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Vitral GLN, Romanelli RMDC, Leonel TA, Souza Gaspar JD, Aguiar RALPD, Reis ZSN. Influence of different methods for calculating gestational age at birth on prematurity and small for gestational age proportions: a systematic review with meta-analysis. BMC Pregnancy Childbirth 2023; 23:106. [PMID: 36774458 PMCID: PMC9921121 DOI: 10.1186/s12884-023-05411-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 01/27/2023] [Indexed: 02/13/2023] Open
Abstract
BACKGROUND Recognizing premature newborns and small-for-gestational-age (SGA) is essential for providing care and supporting public policies. This systematic review aims to identify the influence of the last menstrual period (LMP) compared to ultrasonography (USG) before 24 weeks of gestation references on prematurity and SGA proportions at birth. METHODS Systematic review with meta-analysis followed the recommendations of the PRISMA Statement. PubMed, BVS, LILACS, Scopus-Elsevier, Embase-Elsevier, and Web-of-Science were searched (10-30-2022). The research question was: (P) newborns, (E) USG for estimating GA, (C) LMP for estimating GA, and (O) prematurity and SGA rates for both methods. Independent reviewers screened the articles and extracted the absolute number of preterm and SGA infants, reference standards, design, countries, and bias. Prematurity was birth before 37 weeks of gestation, and SGA was the birth weight below the p10 on the growth curve. The quality of the studies was assessed using the New-Castle-Ottawa Scale. The difference between proportions estimated the size effect in a meta-analysis of prevalence. RESULTS Among the 642 articles, 20 were included for data extraction and synthesis. The prematurity proportions ranged from 1.8 to 33.6% by USG and varied from 3.4 to 16.5% by the LMP. The pooled risk difference of prematurity proportions revealed an overestimation of the preterm birth of 2% in favor of LMP, with low certainty: 0.02 (95%CI: 0.01 to 0.03); I2 97%). Subgroup analysis of USG biometry (eight articles) showed homogeneity for a null risk difference between prematurity proportions when crown-rump length was the reference: 0.00 (95%CI: -0.001 to 0.000; I2: 0%); for biparietal diameter, risk difference was 0.00 (95%CI: -0.001 to 0.000; I2: 41%). Only one report showed the SGA proportions of 32% by the USG and 38% by the LMP. CONCLUSIONS LMP-based GA, compared to a USG reference, has little or no effect on prematurity proportions considering the high heterogeneity among studies. Few data (one study) remained unclear the influence of such references on SGA proportions. Results reinforced the importance of qualified GA to mitigate the impact on perinatal statistics. TRIAL REGISTRATION Registration number PROSPERO: CRD42020184646.
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Affiliation(s)
- Gabriela Luiza Nogueira Vitral
- Faculdade de Medicina, Universidade Federal de Minas Gerais, 30.130.100, Belo Horizonte, Avenida Professor Alfredo Balena, 190, Sala 601, Brazil. .,Faculdade de Ciências Médicas de Minas Gerais, Alameda Ezequiel Dias, 275, Belo Horizonte, 30130-110, Brazil.
