Qualified and trained sonographers in the US can perform early fetal anatomy scans between 11 and 14 weeks

Proposal for standardized prenatal assessment of fetal open dysraphisms by the European reference network for Intellectual disability, TeleHealth, Autism and Congenital Anomalies (ITHACA) and eUROGEN

Open dysraphisms, that is, myelomeningocele and myeloschisis, are rare diseases associated with a risk of severe disability, including lower limb motor and sensory deficiency, sphincter deficiency, and potential intellectual deficiency. Open dysraphism is diagnosed in Europe in 93.5% of cases. In case of suspicion of fetal open dysraphism, a detailed fetal morphologic assessment is required to confirm the diagnosis and exclude associated structural anomalies, as well as genetic assessment. In case of isolated fetal open dysraphism, assessment of prognosis is based on fetal imaging including the level of the lesion, the presence or not of a sac, the presence and nature of intra cranial anomalies, and the anatomical and functional evaluation of the lower extremities. Based on these biomarkers, a personalized prognosis as well as comprehensive information about prenatal management alternatives will allow parents to decide on further management options. Standardization of prenatal assessment is essential to compare outcomes with benchmark data and make assessment of surgical innovation possible. Herein, we propose a protocol for the standardized ultrasound assessment of fetuses with isolated open dysraphism.

First-Trimester Ultrasound Screening in Routine Obstetric Practice

Technologic advances and ultrasonographer-physician experience in fetal imaging have led to significant improvements in our ability to distinguish between normal and abnormal fetal structural development in the latter part of the first trimester. As a critical component of pregnancy care, assessment of fetal anatomy at the end of the first trimester with a standardized imaging protocol should be offered to all pregnant patients regardless of aneuploidy screening results because it has been demonstrated to identify approximately half of fetal structural malformations. Early identification of abnormalities allows focused genetic counseling, timely diagnostic testing, and subspecialist consultation. In addition, a normal ultrasound examination result offers some degree of reassurance to most patients. Use of cell-free DNA alone for aneuploidy screening while foregoing an accompanying early anatomic evaluation of the fetus will result in many anomalies that are typically detected in the first trimester not being identified until later in pregnancy, thus potentially diminishing the quality of obstetric care for pregnant individuals and possibly limiting their reproductive options, including pregnancy termination.

The difference in early trimester fetal growth between singletons after frozen embryo transfer and fresh embryo transfer

BACKGROUND

Frozen embryo transfer resulted in a higher birthweight and an increased risk of macrosomia than fresh embryo transfer. However, the mechanism was still unclear. When the impact of frozen embryo transfer on fetal growth began was unknown. Crown-rump length at 11-13 weeks had been regarded as a good indicator of fetal growth in the first trimester and had been used for gestational age calculation in women with uncertain last menstrual periods.

OBJECTIVE

To evaluate the association between frozen embryo transfer and early fetal growth, particularly the crown-rump length, then fresh embryo transfer. The secondary objective was to investigate the potential correlation between crown-rump length and birthweight.

STUDY DESIGN

This was a retrospective cohort study conducted at the Reproductive Medical Center of Shandong University. A total of 4949 patients who obtained singleton pregnancy after frozen embryo transfer and 1793 patients who got singleton pregnancy after fresh embryo transfer between January 1, 2017 and December 31, 2022 were included. The primary outcome was the crown-rump length measured via ultrasound at 11-13 weeks gestation. The secondary outcomes were perinatal outcomes, including birthweight and the risk of large for gestational age, small for gestational age, macrosomia, low birthweight, and premature delivery. Multivariable linear regression models were used to adjust for potential confounders of crown-rump length.

RESULTS

A total of 6742 live singleton births after frozen embryo transfer or fresh embryo transfer were included in this study. In the univariable analysis, the frozen embryo transfer group had a larger crown-rump length (5.75±0.53 cm vs 5.57±0.48 cm, P<.001) and an increased risk of larger-than-expected crown-rump length (13.5% vs11.2%, P=.013) than the fresh embryo transfer group. After adjusting for confounders in multivariable linear regression models, frozen embryo transfer was still associated with a larger crown-rump length (regression coefficient, 3.809 [95% confidence intervals, 3.621-3.997], P<.001). When subgrouped by fetal gender, the crown-rump length of the frozen embryo transfer group was larger than the fresh embryo transfer group in both male and female fetuses. In addition, the crown-rump length was consistently larger in the frozen embryo transfer group than the fresh embryo transfer group in subgroups of the peak estradiol levels. The comparisons among different crown-rump length groups showed that smaller-than-expected crown-rump length was associated with increased risks of small for gestational age (6.3% vs 3.0%, P<.001) and preterm delivery (9.6% vs 6.7%, P=.004) than normal crown-rump length.

