Fetal Thymus Size at 19-22 Weeks of Gestation: A Possible Marker for the Prediction of Low Birth Weight?

INTRODUCTION: The purpose was to compare thymus size measured during second trimester screening of fetuses who were subsequently small for gestational age at birth (weight below 10th percentile, SGA group) with fetuses with normal birth weight (control group). We hypothesized that measuring the fetal thymic-thoracic ratio (TT-ratio) might help predict low birth weight. METHODS: Using three-vessel view echocardiograms from our archives, we measured the anteroposterior thymus size and the intrathoracic mediastinal diameter to derive TT-ratios in the SGA (n = 105) and control groups (n = 533) between 19+0 and 21+6 weeks of gestation. We analyzed the association between TT-ratio and SGA adjusted to the week of gestation using logistic regression. Finally, we determined the possible TT-ratio cut-off point for discrimination between SGA and control groups by means of receiver operating characteristics (ROC) curve analysis. RESULTS: The TT-ratio was significantly higher in the SGA group than in the control group (p < 0.001). An increase of the TT-ratio by 0.1 was associated with a 3.1-fold increase in the odds of diagnosing SGA. We determined that a possible discrimination cut-off point between SGA and healthy controls was achieved using a TT-ratio of 0.390 (area under the ROC curve 0.695). CONCLUSION: An increased TT-ratio may represent an additional prenatal screening parameter that improves the prediction of birth weight below the 10th percentile. Prospective studies are now needed to evaluate the use of fetal thymus size as predictive parameter for adverse fetal outcome.

Anatomical structure characterization of fetal ultrasound images using texture-based segmentation technique via an interactive MATLAB application.

OBJECTIVE: To describe the texture characteristics in several anatomical structures within fetal ultrasound images by applying an image segmentation technique through an application developed in MATLAB mathematical processing software. METHODS: Prospective descriptive observational study with an analytical component. 2D fetal ultrasound images were acquired in patients admitted to the Maternal Fetal Medicine Unit of the Hospital de San José, Bogotá-Colombia. These images were loaded into the developed application to carry out the segmentation and characterization stages by means of 23 numerical texture descriptors. The data were analyzed with central tendency measures and through an embedding process and Euclidean distance. RESULTS: Forty ultrasound images were included, characterizing 54 structures of the fetal placenta, skull, thorax, and abdomen. By embedding the descriptors, the differentiation of biologically known structures as distinct was achieved, as well as the non-differentiation of similar structures, evidenced using 2D and 3D graphs and numerical data with statistical significance. CONCLUSION: The texture characterization of the labeled structures in fetal ultrasound images through the numerical descriptors allows the accurate discrimination of these structures.

Alcohol exposure before and during pregnancy is associated with reduced fetal growth: the Safe Passage Study.

BACKGROUND: Prenatal alcohol exposure (PAE) is a worldwide public health concern. While PAE is known to be associated with low birth weight, little is known about timing and quantity of PAE on fetal growth. This study investigated the association between periconceptional and prenatal alcohol exposure and longitudinal fetal growth, focusing on timing and quantity in a high exposure cohort. METHODS: The Safe Passage Study was a prospective cohort study, including 1698 pregnant women. Two-dimensional transabdominal ultrasound examinations were performed to measure fetal femur length, abdominal and head circumference, and biparietal diameter, at three time points during pregnancy. Estimated fetal weight and Z-scores of all parameters were calculated. Trimester-specific alcohol exposure was assessed using the Timeline Followback method. To investigate the associations of specific timing of PAE and fetal growth, two models were built. One with alcohol exposure as accumulative parameter over the course of pregnancy and one trimester specific model, in which PAE was separately analyzed. Linear mixed models adjusted for potential confounders were applied with repeated assessments of both alcohol exposure and fetal growth outcomes. RESULTS: This study demonstrated that periconceptional and prenatal alcohol exposure were associated with reduced fetal growth. Effect sizes are displayed as estimated differences (ED) in Z-score and corresponding 95% confidence intervals (95% CIs). When investigated as accumulative parameter, PAE was related to a smaller femur length (ED30; - 0.13 (95% CI; - 0.22; - 0.04), ED36; - 0.14 (95% CI; - 0.25; - 0.04)) and a smaller abdominal circumference (ED36; - 0.09 (95% CI; - 0.18; - 0.01)). Periconceptional alcohol exposure was associated with a smaller abdominal circumference (ED30; - 0.14 (95% CI; - 0.25; - 0.02), ED36; - 0.22 (95% CI; - 0.37; - 0.06)) and a smaller estimated fetal weight (ED36; - 0.22 (95% CI; - 0.38; - 0.05)). Second trimester alcohol exposure was associated with a smaller abdominal circumference (ED30; - 0.49 (95% CI; - 0.86; - 0.12), ED36; - 0.70 (95% CI; - 1.22; - 0.17)) and estimated fetal weight (ED30; - 0.54 (95% CI; - 0.94; - 0.14), ED36; - 0.69 (95% CI; - 1.25; - 0.14)). No additional association of binge drinking was found besides the already observed association of PAE and fetal growth. CONCLUSIONS: This study demonstrated that PAE negatively affects fetal growth, in particular when exposed during the periconception period or in second trimester. Our results indicate that potential negative consequences of PAE are detectable already before birth. Therefore, healthcare providers should actively address and discourage alcohol use during pregnancy.

