L. J. Salomon

International standards for fetal growth based on serial ultrasound measurements: the Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project

BACKGROUND In 2006, WHO produced international growth standards for infants and children up to age 5 years on the basis of recommendations from a WHO expert committee. Using the same methods and conceptual approach, the Fetal Growth Longitudinal Study (FGLS), part of the INTERGROWTH-21(st) Project, aimed to develop international growth and size standards for fetuses. METHODS The multicentre, population-based FGLS assessed fetal growth in geographically defined urban populations in eight countries, in which most of the health and nutritional needs of mothers were met and adequate antenatal care was provided. We used ultrasound to take fetal anthropometric measurements prospectively from 14 weeks and 0 days of gestation until birth in a cohort of women with adequate health and nutritional status who were at low risk of intrauterine growth restriction. All women had a reliable estimate of gestational age confirmed by ultrasound measurement of fetal crown-rump length in the first trimester. The five primary ultrasound measures of fetal growth--head circumference, biparietal diameter, occipitofrontal diameter, abdominal circumference, and femur length--were obtained every 5 weeks (within 1 week either side) from 14 weeks to 42 weeks of gestation. The best fitting curves for the five measures were selected using second-degree fractional polynomials and further modelled in a multilevel framework to account for the longitudinal design of the study. FINDINGS We screened 13,108 women commencing antenatal care at less than 14 weeks and 0 days of gestation, of whom 4607 (35%) were eligible. 4321 (94%) eligible women had pregnancies without major complications and delivered live singletons without congenital malformations (the analysis population). We documented very low maternal and perinatal mortality and morbidity, confirming that the participants were at low risk of adverse outcomes. For each of the five fetal growth measures, the mean differences between the observed and smoothed centiles for the 3rd, 50th, and 97th centiles, respectively, were small: 2·25 mm (SD 3·0), 0·02 mm (3·0), and -2·69 mm (3·2) for head circumference; 0·83 mm (0·9), -0·05 mm (0·8), and -0·84 mm (1·0) for biparietal diameter; 0·63 mm (1·2), 0·04 mm (1·1), and -1·05 mm (1·3) for occipitofrontal diameter; 2·99 mm (3·1), 0·25 mm (3·2), and -4·22 mm (3·7) for abdominal circumference; and 0·62 mm (0·8), 0·03 mm (0·8), and -0·65 mm (0·8) for femur length. We calculated the 3rd, 5th 10th, 50th, 90th, 95th and 97th centile curves according to gestational age for these ultrasound measures, representing the international standards for fetal growth. INTERPRETATION We recommend these international fetal growth standards for the clinical interpretation of routinely taken ultrasound measurements and for comparisons across populations. FUNDING Bill & Melinda Gates Foundation.

ISUOG practice guidelines: performance of first-trimester fetal ultrasound scan.

The International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) is a scientific organization that encourages safe clinical practice and high-quality teaching and research related to diagnostic imaging in women’s healthcare. The ISUOG Clinical Standards Committee (CSC) has a remit to develop Practice Guidelines and Consensus Statements that provide healthcare practitioners with a consensus-based approach for diagnostic imaging. They are intended to reflect what is considered by ISUOG to be the best practice at the time at which they are issued. Although ISUOG has made every effort to ensure that Guidelines are accurate when issued, neither the Society nor any of its employees or members accept any liability for the consequences of any inaccurate or misleading data, opinions or statements issued by the CSC. The ISUOG CSC documents are not intended to establish a legal standard of care because interpretation of the evidence that underpins the Guidelines may be influenced by individual circumstances, local protocol and available resources. Approved Guidelines can be distributed freely with the permission of ISUOG (info@isuog.org).

French fetal biometry: reference equations and comparison with other charts

To construct new reference charts and equations for fetal biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL), using a large sample of fetuses examined at 15–40 weeks in France, and to compare them with previous references.

Cytomegalovirus‐related fetal brain lesions: comparison between targeted ultrasound examination and magnetic resonance imaging

To evaluate the relative contributions to the diagnosis of fetal brain abnormalities of targeted ultrasound examination and magnetic resonance imaging (MRI) in fetuses infected with cytomegalovirus (CMV).

The prognostic value of ultrasound abnormalities and biological parameters in blood of fetuses infected with cytomegalovirus

Objective  To evaluate the prognostic value of ultrasound abnormalities and of selected biological parameters in blood of fetuses infected with cytomegalovirus (CMV).

