Outcome of first-trimester fetal abdominal cysts: cohort study and review of the literature

Revisiting Ultrasound of Fetal Abdominal Cysts; the Common, the Uncommon and the Rare: A Pictorial Review

Fetal abdominal cysts are rare. The significance of antenatally discovered abdominal cysts can range from an innocuous finding to serious conditions needing surgery. It is often difficult to arrive at a correct diagnosis based on ultrasonography, as different types of cysts can have similar appearances. A more specific diagnosis is possible if fetal sex, age at appearance, location of the cyst, shape and appearance of the walls, and contents are considered. This review presents an extensive spectrum of fetal abdominal cysts. The common as well as the very rare causes that have only a few reports are discussed. Ultrasound images of confirmed cases are also presented. An algorithmic approach that enables a more specific diagnosis in many cases has been developed.

Management and outcome of fetal abdominal cyst in first trimester: systematic review of the literature

OBJECTIVE

The detection of a fetal abdominal cyst at the first-trimester ultrasound scan is a rare event, for which the natural history and prognosis are often unknown and unpredictable, owing to various underlying etiologies. The aim of this study was to evaluate the outcome of fetal abdominal cysts detected in the first trimester to better understand their possible clinical significance and improve their clinical management.

METHODS

We present a case report of a fetal abdominal cyst detected in the first trimester, with subsequent diagnosis of congenital multiple arthrogryposis. We also performed a systematic review of the literature to determine the incidence and outcome of similar cases, which was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and registered with PROSPERO (CRD42023491729). PubMed, Web of Science and EMBASE were searched from inception to December 2023 to identify case reports and case series documenting an ultrasound diagnosis of a single fetal abdominal cyst in the first trimester.

RESULTS

Our case presented at 12 + 6 weeks' gestation with an isolated fetal abdominal cyst, which underwent spontaneous resolution in the second trimester, when multiple congenital arthrogryposis was observed. Data on a total of 60 cases of fetal abdominal cyst detected in the first trimester were extracted from the literature. Of these, 35% were associated with concurrent or late-onset structural anomalies, as in our case, and 65% were isolated. In pregnancies with an isolated fetal abdominal cyst, 54% had a live birth with a normal outcome.

CONCLUSIONS

A fetal abdominal cyst in the first trimester is usually an isolated finding with a moderate-to-good prognosis, but it could also be an early sign of other associated abnormalities, including arthrogryposis. Increased ultrasound surveillance and additional genetic testing to rule out possible associated anomalies are necessary to assess the risk of adverse pregnancy outcome and provide appropriate parental counseling. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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.

Prenatal Diagnosis and Intervention in a Fetal Enterogenous Cyst

The ultrasound diagnosis of a fetal intra-abdominal cyst is typically established during the second or third trimester in the majority of cases. They primarily arise from the gastrointestinal or genitourinary system during the development of intra-abdominal structure and if isolated may resolve spontaneously. Enteric or enterogenous or enteric duplication cysts, which are congenital developments from the intestine, are most common. This case of an enterogenous cyst is presented because of its extreme rarity, its large size, and the need for prenatal intervention. Early identification and definitive treatment are necessary for proper management of this condition.

Prenatal ultrasound manifestations of partial urorectal septum malformation sequence from the first trimester to postnatal: a case report

BACKGROUND

Urorectal septum malformation sequence (URSMS) is characterized by incomplete partitioning of the genital, rectal, and urinary tracts, resulting in a severe form of anorectal malformation. The partial URSMS, also known as the persistent cloaca, represents a milder variant where a single perineal opening serves as a passage for the urinary, gastrointestinal, and reproductive tracts.

CASE PRESENTATION

We present a rare case of partial URSMS accompanied by duplicated vagina and uterus, hydronephrosis, ascites, and anal atresia.

CONCLUSIONS

This case report describes the sonographic findings at different stages of pregnancy and their changes throughout gestation.

