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More than one fertile ovulation per cycle?
Gu¨ nther Freundl, M.D. Department of Gynaecology and Obstetrics Staedtisches Krankenhaus Duesseldorf-Benrath Heinrich Heine University Duesseldorf, Germany Joseph B. Stanford, M.D., M.S.P.H. Department of Family and Preventive Medicine University of Utah Salt Lake City, Utah July 24, 2003
References 1. Baerwald A, Adams G, Pierson R. A new model for ovarian follicular development during the human menstrual cycle. Fertil Steril 2003;80: 116 –20. 2. European Natural Family Planning Study Groups. European multicenter study of natural family planning (1989 –1995): efficacy and drop-out. Adv Contracept 1999;15:69 –83. 3. Frank-Herrmann P. Natural family planning with and without barrier method use in the fertile phase: efficacy in relation to sexual behavior: a German prospective long-term study. Adv Contracept 1997;13:179 –89. 4. Stanford JB, Smith KR, Dunson DB. Vulvar mucus observation and the probability of pregnancy. Obstet Gynecol 2003;101:1285–93. 5. Wilcox AJ, Dunson D, Baird DD. The timing of the “fertile window” in the menstrual cycle: day specific estimates from a prospective study. BMJ 2000;321:1259 –62.
doi:10.1016/j.fertnstert.2003.11.016
To the Editor: The article by Baerwald and colleagues (1) has been a lightning rod for controversy. A major component of the controversy has been the expectations generated by the media coverage and the difficulties in interpreting the waveform data. The data from this dynamic, serial ultrasonographic study of follicular diameters and wave patterns in 63 patients does not seem to live up to the media hype. Of the 63 participants, 50 had normal biphasic cycles and could thus be included. Thirteen patients were excluded because of deviations in cycle duration that were considered to be outside the range of normal ovulation. Of the remaining 50 patients, 34 exhibited two waves of follicular development and 16 patients had three waves of follicular diameter. However, it was always the last wave that resulted in a dominant follicle and ovulation. It is not surprising that the women ovulated during the last wave of follicular growth: This wave is under the influence of LH, whereas the first wave is under the domination of P, which stops ovulation altogether until the end of the cycle. This new research serves to confirm what we already knew: Follicular development during the luteal phase is regularly observed by women using the symptothermal method. During this time, they usually note 1 day of cervical fluid increase and a short decrease in basal body temperature. Contrary to reports in the press of this article, women experience only one fertile ovulation per cycle. The still widely unknown safety and usefulness of the symptothermal method of birth regulation remains unchanged. FERTILITY & STERILITY威
R. Harri Wettstein, Ph.D., M.A., M.B.A. Symptotherm Foundation Morges, Switzerland September 8, 2003
References 1. Baerwald AR, Adams AP, Pierson RA. A new model for ovarian follicular development during the human menstrual cycle. Fertil Steril 2003;80:116 –22.
doi:10.1016/j.fertnstert.2003.12.002
To the Editor: If the findings by Baerwald et al. (1) are replicated and relatively large follicles are found to be a normal aspect of late luteal ovarian biology, we suggest that these luteal follicles may have functional significance. Implantation is the critical reproductive event in the late luteal phase. At implantation, concentrations of hCG increase exponentially and rescue the corpus luteum. In a large proportion of conception cycles, P levels surge above midluteal levels within a day or two after hCG is first detected; in others, the surge is delayed by several days, and in some, P is merely maintained at midluteal levels (2). Conceptions lacking the rapid increase in P level are more likely to fail. A dramatic increase in P level at the time of implantation is also seen in other primate species. Perhaps when hCG from the conceptus rescues the corpus luteum, it also luteinizes any large follicles that are present in the late luteal phase, and they contribute to the increase in P level at implantation. Functional accessory corpora lutea are important sources of P during pregnancy in horses (3). Perhaps accessory corpora lutea are important in human reproduction as well. Donna D. Baird, Ph.D. Epidemiology Branch National Institute of Environmental Health Sciences Research Triangle Park, North Carolina September 22, 2003
References 1. Baerwald AR, Adams GP, Pierson RA. A new model for ovarian follicular development during the human menstrual cycle. Fertil Steril 2003;80:116 –22. 2. Baird DD, Weinberg CR, McConnaughey DR, Wilcox AJ. Rescue of the corpus luteum in normal human pregnancy. Biol Reprod 2003;68:448 – 56. 3. Niswender GD, Net TM. The corpus luteum and its control. In: Knobil E, Neill JD, eds. The physiology of reproduction, 1st ed. New York: Raven, 1988:489 –525.
doi:10.1016/j.fertnstert.2003.12.003 Editor’s note: Authors chose not to respond.
