Fetal Abdomen Research Articles

Optimization of Fetal Biometry With 3D Ultrasound and Image Recognition (EPICEA): protocol for a prospective cross-sectional study

ContextVariability in 2D ultrasound (US) is related to the acquisition of planes of reference and the positioning of callipers and could be reduced in combining US volume acquisitions and anatomical...

Ultrasonic predictors of macrosomia in gestational diabetes mellitus

BACKGROUND: The basis of early ultrasound (US) diagnosis of diabetic fetopathy (DF) in pregnant with gestational diabetes mellitus (GDM) is the forehanded detection of macrosomia, especially its asymmetric forms. In pregnant with GDM on a diet therapy, the detection of macrosomia may be an indication for starting the insulin therapy. In pregnant with hyperglycemia due to mutation in the glucokinase gene (GCK), US fetal growth dynamics helps to assume the fetal genotype, as well as to stratify the risks of insulin therapy.
 AIM: To determine the prognostic significance of asymmetric form of macrosomia and the value of the coefficients of proportionality for the diagnosis of DF in pregnant with GDM, including hyperglycemia due to mutation in the GCK gene.
 MATERIALS AND METHODS: US fetometry was performed in 95 pregnant with GDM (including 22 pregnant with hyperglycemia caused by mutation in the GCK gene) (main group) and 427 healthy pregnant women (control group). Estimated fetal weight, standard fetometric indicators and coefficients of proportionality were evaluated. Retrospective analysis of US predictors of macrosomia was carried out after evaluating the weight of the newborn and clarifying the signs of DF.
 RESULTS: In the group with GDM, 51 (53.7%) pregnant had children with phenotypic symptoms of DF, including macrosomia 66,7% (34 children). We found statistically significant differences in fetal weight between the control group and the main group who gave birth to children with DF starting from 32 weeks. The coefficients of proportionality (femur length/abdominal circumference and the head circumference/abdominal circumference), characterizing the formation of the asymmetric macrosomia were significantly from 34 weeks (Р0,05).
 CONCLUSION: The most effective predictive fetometric indicators for the diagnosis of fetal macrosomia are the dimensions of fetal abdomen and fetal weight 90 percentile for gestational age. A specific sign of DF in pregnant with GDM is the asymmetric macrosomia. In pregnant with a mutation in the GCK gene, the tendency to macrosomia was revealed only in the absence of a mutation in the fetus, but insulin therapy in the presence of a similar mutation in fetus did not lead to a significant decrease in its percentile ranges.

Abnormality Detection of Fetus Using Ultrasound Images

This paper includes the procedures of image processing such as image segmentation, feature extraction and classification are used for the abnormality detection of the fetus. It uses the Convex Hull algorithm to the segmented image. The set of convex hull forms a smallest convex polygon which contain all set of points in it.The main aim of our project is to detect abnormality of fetus using ultrasound images. The proposed system has three steps, namely, segmentation, features extraction and classification. Before feature extraction step, it uses convex hull algorithm for segmenting the fetal head and abdomen. Feature extraction is the main task of the system. By using Feature Extraction, the classification method is performed. The result shows that the proposed system is accurate and efficient.

Ultrasound diagnosis of left inferior vena cava and double inferior vena cava in fetus

To evaluate the application of ultrasonography in prenatal diagnosis of left inferior vena cava and double inferior vena cava in fetus. The clinical data and ultrasonographic findings of the fetuses with left inferior vena cava (18 cases) or double inferior vena cava (16 cases) were retrospectively analyzed. The ultrasonographic images of left inferior vena cava showed that in the transverse view of the fetal upper abdomen the inferior vena cava and abdominal aorta were in the normal position; below the level of the hilum, the inferior vena cava was located behind the left side of the abdominal aorta; at the level of the hilum, it crossed the front of the abdominal aorta and run diagonally to the upper right, forming the right inferior vena cava and finally entered into the right atrium. The ultrasonographic images of double inferior vena cava showed that in the transverse view of the fetal lower abdomen, in front of spine there were three transections of blood vessels; in coronal plane of abdomen, the veins run on both sides of the abdominal aorta and entered to the iliac vein of the same side. In 34 cases of abnormal inferior vena cava, there were 17 cases complicated with other system abnormalities, including 13 cases of cardiac anomalies. The left inferior vena cava and double inferior vena cava have characteristic imaging findings, and prenatal diagnosis can be made with ultrasonography. This type of congenital deformity is frequently complicated with other system abnormalities, which should be excluded in fetus, especially for heart system.

