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Stanhiser J, Jukic AMZ, McConnaughey DR, Steiner AZ. Omega-3 fatty acid supplementation and fecundability. Hum Reprod 2022; 37:1037-1046. [PMID: 35147198 PMCID: PMC9308390 DOI: 10.1093/humrep/deac027] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/05/2022] [Indexed: 02/17/2024] Open
Abstract
STUDY QUESTION Is self-reported use of omega-3 fatty acid supplements associated with fecundability, the probability of natural conception, in a given menstrual cycle? SUMMARY ANSWER Prospectively recorded omega-3 supplement use was associated with an increased probability of conceiving. WHAT IS KNOWN ALREADY In infertile women, omega-3 fatty acid intake has been associated with increased probability of pregnancy following IVF. In natural fertility, studies are conflicting, and no study of natural fertility has evaluated omega-3 fatty acid supplementation and fecundity. STUDY DESIGN, SIZE, DURATION Secondary data analysis of 900 women contributing 2510 cycles in Time to Conceive (TTC), a prospective, time to pregnancy cohort study from 2008 to December 2015. PARTICIPANTS/MATERIALS, SETTING, METHODS Women aged 30-44 years, trying to conceive <3 months, without history of infertility were followed using standardized pregnancy testing. While attempting to conceive, women daily recorded menstrual cycle events and supplement and medication intake using the Cerner Multum Drug Database. Supplements and vitamins containing omega-3 were identified. Omega-3 use, defined as use in at least 20% of days in a given menstrual cycle, in each pregnancy attempt cycle was determined. A discrete-time Cox proportional hazards model was used to calculate the fecundability ratio. MAIN RESULTS AND THE ROLE OF CHANCE Women taking omega-3 supplementation were more likely to be younger, thinner, nulligravid, white and to take vitamin D, prenatal and multivitamins compared to women not taking omega-3s. After adjusting for age, obesity, race, previous pregnancy, vitamin D and prenatal and multivitamin use, women taking omega-3 supplements had 1.51 (95% CI 1.12, 2.04) times the probability of conceiving compared to women not taking omega-3s. LIMITATIONS, REASONS FOR CAUTION Our study was not a randomized controlled trial. The women who used omega-3 supplements may represent a more health-conscious population. We sought to address this by adjusting for multiple factors in our model. Additionally, the omega-3 fatty acid supplements that TTC participants used included multiple types and brands with varying dosages of omega-3 fatty acids. Women reported the type of supplement they were taking but not the concentration of omega-3s in that supplement. It is therefore not possible to compare dosing or a dose-response relationship in our study. WIDER IMPLICATIONS OF THE FINDINGS Omega-3 supplementation may present a feasible and inexpensive modifiable factor to improve fertility. Randomized controlled trials are needed to further investigate the benefits of omega-3 supplementation for women trying to conceive naturally. STUDY FUNDING/COMPETING INTERESTS This study was supported by the Division of Reproductive Endocrinology and Infertility at the University of North Carolina at Chapel Hill, the NIH/NICHD (R21 HD060229-01 and R01 HD067683-01), and in part by the Intramural Research Program of the National Institute of Environmental Health Sciences (Z01ES103333). The authors declare that there is no conflict of interest. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
- J Stanhiser
- Reproductive Endocrinology and Infertility, University of North Carolina Chapel Hill, NC, USA
- Reproductive Partners—San Diego, La Jolla, CA, USA
- Department of Obstetrics and Gynecology, University of California San Diego, La Jolla, CA, USA
| | - A M Z Jukic
- Epidemiology Branch, National Institute of Environmental Health Sciences, Durham, NC, USA
| | | | - A Z Steiner
- Department of Obstetrics and Gynecology, Duke University, Durham, NC, USA
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Jukic AMZ, Padiyara P, Bracken MB, McConnaughey DR, Steiner AZ. Analgesic use at ovulation and implantation and human fertility. Am J Obstet Gynecol 2020; 222:476.e1-476.e11. [PMID: 31738897 DOI: 10.1016/j.ajog.2019.11.1251] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/30/2019] [Accepted: 11/07/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND Studies investigating the effects of pain-relieving medication use on conceiving a pregnancy have shown conflicting results. Furthermore, no previous study has examined medication use around ovulation or implantation and the associations with the probability of conception, fecundability. OBJECTIVE The objective of the study was to explore the association between fecundability and analgesic use in 3 different menstrual cycle windows (preovulation, periovulation, and implantation) as well as across the entire menstrual cycle. STUDY DESIGN We analyzed data from a prospective cohort study of women between 30 and 44 years of age who were trying to conceive naturally from 2008 through 2015. Using daily diaries, medication usage was classified as acetaminophen, aspirin, or nonaspirin nonsteroidal antiinflammatory drug during 4 time periods of interest (preovulatory, periovulatory, and implantation) as well as the overall nonmenstrual bleeding days of the cycle. Menstrual cycles during the prospective attempt to become pregnant were enumerated using daily diary menstrual bleeding information. Conception was defined as a positive home pregnancy test. Discrete time fecundability models were used to estimate the fecundability ratio and 95% confidence interval in each of the 4 time windows of interest and for each pain reliever (aspirin use, nonaspirin nonsteroidal antiinflammatory drug use, acetaminophen) compared with no medication use after adjustment for several covariates including age, race, education, body mass index, alcohol and caffeine use, frequency of intercourse, and a history of migraines or uterine fibroids. RESULTS Medication use was infrequent in the 858 women and 2366 cycles in this analysis. Use of nonaspirin nonsteroidal antiinflammatory drugs or acetaminophen was not associated with fecundability in any of the time windows of interest. Although the sample size was small, aspirin use during the implantation window was associated with increased fecundability (adjusted fecundability ratio [confidence interval]: 2.05 [1.23-3.41]). This association remained when limiting the analysis to cycles with minimal missing data or when adjusting for gravidity. None of the other medications were associated with fecundability. CONCLUSION Aspirin use around implantation was associated with increased fecundability. These results expand previous literature to suggest the following: (1) implantation may be an important target for the effects of aspirin on conception and (2) aspirin may be beneficial, regardless of pregnancy loss history. These observations should be tested with a clinical trial.
