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Ultrasound in Obstetrics & Gynecology :... Jun 2019INTRODUCTION These Guidelines aim to describe appropriate assessment of fetal biometry and diagnosis of fetal growth disorders. These disorders consist mainly of fetal...
INTRODUCTION These Guidelines aim to describe appropriate assessment of fetal biometry and diagnosis of fetal growth disorders. These disorders consist mainly of fetal growth restriction (FGR), also referred to as intrauterine growth restriction (IUGR) and often associated with small‐for‐gestational age (SGA), and large‐for‐gestational age (LGA), which may lead to fetal macrosomia; both have been associated with a variety of adverse maternal and perinatal outcomes. Screening for, and adequate management of, fetal growth abnormalities are essential components of antenatal care, and fetal ultrasound plays a key role in assessment of these conditions. The fetal biometric parameters measured most commonly are biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur diaphysis length (FL). These biometric measurements can be used to estimate fetal weight (EFW) using various different formulae1. It is important to differentiate between the concept of fetal size at a given timepoint and fetal growth, the latter being a dynamic process, the assessment of which requires at least two ultrasound scans separated in time. Maternal history and symptoms, amniotic fluid assessment and Doppler velocimetry can provide additional information that may be used to identify fetuses at risk of adverse pregnancy outcome. Accurate estimation of gestational age is a prerequisite for determining whether fetal size is appropriate‐for‐gestational age (AGA). Except for pregnancies arising from assisted reproductive technology, the date of conception cannot be determined precisely. Clinically, most pregnancies are dated by the last menstrual period, though this may sometimes be uncertain or unreliable. Therefore, dating pregnancies by early ultrasound examination at 8–14 weeks, based on measurement of the fetal crown–rump length (CRL), appears to be the most reliable method to establish gestational age. Once the CRL exceeds 84 mm, HC should be used for pregnancy dating2–4. HC, with or without FL, can be used for estimation of gestational age from the mid‐trimester if a first‐trimester scan is not available and the menstrual history is unreliable. When the expected delivery date has been established by an accurate early scan, subsequent scans should not be used to recalculate the gestational age1. Serial scans can be used to determine if interval growth has been normal. In these Guidelines, we assume that the gestational age is known and has been determined as described above, the pregnancy is singleton and the fetal anatomy is normal. Details of the grades of recommendation used in these Guidelines are given in Appendix 1. Reporting of levels of evidence is not applicable to these Guidelines.
Topics: Biometry; Crown-Rump Length; Female; Fetal Growth Retardation; Humans; Obstetrics; Practice Guidelines as Topic; Pregnancy; Societies, Medical; Ultrasonography, Prenatal
PubMed: 31169958
DOI: 10.1002/uog.20272 -
Revista Brasileira de Ginecologia E... Sep 2020The purpose of the present study was to analyze the influence of chorionicity in the biometric parameters crown-rump length (CRL), birthweight (BW), crown-rump length...
OBJECTIVE
The purpose of the present study was to analyze the influence of chorionicity in the biometric parameters crown-rump length (CRL), birthweight (BW), crown-rump length discordancy (CRLD) and birthweight discordancy (BWD), determine the correlation between these latter two in cases of intertwin discordancy, and to analyze the influence of chronicity in the presence of these discordancies with clinical relevance (> 10% and > 15%, respectively).
METHODS
The present study was a retrospective study based on the twin pregnancy database of the Centro Hospitalar S. João (2010-2015), including 486 fetuses among 66 monochorionic (MC) and 177 dichorionic gestations (DC). The inclusion criteria were multiple pregnancies with 2 fetuses and healthy twin gestations. The exclusion criteria were trichorionic gestations and pregnancies with inconclusive chorionicity, multiple pregnancy with ≥ 3 fetuses and pathological twin gestations.