CONCLUSION

Frozen embryo transfer was associated with a larger crown-rump length than fresh embryo transfer, suggesting that the effect of frozen embryo transfer on fetal growth may begin in the early trimester. Suboptimal fetal growth in the first trimester may be associated with low birthweight and premature delivery.

The case for making the first-trimester anatomical survey a standard of care post Dobbs

Currently, 11- to 14-week-detailed anatomic surveys are generally reserved for at-risk populations because of the lower incidence of major fetal anomalies in low-risk populations. Until recently, such standard reflects, in part, the fact that pregnant persons retain the option of abortion even if the initial anatomy scan was in the second trimester of pregnancy. However, on June 24, 2022, the US Supreme Court overturned Roe, and many states subsequently lowered the gestational age at which abortions can legally be performed. Here, we argue for a reconsideration of limitations on first-trimester scans to preserve pregnant persons' reproductive options, particularly in those states that have imposed laws limiting access to abortion. Moreover, we acknowledge and discuss some of the challenges that will be associated with this approach.

Feasibility and learning curve of performing first trimester fetal anatomy screening among operators with varying experience using the protocol of the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG)

OBJECTIVE

To compare the feasibility of performing a complete first trimester fetal anatomy screening between two operators with different levels of experience using the protocol of the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), and to compare the duration of scan and learning curve of each operator as secondary outcomes.

METHODS

A prospective study was conducted on singleton pregnancies at 11⁺⁰-13⁺⁶ weeks of gestation. Transabdominal ultrasound anatomy screening was performed by a maternal fetal medicine (MFM) staff (operator 1) or a first year MFM fellow (operator 2) following ISUOG guidelines. The visibility of fetal structures and time taken by each operator were recorded and analyzed.

RESULTS

Data from 98 participants in operator 1 group and 96 participants in operator 2 group were analyzed. The success rate of visualizing all structures was feasible in 87.8% and 91.7% (p = .370) of cases in operator 1 and operator 2, respectively. The significant improvement in visualization success rate was observed between the first 50 and the last 50 scans in both groups (p = .004 vs. p = .006). Average time spent on the exam by operator 1 was significantly shorter than the time spent by operator 2 (11.3 ± 4.8 min vs. 15.0 ± 6.2 min; p < .001).

CONCLUSION

Completeness of first trimester fetal anatomy screening following ISUOG protocol were feasible with no statistical difference between the two different levels of experienced operators. Moreover, time allocatable with a brief learning curve were demonstrated in both groups.

Megacystis in the first trimester of pregnancy: Prognostic factors and perinatal outcomes

OBJECTIVE

To determine whether bladder size is associated with an unfavorable neonatal outcome, in the case of first-trimester megacystis.

MATERIALS AND METHODS

This was a retrospective observational study between 2009 and 2019 in two prenatal diagnosis centers. The inclusion criterion was an enlarged bladder (> 7 mm) diagnosed at the first ultrasound exam between 11 and 13+6 weeks of gestation. The main study endpoint was neonatal outcome based on bladder size. An adverse outcome was defined by the completion of a medical termination of pregnancy, the occurrence of in utero fetal death, or a neonatal death. Neonatal survival was considered as a favorable outcome and was defined by a live birth, with or without normal renal function, and with a normal karyotype.

RESULTS

Among 75 cases of first-trimester megacystis referred to prenatal diagnosis centers and included, there were 63 (84%) adverse outcomes and 12 (16%) live births. Fetuses with a bladder diameter of less than 12.5 mm may have a favorable outcome, with or without urological problems, with a high sensitivity (83.3%) and specificity (87.3%), area under the ROC curve = 0.93, 95% CI (0.86-0.99), p< 0.001. Fetal autopsy was performed in 52 (82.5%) cases of adverse outcome. In the 12 cases of favorable outcome, pediatric follow-up was normal and non-pathological in 8 (66.7%).

CONCLUSION

Bladder diameter appears to be a predictive marker for neonatal outcome. Fetuses with smaller megacystis (7-10 mm) have a significantly higher chance of progressing to a favorable outcome. Urethral stenosis and atresia are the main diagnoses made when first-trimester megacystis is observed. Karyotyping is important regardless of bladder diameter.

ACR Appropriateness Criteria® Second and Third Trimester Screening for Fetal Anomaly

The Appropriateness Criteria for the imaging screening of second and third trimester fetuses for anomalies are presented for fetuses that are low risk, high risk, have had soft markers detected on ultrasound, and have had major anomalies detected on ultrasound. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Should an Early Anatomy Ultrasound Scan Be Offered Routinely to Obese Pregnant Women?