| | - Roberta Maia de Castro Romanelli
- grid.8430.f0000 0001 2181 4888Faculdade de Medicina, Universidade Federal de Minas Gerais, 30.130.100, Belo Horizonte, Avenida Professor Alfredo Balena, 190, Sala 601 Brazil
| | - Tiago Alves Leonel
- grid.8430.f0000 0001 2181 4888Faculdade de Medicina, Universidade Federal de Minas Gerais, 30.130.100, Belo Horizonte, Avenida Professor Alfredo Balena, 190, Sala 601 Brazil
| | - Juliano de Souza Gaspar
- grid.8430.f0000 0001 2181 4888Faculdade de Medicina, Universidade Federal de Minas Gerais, 30.130.100, Belo Horizonte, Avenida Professor Alfredo Balena, 190, Sala 601 Brazil
| | - Regina Amélia Lopes Pessoa de Aguiar
- grid.8430.f0000 0001 2181 4888Faculdade de Medicina, Universidade Federal de Minas Gerais, 30.130.100, Belo Horizonte, Avenida Professor Alfredo Balena, 190, Sala 601 Brazil
| | - Zilma Silveira Nogueira Reis
- grid.8430.f0000 0001 2181 4888Faculdade de Medicina, Universidade Federal de Minas Gerais, 30.130.100, Belo Horizonte, Avenida Professor Alfredo Balena, 190, Sala 601 Brazil
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Terán JM, Varea C, Bernis C, Bogin B, González-González A. New birthweight charts according to parity and type of delivery for the Spanish population. GACETA SANITARIA 2017; 31:116-122. [PMID: 28160963 DOI: 10.1016/j.gaceta.2016.09.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 09/28/2016] [Accepted: 09/29/2016] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Birthweight by gestational age charts enable fetal growth to be evaluated in a specific population. Given that maternal profile and obstetric practice have undergone a remarkable change over the past few decades in Spain, this paper presents new Spanish reference percentile charts stratified by gender, parity and type of delivery. They have been prepared with data from the 2010-2014 period of the Spanish Birth Statistics Bulletin. METHODS Reference charts have been prepared using the LMS method, corresponding to 1,428,769 single, live births born to Spanish mothers. Percentile values and mean birth weight are compared among newborns according to gender, parity and type of delivery. RESULTS Newborns to primiparous mothers show significantly lower birthweight than those born to multiparous mothers (p<0.036). Caesarean section was associated with a substantially lower birthweight in preterm births (p<0.048), and with a substantially higher birthweight for full-term deliveries (p<0.030). Prevalence of small for gestational age is significantly higher in newborns born by Caesarean section, both in primiparous (p<0.08) and multiparous mothers (p<0.027) and, conversely, the prevalence of large for gestational age among full-term births is again greater both in primiparous (p<0.035) and in multiparous mothers (p<0.007). CONCLUSIONS Results support the consideration of establishing parity and type of delivery-specific birthweight references. These new charts enable a better evaluation of the impact of the demographic, reproductive and obstetric trends currently in Spain on fetal growth.
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Affiliation(s)
- José Manuel Terán
- Department of Biology, Faculty of Sciences, Madrid Autonomous University, Madrid, Spain; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire, United Kingdom.
| | - Carlos Varea
- Department of Biology, Faculty of Sciences, Madrid Autonomous University, Madrid, Spain; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire, United Kingdom
| | - Cristina Bernis
- Department of Biology, Faculty of Sciences, Madrid Autonomous University, Madrid, Spain; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire, United Kingdom
| | - Barry Bogin
- Department of Biology, Faculty of Sciences, Madrid Autonomous University, Madrid, Spain; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire, United Kingdom
| | - Antonio González-González
- Departments of Obstetrics and Gynaecology, Faculty of Medicine, Madrid Autonomous University, Madrid, Spain; School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire, United Kingdom
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Pereira APE, Dias MAB, Bastos MH, da Gama SGN, Leal MDC. Determining gestational age for public health care users in Brazil: comparison of methods and algorithm creation. BMC Res Notes 2013; 6:60. [PMID: 23402277 PMCID: PMC3585703 DOI: 10.1186/1756-0500-6-60] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 02/08/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A valid, accurate method for determining gestational age (GA) is crucial in classifying early and late prematurity, and it is a relevant issue in perinatology. This study aimed at assessing the validity of different measures for approximating GA, and it provides an insight into the development of algorithms that can be adopted in places with similar characteristics to Brazil. A follow-up study was carried out in two cities in southeast Brazil. Participants were interviewed in the first trimester of pregnancy and in the postpartum period, with a final sample of 1483 participants after exclusions. The distribution of GA estimates at birth using ultrasound (US) at 21-28 weeks, US at 29+ weeks, last menstrual period (LMP), and the Capurro method were compared with GA estimates at birth using the reference US (at 7-20 weeks of gestation). Kappa, sensitivity, and specificity tests were calculated for preterm (<37 weeks of gestation) and post-term (>=42 weeks) birth rates. The difference in days in the GA estimates between the reference US and the LMP and between the reference US and the Capurro method were evaluated in terms of maternal and infant characteristics, respectively. RESULTS For prematurity, US at 21-28 weeks had the highest sensitivity (0.84) and the Capurro method the highest specificity (0.97). For postmaturity, US at 21-28 weeks and the Capurro method had a very high sensitivity (0.98). All methods of GA estimation had a very low specificity (≤0.50) for postmaturity. GA estimates at birth with the algorithm and the reference US produced very similar results, with a preterm birth rate of 12.5%. CONCLUSIONS In countries such as Brazil, where there is less accurate information about the LMP and lower coverage of early obstetric US examinations, we recommend the development of algorithms that enable the use of available information using methodological strategies to reduce the chance of errors with GA. Thus, this study calls into attention the care needed when comparing preterm birth rates of different localities if they are calculated using different methods.
