of couples turned to IVF-D cycles compared with couples who dropped out (47.3 versus 21.6% respectively; P < 0.05).
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Couples were allocated to four groups, depending on the outcome of AID cycles [live birth (LB), stopping for personal reasons (SPR), stopping for medical reasons (SMR) and IVF-Dt]. The characteristics of these four groups of patients are shown in Table III. The mean age of women who dropped out for medical reasons (SMR) was significantly higher than for other situations (LB, SPR and IVF-Dt). The duration of infertility was also higher in the SMR group when compared with the LB group.
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The crude cumulative live birth rate per IVF-Dt cycle did not differ between the two main male infertility factors leading couples to frozen semen donor insemination (57.3 versus 45% for azoospermic and oligozoospermic patients respectively). Similarly, the mean number of IVF-Dt cycles necessary to achieve a live birth was similar in azoospermic and oligozoospermic patients (1.7 ± 0.8 versus 1.5 ± 0.7 respectively).
Couples were allocated to three groups depending on the outcome of IVF-Dt cycles (live birth, stopping for personal reasons and stopping for medical reasons). The characteristics of these groups at the end of IVF-Dt cycles are shown in Table V. Mean age of women and duration of infertility were similar in all groups. In contrast, the decision to stop further treatment for personal reasons was taken after a higher number of cycles compared to other groups (P < 0.05). Poor quality oocytes were observed among all couples who stopped further treatment for medical reasons, e.g. 29% couples with fertilization failure, 64% couples with poor fertilization, 7% couples with female age >40 years.
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Discussion |
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The first part of the study concerned AID cycles. The crude cumulative live-birth rate increased progressively and reached a plateau after the seventh cycle. This is in agreement with a previous study reporting a decrease from a mean of 10.3% per cycle during the first six cycles to 2.3% after 24 cycles (Federation CECOS et al., 1989). However the cycle number at which the decline is reported to start remains a matter of debate. Indeed a pregnancy rate of >10% until the 15th cycle was recently reported (Botchan et al., 2001
). However, it is now commonly accepted that a decreasing probability of achieving pregnancy after a given number of unsuccessful cycles may be due to low female fertility (Hershlag et al., 1991
).
In order to keep the fertility status of the couples homogeneous, only couples with primary infertility were included in the cohort. The crude cumulative live-birth rate reached 30.6% after three cycles, 49% after six cycles and 58% after 12 AID cycles in our series, which is similar to a previously reported cumulative conception rate of 19% after three cycles, 33% after six cycles and 54% after 12 cycles for couples in the first course of treatment with cryopreserved donor semen (Shenfield et al., 1993
). Interestingly, higher cumulative conception rates were reported in the same study for couples having achieved a full pregnancy during an earlier course of treatment (40% after three cycles, 67% after six cycles and 79% after 12 cycles). Similarly, the mean success rate was reported to be lower in women who initiated insemination for a first pregnancy (7.2%) than for a second or third pregnancy (11.2%) (Federation CECOS et al., 1989
). Other authors also reported a higher probability to conceive in those couples who had already conceived (Tan et al., 1994
; Croucher et al., 1998
; Williams and Alderman, 2001
). In contrast, other authors found that the pregnancy rate per cycle was similar in women with primary versus secondary infertility (Robinson et al., 1993
). Better results in a first as opposed to a second course of treatment was reported only once (Botchan et al., 2001
). Two factors have been evoked that may explain these contradictory results. The first is that women previously treated by fresh donor sperm insemination returned later for frozen donor sperm insemination, which is expected to give lower results. Alternatively, increased age might explain lower fertility in women initiating AID for a second pregnancy. Thus, in view of the heterogeneity of couples with respect to female fertility status, we decided to include only patients with primary infertility in our cohort.