OBJECTIVE

The primary objective of this study was to determine whether an early anatomic scan (EAS), either on its own or in combination with the routine transabdominal scan (R-TAS), would improve overall completion rates of the fetal anatomic survey in the obese pregnant woman. The study's secondary objectives were to compare patients' and sonographers' satisfaction with EAS versus R-TAS.

METHODS

A prospective observational study was carried out over a 2.5-year period including consecutive pregnant women with a pre-pregnancy BMI ≥30 kg/m² who consented at a dating ultrasound appointment to undergo EAS at 15 ± 1 GA in addition to the second trimester R-TAS. Anatomic structures were categorized as normal, not well seen, or abnormal by using the institutional 26-item anatomic standardized reporting template. Examination completion and study duration were recorded. Neonatal follow-up was performed to evaluate for any missed diagnoses. Patients' and sonographers' satisfaction questionnaires were completed.

RESULTS

A total of 120 pregnant women completed the study. Visualization of all anatomic components was complete in 14% at EAS and in 61% at R-TAS (combined completion rate, 90%). Mean scan time was 30.4 minutes at EAS and 51 minutes at R-TAS. No missed diagnoses of structural anomalies were identified at neonatal follow-up. EAS and R-TAS differed in terms of sonographers' reports of difficult or suboptimal scans (9% vs. 58%), well-seen anatomy (85% vs. 78%), and good visibility (44% vs. 12%). Most sonographers expressed a preference for performing EAS in future pregnancies, rather than the R-TAS (96% vs. 6%). Although patients reported greater satisfaction with EAS (93% vs. 74%), for reasons that could not be determined, they expressed a preference for R-TAS in a subsequent pregnancy (23% vs. 63%).

CONCLUSION

Performing EAS along with R-TAS improves completion rates for anatomic evaluation in the obese gravida and is associated with greater patient and sonographer satisfaction.

First-Trimester Ultrasound

Since the 1980s, development of high-resolution transvaginal ultrasound transducers has significantly improved ultrasound evaluation at earlier gestational ages. Although many indications exist for first-trimester ultrasound in pregnancy, more emphasis has been placed on assessment of fetal anatomy recently. In turn, congenital diagnoses can also be made earlier in pregnancy, raising the question of whether anatomic assessment in the first trimester is one of choice or obligation. Combining transvaginal and transabdominal approach yields the highest detection rate overall. Some studies have shown that more than half of all anomalies and almost all severe anomalies can be detected on early scans.

Uterocervical angle: an ultrasound screening tool to predict satisfactory response to labor induction

Background: A wide uterocervical angle >95° detected during the second trimester was associated with an increased risk for spontaneous preterm birth.Objective: We aimed to determine whether an ultrasonographic marker, uterocervical angle, correlates with satisfactory response to labor induction.Study design: We conducted a prospective cohort study from May 2016 through December 2017 of singleton term gestations undergoing transvaginal ultrasound for cervical length screening and uterocervical angle measurement. Uterocervical angle was measured between the lower uterine segment and the cervical canal. Latent phase duration >720 min was accepted to be a prolonged latent phase. The primary outcome was a prediction of satisfactory response to labor induction (latent phase duration <720 min).Results: Both anterior uterocervical angle (AUC = 0.802, p < .001) and the cervical length (AUC = 0.679, p < .05) significantly predicted satisfactory response to labor induction. Optimal cutoff value was obtained at the value of 97° (64% sensitivity, 91% specificity) for anterior uterocervical angle and 27 mm (64% sensitivity, 64% specificity) for the cervical length. Kaplan-Meier survival analysis showed that duration from labor induction to delivery was significantly higher in a group with longer cervical length (p = .04), additionally labor induction to delivery time was significantly higher in a group with lower UCA (p = .04).Conclusions: Both the cervical length and anterior uterocervical length were predictors for the satisfactory response to labor induction, and both parameters were found to be significantly associated with time from induction to delivery in survival analysis.

Early fetal morphological evaluation (11-13 + 6 weeks) accomplished exclusively by transabdominal imaging and following routine midtrimester fetal ultrasound scan recommendations. Since when can it be performed?

