Sonar Measurement of Fetal Crown-Rump Length as Means of Assessing Maturity in First Trimester of Pregnancy

Robinson, Hugh P.

doi:10.1136/bmj.4.5883.28

Cited by 364 publications

(127 citation statements)

References 9 publications

Supporting

Mentioning

121

Contrasting

Unclassified

Order By: Relevance

“…The series so obtained was made up of 238 neonates (123 females, 115 males) born at term after low-risk, uncomplicated pregnancy. Gestational age was estimated from the last menstrual period and was confirmed by an early ultrasound examination carried out within wk 12, on the basis of the CRL (10). When the difference between the two estimates exceeded 7 d, the pregnancy was excluded from the series.…”

Section: Methodsmentioning

confidence: 99%

Differences in Size at Birth Are Determined by Differences in Growth Velocity during Early Prenatal Life

et al. 2005

View full text Add to dashboard Cite

Physiologic interindividual differences in neonatal size are traditionally thought of as determined by differences in fetal growth occurring only in the second half of pregnancy. Whether possible differences in early intrauterine growth velocity are the effect of random growth fluctuations or may affect size at birth is still debated. This article aims at evaluating to what extent differences in neonatal size are accounted for by differences in fetal growth velocity. We analyzed the fetal growth of 130 healthy singletons for whom head (HC) and abdomen (AC) circumferences and femur diaphysis length (FDL) longitudinal profiles were available, together with the measures of weight (BW), length (BL), and head circumference (BHC) at birth. Individual profiles were fitted with ad-hoc models. Neonatal traits were transformed into standard deviation scores (SDS). Neonates in the upper third of BW-SDS distribution (3618 Ϯ 43 g, mean Ϯ SEM) had, at 22 wk of gestational age, AC growth velocity higher by 0.55 Ϯ 0.10 mm/wk than those in the lower third (2902 Ϯ 36 g). Neonates in the upper third of BL-SDS distribution (51.7 Ϯ 0.21 cm) had, at 20 wk, FDL growth velocity higher by 0.11 Ϯ 0.05 mm/wk than those in the lower third (48.2 Ϯ 0.18 cm). Neonates in the upper third of BHC-SDS distribution (35.7 Ϯ 0.13 cm) had, at 18 wk, HC growth velocity higher by 0.57 Ϯ 0.20 mm/wk than those in the lower third (33.3 Ϯ 0.11 cm). The differences in growth velocity remain constant throughout the second and third trimester for AC, and tend to vanish in the third trimester for HC and FDL. The differences in fetal growth velocity, which in our study were observed as early as mo 4, suggest that the genetic component plays an important role in fetal growth and is precociously expressed. Abbreviations AC, abdomen circumference BHC, head circumference at birth BL, birth length BPD, biparietal diameter BW, birth weight CRL, crown-rump length FDL, femur diaphysis length GA, gestational age HC, head circumference SDS, standard deviation score Physiologic interindividual differences in neonatal size are traditionally thought of as determined by differences in fetal growth occurring only in the second half of pregnancy (1,2). Actually, the assessment of GA derived from the measurement of CRL during the late first trimester (3), as well as of BPD, HC, and FDL during the second trimester (4), rests on the assumption that in this period fetuses of the same size have nearly the same GA. Empirical evidence against the above assumption is unlikely to be provided, inasmuch as differences in size in the first half of pregnancy are expected to be small, growth being a cumulative process, and measurement error being relatively large with respect to size. On the other hand, negligible interindividual differences in size at a given gestational age do not necessarily imply negligible differences in growth velocity, which may be estimated only by means of longitudinal studies.Longitudinal studies presently available, although based on few subjects and limited to t...

show abstract

Section: Methodsmentioning

confidence: 99%

Differences in Size at Birth Are Determined by Differences in Growth Velocity during Early Prenatal Life

et al. 2005

View full text Add to dashboard Cite

show abstract

“…After pregnancy termination for psychosocial reasons (interrupted pregnancies) or missed abortions, tissue samples (Table 1) were collected in Medium 199 supplemented with penicillin/ streptomycin (Gibco, Invitrogen, Carlsbad, CA), washed immediately in PBS, and snap-frozen. The gestational age was calculated from the last menstrual period and corrected after endovaginal ultrasound examination using published charts (27). The study was approved by the institutional review board and ethical committee of the Medical University of Graz and informed consent of the patients.…”

