Clinical significance of first-trimester chorionic bumps: a matched case-control study

Chorionic bump: Progression to a subamniotic hematoma

INTRODUCTION

A chorionic bump is an increasingly recognized ultrasound finding in first-trimester scans, which has been associated with early pregnancy loss. In ongoing second-trimester pregnancies, however, chorionic bumps usually resolve over time with no deleterious effect on the fetus. In this report, we describe the incidental ultrasound detection of a chorionic bump in early pregnancy and its progression to a subamniotic hematoma in the second trimester of pregnancy that persisted as such until delivery.

CASE REPORT

A round, echogenic mass protruding from the choriodecidual surface measuring 13 × 11 × 8 mm was first identified during a transvaginal scan at 6.3 weeks' gestation. Subsequent follow-up scan at 8.3 weeks revealed an increase in the size of the chorionic bump to 25 × 20 × 19 mm, which remained stable as determined by the routine late first-trimester scan. At the second-trimester scan, a subamniotic hematoma was identified in the surface of the placenta, close to the insertion of the umbilical cord. Subsequently, the pregnancy proceeded uneventfully.

DISCUSSION

The etiopathology and clinical significance of a chorionic bump remain unclear. The case herein reported demonstrates that a chorionic bump can grow considerably without having a deleterious effect on the early embryo and, occasionally, can persist throughout pregnancy as a subamniotic hematoma.

CONCLUSION

A chorionic bump can occasionally progress to a subamniotic hematoma from the second trimester onwards. This observation further supports the hypothesis that a chorionic bump is the result of choriodecidual bleeding. An alternative explanation for the development of subamniotic hematomas is proposed.

Case report: Chorionic bump detected in the third trimester

A chorionic bump (CB) is a focal irregular bulge in the surrounding choriodecidual due to hematoma. The incidence of CB is between 1.5 and 7 per 1000 pregnancies. The presence of a chorionic bump is associated with a significantly higher risk of adverse perinatal outcomes. CB often decreases in size with time and rarely persists beyond the first trimester. Our case report presents and discusses a chorionic bump diagnosed in the third trimester. To our knowledge, this is the first case of CB to reported in the third trimester.

Pregnancy and perinatal outcomes in pregnancy with diagnosis of chorionic bump on first-trimester sonography: a systematic review and meta-analysis

OBJECTIVE

To assess the relationship between the presence of the sonographic finding of chorionic bump (CB) during first trimester and miscarriage rate or other perinatal outcomes.

METHODS

PubMed, Medline, Embase, Cinahl and Clinicaltrials.gov databases, from inception to April 8, 2021 were explored utilizing combinations of the relevant medical subject heading (MeSH) terms, key words, and word variants for "CB" and "pregnancy." Prospective and retrospective case-control studies were eligible for inclusion. Odds ratios (ORs) comparing obstetrical outcomes among pregnancies with CB and normal pregnancies were determined with 95% confidence intervals (CI) using random-effects models. Primary outcome of interest was miscarriage rate. Secondary outcomes were: alive newborns (ANB) rate, adverse pregnancy outcomes (APO) and vaginal bleeding. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale.

RESULTS

Five studies including 173 pregnant women with CB (study group) and 1,263 pregnant women without CB (control group) were included. Pregnancies affected by CB resulted to be associated with a significantly higher miscarriage rate (43.3% vs 20.7%; OR 2.95 95% CI 2.02-4.31, p < .00001), and conversely with a significantly lower rate of ANB (60.3% vs 82%; OR 0.35 95% CI 0.20-0.63, p = .0004). In addition, the risk of APO was around three-fold higher in the study group (52.2% vs 4.12%; OR 2.98 95% CI 1.04-8.51, p = .04), while the rate of vaginal bleeding was higher in the study group, without reaching a statistical significance (48% vs 16.4%; OR 2.21 95% CI 0.64-7.65 p = .21).

DISCUSSION

The presence of CB at first trimester ultrasound significantly increases the risk of miscarriage and APO, and intact the rate of ANB. This article is protected by copyright. All rights reserved. Key message: The presence of CB on early first trimester ultrasound increases three-fold the risk of miscarriage and adverse pregnancy outcomes and reduces the rate of alive newborns. It is important to consider CB as an ultrasound marker that requires a close surveillance throughout pregnancy to prevent long-term complications and provide adequate counseling to the patient.

