Prospective detection of open spina bifida at 11–13 weeks by assessing intracranial translucency and posterior brain

Abstract

CASE SERIES Case 1A 30-year-old woman was referred at 13 + 1 weeks' gestation for first-trimester screening. The fetus had a crown-rump length (CRL) of 72 mm and a nuchal Figure 1 The mid-sagittal view is the best plane for evaluating intracranial translucency (IT) and the posterior brain region. This ultrasound image in a 13-week fetus illustrates the landmarks typical of a normal examination. The thalamus (Th) and brainstem (BS) have a hypoechoic appearance. The fourth ventricle, also called the IT, appears as an anechoic region with two horizontal echogenic borders, allowing reliable identification: the anterior border of the IT is the posterior border of the BS, and the posterior border of the IT is the choroid plexus (Chor. plex.) of the fourth ventricle. The choroid plexus is a well-recognized structure floating in the fluid of the IT and the future cisterna magna (f.CM), which are still connected to one another. The brainstem-occipital bone distance (BSOB) appears larger than does the brainstem diameter itself. OB, occipital bone. translucency thickness (NT) of 1.7 mm. Routine examination of the posterior brain failed to show the expected normal anatomy (Figure 1) 1,2 ; instead the brainstem appeared thickened and shifted backward toward the occipital bone (Figure 2), such that the ratio of brainstem diameter to brainstem-occipital bone distance (BS/BSOB ratio) was increased 3 , with a value of 1

Prenatal Diagnosis and Patient Preferences in Patients with Neural Tube Defects around the Advent of Fetal Surgery in Belgium and Holland

“…In the case of legal constrictions on gestational age for TOP, which is often limited to 24 weeks (as in the Netherlands), as well as in the area of fetal surgery (which must be done prior to 26 weeks), late diagnosis does not leave much time for referral, extensive counselling, reflection and, if applicable, a trip abroad to a fetal surgery center and approval by the insurer. Ideally, the diagnosis is made earlier, which is possible at the time of assessment in the first trimester [6,37]. It would, therefore, seem that more education and training is required to improve first-trimester diagnosis, which was infrequent for spinal lesions.…”

“…Secondary findings include ventriculomegaly, the lemon sign of the fetal skull or the banana sign of the cerebellum as a part of the ACM [2,3]. Sonographic signs earlier in gestation include a small biparietal diameter [4], intracranial translucency [5] and abnormalities of the posterior brain [6,7]. As more countries introduce first-trimester screening, the diagnosis may increasingly be made earlier in gestation.…”

The nomogram of intracranial translucency in the first trimester in singletons

“…NT, which is an important sample to these markers, identifies fetuses with trisomy 21 or other major aneuploidies, skeletal dysplasia and cardiac defects in the first trimester. Another such important earlier recognizable sonographic marker which has been suggested for detection of spina bifida, is an intracranial translucency (IT) (1)(2)(3). It is actually the fourth cerebral ventricle, seen as anechoic…”

Rapid initiation of fetal therapy services with a system of learner-centred training under proctorship: the National University Hospital (Singapore) experience

“…TTTS and certain structural anomalies may be anticipated by the presence of discordant NT and other signs on the 11-13-week scan. (46)(47)(48)(49) As high-quality ultrasonography is readily available, early detection of these treatable conditions allows advanced planning of therapy, which is particularly useful with a proctor who is based overseas. There is a smooth referral process that ensures rapid transfer of care of complicated MC twins from clinics in the private sector to NUH.…”