Objectives: To establish the best timing for the realization of first-trimester-morphologic-evaluation, following routine midtrimester fetal-ultrasound-scan-recommendations (RFUSR), by performing exclusive transabdominal exploration, and to determine the sensitivity of the mentioned scan for diagnosis of major structural abnormalities.Method: Prospective observational study with 512 pregnant women with singleton gestations (438 low-risk, 74 high-risk) was conducted. Early fetal morphological evaluation (EFME) is performed in line with RFUSR (18-22 weeks) (ISUOG 2010) and a check-list structured evaluation was followed, between 11-13 + 6 weeks. Its performance is assessed in the correct identification of normal fetal anatomy, and its effectiveness in the detection of structural defectsResults: Five hundred and four pregnant women were evaluated, of which, 58.3% EFME are considered complete fetal anatomical surveys. Complete fetal anatomical surveys scans rise from 23.1% at 11-11 + 6 weeks to 63.8% at 13 + 3-13 weeks, with a clear turning point at 12 + 6-13 + 3 weeks (63.8%) (p < .05). From 12 + 6-13 + 3 weeks only renal (26.3%) and cardiac assessments (31.6%) present an inconclusive evaluation greater than 20%. Body mass index (23.9 versus 29.8) and estimated fetal weight (63 versus 86.7 g) influence EMFE's ability of identifying fetal structures (p < .05). EMFE presents sensitivity for the identification of structural malformations of 83.3% (20/24).Conclusions: From 12 + 6 weeks of gestation onwards, a complete fetal morphological evaluation can be performed in 63.8% of cases following the routine midtrimester fetal ultrasound scan recommendations (ISUOG's 20 weeks scan).

Influence of distribution of mother's abdominal body fat on first trimester fetal growth

Objective: Fetal growth in the first trimester is estimated by measuring the crown to rump length of the fetus (CRL). There are no data on the relation between fetal growth and fat distribution in pregnant women. The objective was to investigate the influence of fat distribution in pregnant women on fetal growth in the first trimester of pregnancy.Methods: This was a controlled observation using a random sampling method. Newly registered pregnant women were included in the sample during a 12-18-month period. The study included 400 pregnant women from Bjelovarsko-bilogorska County, Croatia. Participants were divided into three groups according to their pregravid BMI values, normal weight (n = 254), overweight (n = 103), and obese (n = 43). In the 12th week of pregnancy, the CRL was measured by transvaginal ultrasound. The subcutaneous and preperitoneal fat was measured by transabdominal ultrasound, using the Suzuki method. The correlation was tested by the Pearson's coefficient, and a linear regression analysis was performed on the variables with good correlation.Results: In normal weight pregnant women, there is no correlation between the adipose tissue and fetal length, but there is a significant correlation between overweight and obese ones.Conclusion: The distribution of adipose tissue in obese and overweight pregnant women is associated with fetal length in the first trimester of pregnancy, with a stronger correlation between visceral fat and fetal length. The influence of this correlation on the overall fetal growth should be investigated by longitudinal monitoring of these variables during the entire pregnancy.

Prenatal limb defects: Epidemiologic characteristics and an epidemiologic analysis of risk factors

To analyze prenatal ultrasound data for fetal limb deformities in high-risk pregnant women and the risk factors for prenatal limb defects in high-risk pregnant women.This was a retrospective study of high-risk pregnant women at the multidisciplinary consultation center from January 2006 to December 2015. When deformities were definitively diagnosed in the first trimester by ultrasound, patients were recommended to undergo an abortion, and fetal abnormalities were confirmed by pathological examination (both gross anatomic examinations and fetal chromosome and genetic tests). The risk factors for fetal limb deformities and other congenital malformations were analyzed by multifactor analysis.Of the 4088 fetuses recorded, 144 (3.52%) were diagnosed with limb abnormalities. The abnormalities included 70 (48.61%) clubfoot/clubhand cases, with 5 polydactyly, 5 syndactyly, 4 flexion toe, 4 split hand/foot malformation, 3 overlapping fingers, and 49 congenital talipes equinovarus. A total of 6 (4.17%) and 13 (9.02%) fetuses had phocomelia and imperfect osteogenesis, respectively; 22 (15.28%) cases showed achondrogenesis; 19 (13.19%) and 12 (8.33%) had partial limb deletion absence and joint movement malfunction, respectively.In the high-risk population with limb deformities (144 patients), 19 (13.19%) were ≥35 years old, 6 (4.17%) had family history of congenital malformations, 14 (9.72%) had abnormal reproductive history, 21 (14.6%) had harmful chemical exposure, 6 (4.2%) had early TORCH infections, 16 (11.1%) had gestational diabetes, 9 (6.3%) had hypertension, 3 (2.1%) took glucocorticoid, 9 (6.3%) took sedatives.In the high-risk population with other congenital malformations except limb deformities (3766 patients), 144 pregnant women were randomly selected. In the high-risk population with other congenital malformations (144 patients), 9 (6.25%) were ≥35 years old, 7 (4.86%) had family history of congenital malformations, 10 (6.94%) had abnormal reproductive history, 22 (15.28%) had harmful chemical exposure, 5 (3.47%) had early TORCH infections, 12 (8.33%) had gestational diabetes, 11 (7.64%) had hypertension, 4 (2.78%) took glucocorticoid, 11 (7.64%) took sedatives.Ultrasound can provide adequate evidence for fetal limb deformities evaluation in most patients. Fetal limb deformity cases showed a significantly higher rate than other congenital malformations for advanced maternal age (≥35 years old).

