Shortened fetal long bones: a possible in utero manifestation of placental function

Exploring the Laws of Developmental Direction Using a Documented Skeletal Collection

OBJECTIVES

Many human growth studies note a trend of differential variation in limb segment lengths, where distal elements show greater variability than their proximal counterparts. This has been attributed to their developmental sequence, where bones further from the head develop later and are more impacted by fluctuating growth conditions. We aimed to explore limb dimensions within this framework, known as the laws of developmental direction, in children (0.09-11.75 years) from a documented skeletal collection of low socioeconomic status.

MATERIALS AND METHODS

Z-scores were generated for diaphyseal length measurements of six limb bones. Differences between mean z-score values of the limbs, as well as of the proximal and distal segments of each limb, were assessed using paired samples t-tests.

RESULTS

The lower limb was significantly more stunted in growth relative to the upper limb (p ≤ 0.001), as was the distal segment of the upper limb relative to the proximal segment (p ≤ 0.001). In contrast, the distal segment of the lower limb was significantly less stunted in growth relative to the proximal segment (p ≤ 0.001).

DISCUSSION

The findings of increased sensitivity in the lower limb relative to the upper limb and in the distal segment of the upper limb relative to its proximal segment are consistent with the laws of developmental direction. However, the finding of greater sensitivity in the proximal segment of the lower limb relative to the distal segment does not align with the theorized developmental gradient. These results reveal the complexity of human growth and developmental plasticity in response to biocultural factors.

Long Story of Short Femur: A Single-Center Study with Step-Wise Imaging Approach

PURPOSE

To evaluate the possible outcomes of fetuses diagnosed with short femur length (FL) and to guide diagnosis through a step-wise imaging algorithm.

METHODS

This was a prospective cohort study of 42 pregnancies with fetal femur length (FL) below the 5th centile for gestational age. The cases were divided into two categories of isolated short FL & non-isolated short FL and followed up to determine the etiology.

RESULTS

There were 11 cases of non-isolated short FL with skeletal dysplasia observed in 7 and chromosomal abnormalities in 4 cases. There were 31 cases with isolated short FL in which fetal growth restriction (FGR) occurred in 14/31 (45%) cases; 13 out of 31 (42%) were constitutional (short for gestational age, SGA) whereas 4/31(13%) showed normal interval growth on follow up (false positive).

CONCLUSION

Short femur can be isolated or non-isolated. Short femur length can be a good predictor and early sign of FGR. Serial follow up scan of the all cases of isolated short FL is important since a majority of them are normal and not require any further intervention. Cases of non-isolated short FL require step-wise approach to differentiate into dysplasia or aneuploidy.

Shortened fetal long bones: A notable intrauterine phenotypic feature in SHOX-associated skeletal dysplasia

OBJECTIVE

To explore the intrauterine phenotypic spectrum of short stature homeobox-containing (SHOX) gene-associated skeletal dysplasia and provide genetic counseling at-risk pregnancies.

METHOD

We analyzed the fetuses with SHOX-microdeletions identified by single nucleotide polymorphism (SNP)-array. The intrauterine phenotypes and outcomes were further elaborated.

RESULTS

Nine fetuses carrying a single SHOX-microdeletion were reported, with deletion sizes ranging from 0.134 to 1.35 Mb. Shortened long bones were observed in all fetuses, varying from -2.0 standard deviation (SD) to -5.3 SD. Moreover, all cases had a femur length/foot ratio less than 0.87 and a femur/abdominal circumference ratio greater than 0.16, suggesting that non-lethal skeletal dysplasia may be involved. Two fetuses showed intrauterine growth restriction, and two had nasal bone hypoplasia. Prenatal ultrasonography did not reveal other obvious anomalies, including the Madelung deformity. Five microdeletions were inherited and one was de novo. Five terminations and four newborns were recorded. Two newborns had normal stature, and two were short-statured (height <3rd percentile), with one having inflexible wrists.

CONCLUSIONS

SHOX haploinsufficiency may manifest with shortened fetal long bones. The combination of history taking, prenatal ultrasonography, and SNP-array can prompt early prenatal diagnosis and timely postnatal treatment of SHOX-associated skeletal dysplasia.