RESULTS
No statistically significant difference was found in BW ( = 0.09) and in its discordancy 0.06) nor in CRL 0.48) and its discordancy 0.74) between MCs and DCs. Crown-rump length discordancy and birthweight discordancy were correlated by the regression line "BWD = 0.8864 x CRLD + 0.0743," with r = 0.1599. Crown-rump length discordancy > 10% was found in 7.58% of monochorionic and in 13.56% of dichorionic twins. Birthweight discordancy > 15% was detected in 16.67% of monochorionic and in 31.64% of dichorionic twins.
CONCLUSION
No statistically significant influence of chorionicity was identified in both birthweight and birthweight discordancy, as in crown-rump length and crown-rump length discordancy. Birthweight discordancy was correlated to crown-rump length discordancy in 20% of cases.
Topics: Birth Weight; Chorion; Crown-Rump Length; Female; Humans; Pregnancy; Pregnancy Complications; Pregnancy, Twin; Retrospective Studies
PubMed: 32559796
DOI: 10.1055/s-0040-1712128 -
Prenatal Diagnosis Jan 2020The fetal fraction (FF) is a function of both biological factors and bioinformatics algorithms used to interpret DNA sequencing results. It is an essential quality... (Review)
Review
The fetal fraction (FF) is a function of both biological factors and bioinformatics algorithms used to interpret DNA sequencing results. It is an essential quality control component of noninvasive prenatal testing (NIPT) results. Clinicians need to understand the biological influences on FF to be able to provide optimal post-test counseling and clinical management. There are many different technologies available for the measurement of FF. Clinicians do not need to know the details behind the bioinformatics algorithms of FF measurements, but they do need to appreciate the significant variations between the different sequencing technologies used by different laboratories. There is no universal FF threshold that is applicable across all platforms and there have not been any differences demonstrated in NIPT performance by sequencing platform or method of FF calculation. Importantly, while FF should be routinely measured, there is not yet a consensus as to whether it should be routinely reported to the clinician. The clinician should know what to expect from a standard test report and whether reasons for failed NIPT results are revealed. Emerging solutions to the challenges of samples with low FF should reduce rates of failed NIPT in the future. In the meantime, having a "plan B" prepared for those patients for whom NIPT is unsuccessful is essential in today's clinical practice.
Topics: Algorithms; Aneuploidy; Anticoagulants; Autoimmune Diseases; Body Weight; Cell-Free Nucleic Acids; Chorionic Gonadotropin, beta Subunit, Human; Computational Biology; Crown-Rump Length; DNA Copy Number Variations; Female; Gestational Age; Heparin, Low-Molecular-Weight; High-Throughput Nucleotide Sequencing; Humans; Maternal Age; Mosaicism; Noninvasive Prenatal Testing; Pregnancy; Pregnancy Complications; Pregnancy, Multiple; Pregnancy-Associated Plasma Protein-A; Reproductive Techniques, Assisted; Triploidy
PubMed: 31821597
DOI: 10.1002/pd.5620 -
Ginekologia Polska 2020Significance of the crown-rump length (CRL) measurement criteria in the assessments of gestational age and actual precision in daily clinical practice.
OBJECTIVES
Significance of the crown-rump length (CRL) measurement criteria in the assessments of gestational age and actual precision in daily clinical practice.
MATERIAL AND METHODS
We recruited 806 pregnant women with singleton pregnancy and history of regular menstrual periods.We analysed retrospectively CRL measurements obtained during routine first trimester scan performed between 11 + 0 and 13 + 6 weeks gestation. Gestational age was calculated using both the last menstrual period (LMP) and the CRL. The images of the CRL measurements were assessed by the expert. The visual analysis of the images in terms of meeting the five criteria recommended by the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) was performed. Statistical analysis were used to assess how the above-mentioned criteria influenced calculation of the gestational age.
