Outcome of fetuses with short femur length detected at second-trimester anomaly scan: a national survey

Pathogenic copy number variations are associated with foetal short femur length in a tertiary referral centre study

Shortened foetal femur length (FL) is a common abnormal phenotype that often causes anxiety in pregnant women, and standard clinical treatments remain unavailable. We investigated the clinical characteristics, genetic aetiology and obstetric pregnancy outcomes of foetuses with short FL and provided a reference for perinatal management of such cases. Chromosomal microarray analysis was used to analyse the copy number variations (CNV) in short FL foetuses. Of the 218 foetuses with short FL, 33 foetuses exhibited abnormal CNVs, including 19 with pathogenic CNVs and 14 with variations of uncertain clinical significance. Of the 19 foetuses with pathogenic CNVs, four had aneuploidy, 14 had deletions/duplications, and one had pathogenic uniparental diploidy. The 7q11.23 microdeletion was detected in three foetuses. The severity of short FL was not associated with the rate of pathogenic CNVs. The duration of short FL for the intrauterine ultrasound phenotype in foetuses carrying a pathogenic CNV was independent of the gestational age. Further, maternal age was not associated with the incidence of foetal pathogenic CNVs. Adverse pregnancy outcomes occurred in 77 cases, including termination of pregnancy in 63 cases, postnatal dwarfed foetuses with intellectual disability in 11 cases, and three deaths within 3 months of birth. Pathogenic CNVs closely related to foetal short FL were identified, among which the 7q11.23 microdeletion was highly associated with short FL development. This study provides a reference for the perinatal management of foetuses with short FL.

Role of Sonographic Second Trimester Soft Markers in the Era of Cell-Free DNA Screening Options: A Review

Soft markers are sonographic structural, nonspecific signs with little pathological significance, often transient, usually considered as normal variants. However, they may also be associated with chromosomal abnormalities. The most widely examined soft markers include absent or hypoplastic nasal bone (NB), intracardiac echogenic focus (IEF), ventriculomegaly (VM), thickened nuchal fold (NF), choroid plexus cyst (CPC), echogenic bowel, short long bones, and urinary tract dilation (UTD). Although the use of noninvasive prenatal testing (NIPT) has been spreading quickly in maternal–fetal medicine, it is not a diagnostic test and it still remains unavailable or cost-prohibitive for most of the population in many countries. After normal screening test results in the first trimester, there is no uniform consensus regarding the clinical significance of isolated soft markers for aneuploidy. Nowadays, the search for soft markers in an ultrasound is still part of clinical evaluation, and the interpretation of these findings is often a matter of debate. In the present review, we summarize the recent literature about the role of soft markers in the era of NIPT and propose an overview of the different clinical guidelines.

Diagnostic distribution and postnatal evaluation of prenatally detected short femur: A single center experience

Genetic skeletal disorders (GSDs) are clinically and etiologically heterogeneous group of disorders caused by abnormal growth and development of bone and/or cartilaginous tissues. Timely and accurate diagnosis is essential for prevention of significant comorbidities. In this study demographic, parental, prenatal and natal characteristics, and postnatal diagnostic distribution along with follow-up processes of 104 individuals with the finding of "short femur" detected in routine prenatal ultrasonography were evaluated. Of 104 patients, 19 (18.2%) were medically terminated, 12 (11.6%) were deceased during follow-up and 73 (70.2%) were still under follow-up. Diagnostic distribution of 104 patients was as follows: 77 (74%) had GSD, eight (7.7%) had chromosomal disorder, seven (6.7%) were completely normal, and 12 (11.5%) had no definite diagnosis. Long-term follow up evaluation contributed to clinical diagnosis in four patients. When grouped according to Nosology and Classification of GSDs: 2019 revision, the most frequent (n = 30, 38.5%) group was "FGFR3 chondrodysplasia group", followed by "Type 2 collagen group" (n = 7, 9%), and "Osteogenesis imperfecta and decreased bone density group" (n = 5, 6.4%). The finding of prenatally detected "short femur" represents a group of diverse diagnosis with heterogeneous etiology. GSDs are the most common etiology among fetuses with short extremity.

Clinical significance of soft markers in second trimesterr ultrasonography for pregnant Korean women: a multicenter study and literature review

Objective

To evaluate the clinical significance of soft markers for aneuploidy screening in Korean women.