Various factors may influence the success rate in AID cycles, e.g. female age, male factor, the quality of the inseminated sperm, the timing of the insemination, ovarian stimulation protocols and insemination technique. In this cohort study, we only evaluated the influence of the male factor that led couples to choose donor insemination on the outcome of AID cycles. Pregnancy rates following AID cycles have been reported earlier to be higher in women with an azoospermic partner when compared with women with an oligozoospermic partner (Emperaire et al., 1982; Ecochard et al., 1999
; Williams and Alderman, 2001
). The rationale for this is that women with an azoospermic partner more frequently have normal fertility whereas women with an oligozoospermic partner represent a hypofertile subgroup from which the highly fertile women have been eliminated by achieving a spontaneous conception. In contrast, we did not observe any difference between azoospermic and oligozoospermic patients in terms of cumulative live-birth rate per couple, as reported in some other studies (Robinson et al., 1993
; Shenfield et al., 1993
). Half of the oligozoospermic patients in our cohort had severe oligozoospermia (<1x106 sperm/ml). Therefore, the heterogeneity of sperm characteristics in oligozoospermic patients may explain in part this discrepancy in the literature.
The second part of the study involved patients who turned to IVF-D after previously failed AID cycles. In our cohort, turning to IVF-D achieved a crude cumulative live-birth rate of 52%. Overall IVF-D allowed the cohort to achieve 65 additional live births after failed AID cycles. The overall percentage of multiple pregnancies was 26%, with the higher value being observed after the first IVF-Dt cycle (38 versus 14%, 14 and 0% after the second, third and fourth cycle respectively). The high frequency of multiple pregnancies after IVF-D is a serious iatrogenic complication that should be prevented to a considerable extent. Elective transfer of a single embryo should be considered, particularly during the first two cycles, whenever at least one good quality embryo is available (Van Royen et al., 1999; Vilska et al., 1999
; Gerris and Van Royen, 2000
). Finally, the total crude cumulative live birth rate reached 69% in the whole cohort after this 19% increase in live IVF-Dt births. Taken together these results argue for switching to IVF-Dt, after failure at the seventh cycle, since the chance of obtaining a live birth drastically decreases beyond the seventh cycle.
Before starting infertility treatment, patients need to be clearly informed about their chances of a successful pregnancy according to each available ART technique. Among all variables that express the success rate of an ART programme, live birth is undoubtedly the most meaningful. Additionally, a success rate can be expressed per cycle or per couple, taking into account, in the latter case, the results of consecutive cycles (Wilcox et al., 1993). The chances of achieving a live birth after a specified number of cycles remains the best information for a couple. Cumulative pregnancy rate may therefore be expressed as the crude cumulative pregnancy rate or calculated according to life-table analysis. The cumulative pregnancy rate after a large number of cycles was reported to be overestimated by the life-table method (Stolwijk et al., 1996
; Land et al., 1997
). If the chances of a successful pregnancy are assumed to be the same for patients who dropped out as for patients who continue treatment, the cumulative live-birth rate by life-table analysis considerably exceeds the crude cumulative live birth rate after AID and IVF-D cycles [87.6% (CI95: 84.190.5) versus 69% (CI95: 66.972.8) respectively]. Additionally, it may be expected that couples who discontinue treatment for personal reasons should have a better chance of achieving a pregnancy than patients who discontinue treatment for medical reasons (Doody, 1993
; Walters, 1994
; Stolwijk et al., 1996
; Land et al., 1997
). If it is assumed that the chance of a successful pregnancy is the same for patients who drop out for personal reasons as for patients who continue treatment, whereas patients who drop out for medical reasons would have no chance of a successful pregnancy, the whole cohort results remain slightly overestimated compared to crude cumulative live-birth rate [79.9% (CI95: 78.181.6) versus 69% (CI95: 66.972.8) for corrected and crude cumulative live-birth rates, respectively].
In conclusion, we decided to include only couples with primary infertility and to use live-birth rate and crude cumulative live-birth rate in our cohort study in order to avoid confounding variables, which may hinder interpretation of the results. Thus, although results may appear to be lowered by using such a strategy, it may be assumed that it gives a more realistic assessment of these ART procedures. This study is the first to follow up both AID and IVF-D cycles in the same cohort using live-birth rate as the end-point. At the end of both procedures, 69% couples achieved parenthood, whereas 31% were denied further treatment at various stages of treatment, mainly for personal reasons. Bearing in mind that these results need to be adjusted for each centre, we conclude that, while encouraging medical staff to select the best treatment strategy, such findings may actually help patients to accept or refuse a frozen donor semen programme.
