PubMed | Jacobi Medical Center, University of Leicester and SPD Development Co.
Type: | Journal: Annals of clinical biochemistry | Year: 2016
Human chorionic gonadotrophin (hCG) is a marker of early pregnancy. This study sought to determine the possibility of being able to distinguish between healthy and failing pregnancies by utilising patient-associated risk factors and daily urinary hCG levels.Data were from a study that collected daily early morning urine samples from women trying to conceive (n=1,505); 250 of whom became pregnant. Data from 129 women who became pregnant (including 44 miscarriages) were included in these analyses. A longitudinal model was used to profile hCG, a Cox proportional hazards model to assess demographic/menstrual history data on the time to failed pregnancy, and a two-stage model to combine these two models.The profile for log hCG levels in women suffering miscarriage differs to that of viable pregnancies; rate of hCG rise is slower in those suffering a biochemical loss (loss of a pregnancy only diagnosed by a positive hCG serum/urine test) and tends to plateau at a lower log hCG in women suffering an early miscarriage, compared with viable pregnancies. Maternal age, longest cycle length and time from luteinising hormone (LH) surge to hCG reaching 25 mIU/mL were found to be significantly associated with miscarriage risk. The two-stage model found that for an increase of 1 day in the time from LH surge to hCG reaching 25 mIU/mL, there is a 30% increase in miscarriage risk (hazard ratio: 1.30; 95% confidence interval: 1.04, 1.62).Rise of hCG in early pregnancy could be useful to predict pregnancy viability. Daily tracking of urinary hCG may enable early identification of some pregnancies at risk of miscarriage. KEY: WORDS: Clinical studies > Pregnancy.
Sowers M.R.,University of Michigan |
Zheng H.,University of Michigan |
Greendale G.A.,University of California at Los Angeles |
Neer R.M.,Massachusetts General Hospital |
And 4 more authors.
Journal of Clinical Endocrinology and Metabolism | Year: 2013
Objective: Our objective was to characterize changes in bone resorption in relation to the final menstrual period (FMP), reproductive hormones, body mass index (BMI), and ethnicity. Methods: Urinary type I collagen N-telopeptide (NTX), estradiol, and FSH levels were measured annually for up to 8 years spanning the menopause transition in 918 African American, Chinese, Japanese, or Caucasian women. Results: Urinary NTX began to increase sharply about 2 years before the FMP, reaching its peak level about 1 to 1.5 years after the FMP. NTX levels declined modestly from 2 to 6 years after the FMP but remained about 20% higher than before the menopause transition. The sharp rise in FSH occurred in conjunction with a sharp decline in estradiol and shortly after FSH levels began increasing rapidly. The mean increase in urinary NTX across the menopause transition was greatest in women with BMI <25 kg/m2and smallest in women with BMI >30 kg/m2. Increases in NTX were greatest in Japanese women and smallest in African Americans. These differences were attenuated, but not eliminated, when analyses were adjusted for covariates, particularly BMI. Summary: During the menopause transition, a decline in ovarian function beginning about 2 years before the FMP is followed by an increase in bone resorption and subsequently by bone loss. The magnitude of the increase in bone resorption is inversely associated with BMI. Ethnic differences in changes in bone resorption are attenuated, but not eliminated, by adjustment for BMI. Ethnic differences in BMI, and corresponding ethnic differences in bone resorption, appear to account for much of the ethnic variation in perimenopausal bone loss. Copyright © 2013 by The Endocrine Society.
PubMed | 4BoneHealth, San Diego State University, University of California at Los Angeles, SPD Development Company Ltd and 2 more.
Type: | Journal: Bone reports | Year: 2016
Hyperkyphosis, accentuated curvature of the thoracic spine, is often attributed to osteoporosis, yet its underlying pathophysiology is not well understood. Bone turnover markers (BTM) reflect the dynamic process of bone formation and resorption. This study examined the association between serum BTM levels and kyphosis in community-dwelling older adults.Between 2003 and 2006, 760 men and women in the Rancho Bernardo Study age 60 and older had blood drawn and kyphosis measured. Fasting serum was assayed for N-telopeptide (NTX) and procollagen type 1 n-terminal propeptide (P1NP), markers of bone resorption and formation, respectively. Participants requiring two or more 1.7cm blocks under their head to achieve a neutral supine position were classified as having accentuated kyphosis. Analyses were stratified by sex and use of estrogen therapy (ET). Odds of accentuated kyphosis were calculated for each standard deviation increase in log-transformed BTM.Mean age was 75years. Overall, 51% of 341 non-ET using women, 41% of 111 ET-using women, and 75% of 308 men had accentuated kyphosis. In adjusted models, higher P1NP and NTX were associated with decreased odds of accentuated kyphosis in non-ET using women (P1NP: OR=0.78 [95% CI, 0.58-0.92]; NTX: OR=0.68 [95% CI, 0.54-0.86]), but not in men or ET-using women (The selective association of higher bone turnover with reduced odds of accentuated kyphosis in non-ET using women suggests that elevated BTM were associated with a lower likelihood of hyperkyphosis only in the low estrogen/high BTM environment characteristic of postmenopausal women who are not using ET.