Ultrasonographic classification of 26 cases of fetal umbilical-portal-systemic venous shunts and the correlations with fetal chromosomal abnormalities.

OBJECTIVE: To investigate the ultrasonographic classification of fetal umbilical-portal-systemic venous shunts (UPSVS) and the correlations with fetal chromosomal abnormalities. METHODS: We retrospectively analyzed the ultrasound characteristics and the corresponding chromosomal abnormalities of 26 cases of fetal UPSVS prenatally diagnosed. RESULTS: A total of 26 fetuses diagnosed as UPSVS were included, including four cases of type I UPSVS, ten of type II, three of type IIIA, and nine of type IIIB. Four cases of type I were all complicated by fetal heart enlargement and heart insufficiency, of which one case had multiple malformations, and all four cases terminated pregnancies. Six of ten cases of type II terminated pregnancies, including four of Down's syndrome, one of twin reversed arterial perfusion sequence, one of fetal edema but with normal copy number variation (CNV) by chorionic villus sampling. The other four of ten cases were isolated type II with normal chromosomes, which were delivered at full term and were normal in growth and development when followed up 34 months after birth. Three cases of type IIIA all terminated pregnancies, of which one had multiple malformations, one had right multicystic dysplastic kidney, and one had fetal heart enlargement and heart failure. Among nine of type IIIB, seven with chromosomal abnormalities and/ or complicated malformations terminated pregnancies, and two with isolated type IIIB and normal chromosomes were delivered at full term, and were normal in growth and development (one was followed up to 33 months after birth and the other 20 months after birth). CONCLUSION: Fetal UPSVS can be clearly diagnosed and typed by prenatal ultrasonography. Fetal prognosis is determined by the types of UPSVS and complicated malformations and/ or chromosomal abnormalities. The probability of fetal chromosomal abnormalities in UPSVS fetuses is related to the ultrasonographic classification.

A novel artificial intelligence model for fetal facial profile marker measurement during the first trimester.