Methods

We retrospectively reviewed the medical records of 5,428 singleton pregnant women who underwent sonography during the second trimester at seven institutions in South Korea. We evaluated the prevalence of the following soft markers: intracardiac echogenic focus, choroid plexus cysts, pyelectasis, echogenic bowel, and mild ventriculomegaly. We developed best-fitted regression equations for the fetal femur and humerus length using our data and defined a short femur and humerus as both long bones below the fifth centile. The results of genetic testing and postnatal outcomes were investigated in patients who had been diagnosed with aforementioned soft markers.

Results

The median maternal age of our study population was 33 years, and the median gestational age at the time of ultrasonographic examination was 21 weeks. We detected soft markers in 10.0% (n=540) of fetuses: 9.3% (n=504) were isolated cases and 0.7% (n=36) of cases had two or more markers. We identified only two aneuploides (trisomy 18, 46,XX,t[8;10][q22.1;p13]), of which one was clinically significant. We presented the neonatal outcomes of the fetuses with the respective soft markers. Preterm delivery, low birth weight, and small-for-gestational-age (SGA) were significantly more common in women with a shortened fetal femur (P<0.001, all). However, the presence of a shortened fetal humerus was not associated with those outcomes excluding SGA.

Conclusion

Soft markers in second-trimester ultrasonography have limited use in screening for fetal aneuploidy in Korean women. However, these markers can be used as a screening tool for adverse outcomes other than chromosomal abnormality.

The femur too short? 1373 fetuses with short femur during second-trimester screening

Purpose

A short fetal femur in prenatal diagnosis might be an indicator for intrauterine growth retardation (IUGR), a genetically determined small child (SGA) with or without associated fetal malformations and/or an adverse fetal outcome.

Methods

1373 singleton pregnancies with a femoral length < 5th percentile detected between 1999 and 2015 during second-trimester screening in a tertiary prenatal diagnostic center were subjected to a descriptive retrospective analysis with regard to fetal characteristics as well as pregnancy outcome.

Results

685 (49.9%) fetuses presented an isolated short femur, while 688 (50.1%) showed additional abnormalities. 293 (42.6%) of those were SGA babies without any malformation, while 395 (57.4%) had one or more severe anomaly of the following organ systems: 157 (11.5%) cardiovascular, 101 (7.4%) musculoskeletal, 82 (6.0%) urogenital, 72 (5.2%) cerebrocephalic, 50 (3.6%) gastrointestinal, and 5 (0.4%) thoracic. 75 (5.5%) of the fetuses showed chromosomal aberrations of which Trisomy 13, 18 and 21 were found in 2, 13 and 27 of the cases, respectively. Fetuses with associated malformations had a significantly lower live birth rate than those without (64.2% vs. 98.1%, p < 0.001); in addition, a higher rate of preterm births 36.6% vs. 11.3%, p < 0.001) and SGA babies (51.4% vs. 30.4%, p < 0.001) were observed in the first collective.

Conclusion

Diagnosis of a short fetal femur should lead to an extended organ screening; in the case of associated abnormalities, additional genetic testing has to be offered, as well as intensified pregnancy monitoring in pregnancies at risk for IUGR and/or preterm birth.

Crown-rump length measurement error: impact on assessment of growth

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^th percentile at the 20-week scan to around the 20^th percentile, and the effect of a CRL measurement error of + 2 mm would shift an EFW on the 10^th percentile to around the 5^th percentile. At 32 weeks, a first-trimester CRL measurement error would shift an EFW on the 10^th percentile to the 7^th (+ 2 mm) or 14^th (-2 mm) percentile; at 36 weeks, the EFW would shift from the 10^th percentile to the 8^th (+ 2 mm) or 12^th (-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.

Prenatal diagnosis of genetic aberrations in fetuses with short femur detected by ultrasound: A prospective cohort study

OBJECTIVES

To investigate the genetic aberrations in fetuses with short femur and explore the relationships with respect to degree of femoral shortening and the initial diagnostic gestational age GA.

METHODS

Singleton pregnancies with fetal short femur who consented to amniocentesis and to single nucleotide polymorphism (SNP) array and Sanger sequencing for G380R mutations in FGFR3 gene were enrolled in this 5-year period prospective study. Clinical follow-up assessments were performed after birth.