Larsen J.,George Washington University |
Buchanan P.,George Washington University |
Buchanan P.,Foundation Medicine |
Johnson S.,SPD Development Company |
And 2 more authors.
International Journal of Gynecology and Obstetrics | Year: 2013
Objective To compare gestational age (GA) estimates in early pregnancy, determined by last menstrual period (LMP), human chorionic gonadotropin (hCG) concentration, ultrasound crown-rump length (Hadlock formula), and ovulation day (luteinizing hormone surge plus 1 day). Methods Female volunteers seeking to conceive (at 5 US sites) collected daily early-morning urine for up to 3 menstrual cycles. Pregnant women underwent ultrasound dating scans. Conception cycle urine was quantitatively assessed for luteinizing hormone and hCG. Summary statistics for GA using each reference method were determined (n = 131). Results Correlation between GA determined by ultrasound and ovulation day was excellent (maximum difference 10 days); however, pregnancies dated by ultrasound were 3 days advanced. The difference between LMP estimates and estimates based on ovulation day or ultrasound was 9 and 12 days, respectively. A uniform rise in hCG on each day of pregnancy was seen using all reference methods. The accuracy of hCG measurement in determining the week since conception was more than 93%. Conclusion Methods for establishing pregnancy duration vary in their accuracy and their GA estimates. The rise in hCG concentration in early pregnancy is uniform and therefore hCG levels provide the most accurate, early estimation of GA in single, viable pregnancies. ClinicalTrials.gov: NCT01077583 © 2013 International Federation of Gynecology and Obstetrics.
Cowsill B.J.,University of Manchester |
Waigh T.A.,University of Manchester |
Eapen S.,SPD Development Co. |
Davies R.,SPD Development Co. |
Lu J.R.,University of Manchester
Soft Matter | Year: 2012
Experimental studies of antibody adsorption and antigen binding that mimicked the key molecular processes of pregnancy tests were performed using dual polarisation interferometry (DPI). The model tests were built up in stages so that the interfacial structure and dynamics of antibody adsorption could be examined in detail. The near real time data acquisition of DPI also allowed the monitoring of the kinetics of co-adsorption of bovine serum albumin (BSA) into the pre-adsorbed antibody layer, revealing time-dependent clustering. The amount of BSA co-adsorbed was found to decrease steadily with increasing antibody adsorption and the almost constant total layer thickness indicated that BSA molecules mainly filled the gaps within the pre-adsorbed antibody layer. The specific binding capacity of the target antigen was subsequently found to be constant at 0.15 mg m-2, showing a clear trend of decreasing surface binding capacity with increasing antibody surface packing density. © 2012 The Royal Society of Chemistry.
Tiplady S.,SPD Development Company Ltd |
Jones G.,University of Sheffield |
Campbell M.,University of Sheffield |
Johnson S.,SPD Development Company Ltd |
Ledger W.,University of New South Wales
Human Reproduction | Year: 2013
Study Question Does the use of a digital home ovulation test have any effect on the level of stress in women seeking to conceive? Summary Answer No difference was found in levels of stress between women using digital ovulation tests to time intercourse compared with women who were trying to conceive without any additional aids: in addition, their use did not negatively impact time to conception in users but may provide additional benefits, including an increased understanding of the menstrual cycle, reassurance and confidence in focusing conception attempts to the correct time in the cycle. What is Known Already It has been suggested that timing of intercourse in such a way that it coincides with ovulation by using ovulation tests can lead to emotional distress; however, no study has been conducted to investigate this hypothesis specifically, until now. Study Design, Sizeand DurationThe study was performed over two complete menstrual cycles as a prospective, randomized, controlled trial including quantitative and qualitative Methods . The intervention (test) group were given digital ovulation tests to time intercourse to the most fertile time of the cycle and the control group were provided with the current National Institute for Health and Clinical Excellence guidelines for increasing the chances of conception (intercourse every 2-3 days) and asked not to use any additional Methods to time when ovulation occurs. Participants/Materials, Setting and Methods A total of 210 women who were seeking to conceive were recruited from the general UK population. A total of 115 women were randomized to the test group and 95 to the control group through block randomization. The positive and negative affect schedule (PANAS) and the Perceived Stress Scale (PSS) were used to measure subjective stress levels, the Short-Form 12 health survey was used as a measure of general health and well-being and urine samples were measured for biochemical markers of