Early Fetal Corpus Callosum: Demonstrating Normal Growth and Detecting Pathologies in Early Pregnancy.

BACKGROUND AND PURPOSE: A malformed corpus callosum carries a risk for abnormal neurodevelopment. The advent of high-frequency transducers offers the opportunity to assess corpus callosum development in early pregnancy. The aim of the study was to construct a reference chart of the fetal corpus callosum length on ultrasound between 13 and 19 weeks of gestation and to prospectively examine growth patterns in pathologic cases. MATERIALS AND METHODS: We performed a prospective cross-sectional study between 2020 and 2022 in well-dated, low-risk, singleton pregnancies between 13 and 19 weeks of gestation. A standardized image was obtained in the midsagittal plane. Imaging criteria were used as a confirmation of the early corpus callosum. Measurements were taken by 4 trained sonographers. Intra- and interobserver variability was assessed. Corpus callosum length in centiles were calculated for each gestational week. RESULTS: One hundred eighty-seven fetuses were included in the study. All cases met inclusion criteria. At 13 weeks of gestation, the margins of the early corpus callosum were sufficiently clear to be measured in 80% (20/25) of fetuses. A cubic polynomial regression model best described the correlation between corpus length and gestational age. The correlation coefficient (r 2) was 0.929 (P < .001). Intra- and interobserver variability had high interclass correlation coefficients (>0.99). Presented is the earliest published case of agenesis of corpus callosum and a case of dysgenetic corpus callosum in Rubinstein-Taybi syndrome. CONCLUSIONS: Provided is a nomogram of the early fetal corpus callosum. Applying imaging criteria helped to identify a case of complete agenesis of the corpus callosum as early as 14 weeks.

Prevention of preterm delivery in twin gestations (PREDICT): a multicenter, randomized, placebo-controlled trial on the effect of vaginal micronized progesterone.

OBJECTIVE: Studies on high-risk singleton gestations have shown a preventive effect of progesterone treatment on preterm delivery. This study was conducted to investigate the preventive effect of vaginal micronized progesterone in a large population of twin gestations. METHODS: This was a double-blind, placebo-controlled randomized trial performed in 17 centers in Denmark and Austria. Women with twin gestations were randomized to daily treatment with progesterone pessaries or apparently identical placebo pessaries, starting from 20-24 weeks until 34 weeks' gestation. Primary outcome was incidence of delivery before 34 weeks' gestation. Secondary outcomes were maternal and neonatal complications and long-term infant follow-up, by Ages and Stages Questionnaire (ASQ), 6 months and 18 months after the expected date of delivery. We also updated a published meta-analysis to include our data and those of another recently published twin trial. RESULTS: A total of 677 women were randomized to the two treatments. Two women in the placebo group were lost to follow-up. Baseline characteristics for the groups were similar. Incidence of delivery before 34 weeks was 15.3% in the progesterone group vs 18.5% in the placebo group (odds ratio, 0.8 (95% CI, 0.5-1.2)). Risks of maternal and neonatal complications were comparable for the two groups. Mean ASQ scores at 6 months and 18 months were not significantly different between the two groups (215 for infants in the progesterone group and 218 for infants in the placebo group at 6 months (P = 0.45) and 193 and 194, respectively, at 18 months (P = 0.89)). The meta-analysis gave a pooled odds ratio of 1.06 (95% CI, 0.86-1.31). CONCLUSION: Progesterone treatment did not prevent preterm delivery in twin gestations. There were no harmful effects to fetuses and infants of maternal progesterone treatment.

Vaginal micronized progesterone and risk of preterm delivery in high-risk twin pregnancies: secondary analysis of a placebo-controlled randomized trial and meta-analysis.

OBJECTIVES: Progesterone treatment reduces the risk of preterm delivery in high-risk singleton pregnancies. Our aim was to evaluate the preventive effect of vaginal progesterone in high-risk twins. METHODS: This was a subanalysis of a Danish-Austrian, double-blind, placebo-controlled, randomized trial (PREDICT study), in which women with twin pregnancies were randomized to daily treatment with progesterone or placebo pessaries from 20-24 weeks until 34 weeks' gestation. This subpopulation consisted of high-risk pregnancies, defined by the finding of cervical length ≤ 10th centile at 20-24 weeks' gestation or history of either spontaneous delivery before 34 weeks or miscarriage after 12 weeks. Primary outcome was delivery before 34 weeks. Secondary outcomes were complications for infants including long-term follow-up by Ages and Stages Questionnaire (ASQ) at 6 and 18 months of age. RESULTS: In 72 (10.6%) of the 677 women participating in the PREDICT study, the pregnancy was considered to be high-risk, including 47 with cervical length ≤ 10th centile, 28 with a history of preterm delivery or late miscarriage and three fulfilling both criteria. Baseline characteristics for progesterone and placebo groups were similar. Mean gestational age at delivery did not differ significantly between the two groups either in patients with a short cervix (34.3 ± 4.1 vs. 34.5 ± 3.0 weeks, P = 0.87) or in those with a history of preterm delivery or late miscarriage (34.6 ± 4.2 vs. 35.2 ± 2.7 weeks, P = 0.62). Similarly, there were no significant differences between the treatment groups in maternal or neonatal complications and mean ASQ score at 6 and 18 months of age. CONCLUSION: In high-risk twin pregnancies, progesterone treatment does not significantly improve outcome.

