Eur J Obstet Gynecol Reprod Biol 2013; 167:100–3. 10. Concato J, Peduzzi P, Holfold TR, Feinstein AR. Importance of events per independent variable in proportional hazards analysis. I. background, goals, and general strategy. J Clin Epidemiol 1995;48:1495–501. 11. Peduzzi P, Concato J, Feinstein AR, Holford TR. Importance of events per independent variable in proportional hazards regression analysis. II. accuracy and precision of regression estimates. J Clin Epidemiol 1995;48: 1503–10. 12. Vittinghoff E, McCulloch CE. Relaxing the rule of ten events per variable in logistic and Cox regression. Am J Epidemiol 2007;165:710–8.
Advanced Reproductive Age and Maternal Mortality To the Editor: The upward trend in U.S. maternal mortality documented by Creanga et al1 and the subject of an editorial in the same issue of the Green Journal,2 while shocking, is not at all surprising. National vital statistics have clearly documented that, in recent years, women are delaying childbearing to their late 30s and 40s.3 Figure 2 in Creanga et al’s article demonstrates that pregnancy-related mortality in these advanced age groups is several-fold higher compared with younger women. Therefore, one of the primary drivers of increased national maternal mortality is the aging of the pregnant patient cohort in the United States. This conclusion is further supported by the increasing contributions of chronic diseases and cardiovascular complications to maternal mortality, identified in the report.1 Our group (Gleicher N, Kushnir VA, Barad DH. Prospectively assessing risk for premature ovarian senescence in young females: a new paradigm. Reprod Biol Endocrinol 2015. In press.)4 and others5 recently have proposed a paradigm shift, characterized by assessing a young woman’s childbearing priorities, counseling about risks arising from delaying reproduction, and offering early assessment of functional ovarian reserve. Only such early counseling will enable women to formulate an informed reproductive life plan. Women who become aware that female fertility declines with age and
984
Letters
the approximately 10% with prematurely low functional ovarian reserve, as studies have demonstrated, often will alter reproductive life plans by having children sooner, considering fertility preservation options, or both. This lifespan approach to encourage individual responsibility through the development of a reproductive life plan is in line with efforts to improve maternal, infant, and child health through health promotion and disease prevention.6 If our specialty hopes to affect maternal mortality, we must realize its root causes and address them directly. Even with successful preventive programs, however, our specialty has to recognize the challenges of pregnancy for women older than age 40, comparatively, who represent the most rapidly growing age group having children in the United States. As we recently pointed out,7 this demographic trend appears unstoppable and, therefore, requires adjustments in medical care by obstetricians, who have to be prepared for more high-risk patients, but also by other medical specialties, which have to adjust to comanaging older women with more cardiovascular and other chronic medical problems through pregnancy. Finally, society as a whole has to adjust to everolder women having children and the social and societal consequences of such a development. Financial Disclosure: The authors did not report any potential conflicts of interest.
Vitaly A. Kushnir, MD Center for Human Reproduction, New York, New York David H. Barad, MD Norbert Gleicher, MD Center for Human Reproduction and Foundation for Reproductive Medicine, New York, New York
REFERENCES 1. Creanga AA, Berg CJ, Syverson C, Seed K, Bruce FC, Callaghan WM. Pregnancy-related mortality in the United States, 2006–2010. Obstetrics Gynecol 2015;125:5–12. 2. Chescheir NC. Enough already! Obstetrics Gynecol 2015;125:2–4. 3. National Vital Statistics Reports. Births: preliminary data for 2013. Available at:
http://www.cdc.gov/nchs/data/nvsr/nvsr63/ nvsr63_02.pdf. Retrieved January 1, 2015. 4. Kushnir VA, Barad DH, Gleicher N. Ovarian reserve screening before contraception? Reprod Biomed Online 2014; 29:527–9. 5. Seifer DB, Minkoff H, Merhi Z. Putting “family” back in family planning. Hum Reprod 2015;30:16–9. 6. Johnson K, Posner SF, Biermann J, Cordero JF, Atrash HK, Parker CS, et al. Recommendations to improve preconception health and health care—United States. A report of the CDC/ATSDR Preconception Care Work Group and the Select Panel on Preconception Care. MMWR Recomm Rep 2006;55:1–23. 7. Gleicher N, Kushnir VA, Weghofer A, Barad DH. The “graying” of infertility services: an impending revolution nobody is ready for. Reprod Biol Endocrinol 2014;12:63.