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Affiliation(s)
- Anne Marie Z Jukic
- Department of Chronic Disease Epidemiology, New Haven, CT; Center for Perinatal Pediatric and Environmental Epidemiology, Yale School of Public Health, New Haven, CT.
| | - Ponnu Padiyara
- Department of Chronic Disease Epidemiology, New Haven, CT; Center for Perinatal Pediatric and Environmental Epidemiology, Yale School of Public Health, New Haven, CT
| | - Michael B Bracken
- Department of Chronic Disease Epidemiology, New Haven, CT; Center for Perinatal Pediatric and Environmental Epidemiology, Yale School of Public Health, New Haven, CT
| | | | - Anne Z Steiner
- Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, NC
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Jukic AMZ, Baird DD, Weinberg CR, Wilcox AJ, McConnaughey DR, Steiner AZ. Pre-conception 25-hydroxyvitamin D (25(OH)D) and fecundability. Hum Reprod 2019; 34:2163-2172. [PMID: 31665286 PMCID: PMC7209776 DOI: 10.1093/humrep/dez170] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 07/15/2019] [Indexed: 12/28/2022] Open
Abstract
STUDY QUESTION Is pre-conception 25(OH)D associated with the per cycle probability of conception, i.e fecundability, in a prospective cohort study? SUMMARY ANSWER There are suggestive associations of high 25(OH)D (at least 50 ng/ml) with increased fecundability and low 25(OH)D (<20 ng/ml) with reduced fecundability, but the estimates were imprecise. WHAT IS KNOWN ALREADY Vitamin D has been associated with reproductive function and fertility in animal studies, but few human studies exist. STUDY DESIGN, SIZE, DURATION This community-based prospective cohort study included 522 women attempting to become pregnant between 2010 and 2016. The women completed online daily and monthly diaries until a positive home pregnancy test was observed or 12 months had elapsed. PARTICIPANTS/MATERIALS, SETTING, METHODS The study included women from central North Carolina who were aged 30-44 with no history of infertility, with no more than 3 months of attempt time at recruitment. Women recorded vaginal bleeding so that the ongoing number of attempt cycles could be counted and used to quantify a woman's pregnancy attempt time. Blood collected at the study entry was analysed for 25(OH)D using liquid chromatography tandem mass spectrometry. Associations with fecundability were estimated with a log-binomial discrete time-to-event model. MAIN RESULTS AND THE ROLE OF CHANCE Among 522 women, 257 conceived during the study. The mean age was 33 years and the mean 25(OH)D was 36 ng/ml. There was an estimated 10% higher fecundability with each 10 ng/ml increase in 25(OH)D (fecundability ratio (FR) 1.10, 95% CI: 0.96, 1.25). The suggestive dose-response association with the continuous measure of 25(OH)D was driven by women in the lowest and the highest categories of 25(OH)D. Compared to women with 25(OH)D of 30-40 ng/ml, women below 20 ng/ml had an estimated 45% reduction in fecundability (FR (CI): 0.55 (0.23, 1.32)), and women with at least 50 ng/ml had an estimated 35% increase in fecundability (FR (CI): 1.35 (0.95, 1.91)). Across these three categories (25(OH)D of <20 ng/ml, 30-40 ng/ml and > 50 ng/ml), the probability of taking longer than 6 months to conceive was, respectively, 51% (17%, 74%), 28% (17%, 39%) and 15% (10%, 37%). LIMITATIONS, REASONS FOR CAUTION While the distribution of 25(OH)D was wide, the number of observed cycles with high 25(OH)D (N = 107) or low 25(OH)D (N = 56) was small. WIDER IMPLICATIONS OF THE FINDINGS Our findings are consistent with prior reports of reduced fertility in women with 25(OH)D concentrations below the clinically defined deficiency level (20 ng/ml). Further studies are needed to evaluate the possible reproductive benefits of considerably higher 25(OH)D concentration (>50 ng/ml). STUDY FUNDING/COMPETING INTEREST(S) This research was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (NIH) under award numbers R00HD079659 and R01HD067683 and supported in part by the Intramural Research Program of the National Institute of Environmental Health Sciences, under projects ES103086, ES049003 and ES044003. ClearBlue ovulation predictor kits were generously donated to AMZJ and AJW by Swiss Precision Diagnostics. Drs Wilcox and Jukic report non-financial support from Swiss Precision Diagnostics during the conduct of the study; Dr Jukic reports non-financial support from Theralogix, LLC, outside the submitted work. Otherwise there are no competing interests. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
- A M Z Jukic
- Department of Chronic Disease Epidemiology, Yale School of Public Health, One Church St, 6th floor, New Haven, CT 06510, USA
- Epidemiology Branch, National Institute of Environmental Health Sciences, PO Box 12233, Research Triangle Park, NC 27709, USA
| | - D D Baird
- Epidemiology Branch, National Institute of Environmental Health Sciences, PO Box 12233, Research Triangle Park, NC 27709, USA
| | - C R Weinberg
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, PO Box 12233, Research Triangle Park, NC 27709, USA
| | - A J Wilcox
- Epidemiology Branch, National Institute of Environmental Health Sciences, PO Box 12233, Research Triangle Park, NC 27709, USA
| | | | - A Z Steiner
- Duke University Hospital, 5704 Fayetteville Road, Durham, NC 27713, USA
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Chin HB, Jukic AM, Wilcox AJ, Weinberg CR, Ferguson KK, Calafat AM, McConnaughey DR, Baird DD. Association of urinary concentrations of early pregnancy phthalate metabolites and bisphenol A with length of gestation. Environ Health 2019; 18:80. [PMID: 31470855 PMCID: PMC6717338 DOI: 10.1186/s12940-019-0522-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 08/23/2019] [Indexed: 05/09/2023]
Abstract
BACKGROUND Environmental exposure to phthalates and bisphenol A (BPA) may have endocrine disrupting effects that alter length of gestation. We assessed the association between the urinary concentrations of 11 phthalate metabolites and BPA with length of gestation in a cohort of women followed from before conception with daily 1st-morning urinary hormone measures that identified day of implantation. METHODS Pre-implantation and post-implantation urinary phthalate metabolites and BPA concentrations were measured in pooled urine samples designed to limit single-measure variability due to the likely episodic nature of these exposures and the short half-life of these compounds. We estimated associations between these exposure biomarkers early in pregnancy with length of gestation from implantation to spontaneous birth. Cox proportional hazards models were used to estimate the hazard of birth among 125 naturally-conceived, singleton live births with censoring for medical interventions that artificially shortened pregnancy. RESULTS Higher concentrations of mono (2-ethyl-5-hydroxyhexyl) phthalate (a metabolite of di (2-ethylhexyl) phthalate (DEHP)) during the pre-implantation window were associated with reduced probability of birth, i.e., longer gestations (hazard ratio (HR): 0.55, 95% CI: 0.35, 0.86; p = 0.01). The HR for the molar sum of the four DEHP metabolites measured showed a similar association (HR: 0.67, 95% CI: 0.43, 1.05). Higher concentrations of mono (3-carboxypropyl) phthalate (MCPP), a non-specific metabolite of several high molecular-weight phthalates, measured post-implantation were associated with increased risk of earlier birth, i.e. shorter length of gestation, HR: 1.59, CI: 1.02, 2.49. CONCLUSIONS Early gestational exposure to DEHP and possibly other high-molecular weight phthalates, (as reflected by urinary MCPP concentrations) may influence the length of pregnancy. Such effects could have consequences for neonatal and maternal health.