SRY-specific cell free fetal DNA in maternal plasma in twin pregnancies throughout gestation.

OBJECTIVES: Levels of SRY-specific cell free fetal DNA (SRY-cffDNA) in maternal plasma were investigated in twin pregnancies with two male fetuses versus one male and one female fetus and singleton male pregnancies during second and third trimester. The aim was to evaluate at which gestational age the amount of SRY-cffDNA reflects the number of fetuses and placentas respectively. METHODS: 251 venous blood samples were analyzed from a total of 178 women with male or mixed-gender twin pregnancies and male singleton pregnancies in the second and the third trimester. The concentration of SRY-cffDNA was determined by quantitative real time PCR using the Y-chromosome specific SRY assay. For statistical analysis these three groups were divided into four subgroups according to their gestational age. RESULTS: During second trimester levels of SRY-cffDNA showed no differences between twin and singleton pregnancies. After 28 weeks SRY-cffDNA of male twin pregnancies was significantly increased compared to singleton male pregnancies and mixed-gender twin pregnancies with no differences between the latter two. CONCLUSION: The level of SRY-cffDNA in maternal serum of twin pregnancies reflects the number of fetuses only during the third trimester. Hence its use as a diagnostic tool for complications related to altered SRY-cffDNA levels in twin pregnancies should be evaluated at different weeks of gestation, especially during the second trimester.

What does magnetic resonance imaging add to the prenatal ultrasound diagnosis of facial clefts?

OBJECTIVE: Ultrasound is the modality of choice for prenatal detection of cleft lip and palate. Because its accuracy in detecting facial clefts, especially isolated clefts of the secondary palate, can be limited, magnetic resonance imaging (MRI) is used as an additional method for assessing the fetus. The aim of this study was to investigate the role of fetal MRI in the prenatal diagnosis of facial clefts. METHODS: Thirty-four pregnant women with a mean gestational age of 26 (range, 19-34) weeks underwent in utero MRI, after ultrasound examination had identified either a facial cleft (n = 29) or another suspected malformation (micrognathia (n = 1), cardiac defect (n = 1), brain anomaly (n = 2) or diaphragmatic hernia (n = 1)). The facial cleft was classified postnatally and the diagnoses were compared with the previous ultrasound findings. RESULTS: There were 11 (32.4%) cases with cleft of the primary palate alone, 20 (58.8%) clefts of the primary and secondary palate and three (8.8%) isolated clefts of the secondary palate. In all cases the primary and secondary palate were visualized successfully with MRI. Ultrasound imaging could not detect five (14.7%) facial clefts and misclassified 15 (44.1%) facial clefts. The MRI classification correlated with the postnatal/postmortem diagnosis. CONCLUSIONS: In our hands MRI allows detailed prenatal evaluation of the primary and secondary palate. By demonstrating involvement of the palate, MRI provides better detection and classification of facial clefts than does ultrasound alone.

Prenatal magnetic resonance imaging: towards optimized patient information.

OBJECTIVES: To investigate the perception of fetal magnetic resonance imaging (MRI) by women confronted with the necessity of a targeted prenatal examination because of suspicion of an abnormality, in order to develop a pre-scan information leaflet tailored to the information requirements of these women. METHODS: Sixty-two women were assessed by qualitative interview immediately before and after scanning. Data were analyzed by means of a qualitative content analysis. The transcribed interviews were coded within established categories, including knowledge of the purpose of the exam, understanding of the procedure, expectation of the baby's reaction, satisfaction with pre-information, experience of fetal MRI, distressing conditions during scanning, anxiety and suggestions for improvement of the scanning procedure. RESULTS: Pre-scan interviews indicated 66% of our sample to be well-informed about the purpose of fetal MRI. A realistic, detailed description of the examination was given by 37%. Only 32% expected the scanning to be safe for their baby. Despite the overall good tolerance of fetal MRI (63%), post-scan interviews revealed that 58% of women had experienced anxiety during MRI, which was partly due to the fearful perception of intensified fetal body movements during scanning. The quality of the pre-information leaflet was rated as sufficiently informative by 68% of the women. Suggestions for improvement were centered on physical conditions, the presence of the partner during scanning, and the availability of pre-scan briefings. CONCLUSIONS: Based on women's needs, detailed information about the fetal MRI procedure should be provided, containing clear-cut explanations about the purpose, course, method and possible distressing conditions. A leaflet describing these details should be given to women by the referring physician well in advance of the examination, and the woman given the opportunity to discuss unclear points.