Long-term developmental follow-up of infants who participated in a randomized clinical trial of amniocentesis vs laser photocoagulation for the treatment of twin-to-twin transfusion syndrome

OBJECTIVE We sought to assess long-term neurodevelopment of children who were treated prenatally as part of the Eurofoetus randomized controlled trial. STUDY DESIGN The study population was composed of 128 cases of twin-to-twin transfusion syndrome (TTTS) included and followed up in France. Survivors were evaluated by standardized neurological examination and by Ages and Stages Questionnaires (ASQ). Primary outcome was a composite of death and major neurological impairment. RESULTS A total of 120 children (47%) were alive at the age of 6 months and were followed up to the age of 6 years. At the time of diagnosis, only treatment and Quintero stage were predictors of a poor outcome (hazard ratio, 0.61; 95% confidence interval, 0.41-0.90; P = .01 and hazard ratio, 3.23; 95% confidence interval, 2.19-4.76; P < .001, respectively). Children treated by fetoscopic selective laser coagulation (FSLC) had higher ASQ scores at the end of follow-up (P = .04). CONCLUSION FSLC was significantly associated with a reduction of the risk of death or long-term major neurological impairment at the time of diagnosis and treatment.

Estimation of fetal weight: reference range at 20–36 weeks' gestation and comparison with actual birth‐weight reference range

To formulate reference charts and equations for estimated fetal weight (EFW) from a large sample of fetuses and to compare these charts and equations with those obtained for birth weight during the same study period and in the same single health authority.

Twin pregnancies: guidelines for clinical practice from the French College of Gynaecologists and Obstetricians (CNGOF)

The rate of twin deliveries in 2008 was 15.6 per 1000 in France, an increase of approximately 80% since the beginning of the 1970s. It is recommended that chorionicity be diagnosed as early as possible in twin pregnancies (Professional Consensus). The most relevant signs (close to 100%) are the number of gestational sacs between 7 and 10 weeks and the presence of a lambda sign between 11 and 14 weeks (Professional Consensus). In twin pregnancies, nuchal translucency is the best parameter for evaluating the risk of aneuploidy (Level B). The routine use of serum markers during the first or the second trimester is not recommended (Professional Consensus). In the case of a choice about sampling methods, chorionic villus sampling is recommended over amniocentesis (Professional Consensus). Monthly follow-up by a gynaecologist-obstetrician in an appropriate facility is recommended for dichorionic pregnancies (Professional Consensus). A monthly ultrasound examination including an estimation of fetal weight and umbilical artery Doppler is recommended (Professional Consensus). It is recommended to plan delivery of uncomplicated dichorionic diamniotic twin pregnancies from 38 weeks and before 40 weeks (Level C). Monthly prenatal consultations and twice-monthly ultrasound are recommended for monochorionic twins (Professional Consensus). It is reasonable to consider delivery from 36 weeks but before 38 weeks+6 days, with intensified monitoring during that time (Professional Consensus). Prenatal care of monochorionic pregnancies must be provided by a physician working in close collaboration with a facility experienced in the management of this type of pregnancy and its complications (Professional Consensus). The increased risk of maternal complications and the high rate of medical interventions justify the immediate and permanent availability of a gynaecologist-obstetrician with experience in the vaginal delivery of twins (Professional Consensus). It is recommended that the maternity ward where delivery takes place have rapid access to blood products (Professional Consensus). Only obstetric history (history of preterm delivery) (Level C) and transvaginal ultrasound measurement of cervical length (Level B) are predictive factors for preterm delivery. No study has shown that the identification by transvaginal sonography (TVS) of a group at risk of preterm delivery makes it possible to reduce the frequency of such deliveries in asymptomatic patients carrying twins (Professional Consensus). It is important to recognize signs of TTTS early to improve the management of these pregnancies (Professional Consensus). Treatment and counseling must be performed in a center that can offer fetoscopic laser coagulation of placental anastomoses (Professional Consensus). This laser treatment is the first-line treatment (Level B). In the absence of complications after laser treatment, planned delivery is recommended from 34 weeks and no later than 37 weeks (Professional Consensus). For delivery, it is desirable for women with a twin pregnancy to have epidural analgesia (Professional Consensus). The studies about the question of mode of delivery have methodological limitations and lack of power. Active management of the delivery of the second twin is recommended to reduce the interval between the births of the two twins (Level C). In the case of non-cephalic presentation, total breech extraction, preceded by internal version manoeuvres if the twins position is transverse, is associated with the lowest cesarean rates for second twins (Level C). In the case of high and not yet engaged cephalic presentation and if the team is appropriately trained, version by internal manoeuvres followed by total breech extraction is to be preferred to a combination of resumption of pushing, oxytocin perfusion, and artificial rupture of the membranes, because the former strategy appears to be associated with fewer cesareans for the second twin (Level C).

The impact of choice of reference charts and equations on the assessment of fetal biometry

The assessment of fetal biometry is usually based on the comparison of measured values with predicted values derived from reference charts or equations in a normal population. This study was undertaken to assess the impact of the choice of reference charts and to develop a Z‐score‐based tool that could help sonographers to choose the reference charts that best fit their practice.

Growth discrepancy in twins in the first trimester of pregnancy

The prevalence and significance of intertwin growth discrepancy in the first trimester of pregnancy are controversial. The aim of this study was to refine the incidence and outcome of this discrepancy in relation to dating of the pregnancy and other biometric parameters.