First trimester cervical length is associated with mid-trimester loss.

OBJECTIVE: To study the value of the cervical length (CL) measurement at 11-14 weeks in predicting second trimester miscarriage occurring at 16-24 weeks. METHODS: Prospective study in routine obstetric population using transvaginal ultrasound examination to measure the length of the endocervical canal at 11-14 weeks. RESULTS: The study group consisted of 2836 singleton pregnancies. Eleven (0.0038%) women miscarried between 16 and 24 weeks whereas 2825 delivered after 34 weeks. CL was significantly shorter (Mann-Whitney U test, p = 0.001), in women that had a second trimester miscarriage in comparison to those who delivered after 34 weeks (median CL 28 mm versus 32 mm, respectively). First trimester CL was predictive of a late miscarriage (OR = 0.7093304, R(2 )= 0.1211, AUC = 0.7838, p < 0.001). The detection rate was 63.64% for 20% screen positive rate. CONCLUSIONS: First trimester endocervix is significantly shorter in women destined to miscarry between 16 and 24 weeks. In low risk singleton pregnancies, first trimester CL can be useful in predicting second trimester miscarriage.

Towards detecting open spina bifida in the first trimester: the examination of the posterior brain.

INTRODUCTION: Our aim was to examine the value of indirect signs of open spina bifida in the mid-sagittal view of the posterior brain at the 11-13 weeks' ultrasound examination and to summarize the current evidence for the first-trimester diagnosis of spina bifida. METHODS: This was a prospective study in routine obstetric population. The presence of four almost parallel lines (four-line view) in the posterior brain was recorded. Biparietal diameter (BPD), intracranial translucency (IT) and cisterna magna (CM) were measured. The ratio of IT to CM (R ratio) was calculated. RESULTS: 2,491 pregnancies were examined prospectively. Updated reference ranges for IT and CM were constructed. There were 3 cases with open spina bifida, and the four-line view was abnormal in 2 of them. The abnormal fetuses had smaller BPD as well as pronounced reduction in the CM and increase in the R ratio. DISCUSSION: Examination of the posterior brain was feasible in all fetuses in the setting of the routine 11-13 weeks' ultrasound examination. Indirect signs of spina bifida are visible in the mid-sagittal view of the posterior brain, and the assessment of these structures can be a reliable tool in the early identification of this abnormality.

Assessment of the posterior brain at 11-14 weeks for the prediction of open neural tube defects.

OBJECTIVE: To evaluate the routine midsagittal view of the posterior brain at the 11-13 weeks' ultrasound examination, for predicting open neural tube defects. METHODS: Posterior brain was examined midsagittally for normality of the four-line view (upper and lower border of the brain stem, the choroid plexus of the fourth ventricle and the occipital bone). Intracranial translucency and cisterna magna (CM) were measured. RESULTS: The posterior brain was assessed in 1330 cases. The four-line view was normal in all but one case. In the two cases of open spina bifida contained in the study population, intracranial translucency was within normal range. The CM and the four-line view were normal in the first case, whereas in the second case, the four-line view was abnormal, and CM was obliterated and impossible to measure. No other cases of abnormal four-line view were observed in the study population. CONCLUSION: Obliteration of the CM appears to be the most consistent early sign of open neural tube defects. Attention should focus on either measuring the cisterna magna or simply observing the presence of four lines in the midsagittal view of the posterior brain. However, these early signs of brain herniation are not present in all abnormal cases.

Screening for major structural abnormalities at the 11- to 14-week ultrasound scan.

OBJECTIVE: The purpose of this study was to examine the value of performing a detailed examination of the fetus as part of the routine 11 to 14 weeks' ultrasound scan in a 2-stage screening process for major structural defects in low-risk pregnancies. STUDY DESIGN: This was a prospective study in 1148 singleton pregnancies at 11 to 14 weeks of gestation using a combination of transabdominal and transvaginal sonography to estimate the sensitivity of the first and second trimester ultrasound scan in the detection of major anomalies. RESULTS: Seven of the 14 major anomalies were detected at the 11 to 14 weeks scan, and an additional 6 at the second trimester scan. The sensitivity of the early anatomic examination and the overall sensitivity of the 2-stage screening were 50% and 92.8%, respectively. Nuchal translucency was increased in 5 of the 14 (35.7%) abnormal fetuses and in 1 of the 4 cases (25%) with major heart defects. CONCLUSION: Detailed, structured examination of fetal anatomy during the routine 11 to 14 weeks' scan can detect half of major structural defects in low-risk pregnancies.