BACKGROUND: To study the validity of an artificial intelligence (AI) model for measuring fetal facial profile markers, and to evaluate the clinical value of the AI model for identifying fetal abnormalities during the first trimester. METHODS: This retrospective study used two-dimensional mid-sagittal fetal profile images taken during singleton pregnancies at 11-13+ 6 weeks of gestation. We measured the facial profile markers, including inferior facial angle (IFA), maxilla-nasion-mandible (MNM) angle, facial-maxillary angle (FMA), frontal space (FS) distance, and profile line (PL) distance using AI and manual measurements. Semantic segmentation and landmark localization were used to develop an AI model to measure the selected markers and evaluate the diagnostic value for fetal abnormalities. The consistency between AI and manual measurements was compared using intraclass correlation coefficients (ICC). The diagnostic value of facial markers measured using the AI model during fetal abnormality screening was evaluated using receiver operating characteristic (ROC) curves. RESULTS: A total of 2372 normal fetuses and 37 with abnormalities were observed, including 18 with trisomy 21, 7 with trisomy 18, and 12 with CLP. Among them, 1872 normal fetuses were used for AI model training and validation, and the remaining 500 normal fetuses and all fetuses with abnormalities were used for clinical testing. The ICCs (95%CI) of the IFA, MNM angle, FMA, FS distance, and PL distance between the AI and manual measurement for the 500 normal fetuses were 0.812 (0.780-0.840), 0.760 (0.720-0.795), 0.766 (0.727-0.800), 0.807 (0.775-0.836), and 0.798 (0.764-0.828), respectively. IFA clinically significantly identified trisomy 21 and trisomy 18, with areas under the ROC curve (AUC) of 0.686 (95%CI, 0.585-0.788) and 0.729 (95%CI, 0.621-0.837), respectively. FMA effectively predicted trisomy 18, with an AUC of 0.904 (95%CI, 0.842-0.966). MNM angle and FS distance exhibited good predictive value in CLP, with AUCs of 0.738 (95%CI, 0.573-0.902) and 0.677 (95%CI, 0.494-0.859), respectively. CONCLUSIONS: The consistency of fetal facial profile marker measurements between the AI and manual measurement was good during the first trimester. The AI model is a convenient and effective tool for the early screen for fetal trisomy 21, trisomy 18, and CLP, which can be generalized to first-trimester scanning (FTS).

Impact of a prenatal screening program on the Down syndrome phenotype: An interrupted time series analysis.

INTRODUCTION: We hypothesized that children with Down syndrome who were born after the implementation of first-trimester combined screening for trisomy 13, 18, and 21 and a second-trimester ultrasound scan in Denmark would show a milder syndrome phenotype. We investigated the birth biometry, prevalence of congenital malformations, and early childhood morbidity of children with Down syndrome before and after implementation of this screening program. MATERIAL AND METHODS: A nationwide register-based study of all live born singletons with Down syndrome in Denmark from 1995 to 2018. In interrupted time series analyses, we studied the temporal developments in birth biometry, prevalence of congenital malformations, and early childhood morbidity related to the implementation of a national prenatal screening program. RESULTS: We included 602 singletons with Down syndrome born before and 308 after implementation of the screening program. Z-scores of birthweight and head circumference increased over time before screening, but this temporal development changed after implementation by -0.05 (95% confidence interval [CI]: -0.11 to 0.01) and -0.05 (95% CI -0.12 to 0.02), respectively. Just after implementation, the prevalence of non-severe congenital heart disease decreased (relative change in odds 0.48 [95% CI: 0.24-0.94]). For severe congenital heart disease, atrioventricular septal defect, and non-heart malformations, this change was 1.16 (95% CI: 0.56-2.41), 0.95 (95% CI: 0.43-2.03), and 0.98 (95% CI: 0.33-2.76), respectively. For all malformations, pre-existing temporal developments did not change following implementation of screening. The implementation was associated with higher odds of admission to a neonatal intensive care unit (relative change 1.98 [95% CI: 0.76-5.26]) and an increased risk of hearing impairment (risk difference 3.4% [95% CI: -0.4% to 7.1%]). In contrast, the implementation was not associated with the incidence of hospital admissions by 2 years of age or with the probability of a thyroid disorder. CONCLUSIONS: After implementation of a national prenatal screening program, we did not observe a milder Down syndrome phenotype apart from an apparent reduction in the proportion of children with non-severe congenital heart disease; this result is, however, limited by small numbers.

Ultrasonographic monitoring of fetal eye growth parameters throughout gestation in the common marmoset (Callithrix jacchus).