Exome sequencing in fetuses with short long bones detected by ultrasonography: A retrospective cohort study

Background: Prenatal diagnosis of fetal short long bones (SLBs) was reported to be associated with skeletal dysplasias, chromosomal abnormalities, and genetic syndromes. This study aims to identify the genetic causes for fetal short long bones, and retrospectively evaluate the additional diagnostic yield of exome sequencing (ES) for short long bones following the use of conventional genetic testing. Methods: A cohort of ninety-four fetuses with sonographically identified short long bones was analyzed by trio-exome sequencing between January 2016 and June 2021. Fetuses with abnormal results of karyotype or chromosomal microarray analysis were excluded. Variants were interpreted based on ACMG/AMP guidelines. All diagnostic de novo variants were validated by Sanger sequencing. Results: Of the 94 fetuses, 38 (40.4%) were found to carry causal genetic variants (pathogenic or likely pathogenic) in sixteen genes with 38 variants. Five fetuses (5.3%) had variant(s) of uncertain significance. Thirty-five cases (37.2%) were diagnosed as genetic skeletal dysplasias including 14 different diseases that were classified into 10 groups according to the Nosology and Classification of Genetic Skeletal Disorders. The most common disease in the cohort was achondroplasia (28.9%), followed by osteogenesis imperfecta (18.4%), thanatophoric dysplasia (10.5%), chondrogenesis (7.9%), and 3-M syndrome (5.3%). The diagnostic yield in fetuses with isolated short long bones was lower than the fetuses with non-isolated short long bones, but not reached statistical significance (27.3% vs. 44.4%; p = 0.151). Whereas, the rate in the fetuses with other skeletal abnormalities was significantly higher than those with non-skeletal abnormalities (59.4% vs. 32.5%, p = 0.023), and the diagnostic rate was significantly higher in femur length (FL) below -4SDs group compared with FL 2-4SDs below GA group (72.5% vs. 16.7%; p < 0.001). A long-term follow-up showed that outcomes for fetuses with FL 2-4SDs below GA were significantly better than those with FL below -4SDs. Additionally, fourteen (36.8%) novel short long bones-related variants were identified in the present study. Conclusion: The findings suggest that in fetuses with short long bones routine genetic tests failed to determine the underlying causes, exome sequencing could add clinically relevant information that could assist the clinical management of pregnancies. Novel pathogenic variants identified may broaden the mutation spectrum for the disorders and contributes to clinical consultation and subsequent pregnancy examination.

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 chromosomal microarray analysis in 2466 fetuses with ultrasonographic soft markers: a prospective cohort study

BACKGROUND

Soft markers are nonspecific findings detected by ultrasonography during the second trimester that are often transient and nonpathologic but may imply an increased risk of underlying fetal aneuploidy. However, large-scale prospectively stratified studies focusing on the prevalence of chromosomal aberrations, including copy number variants, in fetuses with different types of isolated soft markers have rarely been published in the literature.

OBJECTIVE

This study aimed to investigate clinical outcomes in fetuses with isolated soft markers by single nucleotide polymorphism array with long-term follow-up and to propose a diagnostic algorithm based on specific types of soft markers.

STUDY DESIGN

The prevalence of fetal isolated soft markers was 13.2% (7869 of 59,503). A total of 2466 fetuses with ultrasonographic soft markers during the second trimester, which were subjected to single nucleotide polymorphism array with long-term follow-up, were selected in this prospective study over a 5-year period. Soft markers were categorized into 12 groups. The demographic profile and chromosomal microarray analysis detection results were analyzed and compared among different groups.

RESULTS

The overall prevalence of chromosomal aberrations in fetuses with soft markers was 4.3% (107 of 2466), which comprised 40.2% with numeric chromosomal abnormalities, 48.6% with pathogenic copy number variants, and 11.2% with likely pathogenic copy number variants. The incidence of numeric chromosomal abnormalities was significantly higher in multiple soft markers (5.5% vs 1.5%; P=.001) and the thickened nuchal fold group (8.3% vs 1.7%; P=.024). Meanwhile, the incidence of pathogenic copy number variants was significantly higher in multiple soft markers (5.5% vs 2.4%; P=.046) and the short femur length group (6.6% vs 2.2%; P<.0001). The incidences of pathogenic copy number variants in fetuses with isolated echogenic intracardiac focus, enlarged cisterna magna, choroid plexus cysts, echogenic bowel, or single umbilical artery were lower than 1.5%. The normal infant rate in fetuses without chromosomal aberrations was 91.7%; however, it was significantly lower in the mild ventriculomegaly (86.2% vs 93.0%; P<.0001) and short femur length groups (71.4% vs 93.6%; P<.0001).

