- Email: [email protected]
Giving credit where credit is due?
Letters to the Editors
www.AJOG.org Meiling Hua, MD Alison G. Cahill, MD, MSCI Department of Obstetrics and Gynecology Washington University School of Medicine 4566 Scott Ave., Campus Box 8064 St. Louis, MO 63110 [email protected]
REFERENCE 1. Hua M, Odibo AO, Longman RE, Macones GA, Roehl KA, Cahill AG. Congenital uterine anomalies and adverse pregnancy outcomes. Am J Obstet Gynecol 2011;205:558.e1-5. © 2012 Mosby, Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2012.06.016
The authors report no conflict of interest.
Giving credit where credit is due? TO THE EDITORS: With deep interest, I read the article by Kramer et al1 on preterm birth syndrome challenges. The authors mention the importance of the way gestational age is determined because differences in menstrual cycle length account for considerable variability in day of conception (between women and usually not in 1 woman). In my opinion they suggest using Ogino-Knaus method (see reference 10 in article) to calculate expected date of delivery in women recalling the first day of the last menstrual period with certainty. Gestational age at any moment in pregnancy is determined by expected date of delivery. The way in which prevalences of preterm, term, and postterm births are influenced by gestational age calculation, either using amenorrhea or corrected for differences in follicular phase length, is graphically visualized by Boyce et al.2 They used, like Saito et al (reference 9 in article), temperature curves to determine ovulation. The relation between follicular phase length and date of delivery is also brought forward by Carus.3 He described due date calculation in 3 situations that are follicular phase length related. Firstly, multiparae (in that era) often correctly calculated due date since they knew the conception date. Secondly, when conception date was unknown, the physician deduced an accurate estimate; due date was 280 days later. Carus3 noticed that in this group, women often gave birth earlier or later than due date and wrote that when the last menstrual period occurred 8-14 days before conception, delivery also started ⱖ8 days earlier than expected. Based on experience, he questioned the accuracy of 280 days and stated that conception did not always take place 280 days before delivery. Thirdly, when conception date could not be estimated accurately, the first day of the last menstrual period was used. Due date was then 40-42
weeks later because conception might have occurred 8-14 or even 21 days after the first day. The due date of Carus3 matches 420/7 weeks of gestation nowadays; accepting that pregnancy duration is 280 days (including 14 days without embryo) from the first day of the last normal menstrual period in women with regular menstrual cycles of 28 days. Carus3 could be credited for relating differences in preovulatory phase length to due date calculation and Ogino and Knaus for describing the constant postovulatory phase. As regards studies on preterm birth syndrome, one wonders whether heterogeneity decreases if only naturally conceived f pregnancies with known ovulation are included. Pieter Hummel, MD Department of Obstetrics, Gynecology, and Reproductive Medicine Medical Center Alkmaar Wilhelminalaan 19 1815 JD Alkmaar, the Netherlands [email protected] The author reports no conflict of interest.
REPLY DECLINED REFERENCES 1. Kramer MS, Papageorghiou A, Culhane J, et al. Challenges in defining and classifying the preterm birth syndrome. Am J Obstet Gynecol 2012;206:108-12. 2. Boyce A, Mayaux MJ, Schwartz D. Classical and “true” gestational postmaturity. Am J Obstet Gynecol 1976;125:911-4. 3. Carus CG. Zeitrechnung der Schwangerschaft. In: Carus CG, ed. Lehrbuch der Gynäkologie. Zweiter Theil. Leipzig: Gerhard Fleischer; 1820: 87-9. © 2012 Mosby, Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2012.06.017
Comment on “Vaginal cuff dehiscence: risk factors and management” TO THE EDITORS: We read the article from Cronin et al,1 “Vaginal cuff dehiscence: risk factors and management,” with great interest. With the increasing rates of video-assisted laparoscopic and robot-assisted hysterectomy, the prevention of
vaginal dehiscence and evisceration with minimally invasive techniques is of utmost importance. Because the authors have recommended that other institutions continue to report their experiences with video-assisted laparoscopic hysterectomy OCTOBER 2012 American Journal of Obstetrics & Gynecology
e9
www.AJOG.org Meiling Hua, MD Alison G. Cahill, MD, MSCI Department of Obstetrics and Gynecology Washington University School of Medicine 4566 Scott Ave., Campus Box 8064 St. Louis, MO 63110 [email protected]
REFERENCE 1. Hua M, Odibo AO, Longman RE, Macones GA, Roehl KA, Cahill AG. Congenital uterine anomalies and adverse pregnancy outcomes. Am J Obstet Gynecol 2011;205:558.e1-5. © 2012 Mosby, Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2012.06.016
The authors report no conflict of interest.