A partial supernumerary umbilical vein: a case report

BackgroundAbnormalities in the number of vessels can be found for both the umbilical artery and vein. We sometimes encounter cases of a decreased number of umbilical cord vessels, such as a single umbilical artery. In contrast, there may be an increase from three to four vessels within the umbilical cord. A supernumerary umbilical vein is particularly very rare, and it is generally found in combination with congenital anomalies. We report a case of a partial supernumerary umbilical vein.Case presentationThe previous pregnancy of a 37-year-old healthy Japanese woman (gravida 2, para 1) had been uncomplicated, and the resulting child was alive and well. Prenatal examination at 36 weeks of gestation revealed the coexistence of a four-vessel part and a normal three-vessel part of the umbilical cord. A healthy female neonate weighing 2726 g was born at 38 weeks of gestation. The umbilical cord measured 40 cm in length; the four-vessel part continued to a distance of 18 cm from the surface of the infant’s body, and the remaining umbilical cord comprised three vessels. On histological examination, the fetal side of the umbilical cord had two arteries and two veins, and the placental side had two arteries and one vein. Isolated supernumerary umbilical veins tend to be overlooked. We consider that it is important to evaluate the number of umbilical cord vessels in the second trimester using ultrasound combined with color Doppler in at least three sites: the insertion sites on both the fetal abdomen and placenta, and the free loop of the umbilical cord.ConclusionsPrenatal diagnosis of isolated supernumerary umbilical cord vessels tends to be overlooked. However, supernumerary vessels of the umbilical can be associated with fetal congenital anomalies. The number of vessels within the umbilical cord must be examined because the detection of such abnormalities may lead to the prenatal diagnosis of other congenital anomalies.

Fetal hepatic hemangioma: a case report

Fetal liver tumors represent approximately 5% of all congenital tumors and hemangiomas account for approximately 15% of all fetal liver tumors. Hemangioma and hemangioendothelioma are benign vascular tumors but they are associated with a significant morbidity and mortality due to high output congestive heart failure and arteriovenous shunting. Ultrasound features of hepatic hemangioma can overlap with arteriovenous malformation. This is a case report of fetal hepatic hemangioma with aretriovenous shunting detected on routine anomaly scan at 20 weeks of gestation in 22 years old Nepalese women who was asymptomatic. Prenatally, a 3.2cm x 2.8cm multicystic mass was seen in the left hypochondrium of the fetal abdomen displacing the stomach. On color Doppler examination, the mass showed internal color flow and multiple tortuous dilated vessels noted around the lesion. After counseling regarding the lesion to the mother and her family; decision to abort the fetus was made. Autopsy was done for the final diagnosis of the lesion, which showed vascular mass in the left lobe of liver insinuating between stomach and spleen.

Congenital cytomegalovirus infection presenting as a fetal intra-abdominal cyst

Abstract Background Fetal intra-abdominal cysts have an incidence of 1/500–1/1000 live births. Cysts can be physiologic or pathologic and can either spontaneously regress or require intervention and treatment. Cytomegalovirus (CMV) is the most common cause of congenital infection in the USA with an incidence of 0.2–2%. The risk of transmission is greatest with a primary maternal infection and the severity of fetal injury increases when transmission occurs in the first half of the pregnancy. An infectious etiology for a fetal intra-abdominal cyst has not been reported to the best of our knowledge. Case presentation A 31-year-old multigravida presented at 19 weeks’ gestation for an anatomical survey. The female fetus was noted to have a 2.4 × 2.0 × 3.1 cm echolucent cyst in the right side of the abdomen. Three weeks later, the cyst was not seen; however, there was free fluid and a few echogenic areas within the fetal abdomen. Maternal serum tested positive for CMV IgM and IgG titers, and the CMV IgG avidity test was 0.75, consistent with high avidity. At 27 weeks’ gestation, ascites remained and a pericardial effusion was noted. Amniocentesis resulted in >2,000,000 copies of CMV DNA by polymerase chain reaction (PCR) in the amniotic fluid. The patient underwent termination of the pregnancy at 29 weeks of gestation. Conclusion It would be important to consider an infectious etiology in the differential diagnosis of fetal intra-abdominal cysts as the outcome in the fetus with congenital CMV infection could be much different. Amniocentesis is considered the best option for the diagnosis of fetal congenital CMV infection if performed after 21 weeks’ gestation and more than 6 weeks from maternal infection.