Prenatal diagnosis at different gestational times and clinical features of choledochal cysts: a single tertiary center report

PURPOSE

This study aimed to evaluate the effect of prenatal diagnosis at different gestational times on the clinical features of patients with choledochal cysts (CDCs).

METHODS

Medical records of patients with prenatally diagnosed CDCs admitted to our hospital (April 2013-April 2018) were retrospectively reviewed. The clinical characteristics and pathological CDC features were analyzed.

RESULTS

Two hundred eighteen cases were included. Patients were divided into two groups. Group 1 and group 2 had a prenatal diagnosis at ≤ 27 weeks of gestation (second trimester of gestation, n = 157) and > 27 weeks (third trimester of gestation, n = 61), respectively. The incidence of jaundice and the TBIL, IBIL and GGT levels were higher in Group 1 (P = 0.021, P = 0.029, P = 0.042, P = 0.007, respectively). The maximum cyst diameter at the time of surgery was larger in Group 1 (P = 0.015). An association study showed that the time of prenatal diagnosis was negatively correlated with the maximum cyst diameter both postnatally (r = - 0.223, P = 0.001) and at the time of surgery (r = - 0.268, P < 0.001).

CONCLUSION

Unlike patients diagnosed at a late prenatal age, patients diagnosed at an early prenatal age tend to present clinical symptoms (jaundice, manifested as high indirect bilirubin), hepatic function damage, and large cysts at the time of surgery.

Outcomes of sonographically-suspected fetal intra-abdominal cysts: Surgical intervention, conservative management and spontaneous regression

OBJECTIVE

The prenatal diagnosis of fetal intra-abdominal cysts is challenging. This study aimed to evaluate the diagnostic ability of prenatal ultrasound for fetal intra-abdominal cysts and to develop a predictive method for pre- and postnatal outcomes.

METHODS

We retrospectively reviewed fetuses with ultrasound-detected intra-abdominal cysts between January 2013 and January 2020. The maternal-fetal clinical characteristics and ultrasound parameters were integrated into a model of pre- or postnatal outcomes.

RESULTS

The study enrolled 190 eligible fetuses, including 94 cases of spontaneous regression, 33 cases of conservative management and 63 cases of surgical intervention. For the 63 cases of surgical intervention, prenatal ultrasound was found to identify fetal intra-abdominal cysts with 80.00% sensitivity (95% CI: 67.03%-89.57%), 37.50% specificity (95% CI: 8.52%-75.51%), 89.80% positive predictive value (95% CI: 83.51%-93.86%), 21.43% negative predictive value (95% CI: 8.80%-43.53%) and 74.60% accuracy (95% CI: 62.06%-84.73%). The predictive model of prenatal spontaneous regression was as follows: y = -3.291 + 0.083 × gestational age + 1.252 × initial diameter, with an area under the curve (AUC) of 0.819 (95% CI: 0.739-0.899) and an optimal cut-off value of 0.74. The large cyst diameter before delivery was an independent predictor of postnatal surgical intervention (p < 0.001), with an AUC of 0.710 (95% CI: 0.625-0.794) and an optimal cut-off value of 3.35 cm.

CONCLUSION

Although ultrasound has a limited ability in the accurate diagnosis of fetal abdominal cysts, a simple method of measuring the diameter can predict fetal outcomes and identify the cases that may require surgical intervention or spontaneous regression.