RESULTS

Of a total of 161 fetuses, the prevalence of genetic aberrations was 16.2% (26/161), comprised of 65.4% (17/26) with chromosomal abnormalities and 34.6% (9/26) with G380R mutations. All fetuses with chromosomal abnormalities had FL 2-4SDs below GA. Fewer chromosomal abnormalities were detected in fetuses with short femurs presenting in the third trimester. Significantly more FGFR3 mutations were detected in fetuses with FL below -4SDs. All fetuses with FL 2-4SDs below GA diagnosed as achondroplasia were between 22 and 24 gestational weeks, and all of those diagnosed in third trimester had FL below -4SDs.

CONCLUSION

In this small cohort study, we demonstrated that different degrees of femur shortness may be attributed to different genetic aberrations. SNP array should be regarded as the first-tier test for fetuses with FL 2-4SDs below GA. The prognoses for fetuses with FL 2-4SDs below GA was significantly better than those with FL below 4SDs.

Prenatal diagnosis of fetal skeletal dysplasia using 3-dimensional computed tomography: a prospective study

Background

Fetal skeletal dysplasia (FSD) comprises a complex group of systemic bone and cartilage disorders. Many FSD phenotypes have indistinct definitions, making definitive prenatal diagnosis difficult. The condition is typically diagnosed using sonography; however, three-dimensional computed tomography (3D-CT) also aids in making a prenatal diagnosis. This study aimed to examine the efficacy of 3D-CT in the prenatal diagnosis of FSD by comparing the diagnostic accuracy of fetal sonography and 3D-CT.

Methods

On suspicion of FSD based on ultrasound examination, we performed 3D-CT prenatally to obtain detailed skeletal information on FSD. To minimize exposure of the fetuses to radiation without compromising image quality, we used predetermined 3D-CT settings for volume acquisition.

Results

Nineteen fetuses were suspected of having skeletal dysplasia based on ultrasonography findings. Of these, 17 were diagnosed with FSD using 3D-CT. All 17 fetuses diagnosed with FSD prenatally were confirmed postnatally to have the condition. The postnatal diagnosis (campomelic dysplasia) differed from the prenatal diagnosis (osteogenesis imperfecta) in only one infant. Sixteen cases (94.1%) were diagnosed both prenatally and postnatally with FSD. Five infants had lethal skeletal dysplasia; one died in utero, and four died as neonates. We determined the appropriate delivery method for each infant based on the prenatal diagnosis.

Conclusions

3D-CT is a valuable tool for augmenting ultrasound examinations in the diagnosis of FSD. While improving the diagnostic tool of sonography is essential in cases of suspected FSD, 3D-CT imaging is indispensable for diagnosis and classification, enabling better planning for resuscitation of the infant after birth.

Trial registration

University Hospital Medical Information Network (UMIN) Center trial registration number is UMIN000034744. Registered 1 October, 2018 – Retrospectively registered.

Obstetrical and perinatal outcomes in fetuses with early versus late sonographic diagnosis of short femur length: A single-center, prospective, cohort study

OBJECTIVES

The aim of this study was to evaluate obstetrical and perinatal outcomes in fetuses with short femur length diagnosed before or after 24 weeks of gestation.

STUDY DESIGN

This was a prospective cohort study on singleton pregnancies with a diagnosis of fetal femur < 5 centile. Included patients were divided into two groups: patients with a first diagnosis of femur length < 5th percentile at 14-24 weeks (group A) and those with the first diagnosis made at > 24 weeks (group B).

RESULTS

147 patients were included for the analysis. Group A and group B included 66 (44.9%) and 81 (55.1%) cases. Abnormal fetal karyotype and skeletal dysplasia rates were significantly higher (27.3% vs 3.7%,P < 0.001 and 19.7% vs 3.7%, P = 0.002) in group A. Women in group B had a higher incidence of small for gestational age and intrauterine growth restriction (7.6% vs 24.7%, P = 0.007 and 19.7% vs 44.4%, P = 0.002). There was a significant higher incidence of live births in group B (34.9% vs 97.5%, P < 0.001), while the rate of termination of pregnancy was increased in group A (56.1% vs 1.2%, P < 0.001). No significant difference was found in perinatal outcomes of live births, when comparing group A and B.

CONCLUSIONS

The incidence of abnormal karyotype and skeletal dysplasia is higher when short femur length diagnosed earlier in gestation, while the incidence of small for gestational age, intrauterine growth restriction and the rate of live births are significantly increased when short femur length is diagnosed later during pregnancy.