CONCLUSION

The potential chromosomal aberrations and clinical prognoses varied widely among different types of isolated soft markers. Pathogenic copy number variants are more often present in specific soft markers, especially when multiple soft markers are found. Thus, a specific soft marker type-based prenatal genetic testing algorithm was proposed.

"The First Thousand Days" Define a Fetal/Neonatal Neurology Program

Gene-environment interactions begin at conception to influence maternal/placental/fetal triads, neonates, and children with short- and long-term effects on brain development. Life-long developmental neuroplasticity more likely results during critical/sensitive periods of brain maturation over these first 1,000 days. A fetal/neonatal program (FNNP) applying this perspective better identifies trimester-specific mechanisms affecting the maternal/placental/fetal (MPF) triad, expressed as brain malformations and destructive lesions. Maladaptive MPF triad interactions impair progenitor neuronal/glial populations within transient embryonic/fetal brain structures by processes such as maternal immune activation. Destructive fetal brain lesions later in pregnancy result from ischemic placental syndromes associated with the great obstetrical syndromes. Trimester-specific MPF triad diseases may negatively impact labor and delivery outcomes. Neonatal neurocritical care addresses the symptomatic minority who express the great neonatal neurological syndromes: encephalopathy, seizures, stroke, and encephalopathy of prematurity. The asymptomatic majority present with neurologic disorders before 2 years of age without prior detection. The developmental principle of ontogenetic adaptation helps guide the diagnostic process during the first 1,000 days to identify more phenotypes using systems-biology analyses. This strategy will foster innovative interdisciplinary diagnostic/therapeutic pathways, educational curricula, and research agenda among multiple FNNP. Effective early-life diagnostic/therapeutic programs will help reduce neurologic disease burden across the lifespan and successive generations.

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.

The role of sonographic phenotyping in delivering an efficient noninvasive prenatal diagnosis service for FGFR3-related skeletal dysplasias

OBJECTIVES

To evaluate the diagnostic yield of noninvasive prenatal diagnosis (NIPD) for FGFR3-related skeletal dysplasias and assess the accuracy of referrals based on sonographic findings to inform guidelines for referral.

METHODS

We retrospectively reviewed laboratory and referral records from 2012 to 2018 to ascertain all NIPD tests performed using our next generation sequencing panel to detect FGFR3 mutations. We calculated the diagnostic yield of the test overall and when sub-divided according to the phenotypic features identified on ultrasound before testing. Pregnancy outcomes were ascertained wherever possible from referring centers.

RESULTS

Of 335 tests, 261 were referred because of sonographic findings, of which 80 (31.3%) had a mutation. The diagnostic yield when short limbs were the only abnormal sonographic feature reported was 17.9% (30/168), increasing to 48.9% (23/47) in the presence of one, and 82.6% (19/23) in the presence of two or more characteristic features in addition to short limbs.

CONCLUSIONS

Accurate sonographic phenotyping can maximise the diagnostic yield of NIPD in fetuses suspected to have FGFR3-related skeletal dysplasias. We suggest that clear guidelines for referral are necessary to increase benefits, decrease costs by preventing unnecessary NIPD, and potentially allow first-line broader spectrum testing for fetuses where the aetiology may be more heterogeneous.

Short Femur in the Second Trimester Scan Is Related to Maternal Preeclampsia and Small for Gestational Age Newborns

OBJECTIVE

To determine the contribution of short femur diaphysis length (FDL) at 19-22 weeks of gestation in the prediction of adverse pregnancy outcomes.

METHODS

The study included singleton pregnant women who underwent a routine anomaly scan at 19-22 weeks of gestation at the Virgen de la Arrixaca University Clinical Hospital (Murcia, Spain) between August 2011 and August 2012. Fetal biometry and Doppler ultrasound of uterine arteries were assessed as part of the anomaly scan, and the mean pulsatility index of both uterine arteries was recorded. Maternal obstetric characteristics, such as ethnicity, age, weight, parity, cigarette smoking, and medical history including hypertension and diabetes mellitus were collected from our database system.