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Stirnemann JJ, Samson A, Bernard JP, Thalabard JC. Day-specific probabilities of conception in fertile cycles resulting in spontaneous pregnancies. Hum Reprod 2013; 28:1110-6. [PMID: 23340057 DOI: 10.1093/humrep/des449] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
STUDY QUESTION When, within the female cycle, does conception occur in spontaneously fertile cycles? SUMMARY ANSWER This study provides reference values of day-specific probabilities of date of conception in ongoing pregnancies. The maximum probability of being within a 5-day fertile window was reached on Day 12 following the last menstrual period (LMP). WHAT IS KNOWN ALREADY The true date of conception is not observable and may only be estimated. Accuracy of these estimates impacts on obstetric management of ongoing pregnancies. Timing of ovulation and fertility has been extensively studied in prospective studies of non-pregnant fertile women using error-prone proxies, such as hormonal changes, body-basal temperature and ultrasound, yielding day-specific probabilities of conception and fertile windows. In pregnant women, date of conception may be retrospectively estimated from early pregnancy fetal measurement by ultrasound. STUDY DESIGN, SIZE, DURATION Retrospective analysis of consecutive pregnancies in women referred for routine first-trimester screening, over a 3-year period (2009-2011) in a single ultrasound center (n = 6323). PARTICIPANTS/MATERIALS, SETTING, METHODS Within the overall population, 5830 cases with a certain date of last menses were selected for analysis. The date of conception was estimated using a crown-rump length biometry and an equation derived from IVF/ICSI pregnancies. Day-specific probabilities of conception were estimated across several covariates, including age, cycle characteristics and ethnicity, using deconvolution methods to account for measurement error. MAIN RESULTS AND THE ROLE OF CHANCE Overall, the day-specific probability of conception sharply rises at 7 days after the LMP, reaching its maximum at 15 days and returning to zero by 25 days. Older women tend to conceive earlier within their cycle, as did women with regular cycles and white and black women compared with Asian ethnicity. The probability of being within the fertile window was 2% probability at Day 4, a maximum probability of 58% at Day 12 and a 5% probability by Day 21 of the cycle. LIMITATIONS, REASONS FOR CAUTION Although conception is believed to occur within hours following ovulation, a discrepancy is theoretically possible. However, when comparing our results to those of prospective studies, no such difference was found. The equation used for estimating the date of pregnancy was estimated in IVF/ICSI pregnancies, which could lead to potential bias in spontaneous pregnancies. However, in our population, the observed bias was negligible. Non-fertile cycles and early pregnancy losses are necessarily overlooked because of the nature of our data. WIDER IMPLICATIONS OF THE FINDINGS Because of the wider access to retrospective data and the potential bias in prospective studies of ovulation monitoring, this study should broaden the perspectives of future epidemiologic research in fertility and pregnancy monitoring. STUDY FUNDING/COMPETING INTERESTS None.
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Affiliation(s)
- Julien J Stirnemann
- Department of Obstetrics and Maternal Fetal Medicine, Hôpital Necker-Enfants Malades, AP-HP, Université Paris Descartes, Paris, France.
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Stirnemann JJ, Comte F, Samson A. Density estimation of a biomedical variable subject to measurement error using an auxiliary set of replicate observations. Stat Med 2012; 31:4154-63. [PMID: 22593032 DOI: 10.1002/sim.5392] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 02/28/2012] [Accepted: 03/14/2012] [Indexed: 11/08/2022]
Abstract
Correcting for measurement error when estimating the density of a routinely collected biomedical variable is an important issue when describing reference values for both healthy and pathological states. The present work addresses the problem of estimating the density of a biomedical variable observed with measurement error without any a priori knowledge on the error density. Assuming the availability of a sample of replicate observations, either internal or external, which is generally easily obtained in clinical settings, we propose an estimator based on the non-parametric deconvolution theory with an adaptive procedure for cutoff selection, the replicates being used for an estimation of the error density. We illustrate this approach in two applicative examples: (i) the systolic blood pressure distribution density, using the Framingham Study data set, and (ii) the distribution of the timing of onset of pregnancy within the female cycle, using ultrasound measurements in the first trimester of pregnancy.