Fetal Anatomic Imaging Between 11 and 14 Weeks Gestation

Fetal imaging between 11 and 14 weeks is a standard component of prenatal risk assessment for aneuploidy. Evaluating the fetus during this gestational age window provides the opportunity to reliably examine anatomic structures. Using a defined imaging protocol, approximately 50% of major abnormalities can be detected. Some abnormalities should almost always be detected, some may be detected on occasion and others are not currently detectable. Imagers must be familiar with embryologic patterns of development and natural history of anomalies. Patients must be informed of the limitations of early anatomic evaluation. Currently, early anatomic evaluation does not replace the standard second trimester evaluation.

Uterocervical angle: a novel ultrasound screening tool to predict spontaneous preterm birth

BACKGROUND

Mechanical alteration of the cervical angle has been proposed to reduce spontaneous preterm birth. Performance of the uterocervical angle as measured by ultrasound for predicting spontaneous preterm birth is poorly understood.

OBJECTIVE

We sought to determine whether a novel ultrasonographic marker, uterocervical angle, correlates with risk of spontaneous preterm birth in a general population.

STUDY DESIGN

We conducted a retrospective cohort study from May 2014 through May 2015 of singleton gestations between 16 0/7-23 6/7 weeks undergoing transvaginal ultrasound for cervical length screening. Images were remeasured for uterocervical angle between the lower uterine segment and the cervical canal. Primary outcome was prediction of spontaneous preterm birth <34 weeks and <37 weeks by uterocervical angle and secondary outcome evaluated cervical length and spontaneous preterm birth.

RESULTS

A total of 972 women were studied. The rate of spontaneous preterm birth in this cohort was 9.6% for delivery <37 weeks and 4.5% for <34 weeks. Uterocervical angle of ≥95 degrees was significantly associated with spontaneous preterm birth <37 weeks with sensitivity of 80% (P < .001; confidence interval, 0.70-0.81; negative predictive value, 95%). Uterocervical angle of ≥105 degrees predicted spontaneous preterm birth <34 weeks with sensitivity of 81% (P < .001; confidence interval, 0.72-0.86; negative predictive value, 99%). Cervical length ≤25 mm significantly predicted spontaneous preterm birth <37 weeks (P < .001; sensitivity, 62%; negative predictive value, 95%) and <34 weeks (P < .001; sensitivity, 63%; negative predictive value, 97%). Regression analysis revealed a significant association of maternal age, nulliparity, race, and obesity at conception with spontaneous preterm birth and uterocervical angle. There was no correlation identified between history of dilation and curettage, abnormal Pap smear results, excisional cervical procedures, smoking, or obesity at delivery on spontaneous preterm birth and uterocervical angle.

CONCLUSION

A wide uterocervical angle ≥95 and ≥105 degrees detected during the second trimester was associated with an increased risk for spontaneous preterm birth <37 and <34 weeks, respectively. Uterocervical angle performed better than cervical length in this cohort. Our data indicate that uterocervical angle is a useful, novel transvaginal ultrasonographic marker that may be used as a screening tool for spontaneous preterm birth.

Sonographic detection of central nervous system defects in the first trimester of pregnancy

The fetal central nervous system can already be examined in the first trimester of pregnancy. Acrania, alobar holoprosencephaly, cephaloceles, and spina bifida can confidently be diagnosed at that stage and should actively be looked for in every fetus undergoing first-trimester ultrasound. For some other conditions, such as vermian anomalies and agenesis of the corpus callosum, markers have been identified, but the diagnosis can only be confirmed in the second trimester of gestation. For these conditions, data on sensitivity and more importantly specificity and false positives are lacking, and one should therefore be aware not to falsely reassure or scare expecting parents based on first-trimester findings. This review summarizes the current knowledge of first-trimester neurosonography in the normal and abnormal fetus and gives an overview of which diseases can be diagnosed.

Variation of ultrasound findings in the first trimester examination of recurrent cases with trisomy 21

Increased nuchal translucency (NT) is present in about 50% of cases with trisomy 21. Very often the nuchal edema evolves in hydrops fetalis until the second trimester. Furthermore, a small amount of cases with a normal NT and trisomy 21 exhibit anatomical anomalies. We present a case of a 21-year-old woman, nulliparous, with a history of one termination of pregnancy and a smoking quitter. The prenatal control was negative for TORCH. During the first trimester scan on the 13th week, the NT was found 2.7 mm, the ductus venosus Doppler was normal, and the nasal bone was present. Hydrops fetalis was present though, and the parents were advised for chorionic villus sampling (CVS), but they opted for termination of pregnancy. The molecular control by QF-PCR showed normal karyotype for 13 and 18, a male fetus, but non-dysjunction trisomy 21 was present. Parental karyotype was advised, but they refused to perform it. One year later, the couple had another pregnancy. On the 12th week scan, the NT was found 1.0 mm, the ductus venosus Doppler was normal, and the nasal bone was present, but encephalocele was also found, and the parents consented again for termination of pregnancy. The new molecular control showed the same results. This time parental karyotype was performed. The father had a normal one, whereas the mother showed reversed p11 and q13 zones in chromosome 2. Genetical consulting and prenatal cytological control was advised in before next pregnancy.