stress including urinary cortisol. Qualitative data were collected in the form of a telephone interview upon study completion. Main Results AND THE ROLE OF CHANCEThere was no evidence for a difference either in total stress as measured using the PSS or in total positive or negative affect using the PANAS questionnaire between the test and control groups at any time point for the duration of the study. During cycle 1, for example, on Day 6, the difference in total stress score (test-control) was-0.62 [95% confidence interval (CI)-2.47 to 1.24] and on the day of the LH surge, it was 0.53 (95% CI-1.38 to 2.44). In addition, no correlation was observed between time trying to conceive and levels of stress, or between age and levels of stress, and no evidence was found to show that stress affected whether or not a pregnancy was achieved. There is also no evidence that the biochemistry measurements are related to whether a pregnancy was achieved or of a difference in biochemistry between the treatment groups. The use of digital ovulation tests did not negatively affect time to conception and with an adequately sized study, could potentially show improvement. To ensure that the results of this study were not affected by chance, we used a number of different Methods for measuring stress, each of which had been independently validated. Limitations and Reasons for CautionRandomization occurred before the start of the study because of the need to provide the ovulation tests in readiness for Day 6 of the first cycle. As a consequence, a number of women fell pregnant during this period (22 and 13 in the test and control groups, respectively). A further 15 women were either lost to follow-up or withdrew consent prior to study start. Pregnancy rate was higher overall in the test group, so to ensure that there were sufficient data from women who failed to become pregnant in the test group, we implemented an additional biased recruitment. This second cohort may have been different from the first, although no significant differences were observed between the two phases of recruitment for any of the information collected upon admission to the study. Wider Implications of the Findings Women who seek medical advice while trying to conceive should not be discouraged by health care professionals from using digital ovulation tests in order to time intercourse. The cohort of women recruited to this study initially had no evidence of infertility and were looking to conceive in a non-medical setting. A separate study to assess the impact of home ovulation tests in a subfertile population would be of interest and complementary to the present study. Study Funding/Competing Interest SThis study was funded by SPD Swiss Precision Diagnostics, GmbH, manufacturer of Clearblue® pregnancy and ovulation tests. SPD Development Company Ltd is a wholly owned subsidiary of SPD Swiss Precision Diagnostics GmbH; together referred to as SPD. Trial Registration Number NCT01084304 (www.clinicaltrials.gov). © 2012 The Author.
Johnson S.,SPD Development Company Ltd |
Weddell S.,SPD Development Company Ltd |
Godbert S.,SPD Development Company Ltd |
Freundl G.,University of Cologne |
And 2 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2015
Urinary hormone level analysis provides valuable fertility status information; however, previous studies have not referenced levels to the ovulation day, or have used outdated methods. This study aimed to produce reproductive hormone ranges referenced to ovulation day determined by ultrasound. Methods: Women aged 18-40 years (no reported infertility) collected daily urine samples for one complete menstrual cycle. Urinary luteinising hormone (LH), estrone-3-glucuronide (E3G, an estradiol metabolite), follicle stimulating hormone (FSH) and pregnanediol-3-glucuronide (P3G, a progesterone metabolite) were measured using previously validated assays. Volunteers underwent trans-vaginal ultrasound every 2 days until the dominant ovarian follicle size reached 16 mm, when daily scans were performed until ovulation was observed. Data were analysed to create hormone ranges referenced to the day of objective ovulation as determined by ultrasound. Results: In 40 volunteers, mean age 28.9 years, urinary LH surge always preceded ovulation with a mean of 0.81 days; thus LH is an excellent assay-independent predictor of ovulation. The timing of peak LH was assay-dependent and could be post-ovulatory; therefore should no longer be used to predict/determine ovulation. Urinary P3G rose from baseline after ovulation in all volunteers, peaking a median of 7.5 days following ovulation. Median urinary peak E3G and FSH levels occurred 0.5 days prior to ovulation. A persistent rise in urinary E3G was observed from approximately 3 days pre-until 5 days post-ovulation. Conclusions: This study provides reproductive hormone ranges referenced to the actual day of ovulation as determined by ultrasound, to facilitate examination of menstrual cycle endocrinology. © 2015 by De Gruyter.
Gnoth C.,Green ivf |
Gnoth C.,University of Cologne |
Johnson S.,SPD Development Co.