Giving credit where credit is due? TO THE EDITORS: With deep interest, I read the article by Kramer et al1 on preterm birth syndrome challenges. The authors mention the importance of the way gestational age is determined because differences in menstrual cycle length account for considerable variability in day of conception (between women and usually not in 1 woman). In my opinion they suggest using Ogino-Knaus method (see reference 10 in article) to calculate expected date of delivery in women recalling the first day of the last menstrual period with certainty. Gestational age at any moment in pregnancy is determined by expected date of delivery. The way in which prevalences of preterm, term, and postterm births are influenced by gestational age calculation, either using amenorrhea or corrected for differences in follicular phase length, is graphically visualized by Boyce et al.2 They used, like Saito et al (reference 9 in article), temperature curves to determine ovulation. The relation between follicular phase length and date of delivery is also brought forward by Carus.3 He described due date calculation in 3 situations that are follicular phase length related. Firstly, multiparae (in that era) often correctly calculated due date since they knew the conception date. Secondly, when conception date was unknown, the physician deduced an accurate estimate; due date was 280 days later. Carus3 noticed that in this group, women often gave birth earlier or later than due date and wrote that when the last menstrual period occurred 8-14 days before conception, delivery also started ⱖ8 days earlier than expected. Based on experience, he questioned the accuracy of 280 days and stated that conception did not always take place 280 days before delivery. Thirdly, when conception date could not be estimated accurately, the first day of the last menstrual period was used. Due date was then 40-42
weeks later because conception might have occurred 8-14 or even 21 days after the first day. The due date of Carus3 matches 420/7 weeks of gestation nowadays; accepting that pregnancy duration is 280 days (including 14 days without embryo) from the first day of the last normal menstrual period in women with regular menstrual cycles of 28 days. Carus3 could be credited for relating differences in preovulatory phase length to due date calculation and Ogino and Knaus for describing the constant postovulatory phase. As regards studies on preterm birth syndrome, one wonders whether heterogeneity decreases if only naturally conceived f pregnancies with known ovulation are included. Pieter Hummel, MD Department of Obstetrics, Gynecology, and Reproductive Medicine Medical Center Alkmaar Wilhelminalaan 19 1815 JD Alkmaar, the Netherlands [email protected] The author reports no conflict of interest.
REPLY DECLINED REFERENCES 1. Kramer MS, Papageorghiou A, Culhane J, et al. Challenges in defining and classifying the preterm birth syndrome. Am J Obstet Gynecol 2012;206:108-12. 2. Boyce A, Mayaux MJ, Schwartz D. Classical and “true” gestational postmaturity. Am J Obstet Gynecol 1976;125:911-4. 3. Carus CG. Zeitrechnung der Schwangerschaft. In: Carus CG, ed. Lehrbuch der Gynäkologie. Zweiter Theil. Leipzig: Gerhard Fleischer; 1820: 87-9. © 2012 Mosby, Inc. All rights reserved. http://dx.doi.org/10.1016/j.ajog. 2012.06.017
Comment on “Vaginal cuff dehiscence: risk factors and management” TO THE EDITORS: We read the article from Cronin et al,1 “Vaginal cuff dehiscence: risk factors and management,” with great interest. With the increasing rates of video-assisted laparoscopic and robot-assisted hysterectomy, the prevention of
vaginal dehiscence and evisceration with minimally invasive techniques is of utmost importance. Because the authors have recommended that other institutions continue to report their experiences with video-assisted laparoscopic hysterectomy OCTOBER 2012 American Journal of Obstetrics & Gynecology
e9