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Affiliation(s)
- Helen B. Chin
- Epidemiology Branch, National Institute of Environmental Health Sciences, 111 T W Alexander Drive, Mailstop A3-05, Research Triangle Park, NC 27709 USA
| | - Anne Marie Jukic
- Epidemiology Branch, National Institute of Environmental Health Sciences, 111 T W Alexander Drive, Mailstop A3-05, Research Triangle Park, NC 27709 USA
| | - Allen J. Wilcox
- Epidemiology Branch, National Institute of Environmental Health Sciences, 111 T W Alexander Drive, Mailstop A3-05, Research Triangle Park, NC 27709 USA
| | - Clarice R. Weinberg
- Biostatistics Branch, National Institute of Environmental Health Sciences, 111 T W Alexander Drive, Research Triangle Park, NC 27709 USA
| | - Kelly K. Ferguson
- Epidemiology Branch, National Institute of Environmental Health Sciences, 111 T W Alexander Drive, Mailstop A3-05, Research Triangle Park, NC 27709 USA
| | - Antonia M. Calafat
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Mail Stop F-17, 4770 Buford Highway, NE, Atlanta, GA 30341-3724 USA
| | | | - Donna D. Baird
- Epidemiology Branch, National Institute of Environmental Health Sciences, 111 T W Alexander Drive, Mailstop A3-05, Research Triangle Park, NC 27709 USA
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Chin HB, Jukic AM, Wilcox AJ, Weinberg CR, Ferguson KK, Calafat AM, McConnaughey DR, Baird DD. Association of urinary concentrations of phthalate metabolites and bisphenol A with early pregnancy endpoints. Environ Res 2019; 168:254-260. [PMID: 30321738 PMCID: PMC6263801 DOI: 10.1016/j.envres.2018.09.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 09/23/2018] [Accepted: 09/28/2018] [Indexed: 05/21/2023]
Abstract
BACKGROUND Phthalates and bisphenol A (BPA) are environmental contaminants that may affect early embryonic development. OBJECTIVE To assess the association between phthalate metabolites and BPA with early pregnancy endpoints in a cohort of women followed from before conception. METHODS We quantified 11 phthalate metabolites and BPA in 137 conception cycles from naturally conceived clinical pregnancies. Phthalate metabolites and BPA concentrations were measured in a pooled sample of three daily morning urine specimens. Daily urinary hormone measurements had previously been used to define ovulation, implantation, and corpus luteum rescue. We assessed associations between conception cycle exposures (phthalate biomarkers and BPA) and 1) time from ovulation to implantation; 2) type of corpus luteum rescue (timing and pattern of rise in progesterone: early, late, or no rise); and 3) rate of initial rise in hCG. RESULTS Mono(3-carboxypropyl) phthalate (MCPP) and mono-isobutyl phthalate (MiBP) were associated with earlier implantation (6-8 days vs. 9 days (the most commonly observed); per natural log-unit, OR (95% CI) = 2.8 (1.2, 6.7) and OR (CI) = 2.1 (1.2, 3.7), respectively). Monoethyl phthalate (MEP) was associated with later implantation (10-12 days vs. 9 days); OR (CI) = 1.5 (1.0, 2.1). Compared with implantation on day 9, BPA was significantly associated with both earlier and later implantation (OR=2.2 for both). Women with concentrations above the median of monobenzyl phthalate (MBzP) (p = 0.04) or above the median of the molar sum of four di(2-ethylhexyl) phthalate metabolites (∑DEHP) (p = 0.08) had a slower initial rise in hCG. Increasing MCPP was associated with an increased odds of a late rise rescue (OR (CI) = 2.9 (1.0, 8.5); late rise vs. early rise), while increasing MEP was associated with a no rise rescue (OR (CI) = 1.6 (0.9, 2.8); no rise vs. early rise). CONCLUSIONS The reported associations varied in their direction of effect, some potentially protective, others adverse. This may reflect the complexity with which these potential endocrine disrupting chemicals can be acting, but chance findings are also possible. Given that women continue to be exposed to these compounds (or their precursors), continued research on the effects they may have on pregnancy is warranted.