RESULTS

A total of 6,366 women were included in the study after excluding cases with abnormal karyotype, major fetal abnormalities, or termination of pregnancy. There were 88 cases of preeclampsia (PE) (1.4%). Logistic regression was performed including maternal and fetal characteristics. Short FDL at 19-22 weeks was significantly associated with subsequent development of PE (OR = 0.89, 95% CI: 0.80-0.99, p = 0.025). The best model to predict PE from our sample included gestational age at scan, parity, maternal weight, chronic hypertension, mean pulsatility index in the uterine arteries, and FDL (AUC = 0.78, 95% CI: 0.71-0.84). Regarding small for gestational age (SGA) neonates, there were also significant differences in FDL and FDL <5th centile between the control group and SGA newborns below the 3rd, 5th, and 10th centile. In the groups of preterm births (delivery before 32, 34, and 37 weeks), there were no differences in FDL compared with the control group (term births).

DISCUSSION

Our results suggest that FDL at 19-22 weeks of gestation is an independent predictor of PE and SGA newborns.

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.

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.

Mid-pregnancy fetal growth, uteroplacental Doppler indices and maternal demographic characteristics: role in prediction of stillbirth

INTRODUCTION

To evaluate the relative value of mid trimester fetal growth, uterine artery Doppler indices and maternal demographics in prediction of stillbirth.

MATERIAL AND METHODS

Retrospective cohort study; 23 894 singleton pregnancies routinely scanned between 19 and 24 weeks' gestation. Maternal characteristics included age, body mass index, ethnicity and medical history. Fetal biometry indices, birthweight and uterine artery pulsatility index values were converted to percentiles and multivariable logistic regression analysis was performed. The predictive accuracy was assessed using receiver operating characteristic curves analysis. The main outcome was prediction of preterm and term stillbirths.

RESULTS

Non-Caucasian ethnicity, femur length centile and uterine artery pulsatility index were significantly associated with the risk of stillbirth (all p < 0.01). The detection rate of screening by maternal factors alone was 19% for all stillbirths, and 12 and 14% for term and preterm stillbirth at a 10% false positive rate, respectively. Using femur length centile alone, the detection rates were 27 and 23%, respectively. Uterine artery pulsatility index alone was able to predict 24 and 31% of term and preterm stillbirths. Screening by combining maternal factors, femur length centile and uterine artery Doppler detected 27 and 35% of term and preterm stillbirths at a 10% false positive rate.

CONCLUSIONS

Second trimester ultrasound assessment offers an opportunity to identify pregnancies at the highest risk of stillbirth occurring as a consequence of placental dysfunction. This information may be useful to improve pregnancy outcome by identifying women who may benefit from increased ultrasound surveillance and/or timely intervention.

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.

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.

Midtrimester Isolated Short Femur Length as a Predictor of Adverse Pregnancy Outcome

Objective: The aim of this study was to investigate whether midtrimester isolated short femur length is associated with pregnancy complications. Study Design: Retrospective analysis of pregnancies with a midtrimester femur length <5th percentile for gestational age compared to controls with a femur length ≥5th percentile. Outcome measures included hypertensive disorders, being small for gestational age, oligohydramnios and preterm delivery. Results: 2,105 women were eligible for this study, 85 (3.45%) of whom were in the study group and 2,020 were controls. Birth weight <10th percentile for gestational age (OR 4.4, 95% CI 2.5-7.8), birth weight <3rd percentile for gestational age (OR 31.0, 95% CI 13.3-72.3) and severe preeclampsia (OR 6.3, 95% CI 1.4-28.6) were significantly associated with midtrimester isolated short femur length. Conclusions: Midtrimester isolated short femur length is associated with higher rates of being small for gestational age and preeclampsia.