Chromosomal microarray should be performed for cases of fetal short long bones detected prenatally

PURPOSE

To investigate the prevalence of pathogenic and likely-pathogenic variants detected by chromosomal microarray analysis (CMA), among pregnancies with fetal short long bones diagnosed by ultrasound.

METHODS

The study cohort was based on cases of chromosomal microarray analyses performed nationwide for the indication of short long bones.

RESULTS

CMA was performed in 66 cases of short long bones. There were 4 cases with a pathogenic/likely pathogenic result (6%). The rate of chromosomal abnormalities was significantly higher compared to the background risk for copy number variations (CNVs) in pregnancies with no sonographic anomalies (P < 0.001). The yield of CMA in our cohort was significantly higher for both isolated and non-isolated cases, for cases in which the lowest estimated bone length percentile was above the 3rd percentile (below 5th percentile), and for cases diagnosed with short long bones after 22 weeks but not for cases diagnosed after 24 weeks.

CONCLUSION

The yield of CMA in cases with short long bones (both isolated and non-isolated) is significantly higher than the background risk for chromosomal anomalies in pregnancies with no sonographic anomalies. This suggests that CMA should be offered in pregnancies with a diagnosis of fetal short long bones.

Long-term follow-up on fetuses with isolated sonographic finding of short long bones: a cohort study

PURPOSE

To evaluate the long-term outcome of fetuses with a diagnosis of isolated short long bones.

METHODS

A retrospective review was conducted of all cases diagnosed with short long bones above 20 weeks of gestation during 2010-2017 in a single tertiary center. Exclusion criteria included abnormal sonographic findings other than short long bones, suspected genetic syndromes, chromosomal abnormalities, and abnormal Doppler flow indices. Follow-up was carried out by telephone questionnaire.

RESULTS

During the study period, 54 (24.32%) women met inclusion criteria. Mean gestational age at delivery was 38.05 years (± 2.42 SD). Mean birth weight was 12-19th percentile according to the local fetal growth charts [2645 g (± 684 SD) 95% CI 2173-2980]. Median time for post-natal follow-up was 9.3 years (IQR 6.6-10.75). Growth below the 10th percentile was demonstrated in 27 (50%) children. 11 (20.37%) children were followed up by endocrinological clinics, of them 7 (12.96%) were treated with growth hormone. Three (5.6%) of the children were diagnosed with attention deficit hyperactivity disorder, an incidence that is considered lower than that of the general population (± 9%).

CONCLUSIONS

Prenatal fetal isolated short long bones diagnosed during the late second and third trimester is associated with short stature. No neurodevelopmental impact was observed in our study group.

Clinical value of genetic analysis in prenatal diagnosis of short femur

Background

Fetal femur length (FL) is an important biometric index in prenatal screening. The etiology of short femur is diverse, with some pathogenic causes leading to adverse outcomes. To improve the accuracy and practicability of diagnosis, we investigated the value of genetic analysis in prenatal diagnosis of short femur.

Methods

We examined chromosomal microarray analysis (CMA) (64 fetuses) and karyotyping (59 fetuses) data retrospectively for short femur without fetal growth restriction (FGR). Genetic testing was conducted for 15 fetuses.

Results

Karyotyping and CMA detected chromosomal aberrations at rates of 13.6% and 27.2%, respectively. Among fetuses with other abnormalities, detection rates were 21.0% higher with CMA than karyotyping. CMA identified chromosomal abnormalities in 36.4% of cases with a FL 2–4 standard deviations (SDs) below the gestational age (GA) mean. Abnormality detection by CMA reached 38.5% in the second trimester. Duplication of 12p, 16p13.1 deletion, and uniparental disomy 16 were identified by CMA in three cases of short femur. Gene sequencing detected clinically notable mutations in 12/15 fetuses, among which 9/12 fetuses had FLs >4 SDs below the GA mean.

Conclusions

CMA yielded a higher detection value than karyotyping in fetuses with other abnormalities or a FL 2–4 SDs below the GA mean during the second trimester. Gene sequencing should be performed when FL is >4 SDs below the mean.

Second-trimester fetal head circumference in more than 350 000 pregnancies: Outcome and suggestion for sex-dependent cutoffs for small heads

OBJECTIVE

To explore the relationship between small fetal second-trimester head circumference (HC) and pregnancy outcome and identify a cutoff point for offering genetic testing.