Fetal abdominal tumors and cysts

This article reviews the contemporary diagnosis and management of the most common abdominal neoplasms and cystic lesions diagnosed in the fetus. Fetal tumors discussed include teratomas (sacrococcygeal, cervical or mediastinal), mesoblastic nephroma, nephroblastoma (Wilms' tumor), neuroblastoma, and hepatoblastoma. Fetal abdominal cystic lesions discussed include ovarian cyst, choledochal cyst, intestinal duplication cyst, mesenteric cyst, simple hepatic cyst, and meconium pseudocyst. We discuss the rare indications for fetal intervention or fetal surgery and other perinatal management, including prenatal interventions and fetal surgery for sacrococcygeal teratoma. The lesions reviewed are detected by widespread use of screening ultrasonography during pregnancy. Work-up for these abnormalities may include fetal MRI which enhances the diagnostic accuracy of abdominal tumors and cystic lesions and can aid in characterization of the lesion in relationship to surrounding anatomic structures. Accurate prenatal diagnosis of such lesions permits recommendations for optimal location and timing of delivery, and inclusion of appropriate caregivers and expertise to facilitate postnatal management. Perinatal management of the fetus with a neoplasm requires consideration of the optimal timing and mode of delivery, and pediatric oncology and surgical specialty care. The majority of tumors diagnosed antenatally have good prognosis with current multimodality treatment.

Can Anorectal Atresia Be Diagnosed in the First Trimester of Pregnancy? A Systematic Literature Review

Anorectal atresia (ARA) is a common congenital anomaly, but prenatal diagnosis is difficult, late, and unspecific. Utilizing a case of a 46 year old primipara with an egg donation In Vitro Fertilization (IVF) pregnancy, diagnosed at the first trimester scan with an anechoic isolated structure, which indicates anal atresia, we performed a systematic literature review in order to evaluate early prenatal ARA diagnosis. A total of 16 cases were reported as first trimester ARA suspicion, and only three had no associated anomalies. The most frequent ultrasound (US) sign was the presence of a cystic, anechoic pelvic structure of mainly tubular shape, or a plain abdominal cyst. In the majority of cases, structures were thin-walled and delimitated from the bladder. The presence of hyperechoic spots signifying enterolithiasis and peristaltic movements were helpful in order to establish the bowel origin of the lesion. Considering the high eventuality that the lesion is transitory, meaning later in pregnancy the fetus looks normal, early detection of such a sign should prompt further structural detailed evaluation, karyotyping, and appropriate pregnancy and postnatal counselling.

Fetal abdominal cysts: antenatal course and postnatal outcomes

Background There is little information on which to base the prognostic counselling as to whether an antenatally diagnosed fetal abdominal cyst will grow or shrink, or need surgery. This study aims to provide contemporary data on prenatally diagnosed fetal abdominal cysts in relation to their course and postnatal outcomes. Methods Fetal abdominal cysts diagnosed over 11 years in a single centre were identified. The gestational age at diagnosis and cyst characteristics at each examination were recorded (size, location, echogenity, septation and vascularity) and follow-up data from postnatal visits were collected. Results Eighty abdominal cysts were identified antenatally at 28+4 weeks (range 11+0-38+3). Most (87%) were isolated and the majority were pelvic (52%), simple (87.5%) and avascular (100%). Antenatally, 29% resolved spontaneously; 29% reduced in size; 9% were stable and 33% increased in size. Forty-one percent of cysts under 20 mm diameter increased in size, while only 20% of cysts with a diameter of over 40 mm increased in size. The majority of cysts were ovarian in origin (n=45, 56%), followed by intestinal (n=15, 18%), choledochal (n=3, 4%), liver (n=2, 3%) and renal/adrenal origins (n=2, 3%), respectively. In 16% (n=13), the antenatal diagnosis was not obvious. Seventy-five percent of the cysts that persisted postnatally required surgical intervention. Conclusion Most antenatally diagnosed fetal abdominal cysts were ovarian in origin. Though most disappeared antenatally, nearly three quarters required surgical intervention when present after birth. Cysts of intestinal origin are more difficult to diagnose antenatally and often require surgery.