Fetal imaging: executive summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging workshop

Given that practice variation exists in the frequency and performance of ultrasound and magnetic resonance imaging (MRI) in pregnancy, the Eunice Kennedy Shriver National Institute of Child Health and Human Development hosted a workshop to address indications for ultrasound and MRI in pregnancy, to discuss when and how often these studies should be performed, to consider recommendations for optimizing yield and cost effectiveness, and to identify research opportunities. This article is the executive summary of the workshop.

Advances in ultrasound imaging for congenital malformations during early gestation

BACKGROUND

With refinement in ultrasound technology, detection of fetal structural abnormalities has improved and there have been detailed reports of the natural history and expected outcomes for many anomalies. The ability to either reassure a high-risk woman with normal intrauterine images or offer comprehensive counseling and offer options in cases of strongly suspected lethal or major malformations has shifted prenatal diagnoses to the earliest possible gestational age.

METHODS

When indicated, scans in early gestation are valuable in accurate gestational dating. Stricter sonographic criteria for early nonviability guard against unnecessary intervention. Most birth defects are without known risk factors, and detection of certain malformations is possible in the late first trimester.

RESULTS

The best time for a standard complete fetal and placental scan is 18 to 20 weeks. In addition, certain soft anatomic markers provide clues to chromosomal aneuploidy risk. Maternal obesity and multifetal pregnancies are now more common and further limit early gestation visibility.

CONCLUSION

Other advanced imaging techniques during early gestation in select cases of suspected malformations include fetal echocardiography and magnetic resonance imaging.

Detection of fetal structural anomalies in a basic first-trimester screening program for aneuploidy

OBJECTIVES

The purpose of this study was to determine whether first-trimester aneuploidy screening sonography initially performed by credentialed sonographers was useful for detecting fetal anomalies between 11 and 14 weeks' gestation.

METHODS

We conducted a retrospective cohort study of consecutive patients referred to a private ultrasound facility between January 1, 2008, and June 30, 2012, for measurement of the nuchal translucency (NT) and crown-rump length as part of a screening protocol for aneuploidy. Patients were included if there was at least 1 live fetus with a crown-rump length between 34 and 84 mm. No specific anatomic imaging protocol was followed. The presence of anomalies was based on the sonographic report and review of the medical record. The absence of anomalies was based on the report from the anatomic survey. Anomalies were categorized as lethal, major, and minor. The anomaly category and gestational age at diagnosis (≤14 versus >14 weeks) were compared.

RESULTS

An NT scan was performed on 9692 fetuses. Anatomic surveys were done on 9077 (93.7%) of these fetuses at a mean of 18 weeks' gestation. Anomalies were detected in 180 fetuses (1.8%): 50 (0.5%) at the NT scan and 130 (1.3%) at the anatomic scan. Overall, 46 of 111 fetuses (41.4%) with major or lethal anomalies were detected at the NT scan. Two suspected abnormalities at the NT scan were not present at the anatomic scan.

CONCLUSIONS

First-trimester aneuploidy screening sonography initially performed by credentialed sonographers can identify a substantial proportion of major and lethal anomalies.

Ultrasound evaluation of the first trimester

Ultrasound is a valuable diagnostic test throughout the first trimester of pregnancy. Early in this trimester, it is used to distinguish between normal intrauterine, failed intrauterine, and ectopic pregnancies. Later it can be used with maternal blood tests to screen for trisomy 21 and other forms of aneuploidy, and in some centers to assess fetal anatomy and diagnose structural anomalies. First trimester sonography is also useful for accurate assessment of gestational age. This article reviews these applications, the approach to establishing diagnoses, and ways to avoid diagnostic mistakes that can lead to serious errors in patient management and adverse pregnancy outcome.

Fetal imaging: Executive summary of a Joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging Workshop

Given that practice variation exists in the frequency and performance of ultrasound and magnetic resonance imaging in pregnancy, the Eunice Kennedy Shriver National Institute of Child Health and Human Development hosted a workshop to address indications for ultrasound and magnetic resonance imaging in pregnancy, to discuss when and how often these studies should be performed, to consider recommendations for optimizing yield and cost-effectiveness and to identify research opportunities. This article is the executive summary of the workshop.

