ment from units that either quote extremely selective statistics, or quote as their own other's results. We need to distinguish ourselves from charlatans and dabblers. Is it not time for The American Fertility Society to take a lead on this issue? In the United Kingdom the Interim Licensing Authority collects voluntary uncertified data from IVF and gamete intrafallopian transfer units. These are then amalgamated and published as data for the whole country. This is unsatisfactory. It should be possible for The American Fertility Society to collect data from units where members work and publish results either openly or with identification details removed. If the data were anonymous then clinics could provide their copy of the results to prospective couples, along with an explanation should they feel one necessary. Should there be concern about the integrity of the data on which the survey will be based, certification is easy. In the United Kingdom, in both the state and private sectors, accountants have access to medical records, and they could certify returns. The same could happen elsewhere, on a voluntary basis if necessary. This unit would be happy to cooperate with such a service.
Peter Bromwich, M.R.C.O.G. Midland Fertility Services West Midlands, England November 30, 1989 REFERENCES 1. Younger JB: Truth in advertising (Editor's Corner). Fertil
Steril 52:726, 1989
Reply of the Author: These words of wisdom from a United Kingdom colleague are appreciated, particularly when we recall that the experience there is longer lasting than is ours. We should all know that many physicians in the United Kingdom involved in in vitro fertilization (lVF) have encouraged the government to change the licensing authority from an interim and voluntary basis, to a statutory and long lasting authority. It is equally important to recognize that that authority has a great deal to do with approving research involving IVF and gamete intrafallopian transfer, and also that the government there financially supports the IVF· process in many instances. In our country, the major governmental interest appears to be in the data collection process and in the regulation or licensing of laboratories. It 756
Letters-to·the-editor
is too bad that our government does not support either the research or patient care aspect of IVF. The hope is that a cooperative relationship between reproductive medicine and government can lead to the removal of barriers which prevent the solving of these latter issues. Advertising means to make known, to call something to the attention of the public (Webster's Ninth New Collegiate Dictionary, 1988). An advertisement says much more about us than the words you see or hear. Advertisement is really what one wants to say about himself. To maintain creditability, the results shown in advertisements and those from clinic data in the United States IVF Registry should be the same. J. Benjamin Younger, M.D.
Department of Obstetrics and Gynecology University of Alabama School of Medicine Birmingham, Alabama January 25,1990 The "Holy Grail"-A Test for Ovulation With Metaphysical Certainty?
To the Editor: Isolated coitus ~ 7 days in advance of ovulation resulting in conception?! "How can that be, how long can sperm survive?" Carl Hartman 2 was asked. He used to time ovulation in monkeys by daily rectal examination. His comment: "I keep my monkeys in cages." Since the selected natural family planning (NFP) pregnancy charts that Kambic and Gray! studied were made under circumstances beyond their control, they are on the same insecure ground as were Guerrero or Bauman. In 1984 I received copies of all Bauman's charts. Six experienced physicians had estimated the day of ovulation on them. Unfortunately, untrained women had made-or made up-several of those charts; one recorded exactly 97.0°F each day until it jumped to exactly 98.0°F each day for the rest of the cycle. Experts should decline to "interpret" basal body temperature (BBT) or NFP charts of inferior quality. In regulating fertility by periodic continence, the temperature chart delimits empirically, but quite effectively, the possible days of fertility; a "day of the rise" on the chart is not a marker of the day of ovulation. Kambic and Gray! excluded the first day of the BBT rise for that purpose with good reason. 3 In the Billings ovulation method it is the user who is supposed to chart as her "peak day" the last day any mucus discharge is clear, stretchy, or lubricative. Then to avoid pregnancy the couple should Fertility and Sterility
abstain for 4 more days. Kambic and Gray, I by contrast, asked four different experts to identify on users' charts an undefined peak mucus day or an undefined periovulatory peak in cervical mucus as a marker of the day of ovulation. When these experts used such a peak as a marker, while they did agree (±1 day) on the day, it turns out that in 11 of their 27 cases they estimated the day of ovulation as having been 6 or more days after the probable conception day. Are human spermatozoa fertile in the female tract after 7 days, and even after> 7 days as in four of these cases? The premise about a mucus peak being the day of ovulation, from which they calculated the coitus-to-ovulation interval, must be an error. In fact no markers pinpoint the day of ovulation. Therefore I cannot agree that NFP charts are ideal to determine a relationship between adverse pregnancy outcome and NFP use. To determine that one ought to have a more valid index of the day of ovulation than an NFP pregnancy chart and one ought to know the maximum fertile life of human spermatozoa-as yet not clearly established.