Section: Methodsmentioning

confidence: 99%

MT1-MMP Expression in First-Trimester Placental Tissue Is Upregulated in Type 1 Diabetes as a Result of Elevated Insulin and Tumor Necrosis Factor-α Levels

et al. 2008

View full text Add to dashboard Cite

OBJECTIVE-In pregestational diabetes, the placenta at term of gestation is characterized by various structural and functional changes. Whether similar alterations occur in the first trimester has remained elusive. Placental development requires proper trophoblast invasion and tissue remodeling, processes involving matrix metalloproteinases (MMPs) of which the membraneanchored members (MT-MMPs) such as MT1-MMPs are key players. Here, we hypothesize a dysregulation of placental MT1-MMP in the first trimester of type 1 diabetic pregnancies induced by the diabetic environment. RESEARCH DESIGN AND METHODS-MT1-MMP proteinwas measured in first-trimester placentas of healthy (n ϭ 13) and type 1 diabetic (n ϭ 13) women. To identify potential regulators, first-trimester trophoblasts were cultured under hyperglycemia and various insulin, IGF-I, IGF-II, and tumor necrosis factor-␣ (TNF-␣) concentrations in presence or absence of signaling pathway inhibitors. RESULTS-MT1-MMPwas strongly expressed in first-trimester trophoblasts. In type 1 diabetes, placental pro-MT1-MMP was upregulated, whereas active MT1-MMP expression was only increased in late first trimester. In isolated primary trophoblasts, insulin, IGF-I, IGF-II, and TNF-␣ upregulated MT1-MMP expression, whereas glucose had no effect. The insulin effect was dependent on phosphatidylinositol 3-kinase, the IGF-I effect on mitogen-activated protein kinase, and the IGF-II effect on both.CONCLUSIONS-This is the first study reporting alterations in the first-trimester placenta in type 1 diabetes. The upregulated MT1-MMP expression in type 1 diabetes may be the result of higher maternal insulin and TNF-␣ levels. We speculate that the elevated MT1-MMP will affect placental development and may thus contribute to long-term structural alterations in the placenta in pregestational diabetes. Diabetes 57:150-157, 2008

show abstract

“…First trimester biometric measurements such as the crown-rump length (CRL) have been proven to perform better than LMP for dating pregnancies. Several formulas, derived from simple regression analysis have been developed for dating pregnancies (Sladkevicius et al [2005]), the most widely used being the formula initially suggested by Robinson [1973]. Denoting by X the interval between LMP and true onset of pregnancy, and by Y the interval between LMP and ultrasound estimate, the purpose of this study is to estimate the density f of X.…”

Section: Introductionmentioning

confidence: 99%

Deconvolution Estimation of Onset of Pregnancy with Replicate Observations

Comte

Samson

Stirnemann

2013

Scandinavian J Statistics

View full text Add to dashboard Cite

To cite this version:Fabienne Comte, Adeline Samson, Julien Stirnemann. Deconvolution estimation of onset of pregnancy with replicate observations. Scandinavian Journal of Statistics, Wiley, 2014, 41 (2) Abstract. In general, the precise date of onset of pregnancy is unknown and may only be estimated from ultrasound biometric measurements of the embryo. We want to estimate the density of the random variables corresponding to the interval between last menstrual period and true onset of pregnancy. The observations correspond to the variables of interest up to an additive noise. We suggest an estimation procedure based on deconvolution. It requires the knowledge of the density of the noise which is not available. But we have at our disposal another specific sample with replicate observations for twin pregnancies. This allows both to estimate the noise density and to improve the deconvolution step. Convergence rates of the final estimator are studied and compared to other settings. Our estimator involves a cut-off parameter for which we propose a cross-validation type procedure. Lastly, we estimate the target density in spontaneous pregnancies with an estimation of the noise obtained from replicate observations in twin pregnancies.En général, la date précise de début de grossesse est inconnue et est seulement estiméeà partir de mesures de l'embryon par ultrasons. Nous voulons estimer la densité de la variable aléatoire correspondantà l'intervalle entre la date des dernières règles et le début réel de la grossesse. Les observations dont nous disposons correspondent aux variables d'intérêt mesurées avec un bruit additif. Nous proposons une procédure d'estimation basée sur des techniques de déconvolution. Cela requiert la connaissance de la loi du bruit mais elle n'est pas disponible. En revanche, nous disposons d'unéchantillon d'observations répétées obtenuesà partir de grossesses gémellaires. Cela nous permetà la fois d'estimer la loi du bruit et d'améliorer la procédure de déconvolution. La vitesse de convergence de l'estimateur résultant estétudiée et comparéeà celles obtenues dans d'autres contextes. Notre estimateur contient un paramètre de troncature pour lequel nous proposons une sélection par validation croisée. Pour finir, nousétudions notre estimateur en simulation puis nous l'appliquons pour estimer la densité visée sur notré echantillon de grossesses spontanées avec estimation du bruit via des données répétées obtenues sur unéchantillon de grossesses gémellaires.

show abstract

Sonar Measurement of Fetal Crown-Rump Length as Means of Assessing Maturity in First Trimester of Pregnancy

Cited by 364 publications

References 9 publications

Differences in Size at Birth Are Determined by Differences in Growth Velocity during Early Prenatal Life

Differences in Size at Birth Are Determined by Differences in Growth Velocity during Early Prenatal Life

MT1-MMP Expression in First-Trimester Placental Tissue Is Upregulated in Type 1 Diabetes as a Result of Elevated Insulin and Tumor Necrosis Factor-α Levels

Deconvolution Estimation of Onset of Pregnancy with Replicate Observations

Contact Info

Product

Resources

About