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Notes |
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References |
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Botchan, A., Hauser, R., Gamzu, R., Yogev, L. and Yavetz, H. (2001) Results of 6139 artificial insemination cycles with donor spermatozoa. Hum. Reprod., 16, 22982304.
Byrd, W., Bradshaw, K., Carr, B., Edman, C., Odom, J. and Ackerman, G (1990) A prospective randomized study of pregnancy rates following intrauterine and intracervical insemination using frozen donor sperm. Fertil. Steril., 53, 521527.[ISI][Medline]
Cohen J., Edwards, R.G., Fehilly, C.B., Fishel, S.B., Hewitt, J., Rowland, G.F., Steptoe, P.C., Walters, D and Webster, J. (1985) In vitro fertilization using cryopreserved donor semen in cases where both partners are infertile. Fertil. Steril., 43, 570574.[ISI][Medline]
Croucher, C.A., Lass, A., Margara, R. and Winston, R.M. (1998) Predictive value of the results of a first in-vitro fertilization cycle on the outcome of subsequent cycles. Hum. Reprod., 13, 403408.[ISI][Medline]
De Vries, M.J., De Sutter, P. and Dhont, M. (1999) Prognostic factors in patients continuing in vitro fertilization or intracytoplasmic sperm injection treatment and dropouts. Fertil. Steril., 72, 674678.[ISI][Medline]
Doody, M.C. (1993) Drop-out behaviour and fertility table analysis of pregnancy rates. Hum. Reprod., 8, 886889.[Abstract]
Ecochard, R., Cottinet, D., Mathieu, C., Rabilloud, M. and Czyba, J.C. (1999) The mean of sperm parameters in semen donations from the same donor. An important prognostic factor in insemination. Int. J. Androl., 22, 163172.[ISI][Medline]
Emperaire, J.C., Gauzere-Soumireu, E. and Audebert, A. (1982) Female fertility and donor insemination. Fertil. Steril., 37, 9093.[ISI][Medline]
Federation CECOS, Le Lannou, D. and Lansac, J. (1989) Artificial procreation with frozen donor semen: experience of the French Federation CECOS. Hum. Reprod., 4, 757761.[Abstract]
Gerris, J. and Van Royen, E. (2000) Avoiding multiple pregnancies in ART: a plea for single embryo transfer. Hum. Reprod., 15, 18841888.
Guzick, D.S., Wilkes, C. and Jones, H.W. (1986) Cumulative pregnancy rates for in-vitro fertilization. Fertil. Steril., 46, 663667.[ISI][Medline]
Haan, G., Bernardus, R.E., Hollanders, H.M.G., Leerentveld, B.A., Prak, F.M. and Naaktgeboren, N. (1991) Selective drop out in successive in-vitro fertilization attempts: the pendulum danger. Hum. Reprod., 6, 939943.[Abstract]
Hershlag, A., Kaplan, E.H., Loy, R.A., DeCherney, A.H. and Lavy, G. (1991) Heterogeneity in patient populations explains differences in in-vitro fertilization programs. Fertil. Steril., 56, 913917.[ISI][Medline]
Land, J.A., Courtar, D.A. and Evers, J.L.H. (1997) Patient dropout in an assisted reproductive technology program: implications for pregnancy rates. Fertil. Steril., 68, 278281.[ISI][Medline]
Mahadevan, M.M., Trounson, A.O. and Leeton, J.F. (1983) Successful use of human semen cryobanking for in-vitro fertilization. Fertil. Steril., 40, 340345.[ISI][Medline]
Morshedi, M., Oehninger, S., Veeck, L.L., Ertunc, H., Bocca, S. and Acosta, A.A. (1990) Cryopreserved/thawed semen for in-vitro fertilization: results from fertile donors and infertile patients. Fertil. Steril., 54, 10931099.[ISI][Medline]
