Third-trimester growth diversity in small fetuses classified as appropriate-for-gestational age or small-for-gestational age at birth.

OBJECTIVE: We have shown previously that third-trimester growth in small fetuses (estimated fetal weight (EFW) < 10th percentile) with birth weight (BW) < 10th percentile is heterogeneous using individualized growth assessment (IGA). We aimed to test our hypothesis that individual growth patterns in small fetuses with BW > 10th percentile are also variable but in different ways. METHODS: This was a study of 191 cases with EFW < 10th percentile and BW > 10th percentile (appropriate-for-gestational-age (AGA) cohort), derived from the PORTO study. Composite size parameters were used to quantify growth pathology at individual third-trimester timepoints (individual composite prenatal growth assessment score (-icPGAS)). The fetal growth pathology score 1 (-FGPS1), calculated cumulatively from serial -icPGAS values, was used to characterize third-trimester growth patterns. Vascular-system evaluation included umbilical artery (UA) and middle cerebral artery (MCA) Doppler velocimetry. Outcome variables were birth age (preterm/term delivery) and BW (expressed as growth potential realization index for weight (GPRIWT ) and percentile). The findings from the AGA cohort were compared with those from small fetuses (EFW < 10th percentile) with BW < 10th percentile (small-for-gestational-age (SGA) cohort). RESULTS: The AGA cohort was found to have 134 fetuses (70%) with normal growth pattern and 57 (30%) with growth restriction based on IGA criteria. Seven growth-restriction -FGPS1 patterns were observed, including the previously defined progressive, late, adaptive and recovering types. The recovering type was the most common growth pattern in the AGA cohort (50.9%). About one-third of fetuses without any evidence of growth restriction had significant unexplained abnormalities in the UA (34%) and MCA (31%) and elevated mean GPRIWT values (113 ± 12.5%). Comparison of the AGA and SGA cohorts indicated a significant difference in the distribution of -FGPS1 growth patterns (P = 0.0001). Compared with the SGA cohort, the AGA cohort had more fetuses with a normal growth pattern (70% vs 38%) and fewer cases with growth restriction (30% vs 62%). While the recovering type was the most common growth-restriction pattern in the AGA cohort (51%), the progressive type was the primary growth-restriction pattern in the SGA cohort (44%). No difference in the incidence of MCA or UA abnormality was found between the SGA and AGA cohorts when comparing subgroups of more than 10 fetuses. CONCLUSIONS: Both normal-growth and growth-restriction patterns were observed in the AGA cohort using IGA, as seen previously in the SGA cohort. The seven types of growth restriction defined in the SGA cohort were also identified in AGA cases, but their distribution was significantly different. In one-third of cases without evidence of growth pathology in the AGA cohort, Doppler abnormalities in the UA and MCA were seen. This heterogeneity underscores the difficulty of accurate classification of fetal and neonatal growth status using conventional population-based methods. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Single-mode operation in symmetric planar waveguides using isotropic chiral media.

We present the dispersion relations for symmetric planar waveguides in general isotropic media. The planar waveguide structure that utilizes chiral media in the cladding regions is emphasized. Unlike other symmetric planar waveguide configurations in isotropic media, this structure possesses a nondegenerate lowest-order mode. Therefore symmetric planar waveguides using chiral cladding materials can support single-mode operation.

Automated phase sensing and control of an external Talbot cavity laser with phase-contrast imaging.

We describe a novel phase-sensing and control system, based on phase-contrast imaging, operating within a linear external cavity laser consisting of 18 GaAlAs edge-emitting gain stripes. The system is used to achieve single-spatial-mode operation and diffraction-limited output from the linear cavity, which uses diffractive coupling at a Talbot plane to achieve coherent operation.

Intracavity phase correction of an external Talbot cavity laser with the use of liquid crystals.

Arrays of GaAlAs emitters have been diffractively coupled by using an external Talbot cavity to support a single spatial mode; however, element-to-element phase differences distort the desired spatial mode. To enable element-to-element phase correction, we incorporated a 20-element array of tunable liquid-crystal phase shifters into a 20-element GaAlAs external Talbot cavity laser. Using the tunable phase shifters, we corrected spatial mode distortions, which resulted in 663 mW of nearly diffraction-limited power.

Pancoast tumor presenting as cervical radiculopathy.

A case of Pancoast tumor presenting as cervical radiculopathy is reported, including the clinical, EMG, and radiologic findings. A 64-year-old man with a two-month history of left shoulder pain and left arm numbness at the medial aspect of the hand and forearm presented for electrodiagnostic examination, and a severe C8 radiculopathy was documented. Subsequent radiologic evaluation (myelogram and routine chest x-ray) yielded the diagnosis of left apical lung tumor (Pancoast tumor), eroding through the C7 and T1 pedicles and T1 vertebral body, with cut-off of the left C8 nerve root. Pancoast tumor has long been implicated as a cause of brachial plexopathy. The EMG presentation of isolated cervical radiculopathy, however, has not been previously reported, despite the tumor's known tendency for local invasion which may include the nerve roots and even the spinal canal in its advanced stages. This patient's normal sensory studies argue against any significant coexisting lower brachial plexopathy. The possibility of Pancoast lesion should be considered not only in the presence of brachial plexopathy, but also when C8 or T1 radiculopathy is found.