The significance of the second trimester sonographic soft markers in pregnancies after normal first trimester screening

Clinical significance of soft markers in second trimesterr ultrasonography for pregnant Korean women: a multicenter study and literature review

Objective

To evaluate the clinical significance of soft markers for aneuploidy screening in Korean women.

Methods

We retrospectively reviewed the medical records of 5,428 singleton pregnant women who underwent sonography during the second trimester at seven institutions in South Korea. We evaluated the prevalence of the following soft markers: intracardiac echogenic focus, choroid plexus cysts, pyelectasis, echogenic bowel, and mild ventriculomegaly. We developed best-fitted regression equations for the fetal femur and humerus length using our data and defined a short femur and humerus as both long bones below the fifth centile. The results of genetic testing and postnatal outcomes were investigated in patients who had been diagnosed with aforementioned soft markers.

Results

The median maternal age of our study population was 33 years, and the median gestational age at the time of ultrasonographic examination was 21 weeks. We detected soft markers in 10.0% (n=540) of fetuses: 9.3% (n=504) were isolated cases and 0.7% (n=36) of cases had two or more markers. We identified only two aneuploides (trisomy 18, 46,XX,t[8;10][q22.1;p13]), of which one was clinically significant. We presented the neonatal outcomes of the fetuses with the respective soft markers. Preterm delivery, low birth weight, and small-for-gestational-age (SGA) were significantly more common in women with a shortened fetal femur (P<0.001, all). However, the presence of a shortened fetal humerus was not associated with those outcomes excluding SGA.

Conclusion

Soft markers in second-trimester ultrasonography have limited use in screening for fetal aneuploidy in Korean women. However, these markers can be used as a screening tool for adverse outcomes other than chromosomal abnormality.

Use of noninvasive prenatal screening with cell-free DNA in late pregnancy with sonographic soft markers

OBJECTIVE

To report the experience on the clinical use of noninvasive cell-free (cf) DNA testing at late pregnancy.

STUDY DESIGN

A cohort of 1539 women with singleton gestations of ≥23 weeks receiving cfDNA testing in a 3-year period were included for this study. Maternal characteristics and data on cfDNA testing, confirming diagnostic testing and pregnancy outcome were reviewed.

RESULTS

During the study period, 1539 patients had cfDNA testing although they had a normal first-trimester screening. Of these, 7 cases had a positive result, including 5 for chromosome 21, one for chromosome 18, and one for chromosome 13. The most common indication was soft markers on ultrasound, followed by polyhydramnios. Cytogenetic testing was done for the 5 trisomy 21 positive cases, and confirmed the cfDNA results. Confirmative testing was declined in the two cases with positive cfDNA for trisomy 18/13, and postnatal placental investigation showed confined placental mosaicism with normal karyotype in the cord blood of newborns. There were no confirmed false negatives reported. The cfDNA screening achieved a positive predictive value of 71.4 % and a negative predictive value of 100 % in late pregnancy for common trisomies.

CONCLUSIONS

There is no gestational age upper limit for cfDNA use in the clinical practice. Most of the time, cfDNA was used in late gestation for reassurance in patients who is at low risk for aneuploidies but had second-trimester soft markers on ultrasound.

Long-Term Outcome of Fetuses with Soft Marker and Without Genetic or Structural Abnormality

Purpose

To determine long-term outcome of infants with isolated or multiple soft markers but no structural or chromosomal abnormalities.

Methods

A retrospective study of 78 pregnant women who were referred for amniocentesis and found to have soft markers including echogenic intracardiac focus/foci (EIF), echogenic bowel (EB), unilateral or bilateral choroid plexus cysts, (UCPCs or BCPCs) mild pyelectasis and single umbilical artery but no structural anomalies and outcomes of the liveborns with a 4- to 9-year follow-up was conducted.

Results

Among 28 fetuses with EIF, allergic asthma and epilepsy were diagnosed in two liveborns. We followed up nine pregnancies with EB, epilepsy was present in one case. Allergic asthma was detected in both UCPCs and BCPCs, whereas epilepsy and attention-deficit/hyperactivity disorder (ADHD) were diagnosed in two liveborns with BCPCs. Twelve liveborns with multiple soft markers were evaluated; no pathology was detected in most of them except one case of allergic asthma, one case of hearing impairment and one case of ADHD.

Conclusions

This study shows longer-term favorable outcomes of the liveborns with isolated or multiple soft markers without any aneuploidy and may provide insight into this debated point.

Isolated intracardiac echogenic focus on routine ultrasound: implications for practice

Ultrasound is widely used as a screening tool for fetal anomalies. An intracardiac echogenic focus (ICEF) is associated with fetal aneuploidy, particularly trisomy 21, when found with other minor abnormalities known as soft markers. However, when found in isolation, intracardiac echogenic foci are morphologic variations with little or no pathologic significance for the fetus. Ambiguity about the significance of ICEF and other soft markers and the lack of preparation prior to ultrasound can result in unnecessary worry for women and their partners. A variety of tools exist that providers can use to help pregnant women and their partners make informed decisions about ultrasound and fetal screening.

Soft markers for aneuploidy following reassuring first trimester screening: what should be done?

PURPOSE OF REVIEW

The present article aims to review the current role of the soft markers on the second trimester ultrasound (STUS) in women after reassuring first trimester screening (FTS) in singleton pregnancies.

RECENT FINDINGS

Improvements in the FTS and the recent implementation of noninvasive prenatal testing (NIPT) for common aneuploidies have important impact on the prevalence of these conditions in the STUS. Some studies suggest that soft markers in the second trimester of the fetus without structural anomalies have a minor or no role in Down syndrome detection in a prescreened population with reassuring results. However, NIPT could be offered as a next step in the management of such pregnancies if the calculated new composite risk (NCR) for aneuploidy is increased. In the case of reassuring results, pregnancy follow-up for certain markers is advised.

SUMMARY

NIPT has emerged as a new method of prenatal testing and is feasible in the second trimester in women with increased NCR. However, apart from the Down syndrome screening, STUS screening remains a powerful tool in screening for other fetal aneuploidies, structural anomalies and pathological placental conditions and detection of specific soft markers that require pregnancy follow-up.

The utilization of circulating cell-free fetal DNA testing and decrease in invasive diagnostic procedures: an institutional experience

OBJECTIVE

To characterize the patient population utilizing circulating cell-free fetal DNA (ccffDNA) testing at a large academic center and evaluate trends in the performance of invasive diagnostic procedures.

STUDY DESIGN

A retrospective cohort study of all patients who underwent cell-free DNA testing from May to December 2012 was performed.

RESULT

During the study period, 206 patients had cell-free DNA testing. Of those, 75% (155/206) were of ages ⩾ 35 years. Of those undergoing ccffDNA testing, 41% had positive aneuploidy screening and 38% had abnormal ultrasound findings. Only 7% of the patients with negative ccffDNA testing opted for an invasive diagnostic procedure compared with 60% with positive testing (P<0.01). The rate of invasive procedures decreased from 5.9% of all visits to the center during a similar 8-month period in 2010 to 4.1% of all visits during the study period (P<0.01).

CONCLUSION

Our data suggest that ccffDNA testing leads to reduced uptake of invasive procedures.