METHOD

Data from second-trimester scans in Denmark were linked to national registers. Fetuses with anomalies diagnosed before this scan were excluded. Fetuses were grouped according to HC z-score.

RESULTS

We included 352 515 singleton fetuses. The mean HC was significantly larger among males than among females with z-scores averaging 0.52 more in males. Small HC was associated with chromosomal anomaly, malformations of the CNS and heart, miscarriage/perinatal death, termination, preterm delivery, and intrauterine growth restriction (test for trend: P < .001 for all outcomes). Fetuses in the group with z-score less than -3 had the highest incidence of adverse outcome, irrespective of fetal sex. In the groups with z-scores between -3 and -2.5, and between -2.5 and -2, risk of adverse outcome was lower for females than males for all outcome categories.

CONCLUSION

Small HC in second trimester is a prognostic marker for adverse outcome. The smaller the HC, the higher the risk of adverse outcome. We suggest an HC cutoff point of -2 SD for males and -2.5 SD for females for offering genetic testing.

Femur length parameters in fetuses with Down syndrome†

Objective: To characterize the natural history of femur length (FL) parameters across gestation in Down syndrome fetuses.Methods: Retrospective review of singletons with fetal Down syndrome delivered at our institution between January 2009 and December 2015. We assessed FL <3rd percentile for gestational age, femur length/abdominal circumference (FL/AC) ratio below 20%, and FL lag, defined as difference in weeks between obstetric gestational age and gestational age corresponding to measured FL. Ultrasound data were grouped into 6-week intervals, with initial examination at each interval selected for analysis. Relationship between FL parameters and small for gestational age (SGA) infant was evaluated.Results: During the study period, 173 pregnancies with fetal Down syndrome had 310 sonograms and subsequent delivery. Prior to 22 weeks, FL <3rd percentile occurred in 38 (26%), and FL/AC ratio below 20% occurred in 73 (51%). At each ultrasound interval, FL/AC ratio below 20% was more prevalent than FL <3rd percentile (all p<.05). Proportion with FL and FL/AC below these thresholds did not vary across gestation (all p>.05). However, FL lag increased from <1 week in the early second trimester to almost 3 weeks  ≥ 34 weeks (p<.001). SGA Down syndrome infants were not more likely to have FL <3rd percentile or FL/AC ratio below 20% than their non-SGA counterparts.Conclusion: Among Down syndrome fetuses, FL/AC ratio below 20% was approximately twice as common as FL <3rd percentile, regardless of gestational age. Neither parameter was associated with SGA. With advancing gestation, degree of FL lag progressively increased.

Midtrimester isolated short femur and perinatal outcomes: A systematic review and meta-analysis

INTRODUCTION

Fetal femur length below the expected value has been described as a marker of aneuploidy, skeletal dysplasia, intrauterine growth restriction and small-for-gestational-age neonate. The aim of this systematic review and meta-analysis was to evaluate the strength of association between isolated short femur length and intrauterine growth restriction or small-for-gestational-age, and perinatal adverse outcomes.

MATERIAL AND METHODS

PubMed, EMBASE and Medline were searched from the inception of each database to May 2018. Selection criteria included prospective and retrospective cohort studies of singleton pregnancies between 18 and 28 weeks of gestation, with sonographic finding of isolated short femur length, without any structural chromosomal abnormality. The meta-analysis was performed by computing odds ratios using both fixed and random-effects models. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale.

RESULTS

Six studies including 3078 cases of isolated short femur length (study group) and 222 303 normal femur length (control group) were included. The prevalence of intrauterine growth restriction or small-for-gestational-age in the study group was 14.2%, compared with 5.2% in the control group (odds ratio of 4.04, 95% confidence interval 3.63-4.50). Isolated short femur length was associated with a higher incidence of low birthweight (study group: 22.10% vs control group: 8.57%, odds ratio 3.24, 95% confidence interval 2.34-4.48), Apgar <7 at 5 minutes (study group: 3.98% vs control group: 1.79%, odds ratio 3.56, 95% confidence interval 1.87-6.77), preterm birth (study group: 12.16% vs control group: 8.16%, odds ratio 3.09, 95% confidence interval 1.57-6.08), fetal death (study group: 1.83% vs control group: 0.44%, odds ratio 6.48, 95% confidence interval 3.70-11.35) and neonatal intensive care unit admission (study group: 15.34% vs control group: 14.81%, odds ratio 2.11, 95% confidence interval 0.56-7.93).