Editorial Commentary
More than one fertile ovulation per cycle? The paper by Baerwald and colleagues (1) published in the July 2003 issue of the journal suggests that there may be 729
References 1. Baerwald A, Adams G, Pierson R. A new model for ovarian follicular development during the human menstrual cycle. Fertil Steril 2003;80: 116 –20. 2. European Natural Family Planning Study Groups. European multicenter study of natural family planning (1989 –1995): efficacy and drop-out. Adv Contracept 1999;15:69 –83. 3. Frank-Herrmann P. Natural family planning with and without barrier method use in the fertile phase: efficacy in relation to sexual behavior: a German prospective long-term study. Adv Contracept 1997;13:179 –89. 4. Stanford JB, Smith KR, Dunson DB. Vulvar mucus observation and the probability of pregnancy. Obstet Gynecol 2003;101:1285–93. 5. Wilcox AJ, Dunson D, Baird DD. The timing of the “fertile window” in the menstrual cycle: day specific estimates from a prospective study. BMJ 2000;321:1259 –62.
doi:10.1016/j.fertnstert.2003.11.016
To the Editor: The article by Baerwald and colleagues (1) has been a lightning rod for controversy. A major component of the controversy has been the expectations generated by the media coverage and the difficulties in interpreting the waveform data. The data from this dynamic, serial ultrasonographic study of follicular diameters and wave patterns in 63 patients does not seem to live up to the media hype. Of the 63 participants, 50 had normal biphasic cycles and could thus be included. Thirteen patients were excluded because of deviations in cycle duration that were considered to be outside the range of normal ovulation. Of the remaining 50 patients, 34 exhibited two waves of follicular development and 16 patients had three waves of follicular diameter. However, it was always the last wave that resulted in a dominant follicle and ovulation. It is not surprising that the women ovulated during the last wave of follicular growth: This wave is under the influence of LH, whereas the first wave is under the domination of P, which stops ovulation altogether until the end of the cycle. This new research serves to confirm what we already knew: Follicular development during the luteal phase is regularly observed by women using the symptothermal method. During this time, they usually note 1 day of cervical fluid increase and a short decrease in basal body temperature. Contrary to reports in the press of this article, women experience only one fertile ovulation per cycle. The still widely unknown safety and usefulness of the symptothermal method of birth regulation remains unchanged. FERTILITY & STERILITY威
R. Harri Wettstein, Ph.D., M.A., M.B.A. Symptotherm Foundation Morges, Switzerland September 8, 2003
References 1. Baerwald AR, Adams AP, Pierson RA. A new model for ovarian follicular development during the human menstrual cycle. Fertil Steril 2003;80:116 –22.
doi:10.1016/j.fertnstert.2003.12.002
To the Editor: If the findings by Baerwald et al. (1) are replicated and relatively large follicles are found to be a normal aspect of late luteal ovarian biology, we suggest that these luteal follicles may have functional significance. Implantation is the critical reproductive event in the late luteal phase. At implantation, concentrations of hCG increase exponentially and rescue the corpus luteum. In a large proportion of conception cycles, P levels surge above midluteal levels within a day or two after hCG is first detected; in others, the surge is delayed by several days, and in some, P is merely maintained at midluteal levels (2). Conceptions lacking the rapid increase in P level are more likely to fail. A dramatic increase in P level at the time of implantation is also seen in other primate species. Perhaps when hCG from the conceptus rescues the corpus luteum, it also luteinizes any large follicles that are present in the late luteal phase, and they contribute to the increase in P level at implantation. Functional accessory corpora lutea are important sources of P during pregnancy in horses (3). Perhaps accessory corpora lutea are important in human reproduction as well. Donna D. Baird, Ph.D. Epidemiology Branch National Institute of Environmental Health Sciences Research Triangle Park, North Carolina September 22, 2003
References 1. Baerwald AR, Adams GP, Pierson RA. A new model for ovarian follicular development during the human menstrual cycle. Fertil Steril 2003;80:116 –22. 2. Baird DD, Weinberg CR, McConnaughey DR, Wilcox AJ. Rescue of the corpus luteum in normal human pregnancy. Biol Reprod 2003;68:448 – 56. 3. Niswender GD, Net TM. The corpus luteum and its control. In: Knobil E, Neill JD, eds. The physiology of reproduction, 1st ed. New York: Raven, 1988:489 –525.
doi:10.1016/j.fertnstert.2003.12.003 Editor’s note: Authors chose not to respond.
Editorial Commentary
More than one fertile ovulation per cycle? The paper by Baerwald and colleagues (1) published in the July 2003 issue of the journal suggests that there may be 729