Prenatal diagnosis and prognosis assessment of fetal intra-abdominal cystic lesions: a retrospective study in 264 cases

To assess the accuracy of prenatal diagnosis and the prognosis of fetal-abdominal masses, we reviewed all of the cases which had been diagnosed as having abdominal masses from January 2014 to December 2016. In total, 264 cases were identified as having abdominal masses. Among them, 141 cases (53%) had received specific prenatal diagnoses by prenatal ultrasound (US). MRI had assisted in the diagnosis and prognostic evaluation in 69 cases, increasing the diagnostic rate to 65%. The prenatal diagnoses of 111 cases (65%) were concordant with the postnatal diagnoses. Surgical intervention after birth was needed in 96 cases (39%). Most outcomes were good (89%). We suggest that prenatal US can detect and identify most fetal abdominal masses and that MRI helps to further describe the masses. With early intervention after birth, the prognosis was good in most cases. Impact Statement What is already known on this subject? Fetal-abdominal masses are commonly detected in antenatal examinations. A prenatal ultrasound is the main screening tool for detecting fetal intra-abdominal cystic lesions. What the results of this study add? We suggest that MRI is more helpful in some systems to reveal locations and structures. Even prenatal diagnosis cannot reach before birth, prognosis is quite good and expectant therapy is sufficient. What the implications are of these findings for clinical practice and/or future research? Our data strengthens the current knowledge of fetal abdominal masses to help relieve anxious parents by telling them that this congenital malformation has good outcomes. But multidiscipline consultation is necessary.

Differences in Origin and Outcome of Intra-Abdominal Cysts in Male and Female Fetuses

OBJECTIVE

To investigate the origin and outcome in a cohort of male and female fetuses with intra-abdominal cysts, in order to provide recommendations on management and to improve prenatal counselling.

METHODS

From 2002 to 2016, intra-abdominal cysts were detected by ultrasound in 158 fetuses. Cases with an umbilical vein varix were excluded. Fetal, neonatal, and maternal characteristics were retrieved from electronic patient files.

RESULTS

In female fetuses (n = 114), intra-abdominal cysts were diagnosed at a later gestational age compared with male fetuses (n = 44) (median 32.0 vs. 21.5 weeks, p < 0.001). The maximum prenatal cyst diameter was larger in female fetuses (median 35 vs. 17 mm, p < 0.001). Associated anomalies were less frequent in females (n = 15, 13.2%) compared with males (n = 15, 34.1%). In females (n = 114), most cysts were of ovarian origin (n = 81, 71.1%). Surgery was performed in 30 (26.3%) female and 15 (34.1%) male neonates (p = 0.33). Anorectal malformations were present in 6 cases and often not recognized prenatally.

CONCLUSIONS

The differences in the origin of intra-abdominal cysts between male and female fetuses, resulting in differences in prenatal presentation and postnatal outcome should be taken into account in prenatal counseling within a multidisciplinary team. Evaluation of the fetal perianal muscular complex is indicated.

First trimester expression of anorectal malformation: Case report and review of the literature

A 26-years-old woman, underwent an ultrasound examination at 13.4 weeks. A cystic structure was identified in the right lower abdomen. Gradually, the cystic mass was replaced by echogenic content and eventually attained the appearance of hyperechoic bowel. At 21.2 weeks, the anal sphincter could not be demonstrated which was consistent with the diagnosis of isolated anal agenesis. Amniocentesis revealed 46XY karyotype with normal comparative genomic hybridization. After termination of pregnancy at 23 weeks, an autopsy revealed an isolated high type anorectal malformation (ARM) without fistula. We reviewed all 14 cases reported in the literature of first trimester sonographic expression of ARM.

A reminder of peristalsis as a useful tool in the prenatal differential diagnosis of abdominal cystic masses

With routine antenatal ultrasound and recent advances in ultrasound technology, fetal intraabdominal cystic masses are recognized more often and are better characterized than in the past. They may be classified as solid and cystic, and may originate from multiple structures. When considering the extensive differential diagnosis of cystic masses, the observation of peristalsis narrows the possibilities to the gastrointestinal tract. To find this feature on ultrasound, the examiner must expressly think and look for it, otherwise it may be missed. Our case report illustrates one of those cases.

[Fetal abdominal cysts at the first trimester scan]

OBJECTIVES

Abdominal cysts are seldom detected at the first trimester scan. The aim of this study is to ascertain their outcome, which is currently not established.