Fetal imaging: executive summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging Workshop

Given that practice variation exists in the frequency and performance of ultrasound and magnetic resonance imaging (MRI) in pregnancy, the Eunice Kennedy Shriver National Institute of Child Health and Human Development hosted a workshop to address indications for ultrasound and MRI in pregnancy, to discuss when and how often these studies should be performed, to consider recommendations for optimizing yield and cost effectiveness, and to identify research opportunities. This article is the executive summary of the workshop.

The role of ultrasound in the diagnosis of fetal genetic syndromes

The use of ultrasound in the prenatal diagnosis of fetal genetic syndromes is rapidly evolving. Advancing technology and new research findings are aiding in the increased accuracy of ultrasound-based diagnosis in combination with other methods of non-invasive and invasive fetal testing. Ultrasound as a screening tool for aneuploidy and other anomalies is increasingly being used throughout pregnancy, beginning in the first trimester. Given the number of recorded syndromes, it is important to identify patterns and establish a strategy for identifying abnormalities on ultrasound. These syndromes encompass a wide range of causes from viral, substance-linked, chromosomal, and other genetic syndromes. Despite the ability of those experienced in ultrasound, it is important to note that not all fetal genetic syndromes can be identified prenatally, and even common syndromes often have no associated ultrasound findings. Here, we review the role of ultrasound in the diagnosis of fetal genetic syndromes.

Should the first trimester ultrasound include anatomy survey?

First trimester scanning has become routine since the introduction of nuchal translucency screening. While most scans have included dating and gross anatomical structures, recent reports have shown that with improvement of ultrasound technology, especially high-frequency transvaginal transducers, detailed analysis of the early fetal anatomy is now possible. Studies included in this manuscript demonstrate the ability to now being able to identify many fetal malformations including some very subtle ones. The literature presented has carefully conducted many prospective studies presenting timelines that show optimal periods to review the anatomical structures by a given gestational age especially noting when these anatomical structures are not optimally seen.

Early fetal anatomical sonography

Over the past decade, prenatal screening and diagnosis has moved from the second into the first trimester, with aneuploidy screening becoming both feasible and effective. With vast improvements in ultrasound technology, sonologists can now image the fetus in greater detail at all gestational ages. In the hands of experienced sonographers, anatomic surveys between 11 and 14 weeks can be carried out with good visualisation rates of many structures. It is important to be familiar with the normal development of the embryo and fetus, and to be aware of the major anatomical landmarks whose absence or presence may be deemed normal or abnormal depending on the gestational age. Some structural abnormalities will nearly always be detected, some will never be and some are potentially detectable depending on a number of factors.

Early fetal echocardiography and anomaly scan in fetuses with increased nuchal translucency

Nuchal translucency (NT) identified at the time of the 11-14 week scan has been established as one of the best tools for screening for Down syndrome. It has also proven to be of value in screening for other conditions such as cardiac defects and extra-cardiac structural abnormalities. In this article, we present data from our fetal medicine unit that highlight the importance of using NT measurement as a stratifying tool when referring for early scans. We propose that, whenever possible, in selected cases with increased NT, provision should be made for additional early scans at 14-18 weeks of gestation with a view to providing information on fetal structural integrity well ahead of the routine scheduled appointments. Early scans should incorporate detailed assessment of the fetal cardiac as well as extra-cardiac anatomy to diagnose or rule out major structural defects. This strategy will provide reassurance to a large number of prospective parents.

Diagnosis of fetal limb abnormalities before 15 weeks: cause for concern

OBJECTIVES

The purposes of this study were (1) to identify cases of limb abnormalities identified before 15 weeks and correlate with outcomes and (2) to assess first-trimester nuchal translucency examinations to determine how frequently the upper and lower limbs were identified.

METHODS

A retrospective review was conducted of sonographic studies up to 15 weeks' gestational age from 2003 to 2010 at our high-risk fetal center. Data were collected regarding fetal gestational age, limb abnormalities, associated anatomic abnormalities, pregnancy outcomes, karyotypes, autopsy results, and the utility of transabdominal sonography, transvaginal sonography, and 3-dimensional sonography. A retrospective analysis of 100 consecutive first-trimester examinations was also conducted to assess the sensitivity of transabdominal sonography in visualization of limb buds.

RESULTS

A total of 15 cases were identified with a mean gestational age of 12 weeks 6 days. Club hand was the most common abnormality seen (8 cases), followed by absence of long bones (5 cases), a missing limb (5 cases), club foot (5 cases), shortening of long bones (2 cases), abnormal hands (2 cases), clenched hands (2 cases), and overlapping digits (1 case). Trisomy 18 was present in 9 cases. Transabdominal sonography allowed for detection of all limb buds in 100 consecutive nuchal translucency examinations and 9 of 15 cases of limb abnormalities. Four of the cases resulted in fetal death, and the remaining 11 cases were terminated.