CONCLUSIONS

There is a significant association between isolated short femur length and intrauterine growth restriction or small-for-gestational-age and poor perinatal outcome.

Fetal growth restriction in rural Bangladesh: a prospective study

BACKGROUND

Fetal growth restriction (FGR) and low birth weight(LBW) are serious public health problems. In developing countries, the incidence of low birth weight is predominantly the result of FGR, and both low birth weight and FGR are associated with neonatal death and later growth and development. Fetal growth charts are important for assessing the size of the fetus during pregnancy. The aims of this study were to describe the fetal growth pattern of a population in rural Bangladesh where maternal undernutrition is prevalent and to compare the timing of FGR in that population with WHO and INTERGROWTH- 21st international reference values.

METHODS

From November 2001 to October 2003, pregnant women were recruited in Matlab, a sub district of Bangladesh, and underwent three follow-up ultrasound examinations during pregnancy for measurement of the parameters of the fetal head, abdomen, and femur. The data were fitted to a linear-cubic model, and the derived values were compared with international reference values.

RESULTS

A total of 2678 singleton pregnancies were included in the analyses. The mean (SD) maternal age was 25.9 (5.8) years (range, 14-47 years). The mean (SD) early pregnancy BMI was 20.1 (2.6) kg/m2, and 27.6% of the women were underweight (BMI < 18.5 kg/m2). The growth of the biparietal diameter and abdominal circumference was significantly smaller throughout the pregnancy than the reference values (P ≤ 0.05). Moreover, a larger deviation in the growth of Bangladeshi fetuses was observed after 28 weeks of gestation when compared with the WHO and INTERGROWTH-21st reference fetal growth charts (P ≤ 0.05). After 28 weeks of gestation, the average Bangladesh estimated fetal weight gain per week of gestational age was significantly lower than the WHO estimated fetal weight by as much as 67.4 g (P ≤ 0.001).

CONCLUSIONS

The present population-based study showed that fetuses were smaller in the third trimester when compared with the reference charts. Growth faltering started in the second trimester for all the biometric parameters for the head, abdomen, and femur. This finding provides more challenges concerning nutritional interventions.

Fetal growth velocity and body proportion in the assessment of growth

Fetal growth restriction implies failure of a fetus to meet its growth potential and is associated with increased perinatal mortality and morbidity. Therefore, antenatal detection of fetal growth restriction is of major importance in an attempt to deliver improved clinical outcomes. The most commonly used approach towards screening for fetal growth restriction is by means of sonographic fetal weight estimation, to detect fetuses small for gestational age, defined by an estimated fetal weight <10th percentile for gestational age. However, the predictive accuracy of this approach is limited both by suboptimal detection rate (as it may overlook non-small-for-gestational-age growth-restricted fetuses) and by a high false-positive rate (as most small-for-gestational-age fetuses are not growth restricted). Here, we review 2 strategies that may improve the diagnostic accuracy of sonographic fetal biometry for fetal growth restriction. The first strategy involves serial ultrasound evaluations of fetal biometry. The information obtained through these serial assessments can be interpreted using several different approaches including fetal growth velocity, conditional percentiles, projection-based methods, and individualized growth assessment that can be viewed as mathematical techniques to quantify any decrease in estimated fetal weight percentile, a phenomenon that many care providers assess and monitor routinely in a qualitative manner. This strategy appears promising in high-risk pregnancies where it seems to improve the detection of growth-restricted fetuses at increased risk of adverse perinatal outcomes and, at the same time, decrease the risk of falsely diagnosing healthy constitutionally small-for-gestational-age fetuses as growth restricted. Further studies are needed to determine the utility of this strategy in low-risk pregnancies as well as to optimize its performance by determining the optimal timing and interval between exams. The second strategy refers to the use of fetal body proportions to classify fetuses as either symmetric or asymmetric using 1 of several ratios; these include the head circumference to abdominal circumference ratio, transverse cerebellar diameter to abdominal circumference ratio, and femur length to abdominal circumference ratio. Although these ratios are associated with small for gestational age at birth and with adverse perinatal outcomes, their predictive accuracy is too low for clinical practice. Furthermore, these associations become questionable when other, potentially more specific measures such as umbilical artery Doppler are being used. Furthermore, these ratios are of limited use in determining the etiology underlying fetal smallness. It is possible that the use of the 2 gestational-age-independent ratios (transverse cerebellar diameter to abdominal circumference and femur length to abdominal circumference) may have a role in the detection of mild-moderate fetal growth restriction in pregnancies without adequate dating. In addition, despite their limited predictive accuracy, these ratios may become abnormal early in the course of fetal growth restriction and may therefore identify pregnancies that may benefit from closer monitoring of fetal growth.