Use of Magnetic Resonance Imaging in Evaluating Fetal Brain and Abdomen Malformations during Pregnancy

Magnetic resonance imaging (MRI) is used as a clarifying technique after a high-resolution ultrasound examination during pregnancy. Combining ultrasound with MRI, additional diagnostic information is obtained or ultrasound diagnosis is frequently corrected. High spatial resolution provides accurate radiological imaging of internal organs and widens possibilities for detecting perinatal development disorders. The safety of MRI and the use of intravenous contrast agent gadolinium are discussed in this article. There is no currently available evidence that MRI is harmful to the fetus, although not enough research has been carried out to prove enduring safety. MRI should be performed when the benefit outweighs the potential side effects. The narrative review includes several clinical cases of fetal MRI performed in Vilnius University Hospital Santaros Clinics.

The less spoken of extreme: Fetal macrosomia

When describing growth, a fetus may be appropriate for gestational age (AGA), too small (SGA, sometimes confused with intra uterine growth restriction, IUGR) or too large (LGA), a condition often defined as macrosomia. While the literature on IUGR is extensive and many lectures/conferences are dedicated to this topic, macrosomia is less often discussed. Macrosomia is a term that should be applied only to the newborn, since it relates to an actual weight. When describing a fetus, the only term one should use is LGA. There are various definitions for macrosomia. In developed countries, the most commonly used threshold is weight above 4500 g (9 lb 15 oz). Weight above 4000 g (8 lb 13 oz) or 10 lb (4536 g) are also commonly used. When describing fetuses, weight percentiles for gestational age, rather than actual estimated weight, are preferable. Etiologies for macrosomia include metabolic (maternal diabetes), genetic (various overgrowth syndromes such as Beckwith-Wiedemann), constitutional as well as maternal factors, such as obesity and excessive gestational weight gain. There are maternal and fetal risk factors: for example, increased incidence of cesarean deliveries and genital tract lacerations as well as shoulder dystocia. During pregnancy, ultrasound is the ideal diagnostic tool, although its precision declines as fetal weight increases. Sonographic measurements of the fetal head, abdomen and femur are the most commonly employed criteria but soft tissues and volumes (obtained, generally, by 3D methods) have also been described. Measuring the fetal abdominal circumference (AC) may be the best tool for diagnosing risk of macrosomia, with AC >35 cm identifying >90% of fetuses with macrosomia that are at risk for shoulder dystocia.

Efficient Ultrasound Image Analysis Models with Sonographer Gaze Assisted Distillation.

Recent automated medical image analysis methods have attained state-of-the-art performance but have relied on memory and compute-intensive deep learning models. Reducing model size without significant loss in performance metrics is crucial for time and memory-efficient automated image-based decision-making. Traditional deep learning based image analysis only uses expert knowledge in the form of manual annotations. Recently, there has been interest in introducing other forms of expert knowledge into deep learning architecture design. This is the approach considered in the paper where we propose to combine ultrasound video with point-of-gaze tracked for expert sonographers as they scan to train memory-efficient ultrasound image analysis models. Specifically we develop teacher-student knowledge transfer models for the exemplar task of frame classification for the fetal abdomen, head, and femur. The best performing memory-efficient models attain performance within 5% of conventional models that are 1000× larger in size.

Atresia intestinal: a propósito de un caso

El tracto intestinal fetal puede ser alterado por numerosos procesos patológicos, los hallazgos ecográficos típicos de la obstrucción intestinal son dilatación de las asas intestinales en el abdomen fetal proximal a la obstrucción. Aunque la dilatación del intestino grueso de vez en cuando se puede observar, la mayoría de los casos de dilatación del intestino se encuentran en el intestino delgado. El diagnóstico temprano es posible para algunos sitios proximales de obstrucción, como el duodenal y la atresia esofágica.
 De todas las atresias intestinales el 39% corresponde a las de yeyuno íleon y es la causa más común de obstrucción intestinal congénita y de todas estas solo en el 50 a 60% se dan hallazgos ecográficos El objetivo de este trabajo es presentar y discutir en forma crítica el diagnóstico, evaluación y evolución perinatal de un caso de atresia intestinal, así como su diagnóstico diferencial.

Intrauterine Fetal Growth Delay During Late Pregnancy After Maternal Gastric Bypass Surgery.