Edward F. Keefe, M.D. Greenwich, Connecticut November 30, 1989 REFERENCES 1. Kambic R, Gray RH: Interobserver variation in estimation of day of conception intercourse using natural family planning charts. Fertil Steril51:430, 1989 2. Hartman CG: Pelvic (rectal) palpation of the female monkey with special reference to the ascertainment of ovulation time. Am J Obstet Gynecol 26:600, 1933 3. Keefe EF: Basal body temperature (Letter). Fertil Steril38: 502,1982
Reply of the Authors: We thank Dr. Keefe for his observations. However, we did not conclude, as Dr. Keefe suggests, that the mucus peak marks the day of ovulation. We concluded that, of the basal body temperature and mucus peak, the mucus peak "is a more valid indirect measure of ovulation, both because it is subject to less interobserver variation, and because it more closely approximates the timing of ovulation."l We agree that there is individual and population variability in the time of the mucus peak with respect to the time of ovulation. Dr. Keefe notes that for 11 of 27 pregnancies (41 %) the day of mucus peak (not the day of ovulation as Keefe states) is 6 or more days after the Vol. 53, No.4, April 1990
probable conception day. As we point out, these are selected difficult natural family planning (NFP) conception charts, and we do not necessarily expect that 40% of all NFP conception charts would show such long intervals. There are several explanations for these extended intervals. In some couples extended sperm life must be considered. Some couples may have had other sexual contact closer to the peak that was not recorded, and in others ovulation occurred closer to the day of intercourse than the peak mucus day. We agree with Keefe that we do not know the maximum fertile life of human spermatozoa. Studies such as the current pregnancy outcome study2 provide epidemiological and population based data to generate hypotheses for biological studies on sperm life. It seems to us that patient recording errors and variability of the peak with respect to ovulation cannot explain all of the 11 cases of extended time from conception intercourse to the peak, and that the current estimates of 72 hours of maximum fertile life of human spermatozoa may be too short. Dr. Keefe also suggests that NFP charts are not appropriate to study the relationship between timing of conception and pregnancy outcome. We could have chosen to measure urinary luteinizing hormone and steroid excretion to detect ovulation, and human chorionic gonadotropin to detect pregnancy. However, such studies are logistically and economically difficult. Currently we have >400 pregnancies recorded in the pregnancy outcomes study using NFP charts and we expect more. 2 In the abstract, we said NFP charts were ideal because they contain markers of ovulation and records of intercourse, not because they provide information on the exact timing of ovulation.
Robert T. Kambic, M.B.H. Ronald H. Gray, M.D. Johns Hopkins University Department of Population Dynamics Baltimore, Maryland January 19, 1990 REFERENCES 1. Kambic R, Gray RH: Interobserver variation in estimation of day of conception intercourse using selected natural family planning charts. Fertil Steri151:430, 1989 2. Simpson JL, Gray RH, Queenan JT, Mena P, Perez A, Kambic RT, Tagliabue G, Pardo F, Stevenson WS, Barbato M, Jennings VH, Zinaman MJ, Spieler JM: Pregnancy outcome associated with natural family planning (NFP): scientific basis and experimental design for an international cohort study. Adv Contracept 4:247,1988
Letters-to-the-editor
757
Peter Bromwich, M.R.C.O.G. Midland Fertility Services West Midlands, England November 30, 1989 REFERENCES 1. Younger JB: Truth in advertising (Editor's Corner). Fertil
Steril 52:726, 1989
Reply of the Author: These words of wisdom from a United Kingdom colleague are appreciated, particularly when we recall that the experience there is longer lasting than is ours. We should all know that many physicians in the United Kingdom involved in in vitro fertilization (lVF) have encouraged the government to change the licensing authority from an interim and voluntary basis, to a statutory and long lasting authority. It is equally important to recognize that that authority has a great deal to do with approving research involving IVF and gamete intrafallopian transfer, and also that the government there financially supports the IVF· process in many instances. In our country, the major governmental interest appears to be in the data collection process and in the regulation or licensing of laboratories. It 756
Letters-to·the-editor
is too bad that our government does not support either the research or patient care aspect of IVF. The hope is that a cooperative relationship between reproductive medicine and government can lead to the removal of barriers which prevent the solving of these latter issues. Advertising means to make known, to call something to the attention of the public (Webster's Ninth New Collegiate Dictionary, 1988). An advertisement says much more about us than the words you see or hear. Advertisement is really what one wants to say about himself. To maintain creditability, the results shown in advertisements and those from clinic data in the United States IVF Registry should be the same. J. Benjamin Younger, M.D.
Department of Obstetrics and Gynecology University of Alabama School of Medicine Birmingham, Alabama January 25,1990 The "Holy Grail"-A Test for Ovulation With Metaphysical Certainty?