RESULTS
The study showed 323 out of 806 of the CRL measurements (40.1%) were qualified by a specialist as accurate, 279 (34.6%) as inaccurate, and 204 (25.3%) as inaccurate, but not changing the duration of a pregnancy. With the application in the assessment of the five criteria of the ISOUG 217 (26.9%), the following results of qualification were obtained: accurate - fulfilled ≥ 4, inaccurate 341 (42.3%) - fulfilled ≤ 2, whereas inaccurate, but not changing the duration of a pregnancy 248 (30.8%) - 3 criteria fulfilled. We found that only the neutralof the fetus demonstrated a significant corellation with the assessment of the duration of a gestation.
CONCLUSIONS
a) the accurate audit of the CRL measurements is recommended; b) neutral position of the fetus is the most important criterion out of 5.
Topics: Adult; Body Weights and Measures; Crown-Rump Length; Female; Fetus; Gestational Age; Humans; Pregnancy; Retrospective Studies; Ultrasonography, Prenatal
PubMed: 33301161
DOI: 10.5603/GP.a2020.0098 -
Ultrasound in Obstetrics & Gynecology :... Aug 2014The aim of this systematic review was to explore the relationship between crown-rump length (CRL) discordance detected at 11-14 weeks of gestation and adverse outcome in... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The aim of this systematic review was to explore the relationship between crown-rump length (CRL) discordance detected at 11-14 weeks of gestation and adverse outcome in twin pregnancy and to assess its predictive accuracy.
METHODS
A protocol designed a priori following MOOSE guidelines and recommended for systematic review and meta-analysis was used. The outcomes observed were: total fetal and perinatal loss, fetal loss at <24 weeks, fetal loss at ≥ 24 weeks, birth-weight (BW) discordance, preterm delivery (PTD) at < 34 weeks and fetal anomalies. The analysis was performed for all twins and for dichorionic (DC) and monochorionic (MC) twins separately.
RESULTS
A total of 2008 articles were identified and 17 studies were included in the systematic review. Twin pregnancies with CRL discordance ≥ 10% were at significantly higher risk of perinatal loss (RR, 2.80; 95% CI, 1.25-6.27; P = 0.012), fetal loss at ≥ 24 weeks (RR, 4.07; 95% CI, 1.47-11.23; P = 0.006), BW discordance (RR, 2.24; 95% CI, 1.89-2.64; P < 0.001) and PTD at < 34 weeks (RR, 1.49; 95% CI, 1.23-1.80; P < 0.001) but not of fetal loss at < 24 weeks (P = 0.130). A meta-analysis of fetal anomalies was not possible because fewer than two studies explored this outcome. However, when used alone to screen for adverse pregnancy outcome, the predictive accuracy of CRL discordance was low for each of the outcomes explored.
CONCLUSION
CRL discordance is associated with an increased risk of adverse pregnancy outcome. However, the accuracy of CRL discordance in predicting adverse outcome is poor and thus limits its routine use in clinical practice.
Topics: Birth Weight; Crown-Rump Length; Female; Fetus; Humans; Infant, Newborn; Pregnancy; Pregnancy Outcome; Pregnancy, Twin; Twins, Dizygotic; Twins, Monozygotic; Ultrasonography, Prenatal
PubMed: 24585501
DOI: 10.1002/uog.13335 -
BMC Pediatrics Jul 2022To investigate the association of crown-rump length (CRL) during the first trimester of pregnancy with neonatal outcomes.
BACKGROUND
To investigate the association of crown-rump length (CRL) during the first trimester of pregnancy with neonatal outcomes.
METHODS
A total of 15,524 women with a reliable first day of the last menstrual period and a regular menstrual cycle (28 ± 4 days) were included from January 2015 to November 2016. CRL was measured by ultrasound from 7 to 13 weeks during pregnancy and transformed to a standard deviation score (SDS) adjusted for gestational age. Linear regression was used to explore risk factors for CRL. A generalised linear model was used to evaluate the association between CRL and neonatal outcomes.