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Affiliation(s)
- Helen B Chin
- Epidemiology Branch, National Institute of Environmental Health Sciences, Durham, NC, USA.
| | - Anne Marie Jukic
- Chronic Disease Epidemiology, Yale School of Public Health, Yale Center for Perinatal, Pediatric, and Environmental Epidemiology, New Haven, CT, USA
| | - Allen J Wilcox
- Epidemiology Branch, National Institute of Environmental Health Sciences, Durham, NC, USA
| | - Clarice R Weinberg
- Biostatistics Branch, National Institute of Environmental Health Sciences, Durham, NC, USA
| | - Kelly K Ferguson
- Epidemiology Branch, National Institute of Environmental Health Sciences, Durham, NC, USA
| | - Antonia M Calafat
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Donna D Baird
- Epidemiology Branch, National Institute of Environmental Health Sciences, Durham, NC, USA
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Jukic AM, Calafat AM, McConnaughey DR, Longnecker MP, Hoppin JA, Weinberg CR, Wilcox AJ, Baird DD, Calafat AM, McConnaughey DR, Longnecker MP, Hoppin JA, Weinberg CR, Wilcox AJ, Baird DD. Urinary Concentrations of Phthalate Metabolites and Bisphenol A and Associations with Follicular-Phase Length, Luteal-Phase Length, Fecundability, and Early Pregnancy Loss. Environ Health Perspect 2016; 124:321-8. [PMID: 26161573 PMCID: PMC4786975 DOI: 10.1289/ehp.1408164] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 07/07/2015] [Indexed: 05/18/2023]
Abstract
BACKGROUND Certain phthalates and bisphenol A (BPA) show reproductive effects in animal studies and potentially affect human ovulation, conception, and pregnancy loss. OBJECTIVES We investigated these chemicals in relation to follicular- and luteal-phase lengths, time to pregnancy, and early pregnancy loss (within 6 weeks of the last menstrual period) among women attempting pregnancy. METHODS Women discontinuing contraception provided daily first-morning urine specimens and recorded days with vaginal bleeding for up to 6 months. Specimens had previously been analyzed for estrogen and progesterone metabolites and human chorionic gonadotropin. A total of 221 participants contributed 706 menstrual cycles. We measured 11 phthalate metabolites and BPA in pooled urine from three specimens spaced throughout each menstrual cycle. We analyzed associations between chemical concentrations and outcomes using linear mixed models for follicular- and luteal-phase lengths, discrete-time fecundability models for time to pregnancy, and logistic regression for early pregnancy loss. RESULTS Higher concentrations of monocarboxyoctyl phthalate (MCOP) were associated with shorter luteal phase [2nd tertile vs. 1st tertile: -0.5 days (95% CI: -0.9, -0.1), 3rd vs. 1st: -0.4 days (95% CI: -0.8, 0.01), p = 0.04]. BPA was also associated with shorter luteal phase [2nd vs. 1st: -0.8 days (95% CI: -1.2, -0.4), 3rd vs. 1st: -0.4 days (95% CI: -0.8, 0.02), p = 0.001]. CONCLUSIONS BPA and MCOP (or its precursors) were associated with shorter luteal phase. Menstrual cycle-specific estimates of urinary BPA and phthalate metabolites were not associated with detrimental alterations in follicular-phase length, time to pregnancy, or early pregnancy loss, and in fact, DEHP [di(2-ethylhexyl) phthalate] metabolites {MEOHP [mono(2-ethyl-5-oxohexyl) phthalate] and ΣDEHP} were associated with reduced early loss. These findings should be confirmed in future human studies.
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Affiliation(s)
- Anne Marie Jukic
- Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Durham, North Carolina, USA
- Address correspondence to A.M. Jukic, Epidemiology Branch, NIEHS, P.O. BOX 12233, Durham, NC 27709 USA. Telephone: (919) 541-2992. E-mail:
| | - Antonia M. Calafat
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | - Matthew P. Longnecker
- Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Durham, North Carolina, USA
| | - Jane A. Hoppin
- Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Durham, North Carolina, USA
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | | | - Allen J. Wilcox
- Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Durham, North Carolina, USA
| | - Donna D. Baird
- Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Durham, North Carolina, USA
| | - Antonia M. Calafat
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | - Matthew P. Longnecker
- Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Durham, North Carolina, USA
| | - Jane A. Hoppin
- Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Durham, North Carolina, USA
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | | | - Allen J. Wilcox
- Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Durham, North Carolina, USA
| | - Donna D. Baird
- Epidemiology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Durham, North Carolina, USA
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Jukic AM, Baird DD, Weinberg CR, McConnaughey DR, Wilcox AJ. Length of human pregnancy and contributors to its natural variation. Hum Reprod 2013; 28:2848-55. [PMID: 23922246 DOI: 10.1093/humrep/det297] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
STUDY QUESTION How variable is the length of human pregnancy, and are early hormonal events related to gestational length? SUMMARY ANSWER Among natural conceptions where the date of conception (ovulation) is known, the variation in pregnancy length spanned 37 days, even after excluding women with complications or preterm births. WHAT IS KNOWN ALREADY Previous studies of length of gestation have either estimated gestational age by last menstrual period (LMP) or ultrasound (both imperfect measures) or included pregnancies conceived through assisted reproductive technology. STUDY DESIGN, SIZE, DURATION The Early Pregnancy Study was a prospective cohort study (1982-85) that followed 130 singleton pregnancies from unassisted conception to birth, with detailed hormonal measurements through the conception cycle; 125 of these pregnancies were included in this analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS We calculated the length of gestation beginning at conception (ovulation) in 125 naturally conceived, singleton live births. Ovulation, implantation and corpus luteum (CL) rescue pattern were identified with urinary hormone measurements. We accounted for events that artificially shorten the natural length of gestation (Cesarean delivery or labor induction, i.e. 'censoring') using Kaplan-Meier curves and proportional hazards models. We examined hormonal and other factors in relation to length of gestation. We did not have ultrasound information to compare with our gold standard measure. MAIN RESULTS AND THE ROLE OF CHANCE The median time from ovulation to birth was 268 days (38 weeks, 2 days). Even after excluding six preterm births, the gestational length range was 37 days. The coefficient of variation was higher when measured by LMP (4.9%) than by ovulation (3.7%), reflecting the variability of time of ovulation. Conceptions that took longer to implant also took longer from implantation to delivery (P = 0.02). CL rescue pattern (reflecting ovarian response to implantation) was predictive (P = 0.006): pregnancies with a rapid progesterone rise were longer than those with delayed rise (a 12-day difference in the median gestational length). Mothers with longer gestations were older (P = 0.02), had longer pregnancies in other births (P < 0.0001) and were heavier at birth (P = 0.01). We did not see an association between the length of gestation and several factors that have been associated with gestational length in previous studies: body mass index, alcohol intake, parity or offspring sex. LIMITATIONS, REASONS FOR CAUTION The sample size was small and some exposures were rare, reducing power to detect weak associations. WIDER IMPLICATIONS OF THE FINDINGS Human gestational length varies considerably even when measured exactly (from ovulation). An individual woman's deliveries tend to occur at similar gestational ages. Events in the first 2 weeks after conception are predictive of subsequent pregnancy length, and may suggest pathways underlying the timing of delivery. STUDY FUNDING/COMPETING INTEREST This research was supported by the Intramural Research Program of the NIH, National Institute of Environmental Health Sciences. None of the authors has any conflict of interest to declare.