The common marmoset (Callithrix jacchus) is considered an ideal species for developing genetically modified nonhuman primates (NHP) models of human disease, particularly eye disease. They have been proposed as a suitable bridge between rodents and other NHP models due to their similar ophthalmological features to humans. Prenatal ultrasonography is an accurate and reliable diagnostic tool for monitoring fetal development and congenital malformation. We monitored fetal eye growth and development using noninvasive ultrasonography in 40 heads of clinically normal fetuses during pregnancy to establish the criteria for studying congenital eye anomalies in marmosets. The coronal, sagittal, and transverse planes were useful to identify the facial structures for any associated abnormalities. For orbital measurements, biorbital distance (BOD), ocular diameter (OD), interorbital distance (IOD), and total axial length (TAL) were measured in the transverse plane and carefully identified for intraorbital structures. As a result, high correlations were observed between delivery-based gestational age (GA) and biparietal diameter (BPD), BOD, OD, and TAL. The correlation assessments based on BOD provide more reliable results for monitoring eye growth and development in normal marmosets than any other parameters since BOD has the highest correlation coefficient according to both delivery-based GA and BPD among ocular measurements. In conclusion, orbital measurements by prenatal ultrasonography provide reliable indicators of marmoset eye growth, and it could offer early diagnostic criteria to facilitate the development of eye disease models and novel therapies such as genome editing technologies in marmosets.

[Cleft lip and palate : One of the most frequent congenital malformations]. / Lippen-Kiefer-Gaumen-Spalte : Eine der häufigsten angeborenen Fehlbildungen.

With a frequency of 1 per 500 live births, a cleft lip and palate is one of the most frequent congenital malformations. Untreated, it leads to disturbances in feeding, speech, hearing, tooth position and esthetics. A multifactorial genesis is assumed. The fusion of the different facial processes takes place in the first 3 months of pregnancy and a cleft can develop during this time. Surgical treatment includes the early anatomical and functional restoration of the affected structures within the first year of life in order to enable normal intake of food, articulation, nasal breathing and middle ear ventilation. Breastfeeding is possible in children with a cleft formation but alternative feeding methods, such as finger feeding, often have to be used. In addition to the surgery for primary closure of the cleft, otorhinolaryngological (ENT) interventions, speech therapy, orthodontic treatment as well as other surgical interventions are part of the interdisciplinary treatment concept.

Ultrasound Assessment of the Fetal Optic Chiasm.

This article reviews the literature on different methods of prenatal ultrasound visualization of the optic chiasm (OC) and its applications. Prenatal imaging of the OC is feasible from 19 to 37 weeks of gestation. Evaluation of the OC has been shown crucial in differentiating isolated agenesis of the septum pellucidum from septo-optic dysplasia. Multiple methods can be applied for imaging of the OC, including three-dimensional and two-dimensional ultrasounds in different views, as well as color Doppler. According to the literature, both transabdominal and transvaginal routes produce equally acceptable images. OC visualization might be challenging but can be achieved by developing a standard scanning protocol and raising awareness.

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

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

Frontal lobe development in fetuses with growth restriction by using ultrasound: a case-control study.

BACKGROUND: Fetal growth restriction (FGR) occurs in up to 10% of pregnancies and is a leading cause of perinatal mortality and neonatal morbidity. Three-dimensional ultrasonography of intracranial structure volume revealed significant differences between fetuses with FGR and appropriate for gestational age (AGA) fetuses. We aimed to compare the frontal lobe development between fetuses with FGR and appropriately grown fetuses and evaluate the impact of fetal circulatory redistribution (FCR) on frontal lobe development in fetuses with FGR. METHODS: We performed a case-control study at our institution from August 2020 to April 2021. The frontal antero-posterior diameter (FAPD) and occipito-frontal diameter (OFD) were measured on the trans-ventricle view and we calculated the Z-scores for FAPD and OFD standardized for gestational age (GA) and transverse cerebellar diameter (TCD) by performing a standard regression analysis followed by weighted regression of absolute residual values in appropriately grown fetuses. We calculated the FAPD/OFD ratio as 100 × FAPD/OFD and FAPD/HC (head circumference) as 100 × FAPD/HC. To compare intracranial parameters, we randomly selected a control group of appropriately grown fetuses matched with the FGR group at the time of ultrasonography. We performed between-group comparisons of the FAPD Z-score, OFD Z-score, FAPD/OFD ratio and FAPD/HC. Similarly, we compared intracranial parameters between fetuses with FGR with and without FCR. RESULTS: FAPD/OFD ratio was curvilinear related to all the independent variables (GA, BPD, FL, and TCD). Compared with appropriately grown fetuses, fetuses with FGR showed a significantly lower FAPD/OFD ratio, FAPD Z-score, and FAPD/HC. There was no significant difference in the FAPD Z-score, FAPD/OFD ratio, and FAPD/HC between FGR fetuses with and without FCR. CONCLUSIONS: The FAPD/OFD ratio varied during pregnancy, with a mild reduction before and a mild increase after about 33 gestational weeks. Fetuses with FGR showed reduced frontal lobe growth; moreover, fetal frontal lobe development disorders were not significantly different in fetuses with FCR. TRIAL REGISTRATION: Date: 09-27-2017; Number: [2017]239.

