Assessment of the maxilla-mandible-nasion angle in normal and aneuploid foetuses in the first trimester of pregnancy.

PURPOSE: This retrospective study aims to determine whether the maxilla-mandible-nasion (MMN) angle can be reliably measured in the first trimester, to describe normal ranges, and to determine if significant changes occur in foetuses with aneuploidies. METHODS: The MMN angle was measured in stored 2D-ultrasound images of 200 normal fetal profiles between 11+0 and 13+6 weeks of gestation. Each image was analyzed by two observers at two independent time points. Bland-Altmann analysis was performed to evaluate the reliability of the measurements. Additionally, the MMN angle was measured on sonograms from 140 aneuploid foetuses. RESULTS: The mean MMN angle in normal foetuses from 11 to 14 weeks of gestation was 15.4°. Reliability of the measurement was high when repeatedly measured by the same observer (ICC = 0.92 and 0.82) and between two observers (ICC = 0.77 and 0.63). Average MMN values in foetuses with trisomy 21, 13, and Turner syndrome were significantly higher than those measured in normal foetuses. The highest differences were observed in foetuses with trisomy 13. Among those, 62% had an MMN angle above the 95th percentile and 92% above the normal mean. CONCLUSION: The MMN angle can be reliably measured in early pregnancy and is abnormal in about 60% of foetuses with trisomy 13.

Assessment of rapid fetal fibronectin in predicting preterm delivery.

OBJECTIVE: The aim of this study was to estimate the effectiveness of cervical fetal fibronectin assayed by the rapid fetal fibronectin assay in predicting preterm delivery in patients with signs or symptoms of preterm labor. METHODS: Patients with preterm labor between 24 and 34 weeks of gestation were included. At the time of speculum examination, fetal fibronectin samples were collected from the cervix. The probe was analyzed for fetal fibronectin using the rapid fetal fibronectin assay. Managing obstetricians were blinded to fetal fibronectin results. Outcome data were collected after delivery. RESULTS: One hundred seventy patients had fetal fibronectin samples and outcome data. The mean (+/- standard deviation) gestational age at delivery was 38.63 +/- 2.5 weeks among those with negative fetal fibronectin results (n = 124) and 35.71 +/- 3 weeks for those with positive results (n = 46; P < .001). The admission-to-delivery interval was 27.3 days shorter in the group with positive fetal fibronectin results (36.1 +/- 29.9 compared with 63.4 +/- 29.2; P < .001). The rapid fetal fibronectin assays were useful in predicting risk of delivery within 7, 14, or 21 days (sensitivity 81.8%, 87.5%, and 77.3%; specificity 76.7%, 79.2%, and 80.4; positive predictive value 19.6% [9/46], 30.4% [14/46], 37% [17/46]; negative predictive value 98.4% [122/124], 98.4% [122/124], and 96% [119/124], respectively). CONCLUSION: In a population of patients with signs and symptoms of preterm labor, the presence of cervical fetal fibronectin is effective in predicting risk of delivery within 7, 14, or 21 days. The negative predictive values of fetal fibronectin using the Tli systems compared well with data from previous reports using enzyme-linked immunosorbent assay-based assays. LEVEL OF EVIDENCE: III.

Assessment of fetal lung development by quantitative ultrasonic tissue characterization: a methodical study.

OBJECTIVES: This study was performed to evaluate the quantitative ultrasonic tissue characterization of the normal fetal lung development by using acoustic raw data captured after preprocessing. METHODS: One hundred and sixty-two patients with completed gestational ages between 22 and 37 weeks were enrolled in this study. Longitudinal and transverse sections of the fetal thorax and upper abdomen were imaged. A region of interest of constant size was defined and the tissue-specific gray scale was determined by using an interactive software. RESULTS: A total of 162 patients met the inclusion criteria. The echogenicity of the fetal lung showed a particular changing pattern during pregnancy: the mean gray value of the fetal lung (MGV) is almost the same as the MGV of the fetal liver at 22 and 23 weeks, decreases between 22 and 31 weeks and increases between 31 and 37 weeks. The MGV of the fetal liver decreases significantly from 24 weeks to 31 weeks and increases significantly again toward 37 weeks. We stated that the MGV of the lung is smaller than the MGV of the liver during 31 weeks of gestation and the relation reverses in late gestation. At term, the MGV of the liver is greater than the MGV of the lung. The lung-to-liver ratio is <1 between 24 and 29 weeks and >1 between 30 and 35 weeks. CONCLUSION: The echogenicity of the fetal lung showed a particular changing pattern during pregnancy, which corresponds to morphologic changes of the fetal lung development.