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Affiliation(s)
- A M Jukic
- Epidemiology Branch, National Institute of Environmental Health Sciences, PO Box 12233, Durham, NC 27709, USA
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Boyles AL, Ballard JL, Gorman EB, McConnaughey DR, Cabrera RM, Wilcox AJ, Lie RT, Finnell RH. Association between inhibited binding of folic acid to folate receptor alpha in maternal serum and folate-related birth defects in Norway. Hum Reprod 2011; 26:2232-8. [PMID: 21576080 DOI: 10.1093/humrep/der144] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Folic acid intake during pregnancy can reduce the risk of neural tube defects (NTDs) and perhaps also oral facial clefts. Maternal autoantibodies to folate receptors can impair folic acid binding. We explored the relationship of these birth defects to inhibition of folic acid binding to folate receptor α (FRα), as well as possible effects of parental demographics or prenatal exposures. METHODS We conducted a nested case-control study within the Norwegian Mother and Child Cohort Study. The study included mothers of children with an NTD (n = 11), cleft lip with or without cleft palate (CL/P, n= 72), or cleft palate only (CPO, n= 27), and randomly selected mothers of controls (n = 221). The inhibition of folic acid binding to FRα was measured in maternal plasma collected around 17 weeks of gestation. On the basis of prior literature, the maternal age, gravidity, education, smoking, periconception folic acid supplement use and milk consumption were considered as potential confounding factors. RESULTS There was an increased risk of NTDs with increased binding inhibition [adjusted odds ratio (aOR) = 1.4, 95% confidence interval (CI) 1.0-1.8]. There was no increased risk of oral facial clefts from inhibited folic acid binding to FRα (CL/P aOR = 0.7, 95% CI 0.6-1.0; CPO aOR = 1.1, 95% CI 0.8-1.4). No association was seen between smoking, folate supplementation or other cofactors and inhibition of folic acid binding to FRα. CONCLUSIONS Inhibition of folic acid binding to FRα in maternal plasma collected during pregnancy was associated with increased risk of NTDs but not oral facial clefts.
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Affiliation(s)
- A L Boyles
- Epidemiology Branch, NIEHS/NIH, Durham, NC 27709, USA.
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9
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Love LA, Weinberg CR, McConnaughey DR, Oddis CV, Medsger TA, Reveille JD, Arnett FC, Targoff IN, Miller FW. Ultraviolet radiation intensity predicts the relative distribution of dermatomyositis and anti-Mi-2 autoantibodies in women. ACTA ACUST UNITED AC 2009; 60:2499-504. [PMID: 19644877 DOI: 10.1002/art.24702] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Because studies suggest that ultraviolet (UV) radiation modulates the myositis phenotype and Mi-2 autoantigen expression, we conducted a retrospective investigation to determine whether UV radiation may influence the relative prevalence of dermatomyositis and anti-Mi-2 autoantibodies in the US. METHODS We assessed the relationship between surface UV radiation intensity in the state of residence at the time of onset with the relative prevalence of dermatomyositis and myositis autoantibodies in 380 patients with myositis from referral centers in the US. Myositis autoantibodies were detected by validated immunoprecipitation assays. Surface UV radiation intensity was estimated from UV Index data collected by the US National Weather Service. RESULTS UV radiation intensity was associated with the relative proportion of patients with dermatomyositis (odds ratio [OR] 2.3, 95% confidence interval [95% CI] 0.9-5.8) and with the proportion of patients expressing anti-Mi-2 autoantibodies (OR 6.0, 95% CI 1.1-34.1). Modeling of these data showed that these associations were confined to women (OR 3.8, 95% CI 1.3-11.0 and OR 17.3, 95% CI 1.8-162.4, respectively) and suggests that sex influences the effects of UV radiation on autoimmune disorders. Significant associations were not observed in men, nor were UV radiation levels related to the presence of antisynthetase or anti-signal recognition particle autoantibodies. CONCLUSION This first study of the distribution of myositis phenotypes and UV radiation exposure in the US showed that UV radiation may modulate the clinical and immunologic expression of autoimmune disease in women. Further investigation of the mechanisms by which these effects are produced may provide insights into pathogenesis and suggest therapeutic or preventative strategies.