Geburtshilfe und Frauenheilkunde | Year: 2014
The first home pregnancy test was introduced in 1976. Since then, pregnancy tests have become the most common diagnostic assay used at home. Pregnancy tests use antibodies to detect human chorionic gonadotropin (hCG). It is an ideal marker of pregnancy since it rises rapidly and consistently in early pregnancy and can be detected in urine. The most advanced home pregnancy test currently available assesses the level of hCG found in urine and claims to provide women with reliable results within just a few weeks of pregnancy. Today, over 15 different types of home pregnancy test are available to buy over the counter in Germany. Many tests claim to be highly accurate and capable of detecting pregnancy before the next monthly period is due, although claims such as 8 days prior to menstruation are unrealistic. However, users and healthcare professionals should be aware that, although all are labelled as CE, there are currently no standard criteria for testing performance and claims. This review provides an overview of the development of home pregnancy tests and the data on their efficacy together with an analysis of published data on the accuracy of hCG for the detection of early pregnancy and studies on the use of home-based pregnancy tests. Preliminary data on some home pregnancy tests available in Germany are presented which indicate that many results do not match the claims made in the package insert. Healthcare professionals and women should be aware that some of the claims made for home pregnancy tests are inconsistent and that common definitions and testing criteria are urgently needed. © Georg Thieme Verlag KG Stuttgart New York.
Johnson S.,SPD Development Co. |
Cushion M.,SPD Development Co. |
Bond S.,SPD Development Co. |
Godbert S.,SPD Development Co. |
Pike J.,SPD Development Co.
Clinical Chemistry and Laboratory Medicine | Year: 2015
Background: Internationally there are no defined standards for expressing the performance of home-based pregnancy tests, nor any pre-defined accuracy standard requirements. The aim of this study was to evaluate the accuracy of a selection of home-based pregnancy tests relative to their packaging/product insert claims. Methods: Eight home-based pregnancy tests were evaluated using human chorionic gonadotrophin (hCG) urine standards (0, 15, 25 mlU/mL). Testing was performed by a technician and results were read by a technician and a panel of consumer volunteers (each blinded to the expected result) and compared with the expected result based on the manufacturer's claimed accuracy. Volunteers also completed questionnaires relating to various device attributes. Results: The overall agreement between the technician reading and expected reading from the hCG concentration was >90% for the Clearblue® DIGITAL, Clearblue® PLUS, Confirme® Plus, David® and Haus™ tests, and approximately 80% for Predictor® Early; agreement was <50% for Femitest® Jet Ultra and Cyclotest® Early tests. Results were available from 72 volunteers (aged 18-45 years). Overall the percentage agreement between volunteer result and expected result was >95% for Clearblue DIGITAL and Clearblue PLUS tests; agreement for all other tests was <75% (lowest were Cyclotest Early and Femitest Jet Ultra, 33.0% and 39.4%, respectively). The Clearblue DIGITAL test was scored most highly by volunteers in the questionnaires. Conclusions: Many home-based pregnancy tests commonly used by women are not as accurate as their packaging information claims. International test standards which define appropriate performance characteristics for home pregnancy tests are urgently required. © 2015 by De Gruyter.
Pike J.,SPD Development Co. |
Godbert S.,SPD Development Co. |
Johnson S.,SPD Development Co.
Expert Opinion on Medical Diagnostics | Year: 2013
Background: Women suspecting pregnancy need an accurate result when they conduct a home pregnancy test. A variety of tests are available from simple professional style strips to midstream tests with a digitally displayed result. However, it is not known whether all these formats can be used and read correctly by untrained women. Objectives: The aim of this study is to evaluate usability and reading accuracy of home pregnancy test formats. Methods: Female volunteers, 18-45 years (Manchester, UK) completed questionnaires on their home-use experience of six pregnancy tests (strip, cassette, midstream visual and digital formats). These volunteers then evaluated device results using hCG-urine standards at a study centre, thereafter completing a questionnaire and ranking evaluation. Results: Data were available from 111 volunteers. Women preferred midstream test formats; > 70% scored branded midstream digital and easy-use visual tests as 1or 2 (7-point Likert score), compared with ∼ 30% for store-brand and branded midstream visual tests, and < 10% for cassette or strip tests. Many cassette tests (23%) failed to provide a result (4, ≤ 2% for strips, midstream, respectively). Volunteers disagreed with study co-ordinator reading of test results in 30 and 40% of cases for the cassette and strip test results, respectively, compared with < 3% when using midstream digital or easy-use visual tests. Volunteers preferred the branded midstream digital, followed by branded midstream easy-use and visual tests. Conclusions: In this study, the branded midstream digital test was superior to other tests evaluated and fulfilled the criteria of being an easy-to-use and interpret test; strip and cassette tests showed poor performance in women's hands. © 2013 Informa UK, Ltd.