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Affiliation(s)
- J J Stirnemann
- Applied Mathematics, MAP5, UMR CNRS 8145, Université Paris Descartes, Paris, France.
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Moore GS, Kneitel AW, Walker CK, Gilbert WM, Xing G. Autism risk in small- and large-for-gestational-age infants. Am J Obstet Gynecol 2012; 206:314.e1-9. [PMID: 22464070 PMCID: PMC9884028 DOI: 10.1016/j.ajog.2012.01.044] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 01/14/2012] [Accepted: 01/30/2012] [Indexed: 01/31/2023]
Abstract
OBJECTIVE We sought to determine whether small-for-gestational age (SGA) and large-for-gestational age (LGA) birthweights increase autism risk. STUDY DESIGN This was a retrospective cohort analysis comparing children with autism (n = 20,206) within a birth cohort (n = 5,979,605). Stratification by sex and birthweight percentile (SGA, <5th or 5-10th percentile; appropriate size for gestational age [GA], >10th to <90th percentile; LGA, either 90-95th or >95th percentile) preceded Cochran-Mantel-Haenszel analysis for GA effect, and multivariate analysis. RESULTS Autism risk was increased in preterm SGA (<5th percentile) infants 23-31 weeks (adjusted odds ratio [aOR], 1.60; 95% confidence interval [CI], 1.09-2.35) and 32-33 weeks (aOR, 1.83; 95% CI, 1.16-2.87), and term LGA (>95th percentile) infants 39-41 weeks (aOR, 1.16; 95% CI, 1.08-1.26), but was decreased in preterm LGA infants 23-31 weeks (aOR, 0.45; 95% CI, 0.21-0.95). CONCLUSION SGA was associated with autism in preterm infants, while LGA demonstrated dichotomous risk by GA, with increased risk at term, and decreased risk in the premature infants. These findings likely reflect disparate pathophysiologies, and should influence prenatal counseling, pediatric autism screening, and further autism research.
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Affiliation(s)
- Gaea Schwaebe Moore
- Department of Obstetrics and Gynecology, University of California Davis,Department of Obstetrics and Gynecology, University of Colorado Health Sciences Center, Aurora, CO
| | | | - Cheryl K. Walker
- Department of Obstetrics and Gynecology, University of California Davis
| | - William M. Gilbert
- Department of Obstetrics and Gynecology, University of California Davis,Department of Obstetrics and Gynecology, Sutter Medical Center
| | - Guibo Xing
- Department of Obstetrics and Gynecology, University of California Davis,Center for Healthcare Policy and Research, University of California Davis, Sacramento, CA
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Abeysena C, Jayawardana P, Seneviratne RDA. Effect of psychosocial stress and physical activity on preterm birth: a cohort study. J Obstet Gynaecol Res 2010; 36:260-7. [PMID: 20492375 DOI: 10.1111/j.1447-0756.2009.01160.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM To determine trimester-specific effects of risk factors for preterm birth (PTB). METHODS A prospective study was carried out in a district of Sri Lanka. A total of 885 pregnant mothers were recruited at equal to or less than 16 weeks of gestation and followed up until partus. Trimester-specific exposure statuses and potential confounding factors were gathered on average at the 12th, 28th, and 36th weeks of gestation. Physical activities were assessed by obtaining information about the duration of specific postures adopted per day by housewives during each trimester at home and both at home and during working hours for those who were engaged in paid employment. Psychosocial stress was assessed using the Modified Life Events Inventory and the General Health Questionnaire 30. Multiple logistic regression analysis was applied and the results were expressed as adjusted odds ratios (OR) and 95% confidence intervals (95%CI). RESULTS Standing equal to or less than 2.5 h/day during the first or second or both trimesters (OR 1.83, 95%CI 1.03, 3.25), maternal age of <25 years (OR 1.73, 95%CI 1.02, 2.95), education up to primary school level (OR 3.30, 95%CI 1.3, 8.36) and past history of low birthweight (OR 2.52, 95%CI 1.16, 5.48) were risk factors for PTB. Psychosocial stress was not found to be a risk factor for PTB. CONCLUSIONS Standing equal to or less than 2.5 h/day during the early trimesters was a risk factor for PTB among uncomplicated pregnancies. Further studies are recommended to assess the trimester-specific effect of psychosocial stress on PTB.