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Affiliation(s)
- Lori A Love
- Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
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10
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Abstract
There are many studies based on self-reported menstrual cycle length, yet little is known about the validity of this measure. The authors used data collected in 1990 from 352 women born in Chicago, Illinois, aged 37-39 years. Women reported their usual cycle length and behavioral and reproductive characteristics at study enrollment and then completed daily menstrual diaries for up to 6 months. The authors compared this observed cycle length (geometric mean) with the reported length by using kappa coefficients. To assess systematic effects, they performed linear regression of the difference between reported and observed cycle length. Agreement between observed and reported cycle length was moderate. The crude overall kappa coefficient was 0.33; the kappa adjusted for within-woman sampling variability was 0.45 (95% confidence interval: 0.36, 0.55). On average, women overestimated their cycle length by 0.7 days (95% confidence interval: 0.3, 1.0). Reporting by sexually active women and women with a history of infertility was more accurate. Parity, body mass index, prior medical evaluation for irregular cycles, and exercise were all associated with systematic reporting differences. Studies that rely on self-reported cycle length could be prone to artifactual findings because of systematic covariate effects on reporting.
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Affiliation(s)
- Anne Marie Zaura Jukic
- Epidemiology Branch, National Institute of Environmental Health Sciences, Durham, NC 27709, USA.
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11
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Nguyen RHN, Wilcox AJ, Moen BE, McConnaughey DR, Lie RT. Parent's Occupation and Isolated Orofacial Clefts in Norway: A Population-based Case-control Study. Ann Epidemiol 2007; 17:763-71. [PMID: 17664071 DOI: 10.1016/j.annepidem.2007.04.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Revised: 04/25/2007] [Accepted: 04/30/2007] [Indexed: 11/21/2022]
Abstract
PURPOSE Occupational factors have been associated with risk of orofacial clefts in offspring, although data are limited. We explored associations between parent's occupation and isolated orofacial clefts using a population-based case-control study. METHODS Cases were restricted to infants born with an isolated orofacial cleft in Norway during the period 1996 to 2001 (314 with cleft lip with or without palate [CLP] and 118 with cleft palate only [CPO]). Controls (n = 763) were chosen randomly from all Norwegian live births. We considered full-time employment during the first 3 months of pregnancy. RESULTS Several maternal occupations previously associated with clefts showed some evidence of association, including hairdressers (CLP; adjusted odds ratio = 4.8; 95% confidence interval [CI]: 0.99-23). Mothers working in manufacturing and in food production had increased odds for babies with CPO (3.8; 1.3-11, and 7.1; 1.5-33, respectively). Among fathers' occupations previously associated with clefts, an association was suggested for woodworking both for CLP (1.7; 0.85-3.2) and for CPO (2.0; 0.82-4.7). Fathers working as professional housekeepers showed substantial increased odds of CPO (12; 3.3-46). CONCLUSIONS Taken together with previous studies, these results suggest that exposures in certain occupations may influence the risk of orofacial clefting in offspring. Specific exposures accompanying these occupations warrant exploration.
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Affiliation(s)
- Ruby H N Nguyen
- National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC 22709, USA.
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12
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Wilcox AJ, Lie RT, Solvoll K, Taylor J, McConnaughey DR, Abyholm F, Vindenes H, Vollset SE, Drevon CA. Folic acid supplements and risk of facial clefts: national population based case-control study. BMJ 2007; 334:464. [PMID: 17259187 PMCID: PMC1808175 DOI: 10.1136/bmj.39079.618287.0b] [Citation(s) in RCA: 251] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To explore the role of folic acid supplements, dietary folates, and multivitamins in the prevention of facial clefts. DESIGN National population based case-control study. SETTING Infants born 1996-2001 in Norway. PARTICIPANTS 377 infants with cleft lip with or without cleft palate; 196 infants with cleft palate alone; 763 controls. MAIN OUTCOME MEASURES Association of facial clefts with maternal intake of folic acid supplements, multivitamins, and folates in diet. RESULTS Folic acid supplementation during early pregnancy (> or =400 microg/day) was associated with a reduced risk of isolated cleft lip with or without cleft palate after adjustment for multivitamins, smoking, and other potential confounding factors (adjusted odds ratio 0.61, 95% confidence interval 0.39 to 0.96). Independent of supplements, diets rich in fruits, vegetables, and other high folate containing foods reduced the risk somewhat (adjusted odds ratio 0.75, 0.50 to 1.11). The lowest risk of cleft lip was among women with folate rich diets who also took folic acid supplements and multivitamins (0.36, 0.17 to 0.77). Folic acid provided no protection against cleft palate alone (1.07, 0.56 to 2.03). CONCLUSIONS Folic acid supplements during early pregnancy seem to reduce the risk of isolated cleft lip (with or without cleft palate) by about a third. Other vitamins and dietary factors may provide additional benefit.
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Affiliation(s)
- Allen J Wilcox
- Epidemiology Branch, National Institute of Environmental Health Sciences/NIH, Durham, NC 27709, USA.
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13
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Nguyen RHN, Wilcox AJ, Moen BE, McConnaughey DR, Lie RT. 325: Maternal Occupation and Oral Clefts in Norway. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s82] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- R H N Nguyen
- NIEHS/NIH, Durham, NC
- University of Bergen, Norway
| | - A J Wilcox
- NIEHS/NIH, Durham, NC
- University of Bergen, Norway
| | - B E Moen
- NIEHS/NIH, Durham, NC
- University of Bergen, Norway
| | | | - R T Lie
- NIEHS/NIH, Durham, NC
- University of Bergen, Norway
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McChesney R, Wilcox AJ, O'Connor JF, Weinberg CR, Baird DD, Schlatterer JP, McConnaughey DR, Birken S, Canfield RE. Intact HCG, free HCG beta subunit and HCG beta core fragment: longitudinal patterns in urine during early pregnancy. Hum Reprod 2005; 20:928-35. [PMID: 15665026 DOI: 10.1093/humrep/deh702] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Detecting and monitoring early pregnancy depend on the measurement of HCG. Little is known about how production of various forms of HCG may evolve over the earliest weeks of pregnancy, particularly in naturally conceived pregnancies. METHODS We describe the daily excretion of three urinary HCG analytes during the first 6 weeks post-conception in 37 naturally conceived pregnancies ending in singleton birth. We assayed daily first morning urine samples for intact HCG, free beta subunit and beta?core fragment, plus the combined measurement of these HCG forms. We calculated doubling times for each analyte and the inter- and intra-subject day-to-day variation. RESULTS Intact HCG and the free beta subunit were initially the predominant forms of HCG, with the beta core fragment emerging as the predominant form in the fifth week after conception. Intact HCG and the free beta subunit showed the most day-to-day variability, and were transiently undetectable even 10 days after detection of pregnancy. The most stable estimate of doubling time was provided by the combined measurement of all these forms. CONCLUSIONS Although intact HCG is usually regarded as the main analyte for detection and monitoring of early pregnancy, it can fluctuate markedly during early pregnancy. This variability could affect pregnancy test results based on early pregnancy urine, and may distort estimates of doubling time. Assays that combine several forms of HCG may be more reliable.