Alteraciones morfológicas de las vellosidades placentarias asociadas a malformaciones fetales múltiples del sistema esquelético

OBJETIVOS: describir y cuantificar alteraciones morfológicas en vellosidades placentarias de embarazadas cuyo feto desarrolló malformaciones esqueléticas múltiples. MÉTODOS: se analizaron cuatro placentas de abortos terapéuticos a las 13, 16, 20 y 38 semanas de gestación. Estas se compararon con placentas normales a la misma edad de gestación de abortos electivos por indicación médico legal. Tinción de hematoxilinaeosina se aplicó a 10 láminas de 5 regiones de cada placenta utilizando un protocolo con 4 variables cuantitativas: madurez, cambios fibrinoides, edema y fibrosis estromal y una variable cualitativa: trombosis. Los resultados cuantitativos se analizaron utilizando el análisis de varianza (ANAVAR) según arreglo completamente aleatorizado y el test de Tukey. Para la variable cualitativa se aplicó la prueba de tendencia para datos correlacionados. Se empleó el software statistix 8.0 y SAS 9.0 para Windows. RESULTADOS: existen diferencias significativas (p<0,05) entre las placentas asociadas a malformaciones múltiples del sistema esquelético y las placentas control en relación a las variables cuantitativas. No se encontraron diferencias significativas (p>0,05) en relación a la variable cualitativa. CONCLUSIONES: la población de vellosidades placentarias asociadas a malformaciones múltiples del sistema esquelético presentó un alto porcentaje de alteraciones indicando que la barrera placentaria está dañada afectando el intercambio de gases, nutrientes y metabolitos durante el desarrollo del feto.

Isolated short femur length on second-trimester sonography: a marker for fetal growth restriction and other adverse perinatal outcomes

OBJECTIVES

To estimate the association between isolated second-trimester short femur length and fetal growth restriction as well as other adverse perinatal outcomes.

METHODS

We conducted a retrospective cohort study of patients with singleton gestations presenting for sonography between 16 and 24 weeks' gestation from 1990 to 2009. Cases of aneuploidy, skeletal dysplasia, and major anomalies were excluded. Short femur length was defined as length below the 10th percentile for gestational age and was considered isolated when both the estimated fetal weight and abdominal circumference were above the 10th percentile for gestational age. Isolated short femur length below the 5th percentile was also evaluated. The primary outcome was fetal growth restriction, defined as birth weight below the 10th percentile. Secondary outcomes included preeclampsia and preterm birth before 37 and 34 weeks. Univariable and multivariable logistic regression analyses were used to estimate the risk of these outcomes in fetuses with isolated short femur length.

RESULTS

Of 73,884 patients, 569 (0.8%) had a fetus with a femur length below the 10th percentile, of which 268 (47.1%) were isolated; 210 patients (0.3%) had a fetus with a femur length below the 5th percentile, of which 34 (16.2%) were isolated. Isolated short femur lengths below the 10th and 5th percentiles were associated with an increased risk of fetal growth restriction (<10th: adjusted odds ratio [aOR], 3.4; 95% confidence interval [CI], 2.4-4.6; <5th: aOR, 4.6; 95% CI, 2.0-10.7) and also with an increased risk of preterm birth before 37 and 34 weeks. There was no significant association between isolated short femur length and preeclampsia.

CONCLUSIONS

Isolated short femur length on second-trimester sonography is associated with a greater than 3-fold increased risk of fetal growth restriction and an increased risk of preterm birth. Serial growth assessment may be warranted in these cases.

Perinatal outcomes after sonographic detection of isolated short femur in the second trimester

PURPOSE

To determine the association of fetal isolated short femur in the second-trimester ultrasound (US) examination with perinatal outcomes such as small-for-gestational age (SGA) and low-birth weight (LBW) neonates.

METHODS

This is a retrospective cohort study in fetuses routinely assessed by US examination at 18 to 24 weeks during 2006-2009. A fetal isolated short femur was defined as femur length below the 5th percentile and with no chromosomal or structural abnormalities. Fetuses with abdominal circumference below the 5th percentile at the time of US examination were excluded. Each case of short femur was matched with three controls according to gestational age at the time of the US examination.

RESULTS

Sixty-one fetuses met the inclusion criteria. Both the group of women carrying a fetus with isolated short femur and that of women carrying a fetus with normal femur length had similar general and obstetric characteristics. Women carrying a fetus with isolated short femur were significantly more likely to deliver a SGA neonate (19.7% versus 8.7%, p < 0.05) and a LBW neonate (19.7% versus 7.1%, p < 0.05) than women carrying a fetus with normal femur length. Logistic regression analysis found odds ratios for SGA and LBW of 2.6 (95% confidence interval, 1.1-5.9) and 2.9 (95% confidence interval, 1.2-7.1), respectively.