Chorionic Bump: Radiologic Features and Pregnancy Outcomes

Background

Chorionic bump is a rare condition defined as a bulge or protrusion from the choriodecidual surface into the gestational sac. The limited literature on this infrequent entity suggests that the pregnancies with multiple chorionic bumps mostly result in fetal demise.

Aims

To review the available literature and the patients from our institute having sonographic findings of chorionic bump and making the sonographers and radiologists aware of this known cause of first-trimester pregnancy loss.

Study design

A retrospective review of the cases diagnosed at our institute during the last four years.

Methods and materials

Single-center institutional data for four years (January 2016-December 2019) was accessed using ICD codes. IRB approval was waived owing to the anonymized use of patient data.

Results

Six female patients diagnosed with chorionic bump were included, with a mean age of 29.83±12 years. The average gestational age at the time of diagnosis was 8.16±3 weeks. The most common sonographic findings were a protrusion from the chorionic wall into the gestational sac cavity, having a central hypoechoic region with peripheral hyperechoic rim (isoechoic to the chorion) and having no vascularity (n=5), and the less common finding was a hyperechoic protrusion with no vascularity (n=1). n=5 had a single lesion, and n=1 had two lesions. The average diameter of the lesion in the largest dimension was 18±11 mm. n=3 pregnancies resulted in a first-trimester miscarriage, and n=3 pregnancies delivered healthy babies at term. 

Conclusions

A chorionic bump significantly increases the risk of a first-trimester miscarriage.

A single-center retrospective study of the clinical significance of chorionic bump at early stage of gestation

PROBLEM

The chorionic bump is a distinct rare sonographic abnormality. Until now, there is contradictory evidence about if it associates with poor pregnancy outcomes. We performed this retrospective study to provide additional clinical data to investigate the clinical significance of chorionic bump at early stage of pregnancy.

METHOD OF STUDY

A single-center retrospective study was performed using the sonographic and clinical data of the pregnant women who had antenatal checkup and childbirth at Shanghai First Maternal and Child Health Care Center from December 2018 to December 2019. Sonographic examination was performed by experts at 5-10 weeks' gestation. Maternal age and gestational age matched controls from the same period were selected for analysis.

RESULTS

We observed 83 chorionic bump cases showing a prevalence of 0.33%. We found previous intrauterine operations and/or adverse maternal history posed a risk of having chorionic bump. In our cohort, chorionic bump associates with poor pregnancy outcomes. Poor pregnancy outcomes were more frequently found in the patients whose lesions were detected early (<56 days of pregnancy), or in the patients with the lesion relative sizes more than 40% of the sizes of the gestational sac, or in the patients with multiple lesions.

CONCLUSION

Intrauterine operations and/or adverse maternal history associate with an increased incidence of chorionic bump, which associates with poor pregnancy outcomes. Early detection, bigger relative size, and multiple lesions are factors likely leading to poor pregnancy outcomes.

Chorionic bump at 11 to 13 weeks' gestation: Prevalence and clinical significance

OBJECTIVE

To gather additional data on pregnancy outcome when a chorionic bump is detected at the time of the 11- to 13-week scan.

METHODS

The presence of a chorionic bump was prospectively recorded in a database of women presenting for their first-trimester sonographic screening. Clinically relevant information was obtained by reviewing ultrasound reports and medical records or contacting the referring obstetrician or the parents themselves.

RESULTS

During a 4.5-year study period from June 2014 to December 2018, a chorionic bump was identified in 23 out of 3375 pregnancies, for a prevalence of 1/147 or 0.7%. All women were asymptomatic at the time of evaluation. The chorionic bump was single in 21 (91%) cases, located in the central part of the placenta in 17 (74%) cases, and the median largest diameter was 20 mm (range, 10-43). Although the placenta was low-lying in 14 (61%) cases, all but one patient had a normally located placenta at the midtrimester anatomy scan. With the exception of one pregnancy complicated with trisomy 21, the outcome was universally good.

CONCLUSION

Our experience suggests that a chorionic bump detected during the 11- to 13-week scan is usually a transient, is incidental finding, and probably has no clinical significance.

Ultrasound of the First Trimester

Ultrasound is the imaging study of choice for detection and full characterization of early pregnancies based on its accuracy, low cost, safety profile, and abundant availability. This article reviews the goals and utility of first-trimester ultrasound in gestation localization, viability determination, and abnormal pregnancies, including ectopic implantation, retained products, and molar pregnancy.