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Affiliation(s)
- Ruth McChesney
- Brooklyn College, The City University of New York, New York, NY, USA
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15
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Wilcox AJ, Baird DD, Dunson DB, McConnaughey DR, Kesner JS, Weinberg CR. On the frequency of intercourse around ovulation: evidence for biological influences. Hum Reprod 2004; 19:1539-43. [PMID: 15190016 DOI: 10.1093/humrep/deh305] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Intercourse in mammals is often coordinated with ovulation, for example through fluctuations in libido or by the acceleration of ovulation with intercourse. Such coordination has not been established in humans. We explored this possibility by examining patterns of sexual intercourse in relation to ovulation. METHODS Sixty-eight sexually active North Carolina women with either an intrauterine device or tubal ligation provided data for up to three menstrual cycles. These women collected daily urine specimens and kept daily diaries of intercourse and menstrual bleeding. Major estrogen and progesterone metabolites excreted in urine were used to identify the day of ovulation. The fertile days of the cycle were defined as the 6 consecutive days ending with ovulation. Women contributed a total of 171 ovulatory cycles. Menstrual bleeding days were excluded from analysis. RESULTS The frequency of intercourse rose during the follicular phase, peaking at ovulation and declining abruptly thereafter. The 6 consecutive days with most frequent intercourse corresponded with the 6 fertile days of the menstrual cycle. Intercourse was 24% more frequent during the 6 fertile days than during the remaining non-bleeding days (P < 0.001). CONCLUSIONS There apparently are biological factors that promote intercourse during a woman's 6 fertile days.
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Affiliation(s)
- A J Wilcox
- National Institute of Environment Health Sciences, Durham, NC, USA.
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16
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Abstract
Rescue of the corpus luteum from its programmed senescence maintains progesterone production required for pregnancy. In primates, chorionic gonadotropin produced by the developing conceptus acts as the primary luteotrophic signal. The purpose of this research was to assess corpus luteum rescue by examining changes in daily urinary progesterone metabolite levels during the first week after implantation. We determined the variability in progesterone metabolite profiles and evaluated its relationship to early pregnancy loss in 120 naturally conceived human pregnancies, including 43 early pregnancy losses. In other primates, an abrupt increase in the progesterone metabolite occurs at the time of implantation. This pattern occurred in an estimated 45% of the pregnancies in the present study. In the remaining pregnancies, there was a delayed rise (18%), neither a rise or decline (22%), or a decline (15%) during the week after implantation. The estimated rate of early pregnancy loss increased across these categories (from 5% loss with an abrupt rise at implantation to 100% loss with progesterone metabolite decline). Low urinary hCG levels in early pregnancy were significant determinants of a decline in postimplantation progesterone metabolite. However, preimplantation steroid metabolite levels were not significant, suggesting no inherent problem with the corpus luteum. Examination of individual progesterone metabolite profiles in relation to hCG profiles also indicated that few losses were caused by corpus luteum failure. Delineating the functional importance of an abrupt progesterone rise at the time of implantation may provide new strategies for promoting successful implantation in assisted reproduction.
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Affiliation(s)
- Donna Day Baird
- Epidemiology Branch Biostatistics Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
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17
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Baird DD, Weinberg CR, Zhou H, Kamel F, McConnaughey DR, Kesner JS, Wilcox AJ. Preimplantation urinary hormone profiles and the probability of conception in healthy women. Fertil Steril 1999; 71:40-9. [PMID: 9935114 DOI: 10.1016/s0015-0282(98)00419-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To examine hormonal predictors of conception in menstrual cycles from normal women. DESIGN Longitudinal study. SETTING Community. PATIENT(S) Two hundred fifteen healthy female volunteers with no known fertility problems who were trying to conceive. INTERVENTION(S) Participants recorded menstrual bleeding, sexual intercourse, and collected first morning urine specimens daily from when they stopped contraception until they became pregnant or for 6 months if no clinical pregnancy was achieved. Measurements were made of urinary LH and urinary metabolites of estrogen and progesterone. MAIN OUTCOME MEASURE(S) Conception was identified by a sensitive and specific immunoradiometric assay for urinary hCG. RESULT(S) Statistical analyses of 189 conception and 409 nonconception cycles controlled for sexual intercourse and interdependence of cycles from the same woman. Conception was more likely in cycles with lower baseline progesterone metabolite levels, higher ovulatory LH, and higher midluteal progesterone. Midluteal estrogen also was elevated in conception cycles when examined without adjusting for other hormone levels, but this finding did not persist after multivariate adjustment. CONCLUSIONS Menstrual cycles in normal women vary in their hormonal quality in ways that are predictive of cycle fertility.
