Association of isolated short fetal femur with intrauterine growth restriction

[A pragmatic comparison of fetal biometry curves]

INTRODUCTION

The fetal biometrics charts recommended in France for ultrasound screening include measurements of head circumference (HC), biparietal diameter (BIP), abdominal circumference (AC) and femur length (FL). New international growth standards have been recommended since 2022. The aim of this work is to quantitatively describe the differences between these biometric curves.

METHODS

The biometry curves from the French College for Fetal Ultrasound, OMS and INTERGROWTH-21 are pragmatically compared based on their original quantile regression equations (superposition and quantification of differences in millimeters and in proportion) for different percentiles of clinical interest.

RESULTS

Compared with the new charts, CFEF underestimates HC<-3DS and AC<10eP. The proportions of differences between the CFEF and INTERGROWTH-21 or WHO curves always remained <5%. The proportions of difference of the 3rd percentile of HC and FL, 10th and 90th percentile of AC were always lower than 2%, 2%, 5% and 4% respectively, between OMS and INTERGROWTH-21.

CONCLUSION

The switch to prescriptive standards suggests an improvement in the detection of fetuses with AC<10th percentile, an improvement in the detection of prenatal onset microcephaly, with no argument for a decrease in the detection rate of severe constitutional bone disease or modification of obstetrical guidelines.

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.

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.

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.

Course of the sFlt-1/PlGF ratio in fetal growth restriction and correlation with biometric measurements, feto-maternal Doppler parameters and time to delivery

Purpose

The study aimed to assess the course of the soluble Fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio in pregnant women with fetal growth restriction (FGR) and to evaluate potential associations between the sFlt-1/PlGF ratio and feto-maternal Doppler parameters, fetal biometric measurements and the time between study inclusion and birth (“time to delivery”).

Methods

This was a retrospective longitudinal single center study including 52 FGR cases. The serum levels of sFlt-1 and PlGF were measured by using the BRAHMS Kryptor Compact PLUS. Fetal biometric and Doppler parameters, as well as the sFlt-1/PlGF ratio, were obtained both upon study inclusion and upon birth.

Results

Various associations between the levels of the biomarkers in maternal blood upon study inclusion and upon birth and sonographic parameters were observed in FGR cases: umbilical artery (p < 0.01), uterine arteries (p < 0.01), ductus venosus (p < 0.05), cerebroplacental ratio (CPR) (p < 0.01), femur length (p < 0.01) and birth weight (p < 0.01). The higher the sFlt-1/PlGF ratio upon study inclusion, the shorter the “time to delivery” (p < 0.01). The multivariate regression analysis showed that the greater the daily percentage increase of the angiogenic markers, the shorter the “time to delivery” (p < 0.01).

Conclusion

The fetal well-being, as measured by feto-maternal Doppler parameters such as CPR and the severity of the placental dysfunction, as measured by the urgency of birth and birth weight, is reflected by the level of the sFlt-1/PlGF ratio in the maternal serum. A rapid daily increase of the sFlt-1/PlGF ratio is significantly associated with the clinical progression of the disease.

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.

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.

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.

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.

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.

Fetal Growth and the Risk of Spontaneous Preterm Birth in a Prospective Cohort Study of Nulliparous Women

Previous studies have suggested an association between fetal growth restriction and the risk of spontaneous preterm birth (sPTB). However, addressing this association is methodologically challenging. We conducted a prospective cohort study of nulliparous women with a singleton pregnancy in Cambridge, United Kingdom (2008-2012). Ultrasonic fetal biometry was performed at 20 weeks of gestation as per routine clinical care. Participants also had blinded research ultrasonography performed at approximately 28 weeks. Biometric measurements were expressed as gestational-age-adjusted z scores. Fetal growth velocity was quantified by change in z score between 20 weeks and 28 weeks. Risk of sPTB, defined as delivery at ≥28 weeks and <37 weeks associated with labor in the absence of induction, was analyzed using cause-specific Cox regression. Of 3,892 women, 98 (2.5%) had sPTB. When compared with the other decile groups, the lowest decile of growth velocity of the fetal femur between 20 and 28 weeks was associated with increased risk of sPTB (hazard ratio = 2.37, 95% confidence interval: 1.43, 3.93; P < 0.001). Adjustment for maternal characteristics had no material effect (hazard ratio = 2.50, 95% confidence interval: 1.50, 4.14; P < 0.001). There were no significant associations between other fetal measurements and risk of sPTB. To conclude, slow growth velocity of the fetal femur is associated with an increased risk of sPTB.