Fetal autopsy for the diagnosis of skeletal dysplasia and comparison with prenatal ultrasound findings over a 16-year period.

OBJECTIVES: To evaluate the relationship between prenatal ultrasonography (USG) and fetal autopsy findings. METHODS: Among 453 pregnancy terminations performed because of fetal anomalies on prenatal USG, 54 with skeletal dysplasia on fetal autopsy were included in this retrospective study. RESULTS: The most common diagnoses among the 54 fetal autopsies were osteogenesis imperfecta (n=12), dysostosis (n=10), achondroplasia (n=9), arthrogryposis (n=6), and thanatophoric dysplasia (n=6). The prenatal USG and fetal autopsy findings showed complete agreement in 35 cases (64.8%), partial agreement in nine cases (16.6%), and disagreement in 10 cases (18.5%). CONCLUSIONS: Fetal autopsy via perinatal pathology is essential for precise identification of the type of skeletal dysplasia; it should be routinely performed to confirm the diagnosis of prenatally detected fetal anomalies. Autopsy is vital for accurate prenatal diagnosis and the 'gold standard' technique for the identification of clinically important abnormalities.

Second trimester fetal thymus size in association to preterm birth.

OBJECTIVES: The aim of this study was to compare the second trimester thymus-thorax-ratio (TTR) between fetuses born preterm (study group) and those born after 37 weeks of gestation were completed (control group). METHODS: This study was conducted as a retrospective evaluation of the ultrasound images of 492 fetuses in the three vessel view. The TTR was defined as the quotient of a.p. thymus diameter and a.p. thoracic diameter. RESULTS: Fetuses that were preterm showed larger TTR (p<0.001) the second trimester than those born after 37 weeks of gestation were completed. The sensitivity of a binary classifier based on TTR for predicting preterm birth (PTB) was 0.792 and the specificity 0.552. CONCLUSIONS: In our study, fetuses affected by PTB showed enlarged thymus size. These findings led us to hypothesize, that inflammation and immunomodulatory processes are altered early in pregnancies affected by PTB. However, TTR alone is not able to predict PTB.

Prenatal ultrasonic features of a mediastinal teratoma: A case report and literature review.

Fetal mediastinal teratomas represent only 10% of congenital teratomas in children and 2.6% of all mediastinal masses in children. Teratomas have multifactorial etiology, such as chromosomal abnormalities. Fetal mediastinal teratomas are rare. Mediastinal teratomas can cause hydrops fetalis, fetal demise, and neonatal respiratory distress; therefore, accurate perinatal management and interventions are very important. We describe a case of fetal mediastinal teratoma wherein the cystic fluid in the fetal tumor was aspirated and confirmed by surgical pathology after birth at the authors' center. The teratoma in this case was characterized by a large single cystic mass with clear borders in the anterosuperior mediastinum, which grew rapidly and was closely related to the thymus. The infant was healthy at birth, and the tumor was surgically removed the age of 1 year. The postoperative course was uneventful, and the patient was in good health 6 years postoperatively. This case and literature review suggests that ultrasound examination can accurately diagnose fetal mediastinal teratomas, which is beneficial to provide an accurate basis for fetal prenatal intervention and treatment. Additionally, an important ultrasound feature of a fetal unicystic mediastinal teratoma is a saddle-shaped mass with clear boundaries, which provided an accurate reference for the diagnosis of a fetal cystic mediastinal teratoma by prenatal ultrasonography.