To the Editor: Isolated coitus ~ 7 days in advance of ovulation resulting in conception?! "How can that be, how long can sperm survive?" Carl Hartman 2 was asked. He used to time ovulation in monkeys by daily rectal examination. His comment: "I keep my monkeys in cages." Since the selected natural family planning (NFP) pregnancy charts that Kambic and Gray! studied were made under circumstances beyond their control, they are on the same insecure ground as were Guerrero or Bauman. In 1984 I received copies of all Bauman's charts. Six experienced physicians had estimated the day of ovulation on them. Unfortunately, untrained women had made-or made up-several of those charts; one recorded exactly 97.0°F each day until it jumped to exactly 98.0°F each day for the rest of the cycle. Experts should decline to "interpret" basal body temperature (BBT) or NFP charts of inferior quality. In regulating fertility by periodic continence, the temperature chart delimits empirically, but quite effectively, the possible days of fertility; a "day of the rise" on the chart is not a marker of the day of ovulation. Kambic and Gray! excluded the first day of the BBT rise for that purpose with good reason. 3 In the Billings ovulation method it is the user who is supposed to chart as her "peak day" the last day any mucus discharge is clear, stretchy, or lubricative. Then to avoid pregnancy the couple should Fertility and Sterility
abstain for 4 more days. Kambic and Gray, I by contrast, asked four different experts to identify on users' charts an undefined peak mucus day or an undefined periovulatory peak in cervical mucus as a marker of the day of ovulation. When these experts used such a peak as a marker, while they did agree (±1 day) on the day, it turns out that in 11 of their 27 cases they estimated the day of ovulation as having been 6 or more days after the probable conception day. Are human spermatozoa fertile in the female tract after 7 days, and even after> 7 days as in four of these cases? The premise about a mucus peak being the day of ovulation, from which they calculated the coitus-to-ovulation interval, must be an error. In fact no markers pinpoint the day of ovulation. Therefore I cannot agree that NFP charts are ideal to determine a relationship between adverse pregnancy outcome and NFP use. To determine that one ought to have a more valid index of the day of ovulation than an NFP pregnancy chart and one ought to know the maximum fertile life of human spermatozoa-as yet not clearly established.
Edward F. Keefe, M.D. Greenwich, Connecticut November 30, 1989 REFERENCES 1. Kambic R, Gray RH: Interobserver variation in estimation of day of conception intercourse using natural family planning charts. Fertil Steril51:430, 1989 2. Hartman CG: Pelvic (rectal) palpation of the female monkey with special reference to the ascertainment of ovulation time. Am J Obstet Gynecol 26:600, 1933 3. Keefe EF: Basal body temperature (Letter). Fertil Steril38: 502,1982
Reply of the Authors: We thank Dr. Keefe for his observations. However, we did not conclude, as Dr. Keefe suggests, that the mucus peak marks the day of ovulation. We concluded that, of the basal body temperature and mucus peak, the mucus peak "is a more valid indirect measure of ovulation, both because it is subject to less interobserver variation, and because it more closely approximates the timing of ovulation."l We agree that there is individual and population variability in the time of the mucus peak with respect to the time of ovulation. Dr. Keefe notes that for 11 of 27 pregnancies (41 %) the day of mucus peak (not the day of ovulation as Keefe states) is 6 or more days after the Vol. 53, No.4, April 1990
probable conception day. As we point out, these are selected difficult natural family planning (NFP) conception charts, and we do not necessarily expect that 40% of all NFP conception charts would show such long intervals. There are several explanations for these extended intervals. In some couples extended sperm life must be considered. Some couples may have had other sexual contact closer to the peak that was not recorded, and in others ovulation occurred closer to the day of intercourse than the peak mucus day. We agree with Keefe that we do not know the maximum fertile life of human spermatozoa. Studies such as the current pregnancy outcome study2 provide epidemiological and population based data to generate hypotheses for biological studies on sperm life. It seems to us that patient recording errors and variability of the peak with respect to ovulation cannot explain all of the 11 cases of extended time from conception intercourse to the peak, and that the current estimates of 72 hours of maximum fertile life of human spermatozoa may be too short. Dr. Keefe also suggests that NFP charts are not appropriate to study the relationship between timing of conception and pregnancy outcome. We could have chosen to measure urinary luteinizing hormone and steroid excretion to detect ovulation, and human chorionic gonadotropin to detect pregnancy. However, such studies are logistically and economically difficult. Currently we have >400 pregnancies recorded in the pregnancy outcomes study using NFP charts and we expect more. 2 In the abstract, we said NFP charts were ideal because they contain markers of ovulation and records of intercourse, not because they provide information on the exact timing of ovulation.
Robert T. Kambic, M.B.H. Ronald H. Gray, M.D. Johns Hopkins University Department of Population Dynamics Baltimore, Maryland January 19, 1990 REFERENCES 1. Kambic R, Gray RH: Interobserver variation in estimation of day of conception intercourse using selected natural family planning charts. Fertil Steri151:430, 1989 2. Simpson JL, Gray RH, Queenan JT, Mena P, Perez A, Kambic RT, Tagliabue G, Pardo F, Stevenson WS, Barbato M, Jennings VH, Zinaman MJ, Spieler JM: Pregnancy outcome associated with natural family planning (NFP): scientific basis and experimental design for an international cohort study. Adv Contracept 4:247,1988
Letters-to-the-editor
757