Blood pressure and the capacity-load model in 8-year-old children from Nepal: Testing the contributions of kidney size and intergenerational effects

Objectives

Growth patterns in early life are increasingly linked with subsequent cardio-metabolic risk, but the underlying mechanisms require elucidation. We have developed a theoretical model of blood pressure, treating it as a function of homeostatic metabolic capacity, and antagonistic metabolic load. We sought to differentiate prenatal and postnatal components of metabolic capacity, and to identify intergenerational contributions to offspring capacity and load.

Methods

We followed up at 8 years a cohort of children originally recruited into a randomized trial of maternal micronutrient supplementation in pregnancy. Maternal anthropometry was measured at recruitment. Offspring anthropometry was measured at birth, 2 years and 8 years. Offspring blood pressure, kidney size, and body composition were measured at 8 years. Regression analysis was used to investigate potential associations of maternal phenotype, birth phenotype, and current body composition with kidney size and blood pressure.

Results

Blood pressure was positively associated with body fat, but negatively associated with birth weight and relative leg length. Kidney size was positively associated with birth weight but not with relative leg length. Adjusting for adiposity, blood pressure was independently negatively associated with birth weight, relative leg length, and kidney length. Maternal height and BMI predicted offspring size at birth and at 8 years, but not blood pressure.

Conclusions

Our data provide support for the capacity-load model of blood pressure in Nepalese children. Fetal and postnatal growth and kidney dimensions all contribute to metabolic capacity. Maternal phenotype contributed to offspring capacity and load, but these associations did not propagate to blood pressure.

Hepato - Cephalic Index as a Predictor of Intrauterine Growth Restriction

Aim:

The aims of this study were to compare ultrasound fetoplacental parameters and to calculate Hepato-Cephalic Index (HCI) as a new predictor of IUGR.

Methods and material:

A clinical prospective study was conducted and included 120 pregnant women divided in two groups: non IUGR group included healthy pregnant women (n=60) and IUGR group included pregnant women with preeclampsia and IUGR (n=60). Outcome measures were following ultrasound fetoplacental parameters in fetuses with IUGR and non IUGR: Fetal Liver Length (FLL), Femur Length (FL), Biparietal Diameter (BPD), Placental Maturation by Grannum, Amniotic Fluid Index (AFI) and Hepato-Cephalic Index (HCI). Sonography was carried out by probe 3.5 Mhz type MINDRAY DC 7.

Results:

The mean of maternal age was 30.0±6.1 years in women with preeclampsia and IUGR and 28.1±5.1 years in healthy pregnant women, p > 0.05. There was a statistically significant difference in values of: FLL (p < 0.001), FL (p = 0.004), BPD (p < 0.001), AFI (p < 0.001), HCI (p < 0.001) between IUGR and non IUGR groups. The most of women with preeclampsia and IUGR had grade III of placental maturation (48.3%). There is a significant association between the placental maturation and the diagnosis, p < 0.001. There was a statistically significant difference in body mass of newborns between IUGR and non IUGR groups, p < 0.001.

Conclusion:

In a fetus with IUGR in preeclampsia there is a reduction in FLL, FL, BPD, AFI and HCI and there is a early maturation of the placenta. By measurement of fetoplacental ultrasonic parameters of liver, pregnant women will experience prediction of risk pregnancy (preeclampsia with IUGR) due to hypoxia.

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.