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Affiliation(s)
- Chrishantha Abeysena
- Department of Public Health, Faculty of Medicine, University of Kelaniya, Ragama.
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Ananth CV. Menstrual versus clinical estimate of gestational age dating in the United States: temporal trends and variability in indices of perinatal outcomes. Paediatr Perinat Epidemiol 2007; 21 Suppl 2:22-30. [PMID: 17803615 DOI: 10.1111/j.1365-3016.2007.00858.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Accurate estimation of gestational age early in pregnancy is paramount for obstetric care decisions and for determining fetal growth and other conditions that may necessitate timing the iatrogenic intervention or delivery. We sought to examine temporal changes in the distributions of two measures of gestational age, namely, those based on menstrual dating and a clinical estimate. We further sought to evaluate relative comparisons and variability in indices of perinatal outcomes. We utilised the Natality data files in the US, 1990-2002 comprising women that delivered a singleton livebirth between 22 and 44 weeks gestation (n = 42 689 603). Changes were shown in the distributions of gestational age based on menstrual vs. clinical estimate between 1990 and 2002, as well as changes in the proportions of preterm (<37, <32 and <28 weeks) and post-term (>or=42 weeks) birth, and small- (SGA; <10th percentile) and large-for-gestational-age (LGA; birthweight >90th percentile) births. While the absolute rates of preterm birth <37 weeks, SGA and LGA births were lower based on the clinical estimate of gestational age relative to that based on menstrual dating, the increases in preterm birth rate between 1990 and 2002 were fairly similar between the two measures of gestational dating. However, the decline in post-term births was larger, based on the clinical estimate (-73.8%), than on the menstrual estimate (-36.6%) between 1990 and 2002. While the clinical estimate of gestational age appears to provide a reasonably good approximation to the menstrual estimate, disregarding the clinical estimate of gestational age may ignore the advantages of gestational age assessment in modern obstetrics.
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Affiliation(s)
- Cande V Ananth
- Division of Epidemiology and Biostatistics, Department of Obstetrics, Gynecology, and Reproductive Sciences, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ 08901-1977, USA.
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Mladenović-Segedi L, Segedi D. [Accuracy of ultrasonic fetal weight estimation using head and abdominal circumference and femur length]. MEDICINSKI PREGLED 2006; 58:548-52. [PMID: 16673856 DOI: 10.2298/mpns0512548m] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Former investigations have shown that the accuracy of fetal weight estimation is significantly higher if several ultrasonic fetal parameters are measured, because the total body mass depends on the size of fetal head, abdominal circumference and femur length. The aim of this investigation was to establish the best regression model, that is a number of combinations of fetal parameters providing the most accurate fetal weight estimation in utero in our population. MATERIAL AND METHODS This prospective study was carried out at the Gynecology and Obstetrics Clinic of the Clinical Center Novi Sad. It included 270 pregnant women with singleton pregnancies within 72 hours of delivery who underwent ultrasound measurements of the biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). RESULTS In regard to fetal weight estimation formulas, the deviation was lowest using regression models that simultaneously analyzed four fetal parameters (0. 55%) with SD +/- 7.61%. In these models the estimates of fetal weights were within +/- 5% of actual birth weight in 48.89%, and within +/- 10% of actual birth weight in 81.48%. Good results were also obtained using AC, FL measurements (0.92% +/- 8.20) as well as using AC, HC, FL measurements (-1.45% +/- 7.81). In our sample the combination of AC and FL model gave better results in fetal weight estimation (0.92 +/- 8.20%) than the one using BPD and AC (2.97 +/- 8.83%). Furthermore, the model using parameters AC, HC and FL showed a lower error in accuracy (-1.45 +/- 7.81%) than the model using BPD, AC and FL (2.51 +/- 7.82%). CONCLUSION This investigation has confirmed that the accuracy of fetal weight estimation increases with the number of measured ultrasonic fetal parameters. In our population the greatest accuracy was obtained using BPD, HC, AC and FL model. In cases when fast estimation of fetal weight is needed, AC, HC, FL model may be appropriate, but if fetal head circumference cannot be measured (amnion rupture and/or fetal head already in the pelvis) the AC, FL model should be used.
