First-trimester ultrasound: current uses and applications

Is there a role for fetal ductus venosus and hepatic artery Doppler in screening for fetal aneuploidy in the first trimester?

OBJECTIVE

The aim of the present study was to evaluate the utility of ductus venosus (DV) and hepatic artery (HA) doppler in pregnant women who have high risk for aneuploidy in first trimester combined screening.

METHODS

This prospective study was performed between February 2011 and February-2012, at a tertiary referral hospital. Singleton pregnancies with high risk for aneuploidy in combined screening test and normal nuchal translucency (NT) measurements were included in the study group. Measurements of DV Pulsatility Index of Veins (PIV) and HA Pulsatility Index (PI) were compared between the study group and controls.

RESULTS

Within the study period, 104 women with singleton pregnancies were evaluated for DV and HA measurements and among these, 64 women met the inclusion criteria. A control group that comprised 40 women with similar gestational age, normal NT measurements and low-risk in first trimester combined tests was generated. DV-PIV measurements were significantly higher (p = 0.03), whereas HA-PI measurements were similar (p > 0.05) in women who had high-risk for aneuploidy in first trimester combined test.

CONCLUSION

We concluded that the addition of DV-PIV and HA-PI measurements to the first trimester combined screening might increase the accuracy for Down syndrome detection.

A system for investigation of biological effects of diagnostic ultrasound on development of zebrafish embryos

A system for scanning zebrafish embryos with diagnostic ultrasound was developed for research into possible biological effects during development. Two troughs for holding embryos were formed from agarose in a rectangular dish and separated by an ultrasound absorber. A 4.9 MHz linear array ultrasound probe was positioned to uniformly scan all the embryos at the bottom of one trough, with the other used for controls. Zebrafish embryos were scanned continuously from 10-24 h post fertilization (hpf) during the segmentation period and gross morphological parameters were measured at 30 hpf, including viability, length, number of visible axons, and the progression of the lateral line primordium (LLP). Our initial tests were encumbered by the thermal effects of probe self-heating, which resulted in accelerated development of the zebrafish embryos. After subsequent optimization, our test revealed a significant retardation of primary motor axons and the migration of the LLP in embryos scanned with ultrasound, which indicated a potential for nonthermal effects on neuronal development. This diagnostic ultrasound exposure system is suitable for further investigation of possible subtle bioeffects, such as perturbation of neuronal migration.

Utility of First Trimester Ultrasonography before 11 Weeks of Gestation: A Retrospective Study

We showed the utility of first trimester ultrasonography before 11 weeks of gestation for antenatal followup. We retrospectively analyzed 1295 records of patients who underwent first trimester ultrasonography (transvaginal/abdominal) in our antenatal clinic in Ankara, Turkey. Maternal age, parity, gestational age, and maternal gestational history were compared with ultrasonographic findings. Patients were divided into 12 groups based on ultrasonographic diagnoses in the first ultrasonographic scan, and called for a control examination within 10 days if the diagnostic findings were abnormal. The data were statistically analyzed using Kruskal-Wallis and chi-square tests. We noted 81.3% patients to have single, viable, intrauterine pregnancies, while 18.7% had abnormal or complicated pregnancies with uterine anomalies, ovarian cysts, fibroids, or subchorionic hematomas. Normal and anembryonic pregnancies had significantly lower median diagnostic period in the control ultrasonography than in the first examination. First trimester ultrasonography before 11 weeks of gestation is valuable in determining pregnancy outcomes.

First trimester ultrasound: current approaches and practical pitfalls

Revolutionary technological improvements and high-frequency transvaginal scanning have enabled the resolution of ultrasound imaging in the first trimester to increase such that detailed early fetal development can now be well visualized. This investment in imaging technology has enabled not only normal embryonic development but also chromosomal abnormalities and structural anomalies to be more easily and accurately diagnosed before the second trimester. This article is intended to help radiologists in the interpretation and clinical application of normal and abnormal first trimester ultrasound findings in early pregnancy. We review the current literature and applications and interpretations of first trimester ultrasound.