Owens, D.J., Edelmann, R.E. and Humphrey, M.E. (1993) Male infertility and donor insemination: couples' decisions, reactions and counselling needs. Hum. Reprod., 8, 880885.[Abstract]
Patton, P.E., Burry, K.A., Thurmond, A., Novy, M.J. and Wolf, D.P. (1992) Intrauterine insemination outperforms intracervical insemination in a randomized, controlled study with frozen, donor semen. Fertil. Steril., 57, 559564.[ISI][Medline]
Robinson, J.N., Lockwood, G.M., Dokras, A., Egan, D.M., Ross, C. and Barlow, D.H. (1993) A controlled study to assess the use of in vitro fertilization with donor semen after failed therapeutic donor insemination. Fertil. Steril., 59, 353358.[ISI][Medline]
Roest, J., van Heusden, A.M., Zeilmaker, G.H. and Verhoeff, A. (1998) Cumulative pregnancy rates and selective drop-out of patients in in-vitro fertilization treatment. Hum. Reprod., 13, 339341.[Medline]
Shenfield, F., Doyle, P., Valentine, A. Steele, S.J. and Tan, S.L. (1993) Effects of age, gravidity and male infertility status on cumulative conception rates following artificial insemination with cryopreserved donor semen: analysis of 2998 cycles of treatment in one centre over 10 years. Hum. Reprod., 8, 6064.[Abstract]
Stolwijk, A.M., Hamilton, C.J.C.M., Hollanders, J.M.G., Bastiaans, L.A. and Zielhuis, G.A. (1996) A more realistic approach to the cumulative pregnancy rate after in-vitro fertilization. Hum. Reprod., 11, 660663.[Abstract]
Tan, S.L., Doyle, P., Maconochie, N., Edwards, R.G., Balen, A., Bekir, J., Brinsden, P. and Campbell, S. (1994) Pregnancy and birth rates of live infants after in-vitro fertilization in women with and without previous in vitro fertilization pregnancies: A study of eight thousand cycles at one center. Am. J. Obstet. Gynecol., 170, 3440.[ISI][Medline]
Trounson, A.O., Matthews, C.D., Kovacs, G.T., Spiers, A., Steigrad, S.J., Saunders, D.M., Jones, W.R. and Fuller, S. (1981) Artificial insemination by frozen donor semen: results of multicentre Australian experience. Int. J. Androl., 4, 227234.[ISI][Medline]
Van Royen, E., Mangelschots, K., de Neubourg, D., Valkenburg, M., van de Meerssche, M., Ryckaert, G., Eestermans, W. and Gerris, J. (1999) Characterization of a top quality embryo, a step towards single-embryo transfer. Hum. Reprod., 14, 23452349.
Vekemans, M., Englert, Y., Camus, M. and de Maertelaer, G. (1987) In-vitro fertilization with donor sperm after failure of artificial insemination. Hum. Reprod., 2, 121125.[Abstract]
Vilska, S., Tiitinen, A., Hyden-Granskog, C., Hovatta, O. (1999) Elective transfer of one embryo results in an acceptable pregnancy rate and eliminates the risk of multiple birth. Hum. Reprod., 14, 23922395.
Wainer, R., Merlet, F., Ducot, B., Bailly, M., Tribalat, S. and Lombroso, R. (1995) Prospective randomized comparison of intrauterine and intracervical insemination with donor spermatozoa. Hum. Reprod., 10, 29192922.[Abstract]
Walters, D.E. (1994) A plea for more fastidious and objective use of statistics. J. Assist. Reprod. Genet., 11, 6373.[ISI][Medline]
Wilcox, L.S., Peterson, H.B., Haseltine, F.P. and Martin, M.C. (1993) Defining and interpreting pregnancy success rates for in-vitro fertilization. Fertil. Steril., 60, 1825.[ISI][Medline]
Williams, R.S. and Alderman, J. (2001) Predictors of success with the use of donor sperm. Am. J. Obstet. Gynecol., 185, 332333.[ISI][Medline]
Submitted on December 3, 2001; accepted on February 4, 2002.