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Abstract
Assessment of the growth status of the fetus and neonate is an essential component of perinatal care. It requires a distinction to be made between physiological and pathological factors, and the prediction of the optimal growth that a baby can achieve in a normal, uncomplicated pregnancy. Such an individually customised standard can now be easily calculated by computer: it needs to be accurately dated, individually adjusted for physiological characteristics, exclude pathological factors such as smoking, and be based on a fetal weight trajectory derived from normal term pregnancies. Application of a customised standard to calculate the growth status of preterm babies gives us freshly insights into the causes of prematurity. Fetal growth restriction is seen as a strongly associated factor, which is often present before the onset of spontaneous preterm labour. This raises the question whether, in many instances, the initiation of parturition should be seen as a fetal adaptive response aimed at escaping an unfavourable intrauterine environment. These concepts have implications for the understanding of the pathophysiology of preterm labour, as well as its clinical management.
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Affiliation(s)
- Jason O Gardosi
- Perinatal Institute, Crystal Court, Aston Cross, Birmingham B6 5RQ, United Kingdom.
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Glinianaia SV, Rankin J, Bell R, Pless-Mulloli T, Howel D. Particulate air pollution and fetal health: a systematic review of the epidemiologic evidence. Epidemiology 2004; 15:36-45. [PMID: 14712145 DOI: 10.1097/01.ede.0000101023.41844.ac] [Citation(s) in RCA: 240] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Research on the potential impact of air pollution on the health of adults and children has grown rapidly over the last decade. Recent studies have suggested that air pollution could also be associated with adverse effects on the developing fetus. This systematic review evaluates the current level of epidemiologic evidence on the association between ambient particulate air pollution and fetal health outcomes. We also suggest further research questions. METHODS Using database searches and other approaches, we identified relevant publications published between 1966 and 2001 in English. Articles were included if they reported original data on birthweight, gestational age at delivery, or stillbirth related to directly measured nonaccidental exposure to particulate matter. RESULTS Twelve studies met the inclusion criteria. There was little consistency in the evidence linking particulate air pollution and fetal outcomes. Many studies had methodologic weaknesses in their design and adjustment for confounding factors. Even in well-designed studies, the reported magnitude of the effects was small and inconsistently associated with exposure at specific stages of pregnancy. CONCLUSIONS The currently available evidence is compatible with either a small adverse effect of particulate air pollution on fetal growth and duration of pregnancy or with no effect. Further research should be directed toward clarifying and quantifying these possible effects and generating testable hypotheses on plausible biologic mechanisms.
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Affiliation(s)
- Svetlana V Glinianaia
- School of Population and Health Sciences, Faculty of Medical Sciences, University of Newcastle, Newcastle-upon-Tyne, United Kigndom.
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Abstract
Although the association of fetal growth restriction and adverse pregnancy outcomes is well known, lack of sensitivity limits its clinical value. To a large extent, this limitation is a result of traditionally used method to define growth restriction by comparing fetal or birth weight to population norms. The use of population norms, by virtue of their inability to fully consider individual variation, results in high false positive and negative rates. An alternative, calculating fetal individually optimal growth potential, based on physiological determinants of individual growth, is superior in predicting adverse outcomes of pregnancy. Impairment of fetal growth potential identifes some adverse pregnancy outcomes that are not associated with growth restrction defined by population norms. When compared with traditional population-based norms, fetal growth potential is a better predictor of several important adverse outcomes of pregnancy which include: stillbirth, neonatal mortality and morbidity, and long-term adverse neonatal outcomes like neonatal encephalopathy, cerebral palsy and cognitive abilities. Impairment of individual growth potential is also strongly associated with spontaneous preterm delivery. Although definitive interventional trials have not been conducted as yet to validate the clinical value of fetal growth potential, many observational studies, conducted in various populations, indicate its significant promise in this respect.
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Affiliation(s)
- Radek Bukowski
- Department of Obstetrics & Gynecology, University of Texas Medical Branch at Galveston, Galveston, TX 77555-1062, USA.