To investigate intrauterine fetal growth development and birth anthropometry of fetuses conceived after maternal gastric bypass surgery. Longitudinal cohort study describing longitudinal growth estimated by ultrasound on 43 singleton pregnancies after gastric bypass compared to 43 BMI-matched controls. In fetuses after maternal gastric bypass surgery, growth percentiles decreased markedly from the beginning of the second trimester until the end of the third trimester (decrease of 3.1 fetal abdomen circumference percentiles (95 %CI 0.9-5.3, p = 0.007) per four gestational weeks). While in the second trimester, fetal anthropometric measures did not differ between the groups, the mean abdomen circumference percentiles appeared significantly smaller during the third trimester in offspring of mothers after gastric bypass (mean difference 25.1 percentiles, p < 0.001). Similar tendencies have been observed in estimated fetal weight resulting in significantly more SGA offspring at delivery in the gastric bypass group. In children born after maternal gastric bypass surgery, weight percentiles (32.12th vs. 55.86th percentile, p < 0.001) as well as placental weight (525.2 g vs. 635.7 g, p < 0.001) were significantly reduced compared to controls. In fetuses conceived after maternal gastric bypass, intrauterine fetal growth distinctively declined in the second and third trimester, most prominently observed in fetal abdomen circumferences. Birth weight and placental weight at birth was significantly lower compared to BMI-matched controls, possibly due to altered maternal metabolic factors and comparable to mothers experiencing chronic hunger episodes.

AIUM-ACR-ACOG-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetric Ultrasound Examinations.

AIUM-ACR-ACOG-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetric Ultrasound Examinations.

OC27.04: Utility of infectious and cystic fibrosis workup in prenatal diagnosis of echogenic intra‐abdominal structures

To evaluate the incidence of neonatal congenital and infectious outcomes for patients diagnosed with fetal echogenic intra-abdominal structure (EIAS). This is a retrospective cohort study of patients diagnosed with EIAS during anatomical survey ultrasound at a high-volume maternal fetal medicine centre from January 2015-December 2017. EIAS was defined as an echogenic structure in the fetal abdomen >1 mm, and was evaluated by location. Charts were abstracted to determine rates of testing for cystic fibrosis (CF) and infection. Neonatal diagnoses of CF, congenital infection, small for gestational age (SGA), and postpartum bowel findings were evaluated. There were 128 fetuses with EIAS: 110 resulted in live births, 15 terminated the pregnancy (median GA 20.6 weeks) and 3 had intrauterine fetal demise (median GA 20.2 weeks). Sixty-one (47.7%) subjects had CF testing, and there were no fetuses with both partners testing positive on carrier screening. There were also no cases of CF in the 110 live births. Eighty-three (64.8%) mothers were tested antenatally for TORCH infections. Four (4.8%) had positive IgM (3 CMV, 1 Toxoplasma) resulting in amniocentesis, with no cases of fetal infection. No neonates were diagnosed with congenital TORCH infections. Thirteen (10.1%) had a birth weight of <2500g, and of these, 53.8% were preterm. There was no statistical difference in SGA and prematurity between fetuses with echogenic bowel and EIAS. There were three significant neonatal bowel findings (2.7%): one neonate had a meconium plug, one neonate had an imperforate anus requiring anoplasty, and one neonate had a known diagnosis of omphalocele, with no statistical difference between echogenic bowel and EIAS. This study suggests the actual rates of CF or infections in prenatal diagnoses of EB or EIAS may be less than previously thought. The necessity of infection and CF work-up, particularly with newer sequencing technology, needs to be reassessed in larger populations.

Ultrasound Diagnosis of Exomphalos (Omphalocele): Differentiating Exomphalos from Normal Physiologic Gut Herniation and Gastroschisis

An Exomphalos, also known as omphalocele is a congenital midline abdominal wall defect at the base of the umbilical cord insertion with herniation of gut and/or liver or occasionally other content, out of the fetal abdomen. Many chomosomal anomalies are often associated with this embryologic defect. We present a case report describing ultrasound diagnosis of exomphalos associated with hypoplastic nasal bone and increased nuchal translucency thickness.