In Reply: We appreciate the letter from Dr. Kushnir et al regarding the need to examine the influence of advanced maternal age on pregnancy-related mortality trends in the United States. Women have been delaying childbearing, and pregnancy-related mortality increases with maternal age.1 Of all U.S. live births, women aged older than 35 years contributed less than 5% in 1980, about 9% in 1990, and 13–14% throughout 2000–2010.2,3 During this latter period, given modest changes in maternal age composition, crude and age-standardized pregnancy-related mortality trends show similar patterns. Thus, although contemporary trends in pregnancyrelated mortality are not driven by deaths in any particular age group, we agree that taking a life-course approach to reproductive planning is critical to meeting women’s reproductive needs and ensuring good obstetric outcomes. As Dr. Chescheir acknowledges,4 identification of risk factors for maternal mortality and morbidity coupled with risk-appropriate care are paramount to reducing pregnancy-related mortality among women of all ages. To understand current trends in pregnancy-related mortality, especially given changes in both causes of pregnancy-related death and risk profiles of pregnant women in the United States,1 we need to sort out the influence of the actual risk of pregnancy-related death compared with improvements in death
OBSTETRICS & GYNECOLOGY
Copyright ª by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
Advanced Reproductive Age and Maternal Mortality To the Editor: The upward trend in U.S. maternal mortality documented by Creanga et al1 and the subject of an editorial in the same issue of the Green Journal,2 while shocking, is not at all surprising. National vital statistics have clearly documented that, in recent years, women are delaying childbearing to their late 30s and 40s.3 Figure 2 in Creanga et al’s article demonstrates that pregnancy-related mortality in these advanced age groups is several-fold higher compared with younger women. Therefore, one of the primary drivers of increased national maternal mortality is the aging of the pregnant patient cohort in the United States. This conclusion is further supported by the increasing contributions of chronic diseases and cardiovascular complications to maternal mortality, identified in the report.1 Our group (Gleicher N, Kushnir VA, Barad DH. Prospectively assessing risk for premature ovarian senescence in young females: a new paradigm. Reprod Biol Endocrinol 2015. In press.)4 and others5 recently have proposed a paradigm shift, characterized by assessing a young woman’s childbearing priorities, counseling about risks arising from delaying reproduction, and offering early assessment of functional ovarian reserve. Only such early counseling will enable women to formulate an informed reproductive life plan. Women who become aware that female fertility declines with age and
984
Letters
the approximately 10% with prematurely low functional ovarian reserve, as studies have demonstrated, often will alter reproductive life plans by having children sooner, considering fertility preservation options, or both. This lifespan approach to encourage individual responsibility through the development of a reproductive life plan is in line with efforts to improve maternal, infant, and child health through health promotion and disease prevention.6 If our specialty hopes to affect maternal mortality, we must realize its root causes and address them directly. Even with successful preventive programs, however, our specialty has to recognize the challenges of pregnancy for women older than age 40, comparatively, who represent the most rapidly growing age group having children in the United States. As we recently pointed out,7 this demographic trend appears unstoppable and, therefore, requires adjustments in medical care by obstetricians, who have to be prepared for more high-risk patients, but also by other medical specialties, which have to adjust to comanaging older women with more cardiovascular and other chronic medical problems through pregnancy. Finally, society as a whole has to adjust to everolder women having children and the social and societal consequences of such a development. Financial Disclosure: The authors did not report any potential conflicts of interest.
Vitaly A. Kushnir, MD Center for Human Reproduction, New York, New York David H. Barad, MD Norbert Gleicher, MD Center for Human Reproduction and Foundation for Reproductive Medicine, New York, New York
REFERENCES 1. Creanga AA, Berg CJ, Syverson C, Seed K, Bruce FC, Callaghan WM. Pregnancy-related mortality in the United States, 2006–2010. Obstetrics Gynecol 2015;125:5–12. 2. Chescheir NC. Enough already! Obstetrics Gynecol 2015;125:2–4. 3. National Vital Statistics Reports. Births: preliminary data for 2013. Available at:
http://www.cdc.gov/nchs/data/nvsr/nvsr63/ nvsr63_02.pdf. Retrieved January 1, 2015. 4. Kushnir VA, Barad DH, Gleicher N. Ovarian reserve screening before contraception? Reprod Biomed Online 2014; 29:527–9. 5. Seifer DB, Minkoff H, Merhi Z. Putting “family” back in family planning. Hum Reprod 2015;30:16–9. 6. Johnson K, Posner SF, Biermann J, Cordero JF, Atrash HK, Parker CS, et al. Recommendations to improve preconception health and health care—United States. A report of the CDC/ATSDR Preconception Care Work Group and the Select Panel on Preconception Care. MMWR Recomm Rep 2006;55:1–23. 7. Gleicher N, Kushnir VA, Weghofer A, Barad DH. The “graying” of infertility services: an impending revolution nobody is ready for. Reprod Biol Endocrinol 2014;12:63.
In Reply: We appreciate the letter from Dr. Kushnir et al regarding the need to examine the influence of advanced maternal age on pregnancy-related mortality trends in the United States. Women have been delaying childbearing, and pregnancy-related mortality increases with maternal age.1 Of all U.S. live births, women aged older than 35 years contributed less than 5% in 1980, about 9% in 1990, and 13–14% throughout 2000–2010.2,3 During this latter period, given modest changes in maternal age composition, crude and age-standardized pregnancy-related mortality trends show similar patterns. Thus, although contemporary trends in pregnancyrelated mortality are not driven by deaths in any particular age group, we agree that taking a life-course approach to reproductive planning is critical to meeting women’s reproductive needs and ensuring good obstetric outcomes. As Dr. Chescheir acknowledges,4 identification of risk factors for maternal mortality and morbidity coupled with risk-appropriate care are paramount to reducing pregnancy-related mortality among women of all ages. To understand current trends in pregnancy-related mortality, especially given changes in both causes of pregnancy-related death and risk profiles of pregnant women in the United States,1 we need to sort out the influence of the actual risk of pregnancy-related death compared with improvements in death
OBSTETRICS & GYNECOLOGY
Copyright ª by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