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Affiliation(s)
- D D Baird
- Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA
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18
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Baird DD, Wilcox AJ, Weinberg CR, Kamel F, McConnaughey DR, Musey PI, Collins DC. Preimplantation hormonal differences between the conception and non-conception menstrual cycles of 32 normal women. Hum Reprod 1997; 12:2607-13. [PMID: 9455822 DOI: 10.1093/humrep/12.12.2607] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We compared daily urinary concentrations of oestrogen and progesterone metabolites in paired menstrual cycles (conception and non-conception) from 32 women. Volunteers with no known fertility problems were enrolled in the study at the time they began trying to become pregnant. They collected first-morning urine specimens and kept daily records of menstrual bleeding and sexual intercourse for 6 months or until they became clinically pregnant. Intercourse in non-conception cycles was close to the time of ovulation so that failure to conceive was caused by factors other than poorly timed intercourse. Compared with non-conception cycles, conception cycles had a steeper early luteal rise in progesterone and higher mid-luteal oestrogen and progesterone concentrations. These hormonal characteristics may be markers of better quality cycles, but because all these differences were in the luteal phase, we cannot rule out the possibility that the preimplantation embryo had stimulated early increases in steroid production. We propose an analysis strategy that could help support or refute the importance of preimplantation embryonic signalling, but our small sample size limits our own conclusions about this mechanism.
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Affiliation(s)
- D D Baird
- Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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19
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Baird DD, McConnaughey DR, Weinberg CR, Musey PI, Collins DC, Kesner JS, Knecht EA, Wilcox AJ. Application of a method for estimating day of ovulation using urinary estrogen and progesterone metabolites. Epidemiology 1995; 6:547-50. [PMID: 8562634 DOI: 10.1097/00001648-199509000-00015] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Longitudinal epidemiologic studies of menstrual and reproductive function are more informative if one can identify day of ovulation. We previously developed a method for estimating day of ovulation that is feasible for epidemiologic studies. The method relies on the relative concentrations of estrogen and progesterone metabolites in daily first-morning urine specimens and does not require creatinine adjustment. This paper describes results of applying this method to a large study with 724 menstrual cycles from 217 women. The method estimated a credible day of ovulation in 88% of cycles. Missing data accounted for most of the failures. When we excluded anovulatory cycles (1%) and cycles with missing data, the method estimated a day of ovulation in 97% of cycles. Variance in luteal phase length was small for our sample, suggesting that this method of identifying a day of ovulation introduces no more measurement error than when day of ovulation is determined by plasma luteinizing hormone (LH), the standard clinical method.
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Affiliation(s)
- D D Baird
- Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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20
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Baird DD, Weinberg CR, Wilcox AJ, McConnaughey DR, Musey PI, Collins DC. Hormonal profiles of natural conception cycles ending in early, unrecognized pregnancy loss. J Clin Endocrinol Metab 1991; 72:793-800. [PMID: 2005203 DOI: 10.1210/jcem-72-4-793] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Loss of a conceptus early in development can be detected by very sensitive assays specific for hCG. We examined 20 menstrual cycles ending in early loss of a conceptus in order to identify hormonal correlates of loss. Each loss cycle was compared to a successful conception cycle in the same woman, using daily concentration of urinary estrone-3-glucuronide and pregnanediol-3-glucuronide (PdG). The estrone-3-glucuronide and PdG profiles in cycles of early pregnancy loss were very similar to those in successful conception cycles until late in the luteal phase. Early pregnancy loss was not related to a midluteal deficiency in PdG. hCG tended to be detected later in cycles of early pregnancy loss than in successful conception cycles, presumably indicating later implantation. Ten of the early pregnancy losses implanted after luteal-day-10; only one of the successful pregnancies implanted that late. The corpus luteum responded to the conception in only 2 of the 10 loss cycles with late implantation. In contrast, the corpus luteum responded in 8 of 10 loss cycles with normally timed implantation. The similarity of preimplantation hormonal profiles in cycles of early pregnancy loss and in cycles with successful conceptions suggests that most early losses in reproductively normal women do not result directly from deficiencies in ovarian steroid production.
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Affiliation(s)
- D D Baird
- Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
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21
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Baird DD, Weinberg CR, Wilcox AJ, McConnaughey DR, Musey PI. Using the ratio of urinary oestrogen and progesterone metabolites to estimate day of ovulation. Stat Med 1991; 10:255-66. [PMID: 2052803 DOI: 10.1002/sim.4780100209] [Citation(s) in RCA: 126] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have developed a method of estimating day of ovulation using urinary ovarian hormone data. The method identifies a day of luteal transition that occurs at the shift from production of follicular oestrogen to luteal progesterone. The algorithm for identifying this shift was evaluated and judged better than specified alternatives in that it resulted in (1) a high concordance between the day of luteal transition and peaks in urinary luteinizing hormone (LH) for cycles with well-defined peaks, (2) a low variance in the length of the luteal phase of the menstrual cycle, which presumably reflects a low measurement error in estimating day of ovulation, and (3) a high proportion of cycles for which an approximate day of ovulation could be determined. To validate the new algorithm, it was applied to an independent data set. The algorithm identified a day of luteal transition in 88 per cent of these cycles, and the identified day occurred within two days of the urinary LH peak for all the cycles with clear LH peaks. Determination of the day of luteal transition to estimate ovulation requires only first-morning urine specimens, requires no correction for day-to-day variations in urine concentration, and can be applied to a mid-cycle window of data.
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Affiliation(s)
- D D Baird
- Division of Biometry and Risk Assessment, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709
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Abstract
Data from women who enrolled between 1935 and 1939 in a long-term prospective study of menstrual and reproductive health, in which menstrual cycles and other events were recorded as they occurred, were analyzed to examine factors associated with age at natural menopause. Analysis was restricted to 561 women who enrolled before age 25 years and recorded data through at least age 44 years. Women with a median cycle length that was less than 26 days at ages 20-35 years reached menopause 1.4 years earlier than those with cycles between 26 and 32 days. The difference in mean menopausal age between women with short cycle length (less than 26 days) and women with long cycle length (33 days or longer) was 2.2 years. Women who had ever been pregnant reached menopause slightly, but statistically significantly, later than women who had never been pregnant. Similarly, women who had ever had a live birth had a slightly later age at menopause compared with nulliparous women. A trend of later age at menopause with increasing parity was also observed. There was no association with age at menarche. Certain of these observations are consistent with proposed mechanisms of cessation of menstrual function.
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Affiliation(s)
- E A Whelan
- Division of Biometry and Risk Assessment, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709
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