Chorionic bump in a pregnant patient with a history of infertility

Chorionic bump is a rare condition in the first trimester of pregnancy. It appears as a bulge from the choriodecidual surface into the gestational sac. So far, there have been no ultrasound or clinical markers that can predict a difference in outcomeWe report a case of a pregnant woman with history of infertility, diagnosed in the first trimester with a chorionic bump. It disappeared spontaneously at 23 weeks of gestation. The pregnancy went well and she delivered a healthy baby.The aetiology and clinical significance of the chorionic bump remains unclear.

Failed Intrauterine Pregnancy: What Is a Failed Pregnancy, What Is Not?

Pregnancy failure is defined as a lack of sonographic evidence of current or expected viability. Technologic advances in ultrasound imaging continue to redefine diagnostic criteria of pregnancy failure or success. When evaluating a pregnancy, the first step is an assessment of maternal risk factors for failure. Imaging clues such as an empty gestational sac measuring ≥25 mm or an embryo ≥7 mm without cardiac activity are reliable signs of pregnancy failure, whereas embryonic growth <1 mm/d is not. Combinations of sonographic findings can be used for a more accurate prediction of pregnancy success or failure.

Chorionic Bump in First-trimester Sonography

Objectives

The present research was motivated by providing new insight into early pregnancies with a chorionic bump diagnosis in first-trimester sonography and its impact on live birth rate.

Methods

To determine the rate of CB, first trimester sonograms of pregnant women referring to Akbarabadi Hospital, which is a treatment and training center affiliated to Iran University of Medical Sciences as well as those referring to a private center were analyzed. The total number of transvaginal sonographies performed was 1900 cases from whom 8 cases of CB were detected. The chorionic bump size and number and history of infertility or coagulation disorders were considered as our independent variables and multiple gestation with pregnancy outcome as dependent ones.

Results

Overall, the prevalence rate of CB was 0.4% (4 per 1000), with 8 patients diagnosed with CB from 1900 the first trimester pregnant women. Of 8 pregnant women, 5 showed live birth (62.5%) and 3 experienced fetal demise (37.5%). The chorionic bumps ranged in size from 0.1 cc to 1.8 cc (average, 0.73 cc). No significant relationship was found between history of smoking, coagulopathy, infertility, multiple gestation and the size of CB.

Conclusions

The main finding was that the frequency of live birth in our sample was 62.5% (5 from 8). The clinical inference is that a chorionic bump on first-trimester sonography does not definitely guarantee a secure prediction. The correlation between bump size and pregnancy outcome is not clear, which warrants further research.

First-trimester chorionic bump--Association with fetal aneuploidy in a high-risk population

PURPOSE

To determine the relationship between the first-trimester chorionic bump and fetal aneuploidy.

METHODS

This retrospective cohort study included all singleton pregnancies with chromosomal analysis and sonographic examination performed between 5 0/7 and 13 6/7 weeks from January 1, 2010 through August 15, 2015. Interobserver and intraobserver agreement for identifying a chorionic bump was evaluated by the Kappa statistic. Pregnancies with and without a chorionic bump were compared regarding patient characteristics and fetal karyotypes.

RESULTS

Six hundred ninety subjects were included, 16 (2.3%) having a bump. The kappa coefficients for interobserver agreement were 0.88 (95% confidence interval [CI]: 0.71-1.00) and 0.94 (95% CI: 0.82-1.00); those for intraobserver agreement were 0.81 (95% CI: 0.61-1.00) and perfect agreement. One hundred seventeen fetuses (16.9%) were aneuploid, of which five (4.3%) had a bump. The odds of aneuploidy in the presence of a chorionic bump were higher than those in the absence of a chorionic bump, although this difference was not statistically significant (odds ratio [OR] 2.3, 95% CI: 0.8-6.7). In subgroup analyses, odds of aneuploidy were four times higher in the bump group than in the no bump group among those with a sonographically isolated bump (OR 4.5, 95% CI: 1.5-13.5) and 15 times higher among those with an isolated bump and increased first-trimester aneuploidy risk (OR 15.0, 95% CI 2.4-93.3).

CONCLUSIONS

Agreement in identifying chorionic bumps is near-perfect. A sonographically nonisolated chorionic bump is not associated with significant additional aneuploidy risk, whereas a sonographically isolated chorionic bump confers a significantly increased likelihood of aneuploidy in high-risk fetuses. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:3-7, 2017.