CONCLUSIONS

Isolated short femur in the second-trimester US examination is associated with a subsequent delivery of SGA and LBW neonates.

Outcome of fetuses with antenatally diagnosed short femur

OBJECTIVES

To examine the outcome of fetuses diagnosed with short femur length at the time of the routine anomaly scan.

METHODS

This was a retrospective review of all pregnancies referred to a tertiary referral unit with fetal femur length below the 5(th) centile for gestation at 18-24 weeks of gestation. All patients had undergone pregnancy dating and assessment of the risk of chromosomal abnormalities by measurement of fetal nuchal translucency at 11 to 13 + 6 weeks.

RESULTS

Over 5 years, 129 cases were evaluated. Detailed ultrasound examination showed associated fetal abnormalities in 46 (36%) cases, and these were classified as non-isolated. In this group, skeletal dysplasias (n = 16), chromosomal abnormalities (n = 10) and genetic syndromes (n = 4) were the most common associations. In contrast, there were no cases of chromosomal abnormalities or skeletal dysplasia in the 83 (64%) isolated cases. Early severe intrauterine growth restriction (IUGR) with abnormal umbilical artery Doppler findings and delivery before 37 weeks occurred in 33/83 (40%) cases with isolated short femur, and 90% of these had abnormal uterine artery Doppler findings at the time of presentation. These pregnancies also had high rates of pre-eclampsia (36%) and intrauterine death (33%). Those with normal uterine artery Doppler imaging were at low risk for these complications.

CONCLUSIONS

In a population previously screened by first-trimester fetal nuchal translucency measurement, the finding of isolated short femur at 18-24 weeks is unlikely to be due to aneuploidy. Severe IUGR associated with high mortality occurs in 40%, making uterine artery Doppler evaluation a useful clinical tool.

Association of isolated short femur in the mid-trimester fetus with perinatal outcome

OBJECTIVES

To evaluate the prevalence of fetal isolated short femur in a cohort of women screened for Down syndrome by the integrated test, and to compare the outcome of fetuses with isolated short femur in the mid-trimester with that of fetuses with normal femur length (controls).

METHODS

This was a retrospective cohort study of 1262 women booked for antenatal care and delivery at University College London Hospital. All women had integrated testing in the late first and early second trimesters and a detailed anomaly scan in the mid-trimester. All scan reports, screening results and neonatal data were analyzed statistically.

RESULTS

The fetal femur was short (< 5(th) percentile) in 5.1% of patients and 4.7% had isolated short femur. In pregnancies with isolated short femur, the birth weight was significantly lower and there were higher rates of small-for-gestational age (SGA) and low birth weight (LBW) infants, compared with controls (P < 0.01). The odds ratios for SGA and LBW in pregnancies with isolated short femur were 3.0 (95% CI, 1.5-5.9) and 2.60 (95% CI, 1.1-6.2), respectively. Isolated short femur was associated significantly with low levels of pregnancy-associated plasma protein-A (P = 0.001).

CONCLUSIONS

Isolated short femur in the mid-trimester fetus is associated with fetal growth restriction and SGA. In the context of normal Down syndrome screening and a normal anomaly scan, this marker should be regarded as a predictor for SGA, and fetal growth should be monitored during these pregnancies.

Fetal short femur length in the second trimester and the outcome of pregnancy

We reviewed 86 consecutive cases with fetal femur length (FL) below the 10th centile of our reference ranges at midtrimester ultrasonography. Three groups were identified based on perinatal outcome: normal infants (n= 28), newborns with structural and/or chromosomal anomalies (n= 40), small-for-gestational age (SGA) newborns (n= 18). Fetuses with skeletal dysplasias (n= 13) had significantly shorter FL. Aneuploidies were only found in fetuses with malformations other than skeletal dysplasias. The diagnosis of SGA, based on ultrasound abdominal circumference measurement <10th centile, was made 9 weeks (range 5-14) after the finding of a short FL. Half of these cases also developed pre-eclampsia.