Successful visualisation of foetal tracheo-oesophageal fistula in oesophageal atresia with prenatal ultrasonography.

This is the first report describing successful visualisation of a tracheo-oesophageal fistula (TEF) based on fluid flow on prenatal foetal ultrasonography. At 36 weeks of gestation, an anechoic tubular structure with a strong blue-coloured stream of fluid flow was observed extending from the trachea towards the gastric bubble on prenatal ultrasonography. TEF can be visualised prenatally under certain conditions.

The prevalence of brain lesions after in utero surgery for twin-to-twin transfusion syndrome on third-trimester MRI: a retrospective cohort study.

OBJECTIVE: Due to the increased risk of antenatal brain lesions, we offer a third-trimester magnetic resonance imaging (MRI) scan to all patients who underwent an in utero intervention for twin-twin transfusion syndrome (TTTS). However, the usefulness of such a policy has not been demonstrated yet. Therefore, we determined the prevalence of antenatal brain lesions detected on third-trimester MRI and the proportion of lesions detected exclusively on MRI. MATERIALS AND METHODS: We conducted a retrospective cohort study of monochorionic diamniotic twin pregnancies complicated by TTTS that underwent laser coagulation of the vascular anastomoses or fetal reduction by umbilical cord occlusion between 2010 and 2017. We reviewed the third-trimester MRI findings and compared those with the prenatal ultrasonography. RESULTS: Of the 141 patients treated with laser coagulation and 17 managed by cord occlusion, 112/141 (79%) and 15/17 (88%) patients reached 28 weeks. Of those, 69/112 (62%) and 11/15 (73%) underwent an MRI between 28 and 32 weeks. After laser coagulation, MRI detected an antenatal brain lesion in 6 of 69 pregnancies (9%) or in 6 of 125 fetuses (5%). In 4 cases (67%), the lesion was detected only on MRI. In the 11 patients treated with cord occlusion, no brain lesions were diagnosed. CONCLUSION: The prevalence of brain lesions detected by third-trimester MRI is higher compared to prenatal ultrasonography alone, making MRI a useful adjunct to detect antenatal brain lesions in twin pregnancies after in utero treatment for TTTS. KEY POINTS: • In utero interventions for twin-to-twin transfusion syndrome (TTTS) do not prevent the occurrence of antenatal brain lesions. • Fetal magnetic resonance imaging (MRI) has high accuracy in detecting anomalies of cortical development and can be a useful adjunct to ultrasonography in diagnosing certain brain abnormalities. • After laser coagulation of the anastomoses for TTTS, third-trimester MRI diagnosed a brain lesion that was not detected earlier on ultrasound scan in 6% of pregnancies.

Amniotic band syndrome in a monochorionic diamniotic twin pregnancy after rupture of the dividing membrane in the early second trimester: A case report.

BACKGROUND: Amniotic band syndrome is a rare phenomenon, but it can result in serious complications. We report herein our experience of amniotic band syndrome in a monochorionic diamniotic twin pregnancy where rupture of the dividing membrane occurred early in the second trimester. CASE PRESENTATION: A 29-year-old nulliparous woman was referred to us for management of her monochorionic diamniotic twin pregnancy at 10 weeks of gestation. When we were unable to identify a dividing membrane at 15 weeks of gestation using two-dimensional ultrasonography, we used three-dimensional ultrasonography to confirm its absence. Both modalities showed that the left arm of baby B was swollen and attached to a membranous structure originating from the placenta at 18 weeks of gestation. Tangled umbilical cords were noted on magnetic resonance imaging at 18 weeks of gestation. Emergency cesarean delivery was performed at 30 weeks of gestation because of the nonreassuring fetal status of baby A. The left arm of baby B had a constrictive ring with a skin defect. Both neonates had an uncomplicated postnatal course and were discharged around 2 months after delivery. CONCLUSIONS: Attention should be paid to the potential for amniotic band syndrome if rupture of the dividing membrane between twins is noted during early gestation.