RESULTS
In the multivariate analysis, maternal age (0.25 mm, 95% CI = [0.22-0.28], P < 0.001; 0.04 SDS, 95% CI = [0.03-0.04], P < 0.001), multipara (0.30 mm, 95% CI = [0.08-0.52], P = 0.007; 0.04 SDS, 95% CI = [0.00-0.07], P = 0.031) and folic acid supplement use (0.78 mm, 95% CI = [0.49-1.08], P < 0.001; 0.05 SDS, 95% CI = [0.01-0.10], P < 0.019) were positively associated with CRL, while pre-pregnancy BMI (-0.17 mm, 95% CI = [-0.21 to -0.13], P < 0.001; -0.02 SDS, 95% CI = [-0.03 to -0.02], P < 0.001) was negatively related to CRL. For neonatal outcomes, CRL was negatively associated with small for gestational age (SGA) ([risk ratio] (RR) = 0.733, 95% [CI] = 0.673-0.8004, P < 0.001) and neonatal intensive care unit (NICU) admission ([RR] = 0.928, 95% [CI] = 0.883-0.976, P = 0.003), and preterm birth ([RR] = 1.082, 95% [CI] = 1.008-1.162, P = 0.029), but positively related to large for gestational age (LGA) ([RR] = 1.241, 95% [CI] = 1.184-1.301, P = 0.012). When stratified by pre-pregnancy BMI, the risk of SGA and LGA remained significant in all groups, while the increased risk of preterm birth was only observed in the lean group (BMI < 18.5 kg/m) and decreased risk of NICU admission rate in the normal group (BMI 18.5-24 kg/m).
CONCLUSIONS
Maternal characteristics were independently associated with CRL in the first trimester, which was negatively related to foetal size, SGA, preterm birth, and admission rate to the NICU, but positively related to LGA.
Topics: Crown-Rump Length; Female; Fetal Growth Retardation; Humans; Infant, Newborn; Infant, Small for Gestational Age; Pregnancy; Pregnancy Trimester, First; Premature Birth; Risk Factors
PubMed: 35778680
DOI: 10.1186/s12887-022-03426-8 -
Ultrasound in Obstetrics & Gynecology :... Sep 2021
Topics: Crown-Rump Length; Female; Gestational Age; Humans; Pregnancy; Pregnancy Trimester, First; Ultrasonography; Ultrasonography, Prenatal
PubMed: 34131973
DOI: 10.1002/uog.23692 -
Journal of Perinatal Medicine Oct 2016In the current review study, we present recent data regarding the importance of intertwin estimated fetal weight (EFW) and crown rump length (CRL) discordance for the... (Review)
Review
AIM
In the current review study, we present recent data regarding the importance of intertwin estimated fetal weight (EFW) and crown rump length (CRL) discordance for the prediction of adverse perinatal outcome both in monochorionic and in dichorionic diamniotic gestations.
RESULTS
Twins with significant weight disparity are associated with higher rates of perinatal morbidity and mortality, regardless of gestational age at delivery. However, there is no agreement regarding as to the cut off value above which the perinatal outcome is unfavorably affected and the threshold range from 10 to 30%. On the other hand, CRL discrepancy has proved to be a weak predictor of adverse outcomes, such as fetal or neonatal death in fetuses without chromosomal and structural abnormalities. In clinical practice, decisions about obstetric surveillance of discordant twin gestations, frequency of fetal sonographic monitoring and time of delivery are usually based on amniotic fluid volume and Doppler assessments on a weekly basis.
CONCLUSION
Significant EFW discordance leads to adverse perinatal outcome, although the cut-off value has not yet been estimated. CRL discrepancy is not correlated well with adverse perinatal outcome. However, increased monitoring of women with EFW and CRL discrepancy is suggested.
Topics: Chorion; Crown-Rump Length; Diseases in Twins; Female; Fetal Growth Retardation; Fetal Weight; Humans; Infant, Newborn; Placenta; Pregnancy; Pregnancy Outcome; Pregnancy, Twin; Ultrasonography, Prenatal
PubMed: 26540215
DOI: 10.1515/jpm-2015-0242 -
Journal of Clinical Medicine Apr 2024Neonates born from thawed embryo transfers tend to have a significantly higher birthweight compared to those from fresh embryo transfers. The aim of this study was to...