The impact of third-trimester genetic counseling

OBJECTIVE

To evaluate the impact of genetic counseling (GC) during the third trimester by analyzing changes in pregnancy management and the correlation with postnatal findings.

METHODS

This was a retrospective study. Pregnancy course and neonatal follow-up were analyzed according to the reason for referral and implementation of recommendations.

RESULTS

The records of neonates born to 181 women were retrieved. Fifty-two women (group 1-29%) qualified for pregnancy termination under Israeli guidelines and laws, and 129 (group 2-71%) were not at the time they were referred. By another division: 104 women (group 3-57%) followed the physician's diagnostic recommendations completely after counseling including amniocentesis, fetal MRI, targeted ultrasound scans, fetal echocardiography. Seventy-seven declined amniocentesis (group 4-43%). Additional abnormalities were detected postpartum in all groups without statistically difference: 3/52 (10%) in group 1, 9/129 (7%) in group 2, 6/104 (6%) in group 3, and 6/77 (8%) in group 4).

CONCLUSION

GC in the third trimester of pregnancy provided the couple with a sharper more focused picture and assisted them to perceive the significance of new, significant fetal findings which attest to the value of the GC.

Prognosis of 591 fetuses with ultrasonic soft markers during mid-term pregnancy

The present study aimed to examine the value of ultrasonic soft markers in prenatal screening by analyzing the clinical outcome of fetuses with ultrasonic soft markers during the second trimester of pregnancy. A retrospective analysis was performed to evaluate the outcome of 591 fetuses with ultrasonic soft markers from January 2015 to August 2016 in Zhongnan Hospital of Wuhan University, China. It was found that 591 fetuses showed ultrasonic soft markers in 4927 cases with the occurrence rate being 12.0%. Among them, 564 fetuses (95.4%) were delivered and the remaining 27 cases (4.6%) were aborted. Five hundred and sixty-seven cases had single ultrasonic soft marker, including echogenic intracardiac focus (n=343), mild renal pelvis dilatation (n=116), short long bones (n=72), single umbilical artery (n=31), mild lateral ventriculomegaly (n=21), choroid plexus cysts (n=19), and echogenic bowel (n=13), with the disappearing rates in pregnancy being 97.1% (333/343), 77.6% (90/116), 0% (0/72), 0% (0/31), 57.1% (12/21), 89.5% (17/19) and 61.5% (8/13) respectively. The rate of pregnancy termination due to single ultrasonic soft marker was 3.4% (19/567), and that was 33.3% (8/24) due to two ultrasonic soft markers with the difference being statistically significant (P<0.05). The reasons of pregnancy termination included malformations (polycystic kidney, cleft lip and palate, congenital heart diseases, pcromphalus, hypospadias, hydrocephalus), chromosome abnormality, and stillbirth. It was concluded that single ultrasonic soft marker is usually transient manifestation in pregnancy. Without the other structural defects, single ultrasonic soft marker usually disappears spontaneously with favorable prognosis in a low-risk population. It is suggested that ultrasonic soft markers should be appropriately interpreted to avoid unnecessary invasive examination.

Risk of Adverse Outcomes in Euploid Pregnancies With Isolated Short Fetal Femur and Humerus on Second-Trimester Sonography

OBJECTIVES

The purpose of this study was to evaluate pregnancies with isolated short fetal femur and humerus on second-trimester sonography. Short fetal long bones are known to be associated with aneuploidy and structural anomalies. In this study, we wanted to show the risk of adverse pregnancy outcomes in euploid and nonanomalous pregnancies.

METHODS

Singleton pregnancies with short femur and humerus were included. Pregnancies with normal fetal bone lengths and age-matched mothers were selected as controls.