Femur-sparing pattern of abnormal fetal growth in pregnant women from New York City after maternal Zika virus infection

Zika virus is a mosquito-transmitted flavivirus, which can induce fetal brain injury and growth restriction following maternal infection during pregnancy. Prenatal diagnosis of Zika virus-associated fetal injury in the absence of microcephaly is challenging due to an incomplete understanding of how maternal Zika virus infection affects fetal growth and the use of different sonographic reference standards around the world. We hypothesized that skeletal growth is unaffected by Zika virus infection and that the femur length can represent an internal standard to detect growth deceleration of the fetal head and/or abdomen by ultrasound. We sought to determine if maternal Zika virus infection is associated with a femur-sparing pattern of intrauterine growth restriction through analysis of fetal biometric measures and/or body ratios using the 2014 International Fetal and Newborn Growth Consortium for the 21st Century Project and World Health Organization Fetal Growth Chart sonographic references. Pregnant women diagnosed with a possible recent Zika virus infection at Columbia University Medical Center after traveling to an endemic area were retrospectively identified and included if a fetal ultrasound was performed. Data were collected regarding Zika virus testing, fetal biometry, pregnancy, and neonatal outcomes. The 2014 International Fetal and Newborn Growth Consortium for the 21st Century Project and World Health Organization Fetal Growth Chart sonographic standards were applied to obtain Z-scores and/or percentiles for fetal head circumference, abdominal circumference, and femur length specific for each gestational week. A novel 2014 International Fetal and Newborn Growth Consortium for the 21st Century Project standard was also developed to generate Z-scores for fetal body ratios with respect to femur length (head circumference:femur length, abdominal circumference:femur length). Data were then grouped within clinically relevant gestational age strata (<24, 24-27 6/7, 28-33 6/7, >34 weeks) to analyze time-dependent effects of Zika virus infection on fetal size. Statistical analysis was performed using Wilcoxon signed-rank test on paired data, comparing either abdominal circumference or head circumference to femur length. A total of 56 pregnant women were included in the study with laboratory evidence of a confirmed or possible recent Zika virus infection. Based on the Centers for Disease Control and Prevention definition for microcephaly after congenital Zika virus exposure, microcephaly was diagnosed in 5% (3/56) by both the 2014 International Fetal and Newborn Growth Consortium for the 21st Century Project and World Health Organization Fetal Growth Chart standards (head circumference Z-score ≤-2 or ≤2.3%). Using 2014 International Fetal and Newborn Growth Consortium for the 21st Century Project, intrauterine fetal growth restriction was diagnosed in 18% of pregnancies (10/56; abdominal circumference Z-score ≤-1.3, <10%). Analysis of fetal size using the last ultrasound scan for all subjects revealed a significantly abnormal skewing of fetal biometrics with a smaller abdominal circumference vs femur length by either 2014 International Fetal and Newborn Growth Consortium for the 21st Century Project or World Health Organization Fetal Growth Chart (P<.001 for both). A difference in distribution of fetal abdominal circumference compared to femur length was first apparent in the 24-27 6/7 week strata (2014 International Fetal and Newborn Growth Consortium for the 21st Century Project, P= .002; World Health Organization Fetal Growth Chart, P= .001). A significantly smaller head circumference compared to femur length was also observed by 2014 International Fetal and Newborn Growth Consortium for the 21st Century Project as early as the 28-33 6/7 week strata (2014 International Fetal and Newborn Growth Consortium for the 21st Century Project, P= .007). Overall, a femur-sparing pattern of growth restriction was detected in 52% of pregnancies with either head circumference:femur length or abdominal circumference:femur length fetal body ratio <10th percentile (2014 International Fetal and Newborn Growth Consortium for the 21st Century Project Z-score ≤-1.3). An unusual femur-sparing pattern of fetal growth restriction was detected in the majority of fetuses with congenital Zika virus exposure. Fetal body ratios may represent a more sensitive ultrasound biomarker to detect viral injury in nonmicrocephalic fetuses that could impart long-term risk for complications of congenital Zika virus infection.

Value of Fetal MRI in the Era of Fetal Therapy for Management of Abnormalities Involving the Chest, Abdomen, or Pelvis.

The purpose of this article is to present illustrative cases highlighting the value of fetal MRI as a problem-solving tool in evaluating anomalies of the fetal chest, abdomen, and pelvis that are being evaluated for fetal therapy. Fetal MRI is an increasingly valuable noninvasive tool for evaluating fetal anomalies in the age of fetal therapy. Although ultrasound remains the primary diagnostic imaging modality, MRI can provide additional information to assist parental counseling and patient care.

Prenatal diagnosis of persistent right umbilical vein - Incidence and clinical impact. A prospective study.