Neonates born from thawed embryo transfers tend to have a significantly higher birthweight compared to those from fresh embryo transfers. The aim of this study was to compare the crown-rump length (CRL) between thawed and fresh embryos to investigate the potential causes of different growth patterns between them. This was a retrospective study (July 2010-December 2023) conducted at the Third Department of Obstetrics and Gynecology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece. In total, 3082 assisted reproductive technology (ART) pregnancies (4044 embryos) underwent a routine scan at 11-13 gestational weeks and were included in the study. Maternal age, the type of embryo transfer (thawed vs. fresh, donor vs. their own oocytes), CRL, twin and singleton gestations were analyzed. The mean maternal age in thawed was significantly higher than in fresh embryos (39.8 vs. 35.8 years, -value < 0.001). The mean CRL z-score was significantly higher in thawed compared to fresh embryo transfers (0.309 vs. 0.199, -value < 0.001). A subgroup analysis on singleton gestations showed that the mean CRL z-score was higher in thawed blastocysts compared to fresh (0.327 vs. 0.215, -value < 0.001). Accordingly, an analysis on twins revealed that the mean CRL z-score was higher in thawed blastocysts (0.285 vs. 0.184, -value: 0.015) and in oocytes' recipients compared to own oocytes' cases (0.431 vs. 0.191, -value: 0.002). The difference in CRL measurements between thawed and fresh embryos may be a first indication of the subsequent difference in sonographically estimated fetal weight and birthweight. This finding highlights the need for additional research into the underlying causes, including maternal factors and the culture media used.
PubMed: 38731104
DOI: 10.3390/jcm13092575 -
Ultrasound in Obstetrics & Gynecology :... Sep 2021To examine the impact of first-trimester crown-rump length (CRL) measurement error on the interpretation of estimated fetal weight (EFW) and classification of fetuses as...
OBJECTIVE
To examine the impact of first-trimester crown-rump length (CRL) measurement error on the interpretation of estimated fetal weight (EFW) and classification of fetuses as small-, large- or appropriate-for-gestational age on subsequent growth scans.
METHODS
We examined the effects of errors of ± 2, ± 3 and ± 4 mm in the measurement of fetal CRL on percentiles of EFW at 20, 32 and 36 weeks' gestation and classification as small-, large- or appropriate-for-gestational age. Published data on CRL measurement error were used to determine variation present in practice.
RESULTS
A measurement error of -2 mm in first-trimester CRL shifts an EFW on the 10 percentile at the 20-week scan to around the 20 percentile, and the effect of a CRL measurement error of + 2 mm would shift an EFW on the 10 percentile to around the 5 percentile. At 32 weeks, a first-trimester CRL measurement error would shift an EFW on the 10 percentile to the 7 (+ 2 mm) or 14 (-2 mm) percentile; at 36 weeks, the EFW would shift from the 10 percentile to the 8 (+ 2 mm) or 12 (-2 mm) percentile. Published data suggest that measurement errors of 2 mm or more are common in practice.
CONCLUSION
Because of the widespread and potentially severe consequences of CRL measurement errors as small as 2 mm on clinical assessment, patient management and research results, there is a need to increase awareness of the impact of CRL measurement error and to reduce measurement error variation through standardization and quality control. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Topics: Adult; Crown-Rump Length; Diagnostic Errors; Female; Fetal Development; Fetal Growth Retardation; Fetal Weight; Fetus; Gestational Age; Humans; Infant, Newborn; Infant, Small for Gestational Age; Pregnancy; Pregnancy Trimesters; Reference Values; Ultrasonography, Prenatal
PubMed: 33998101
DOI: 10.1002/uog.23690