Correlation of first-trimester thymus size with chromosomal anomalies.

OBJECTIVES: The aim of this study was to investigate the correlation between fetal thymus size measured during first-trimester screening and chromosomal anomalies. METHODS: This study is a retrospective evaluation, in which the anterior-posterior diameter of the thymus in a midsagittal plane was measured in first-trimester ultrasound between 11+0 and 13+6 weeks of gestation in 168 fetuses with chromosomal anomalies (study group) and 593 healthy fetuses (control group). The included cases were subdivided into six groups: (1) trisomy 21, (2) trisomy 18, (3) trisomy 13, (4) Turner syndrome, (5) triploidy and (6) normal controls. Thymus size measurements were adjusted to the week of gestation, which was determined by ultrasound using crown-rump-length (CRL), by calculating a ratio between CRL and thymus size (CRL-thymus-ratio). Each study group was compared with the control group separately. RESULTS: Thymus size in fetuses affected by trisomy 18 or trisomy 13 was noticeably smaller compared to the control group (1.4 mm [1.3, 1.5] and 1.3 mm [1.2, 1.4] vs. 1.8 mm [1.6, 2.1]; all p<0.001; respectively). The thymus size of fetuses with trisomy 21 and Turner syndrome did not differ from healthy fetuses. Between the CRL-thymus-ratios of the separate study groups no statistically noticeable differences could be found. CONCLUSIONS: Fetal thymus size appeared to be smaller in pregnancies affected by trisomy 18 and trisomy 13. The predictive value of fetal thymus size in first-trimester screening should be evaluated prospectively.

Situs inversus totalis and prenatal diagnosis of a primary ciliary dyskinesia.

Situs inversus, a condition in which the major visceral organs are reversed from their normal positions in the body, can be detected by prenatal ultrasonography. Often benign, it may be associated with primary ciliary dyskinesia, an autosomal recessive disorder characterized by chronic respiratory disease. Yet, prenatal diagnosis of primary ciliary dyskinesia has not been reported. We describe a pregnancy in which situs inversus was diagnosed by fetal ultrasound at 20 weeks gestation. Prenatal testing for primary ciliary dyskinesia led to the discovery that both parents were asymptomatic carriers of a pathogenic mutation in the CCDC103 gene, with an affected neonate.

Mild Fetal Tricuspid Regurgitation in the First Trimester as a Predictor of Perinatal Outcomes.

Background and Objectives: This study aimed to investigate whether mild fetal tricuspid regurgitation (TR) at 11+ 0 to 13+ 6 weeks of gestation affects perinatal outcomes. Since fetal right ventricular load is associated with placental resistance, we hypothesized that fetal mild TR would be associated with perinatal outcomes as a consequence of abnormal placentation. Materials and Methods: We retrospectively evaluated 435 women with first-trimester scan data. Blood flow across the tricuspid valve was examined in singleton pregnancies between 11+ 0 and 13+ 6 weeks of gestation. Women were categorized according to the presence or absence of fetal mild TR, and the maternal and pregnancy characteristics and perinatal outcomes were compared. Multiple linear and logistic regression analyses were conducted to identify independent predictors of perinatal outcome. Results: In the group with mild TR, there were more cases of borderline amniotic fluid index, including oligohydramnios (p = 0.031), and gestational age- and sex-specific birth weights were lower (p = 0.012). There were no significant differences in other perinatal outcomes, including preeclampsia, gestational hypertension and small for gestational age. Gestational diabetes (adjusted odds ratio (OR) 0.514, 95% confidence interval (CI) 0.312-0.947) and fetal mild TR (adjusted OR 1.602, 95% CI 1.080-2.384) were identified as factors associated with below borderline amniotic fluid index before birth. The factors that affected gestational age and sex-specific birth weight were also gestational diabetes (adjusted beta coefficient 9.673, p = 0.008) and the presence of fetal mild TR (adjusted beta coefficient -6.593, p = 0.007). Conclusions: Mild fetal TR observed in the first trimester is negatively associated with fetal growth and the amniotic fluid index at term but not with other adverse pregnancy or perinatal outcomes due to abnormal placentation.