CONCLUSIONS

Fetal limb abnormalities can be detected on sonography before 15 weeks' gestational age and are often associated with serious congenital conditions, especially trisomy 18. Transabdominal sonography alone can show most of these abnormalities, although transvaginal and 3-dimensional sonography can provide additional information. Targeted evaluation of fetal limbs during sonography before 15 weeks should be considered in high-risk populations.

Fetal cardiac ventricular volume, cardiac output, and ejection fraction determined with 4-dimensional ultrasound using spatiotemporal image correlation and virtual organ computer-aided analysis

OBJECTIVE

The objective of this study was to quantify fetal cardiovascular parameters using spatiotemporal image correlation (STIC) and virtual organ computer-aided analysis (VOCAL).

STUDY DESIGN

A cross-sectional study was performed in normal pregnancies (19-42 weeks) to evaluate ventricular volume, stroke volume (SV), cardiac output (CO), and ejection fraction (EF). The CO was also expressed as a function of estimated fetal weight and biometric parameters.

RESULTS

The following results were found: (1) 184 STIC datasets; (2) with advancing gestation, ventricular volume, SV, CO, and adjusted CO increased, whereas EF decreased; (3) right ventricular (RV) volume was larger than the left ventricular (LV) volume in systole (0.50 vs 0.27 mL; P < .001) and diastole (1.20 vs 1.03 mL; P < .001); (4) there were no differences between the LV and RV in SV, CO, or adjusted CO; and (5) LV EF was greater than the RV EF (72.2 vs 62.4%; P < .001).

CONCLUSION

Normal fetal cardiovascular physiology is characterized by a larger RV volume and a greater LV EF, resulting in similar LV and RV SV and CO.

13-14-week fetal anatomy scan: a 5-year prospective study

OBJECTIVES

To assess the potential value of an early (first-trimester) ultrasound examination in depicting fetal anomalies by transabdominal (TAS) and transvaginal (TVS) sonography, to compare it with the traditional mid-trimester anomaly ultrasound examination and to evaluate the degree of patient acceptance of early sonography by the transvaginal route.

METHODS

In this prospective study over a 5-year period (January 2002 to January 2007) 2876 pregnant women underwent a 13-14-week ultrasound examination. The scan was performed by TAS at first and then, if a full fetal anatomical survey was not achieved, by TVS. A mid-trimester fetal anatomy scan was then performed in patients who had not dropped out, miscarried or undergone pregnancy termination (n = 2834).

RESULTS

In the early scan, analyzable data for 2876 TAS and 1357 TVS examinations showed that TVS was significantly better in visualizing the cranium, spine, stomach, kidneys, bladder and upper and lower limbs (P < 0.001). Complete fetal anatomical surveys were achieved by TAS in 64% of cases versus 82% of the cases in which it was attempted by TVS (P < 0.001). Patient body mass index significantly affected the ability of the sonographer to achieve a complete anatomical survey by both TAS and TVS (P < 0.001 and P = 0.004, respectively). The duration of the scan was significantly longer using TVS. The heart and kidneys were not properly visualized in 42% and 27% of cases, respectively, at the 13-week scan compared with 1.6% and 0% at the mid-trimester scan. The total number of cases in which anomalies were detected was 31. At the first-trimester scan, anomalies were detected in 21 fetuses and in 14 of these cases the parents chose pregnancy termination. At the second-trimester scan, anomalies were detected in 17 fetuses: 10 new anomalous cases along with seven cases already detected in the first-trimester scan.

CONCLUSION

Besides its importance in screening for chromosomal abnormalities, the early scan has great potential in visualizing with precision fetal anatomy. TVS can be used to compliment difficult TAS examinations; however, patients do not always agree to undergo TVS. The mid-trimester scan remains crucial for detailed fetal anatomical survey.

Performing a fetal anatomy scan at the time of first-trimester screening

Over the past decade, prenatal diagnosis has shifted rapidly from the second trimester into the first trimester. Although the nuchal-translucency scan may detect a small proportion of fetal structural malformations, fetal anatomy is not routinely assessed until the fetal anatomical survey is performed in the second trimester between 18 and 22 weeks. The recent development of high-frequency transvaginal ultrasound transducers has led to vastly improved ultrasound resolution and improved visualization of fetal anatomy earlier in gestation. Several pilot studies of a first-trimester anatomic survey have reported detection rates comparable with those achieved in the routine second-trimester anatomic survey. As advanced ultrasound technology becomes more available, there is an urgent need to evaluate the diagnostic ability of a first-trimester anatomic survey and to determine the role of a first-trimester anatomic survey in the current screening paradigm.