RESULTS

The study group included 30 pregnancies with short fetal femur and humerus, and the control group included 60 normal pregnancies. The overall odds ratio for an adverse pregnancy outcome in the study group was 24.9. Preterm delivery occurred significantly more frequently (odds ratio, 20.8; P < .001), and one-third of pregnancies were complicated by preeclampsia. In the group with short long bones, the odds ratio for a pathologic umbilical Doppler flow pattern was 45.2 (P < .001), and birth weight was significantly lower (P < .001). Also, 3 (10.3%) stillbirths and 4 (13.3%) cases of early neonatal death were recorded in this group. These complications were not recorded in the control group. The risk of emergency cesarean delivery was significantly higher in the group with short long bones (odds ratio, 11.8; P < .001).

CONCLUSIONS

The risk of adverse pregnancy outcomes is significant in euploid and nonanomalous pregnancies with isolated short long bones. Close follow-up is needed during pregnancy.

The Danish Fetal Medicine database

Aim

The aim of this study is to set up a database in order to monitor the detection rates and false-positive rates of first-trimester screening for chromosomal abnormalities and prenatal detection rates of fetal malformations in Denmark.

Study population

Pregnant women with a first or second trimester ultrasound scan performed at all public hospitals in Denmark are registered in the database.

Main variables/descriptive data

Data on maternal characteristics, ultrasonic, and biochemical variables are continuously sent from the fetal medicine units’ Astraia databases to the central database via web service. Information about outcome of pregnancy (miscarriage, termination, live birth, or stillbirth) is received from the National Patient Register and National Birth Register and linked via the Danish unique personal registration number. Furthermore, results of all pre- and postnatal chromosome analyses are sent to the database.

Conclusion

It has been possible to establish a fetal medicine database, which monitors first-trimester screening for chromosomal abnormalities and second-trimester screening for major fetal malformations with the input from already collected data. The database is valuable to assess the performance at a regional level and to compare Danish performance with international results at a national level.

Soft markers for aneuploidy following reassuring first trimester screening: what should be done?

PURPOSE OF REVIEW

The present article aims to review the current role of the soft markers on the second trimester ultrasound (STUS) in women after reassuring first trimester screening (FTS) in singleton pregnancies.

RECENT FINDINGS

Improvements in the FTS and the recent implementation of noninvasive prenatal testing (NIPT) for common aneuploidies have important impact on the prevalence of these conditions in the STUS. Some studies suggest that soft markers in the second trimester of the fetus without structural anomalies have a minor or no role in Down syndrome detection in a prescreened population with reassuring results. However, NIPT could be offered as a next step in the management of such pregnancies if the calculated new composite risk (NCR) for aneuploidy is increased. In the case of reassuring results, pregnancy follow-up for certain markers is advised.

SUMMARY

NIPT has emerged as a new method of prenatal testing and is feasible in the second trimester in women with increased NCR. However, apart from the Down syndrome screening, STUS screening remains a powerful tool in screening for other fetal aneuploidies, structural anomalies and pathological placental conditions and detection of specific soft markers that require pregnancy follow-up.

Isolated Short Fetal Femur Length in the Second Trimester and the Association with Adverse Perinatal Outcome: Experiences from a Tertiary Referral Center

Objective

To determine the association between isolated mid-trimester short fetal femur length and adverse perinatal outcome.

Methods

This is a retrospective cohort study of patients with singleton gestations routinely assessed by second trimester ultrasound examination during 2006-2013. A fetal isolated short femur was defined as a femur length (FL) below the 5^th percentile in a fetus with an abdominal circumference greater than the 10^th percentile. Cases of aneuploidy, skeletal dysplasia and major anomalies were excluded. Primary outcomes of interest included the risk of small for gestational age neonates, low birth weight and preterm birth (PTB). Secondary outcome parameters were a 5-min Apgar score less than 7 and a neonatal intensive care unit admission. A control group of 200 fetuses with FL ≥ 5th percentile was used to compare primary and secondary outcome parameters within both groups. Chi-square and Student’s t-tests were used where appropriate.

Results

Out of 608 eligible patients with a short FL, 117 met the inclusion criteria. Isolated short FL was associated with an increased risk for small for gestational age (19.7% versus 8.0%, p = 0.002) neonates, low birth weight (23.9% versus 8.5%, p<0.001), PTB (19.7% versus 6.0%, p<0.001) and neonatal intensive care unit admissions (13.7% versus 3.5%, p = 0.001). The incidence of a 5-min Apgar score less than 7 was similar in both groups.

Conclusion

Isolated short FL is associated with a subsequent delivery of small for gestational age and Low birth weight neonates as well as an increased risk for PTB. This information should be considered when counseling patients after mid-trimester isolated short FL is diagnosed.