P A Nepomnaschy1, C R Weinberg, A J Wilcox, D D Baird. 1. Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, USA. pablo_nepomnaschy@sfu.com
Abstract
BACKGROUND: Human chorionic gonadotrophin (hCG) is used to monitor pregnancy status. Yet the pattern of hCG excretion in the first week following implantation has not been adequately described. Therefore the aim of this study was to describe the average profile of hCG and its variability during the 7 days following estimated implantation in a population of naturally conceived pregnancies. METHODS: We measured daily hCG concentrations in first-morning urine for 142 clinical pregnancies from women with no known fertility problems. Mixed-effects regression models were used to estimate the hCG trajectory and its variability in relation to pregnancy outcomes. RESULTS: hCG rose 3-fold between the day of detection and the next day (95% CI = 2.7-3.4). The relative rate of rise decreased thereafter, reaching 1.6-fold (95% CI = 1.5-1.8) between days 6 and 7. HCG levels followed a log-quadratic trajectory, and the patterns of rise were unrelated to number of fetuses, risk of spontaneous abortion or sex of the baby. Later implantations (after 10 luteal days) produced slower rates of increase. CONCLUSIONS: Although mean hCG follows a log-quadratic trajectory during the first week of detectability, there is high variability across pregnancies. Later implantation may reflect characteristics of the uterus or conceptus that slow hCG production.
BACKGROUND:Human chorionic gonadotrophin (hCG) is used to monitor pregnancy status. Yet the pattern of hCG excretion in the first week following implantation has not been adequately described. Therefore the aim of this study was to describe the average profile of hCG and its variability during the 7 days following estimated implantation in a population of naturally conceived pregnancies. METHODS: We measured daily hCG concentrations in first-morning urine for 142 clinical pregnancies from women with no known fertility problems. Mixed-effects regression models were used to estimate the hCG trajectory and its variability in relation to pregnancy outcomes. RESULTS:hCG rose 3-fold between the day of detection and the next day (95% CI = 2.7-3.4). The relative rate of rise decreased thereafter, reaching 1.6-fold (95% CI = 1.5-1.8) between days 6 and 7. HCG levels followed a log-quadratic trajectory, and the patterns of rise were unrelated to number of fetuses, risk of spontaneous abortion or sex of the baby. Later implantations (after 10 luteal days) produced slower rates of increase. CONCLUSIONS: Although mean hCG follows a log-quadratic trajectory during the first week of detectability, there is high variability across pregnancies. Later implantation may reflect characteristics of the uterus or conceptus that slow hCG production.
Authors: Marieke J Lambers; Hans G I van Weering; Maud S van't Grunewold; Cornelis B Lambalk; Roy Homburg; Roel Schats; Peter G A Hompes Journal: Eur J Obstet Gynecol Reprod Biol Date: 2006-02-08 Impact factor: 2.435
Authors: E G Armstrong; P H Ehrlich; S Birken; J P Schlatterer; E Siris; W C Hembree; R E Canfield Journal: J Clin Endocrinol Metab Date: 1984-11 Impact factor: 5.958
Authors: A J Wilcox; C R Weinberg; J F O'Connor; D D Baird; J P Schlatterer; R E Canfield; E G Armstrong; B C Nisula Journal: N Engl J Med Date: 1988-07-28 Impact factor: 91.245
Authors: Helen B Chin; Anne Marie Jukic; Allen J Wilcox; Clarice R Weinberg; Kelly K Ferguson; Antonia M Calafat; D Robert McConnaughey; Donna D Baird Journal: Environ Res Date: 2018-10-01 Impact factor: 6.498
Authors: Tina M F Dumont; Jean-Francois Mouillet; Avaraham Bayer; Christina L Gardner; William B Klimstra; Dana G Wolf; Simcha Yagel; Fabiola Balmir; Anna Binstock; Joseph S Sanfilippo; Carolyn B Coyne; Jacob C Larkin; Yoel Sadovsky Journal: Placenta Date: 2017-03-16 Impact factor: 3.481
Authors: Alexandra C Purdue-Smithe; Keewan Kim; Carrie Nobles; Enrique F Schisterman; Karen C Schliep; Neil J Perkins; Lindsey A Sjaarda; Joshua R Freeman; Sonia L Robinson; Jeannie G Radoc; James L Mills; Robert M Silver; Aijun Ye; Sunni L Mumford Journal: Nat Commun Date: 2021-05-13 Impact factor: 14.919
Authors: Dorette J Noorhasan; Peter G McGovern; Michael Cho; Aimee Seungdamrong; Khaliq Ahmad; David H McCulloh Journal: Obstet Gynecol Int Date: 2015-10-26