BackgroundPersistent right umbilical vein (PRUV) is usually an isolated finding but it may be accompanied by other fetal malformations.AimsWe aimed to determine the incidence of prenatally diagnosed PRUV in a referral population, assess the neonatal outcome and discuss the findings together with those from previous publications.Materials and methodsA total of 2360 women with low‐risk singleton pregnancies were examined in the second and third trimesters. A transabdominal convex volume transducer was used. B‐mode was applied in each patient. Scanning of the venous system included imaging of the target vessels with two‐dimensional colour Doppler mapping. The diagnosis of PRUV was made in a transverse section of the fetal abdomen. Three‐dimensional ultrasounds were performed as necessary, when anomalous cases were encountered.ResultsThe incidence of PRUV in our population was 12/2360 = 0.5%, and it was higher than in other retrospective studies. In 75% (n = 9), PRUV was an isolated finding where delivery was uneventful and the postnatal outcome was favourable. In two cases PRUV was accompanied by omphalocele, and in one case by tetralogy of Fallot and single umbilical artery.Conclusions PRUV is an uncommon prenatal finding. Screening for this anomaly can be easily performed in all pregnant patients. A diagnosis of PRUV should be followed by a thorough fetal morphology scan in order to exclude any other malformations, especially those of the cardiovascular system.

Fetal growth restriction in rural Bangladesh: a prospective study

BackgroundFetal growth restriction (FGR) and low birth weight(LBW) are serious public health problems. In developing countries, the incidence of low birth weight is predominantly the result of FGR, and both low birth weight and FGR are associated with neonatal death and later growth and development. Fetal growth charts are important for assessing the size of the fetus during pregnancy. The aims of this study were to describe the fetal growth pattern of a population in rural Bangladesh where maternal undernutrition is prevalent and to compare the timing of FGR in that population with WHO and INTERGROWTH- 21st international reference values.MethodsFrom November 2001 to October 2003, pregnant women were recruited in Matlab, a sub district of Bangladesh, and underwent three follow-up ultrasound examinations during pregnancy for measurement of the parameters of the fetal head, abdomen, and femur. The data were fitted to a linear-cubic model, and the derived values were compared with international reference values.ResultsA total of 2678 singleton pregnancies were included in the analyses. The mean (SD) maternal age was 25.9 (5.8) years (range, 14–47 years). The mean (SD) early pregnancy BMI was 20.1 (2.6) kg/m2, and 27.6% of the women were underweight (BMI < 18.5 kg/m2). The growth of the biparietal diameter and abdominal circumference was significantly smaller throughout the pregnancy than the reference values (P ≤ 0.05). Moreover, a larger deviation in the growth of Bangladeshi fetuses was observed after 28 weeks of gestation when compared with the WHO and INTERGROWTH-21st reference fetal growth charts (P ≤ 0.05). After 28 weeks of gestation, the average Bangladesh estimated fetal weight gain per week of gestational age was significantly lower than the WHO estimated fetal weight by as much as 67.4 g (P ≤ 0.001).ConclusionsThe present population-based study showed that fetuses were smaller in the third trimester when compared with the reference charts. Growth faltering started in the second trimester for all the biometric parameters for the head, abdomen, and femur. This finding provides more challenges concerning nutritional interventions.

523: Correlation between fetal liver length and reticulocyte count in women undergoing PUBS for alloimmunization

To assess the correlation between fetal liver length and reticulocyte count in women undergoing percutaneous umbilical cord blood sampling (PUBS) for alloimmunization. This was a single-center retrospective study. All consecutive singleton gestations with complete data referred to the Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Sidney Kimmel Medical College of Thomas Jefferson University (Philadelphia, PA) from January 2001 to December 2013 for suspected fetal anemia due to maternal alloimmunization (Rh-isoimmunization) were included in the study. Women with suspected fetal anemia were managed with detailed scan, including MCA Doppler and liver length. Only women who underwent PUBS were analyzed. The primary outcome was the correlation between the reticulocyte count at the first PUBS and the liver length at the time of the first PUBS quantified as z-score for gestational age. All fetuses were measured for fetal liver length from the right hemidiaphragm to caudal tip of the right liver lobe on coronal image of the fetal abdomen, using high-resolution real-time ultrasound with a 2- to 4-MHz convex transducer (Voluson E8 or E10). Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) to assess Pearson linear regression and multiple regression analysis. 16 fetuses with red blood cell alloimmunization were analyzed. A positive correlation was found between fetal liver length and reticulocyte count (r = 0.70; p-value = 0.01; Figure 1), and liver length and fetal hemoglobin level (r = 0.67; p-value = 0.03). Liver length measurement may be a useful indicator of the degree of and physiologic response to fetal anemia in isoimmunized pregnancies. This may be useful in timing the need for invasive diagnosis and therapy. Further studies of subsequent PUBS and non-Rh fetal anemia may better elucidate this process.