The chorionic bump: Etiologic insights from two pathologic pregnancies

The clinical significance and etiology of the chorionic bump remain unclear. We describe two pregnancies characterized by chorionic bumps, which subsequently were diagnosed with a complete mole and trisomy 18, respectively. We hypothesize that placental pathology, including edema and hydropic villi, may contribute to or cause the sonographic finding of some chorionic bumps. An association between chorionic bumps and aneuploidy awaits future study. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:452-454, 2016.

Diagnostic Methods of Ectopic Pregnancy and Early Pregnancy Loss: a Review of the Literature

This review article presents recent evidence on early pregnancy loss and ectopic pregnancy. In the light of recent evidence, the β-hCG discriminatory zone may be extended in clinically stable cases without evidence of bleeding. A possible cut-off is 4300 mIU/ml, which corresponds to when a sonographer should detect an intrauterine pregnancy. Embryonic demise can be confirmed when a transvaginal ultrasound finding shows no heartbeat in an embryo of more than 7 mm CRL, no embryo in a gestational sac having a mean sac diameter of more than 25 mm, or no appearance of an embryo within 7-10 days after the primary examination. These are considered definitive signs of embryonic demise. Suggestive signs of embryonic demise require closer monitoring of the pregnancy.

Chorionic bump in pregnant patients and associated live birth rate: a systematic review and meta-analysis

OBJECTIVES

A chorionic bump on first-trimester sonography has been considered a risk factor for nonviability in pregnant patients with this rare finding, although the strength of this association has recently been questioned. We performed a systematic review and meta-analysis to summarize the association between a chorionic bump and nonviability.

METHODS

A comprehensive literature search was performed. We included all studies except case reports. A meta-analysis was performed using a random-effects model.

RESULTS

After screening 5 studies, 2 studies with a total of 67 patients met inclusion criteria. These were combined with a study (n = 52) from our institution. Overall, the live birth rate was 62% (74 of 119). Fifty-one chorionic bump pregnancies were otherwise normal (ie, pregnancies in which a gestational sac, a yolk sac, and an embryo with a heartbeat was seen at some point), and in this subset, the live birth rate was 83% (42 of 51). There was no significant relationship found between vaginal bleeding and live birth (P = .857); there was no significant difference in bump volume between live birth and no live birth (P = .198); and for the subset analysis of pooled odds ratios for the relationship between live birth and history of infertility, there was no significant relationship found (P = .186).

CONCLUSIONS

A chorionic bump remains a risk factor for nonviability in pregnancy; however, if the pregnancy is otherwise normal, then most result in live birth.

Chorionic bump on first-trimester sonography: not necessarily a poor prognostic indicator for pregnancy

OBJECTIVES

The purpose of this study was to determine the live birth rate of pregnancies with a diagnosis of a chorionic bump, a convex bulge from the choriodecidual surface into the first-trimester gestational sac.

METHODS

Pregnant patients at least 18 years old with the finding of a chorionic bump on first-trimester sonography were included in this prospective observational study. The independent variables were chorionic bump size and number and presence or absence of a history of infertility or coagulation disorder. The primary end point was pregnancy outcome.

RESULTS

During the 4-year study period, 52 pregnancies had a diagnosis of a chorionic bump. Overall, 34 resulted in live births, corresponding to an absolute live birth rate of 65%, and 18 were nonviable. Forty-one chorionic bump pregnancies were otherwise normal (ie, pregnancies in which a gestational sac, yolk sac, and embryo with heartbeat were seen at some point), and in this subset, the live birth rate was 83% (34 of 41). All pregnancies with more than 1 chorionic bump (4) ended in demise (100%). The average maximum dimension of the chorionic bump was 1.3 cm (range, 0.5-3.8 cm); however there was not a statistically significant correlation between chorionic bump size and pregnancy outcome (P = .5866; odds ratio, 0.54; 95% confidence interval, 0.06-5.01). Nine patients (17%) had a history of infertility treatment, and 4 (8%) had a history of coagulation disorder. Only 1 chorionic bump pregnancy was associated with a birth defect.

CONCLUSIONS

The live birth rate in our chorionic bump cohort was 65% overall and even higher (83%) if the pregnancy was otherwise normal. The clinical implication is that a chorionic bump on first-trimester sonography is not necessarily associated with a guarded prognosis.