METHODS

The French College of Fetal Ultrasound conducted a prospective observational study of 24months, collecting all cases of abdominal cysts discovered during the first trimester ultrasound. Cases of megacystis were excluded from the study. Ultrasound images, prenatal diagnosis expert reports and pregnancy outcomes were collected by sonographers after patient consent.

RESULTS

Ten cases of abdominal cysts were collected. The cysts had a mean diameter of 15mm. They were anechoic in 5 cases, hyperechoic in 2 cases and mixed in 3 cases. In 6 of 10 cases, complete resolution was observed at 18WG with a good post-natal outcome; the five cases with anechoic images were associated with normal pediatric examination at birth and in the case of the resolved hyperechoic image, an isolated imperforate anus was observed. In the four cases of hyperechoic or mixed images that had not resolved, the outcome was poor with four termination of pregnancies, including two cases of cloacal dysgenesis.

CONCLUSIONS

Abdominal cysts are rare at the first trimester scan. They resolve in two thirds of cases and are then associated with good outcome. When they do not resolve or when they are not strictly anechoic, they require a referral ultrasound examination at 18 and 22WG.

Outcome of fetal gastro-intestinal cysts: a systematic review and meta-analysis

OBJECTIVES

To explore the outcome of fetal gastrointestinal (GI) cysts and to ascertain the detection rate of prenatal ultrasound in identifying these anomalies.

METHODS

Medline and Embase databases were searched. The outcomes explored were: resolution of the cyst, additional GI anomalies detected only at birth, clinical symptoms, need for surgery, post-surgical complications and diagnostic accuracy. Meta-analyses of proportions and hierarchical summary receiver operating characteristics (HSROC) model were used to analyse the data.

RESULTS

Ten studies were included; 27.0% (95% CI 2.6-64.4) of the cysts resolved either pre or post-natally. Additional GI anomalies were detected in 6.0% (95% CI 1.1-14.7). Clinical symptoms occurred in 31.1% (95% CI 14.9-50.2), while 50.6% (95% CI 10.0-90.8) had surgery. Post-surgical complications occurred in 6.1% (95% CI 0.2-19.6). Overall detection rate of prenatal ultrasound in correctly identifying GI cysts was good (sensitivity: 94.5%, 95% CI: 39.1-99.8; specificity: 97.7%, 95% CI 89.9-99.5).

CONCLUSION

GI cysts are usually benign. Clinical symptoms occur in approximately one third of children. About one third of the cysts resolves, while the rate of complications after surgery is low. Prenatal ultrasound has an overall good diagnostic accuracy in identifying these anomalies. © 2016 John Wiley & Sons, Ltd.

Prenatal consultation for foetal anomalies requiring surgery

BACKGROUND

During prenatal screening of pregnant women, foetal anomalies requiring surgery may be diagnosed. Healthcare providers should have a basic knowledge of these diseases, including their workup, comorbidities, prognosis, treatment options and any considerations that need to be made in planning for birth.

AIM

This article aims to provide this information by summarising the most recent literature for some of the most commonly diagnosed foetal anomalies requiring surgical correction.

METHODS

English language studies on prenatal diagnostic modalities, abdominal wall defects, congenital diaphragmatic hernias, surgical conditions leading to airway compromise, hydrops fetalis, intestinal obstruction and abdominal cysts were retrieved from the PubMed database.

FINDINGS

The most recent and relevant literature is summarised regarding the above listed paediatric conditions. The incidence and prevalence (when available), prognosis, workup, common comorbidities, foetal interventions and special birth considerations (when applicable), and postnatal surgical treatment options are reviewed.

CONCLUSIONS

Healthcare providers will occasionally encounter foetal anomalies which may require surgery while performing prenatal screening. They may need to provide early counselling to expectant parents to inform their expectations. When indicated, referrals should be made to a foetal care centre for prenatal consultation. For conditions which may cause danger or distress to the foetus in the immediate postnatal period, preparations should be made to ensure sufficient resources are available at the location of birth.