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Abstract
OBJECTIVE To examine whether routinely measured variables explained the increased risk of preterm delivery in some UK ethnic groups. DESIGN Cross sectional study of deliveries recorded in the Child Health Record System. SETTING North Birmingham, UK. POPULATION All North Birmingham women delivering singletons, 1994-1997 inclusive. METHOD Logistic regression. MAIN OUTCOME MEASURES Odds ratio (OR) and 95% confidence interval (CI) for preterm delivery, defined as less than 37 weeks, less than 34 weeks and less than 28 weeks, unadjusted and adjusted for maternal age, an area-based socio-economic status measure, and marital status, year of birth, fetal sex and past obstetric history. RESULTS For Afro-Caribbean women, the ORs (95% CIs) were: for delivery less than 37 weeks, 1.44 (1.26-1.64) unadjusted and 1.22 (1.07-1.41) adjusted; for delivery less than 34 weeks, 1.55 (1.25-1.92) unadjusted and 1.29 (1.02-1.61) adjusted; for delivery less than 28 weeks, 1.66 (1.08-2.55) unadjusted and 1.32 (0.84-2.06) adjusted. For African women, the risk of delivery less than 37 weeks was not significantly raised; for delivery less than 34 weeks, the OR (95% CI) was 1.88 (0.99-3.58) unadjusted and 1.78 (0.93-3.40) adjusted; for delivery less than 28 weeks, the OR (95% CI) was 4.02 (1.60-10.12) unadjusted and 4.10 (1.66-10.16) adjusted. In Afro-Caribbeans, deprivation and marital status explained the differences between the unadjusted and adjusted ORs. There was a linear relation between deprivation and preterm delivery for all ethnic groups, except for Asians. CONCLUSIONS Factors associated with deprivation and marital status explain about half of the excess of preterm births in Afro-Caribbeans, but not Africans. The risk of preterm delivery might not be related to deprivation in Asians.
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Affiliation(s)
- Paul Aveyard
- Department of Public Health and Epidemiology, University of Birmingham, UK
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Larsen T, Nguyen TH, Greisen G, Engholm G, Møller H. Does a discrepancy between gestational age determined by biparietal diameter and last menstrual period sometimes signify early intrauterine growth retardation? BJOG 2000; 107:238-44. [PMID: 10688508 DOI: 10.1111/j.1471-0528.2000.tb11695.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To assess the association between gestational age estimated from the last menstrual period (GA(LMP)) or from the biparietal diameter (GA(BPD)), and the subsequent birthweight for gestational age. DESIGN Population-based follow up study. SETTING Of 21,936 pregnancies contained in the ultrasound database, 16,387 singleton pregnancies with a reliable last menstrual period date and an ultrasound examination between 12 and 22 weeks of gestation were included. MAIN OUTCOME MEASURES Correlation between: 1) birthweight deviation (birthweight-expected weight for gestation); 2) birthweight; and 3) pregnancy length and (GA(LMP)-GA(BPD)). Relative risk of birthweight < 2,500 g and low birthweight for gestation (> 22% below normal weight) related to five levels of discrepancy between (GA(LMP)-GA(BPD)). RESULTS (GA(LMP)-GA(BPD)) was not associated with deviation of birthweight related to GA(BPD). However the risk of low birthweight (< 2,500 g) and low birthweight for gestational age was significantly increased when (GA(LMP)-GA(BPD)) was > 7 days. CONCLUSION A biparietal diameter smaller than expected from the last menstrual period date is mainly a problem of an error related to estimated time of ovulation. At the same time the relative risk of a low birthweight infant is slightly increased.
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Affiliation(s)
- T Larsen
- Department of Ultrasound, and Obstetrics and Gynaecology, Herlev Hospital, University of Copenhagen, Denmark
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Gardosi J, Geirsson RT. Routine ultrasound is the method of choice for dating pregnancy. BRITISH JOURNAL OF OBSTETRICS AND GYNAECOLOGY 1998; 105:933-6. [PMID: 9763041 DOI: 10.1111/j.1471-0528.1998.tb10253.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J Gardosi
- Perinatal Research, Audit & Monitoring Unit, University Hospital, Queen's Medical Centre, Nottingham, UK
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