Fetal Open and Closed Spina Bifida on a Routine Scan at 11 Weeks to 13 Weeks 6 Days.

OBJECTIVES: This study aimed to determine the sensitivity of a first-trimester routine scan in detecting spina bifida (SB) and evaluating the first-trimester intracranial signs. METHODS: This retrospective study was a review of a prospectively collected database. All cases of SB diagnosed in a tertiary center from 2008 to 2015 were identified. The ultrasound images and medical records were reviewed. All cases of SB diagnosed prenatally were confirmed at birth or autopsy. RESULTS: A total of 24 cases of SB were diagnosed from 53,349 pregnancy cases. Except for 10 cases with a body stalk anomaly, craniorachischisis, or iniencephaly, 7 cases with open spina bifida (OSB) and 7 cases with closed spina bifida (CSB) were analyzed. The first-trimester detection rates were 100% (7 of 7) for OSB and 28.5% (2 of 7) for CSB. Eight cases were highly suspected of SB in the first trimester because of an abnormal appearance of the posterior brain; 3 were false-positive cases. Two isolated cases of OSB had first-trimester intracranial signs. An obliterated cisterna magna (CM) showed the highest sensitivity for OSB but low specificity. Two cases of OSB had no discernible landmark of intracranial translucency and the CM, and 4 showed normal intracranial translucency with an obliterated CM. All CSB cases were coupled with a normal hind brain except for 2 cases. CONCLUSIONS: A first-trimester routine scan has high sensitivity in screening for OSB. The CM may be the most sensitive intracranial sign.

Routine first-trimester ultrasound screening using a standardized anatomical protocol.

BACKGROUND: First-trimester ultrasound scans were introduced to China for nearly 20 years. The ability of first-trimester ultrasound screening to detect different malformations was variable. A recent systematic review concluded that the use of a standardized anatomic protocol was the most crucial factor to improve the sensitivity of first-trimester ultrasound screening for anomalies. Standardized sectional scans have long been used for routine anatomy screening during the second trimester. However, during the first trimester, most of the previous studies have described the observation of anatomic structures but have not specified clearly the standard sectional views. OBJECTIVE: We aimed to determine the performance of routine first-trimester scans using a standardized anatomic protocol for detecting structural abnormalities in China. STUDY DESIGN: This was a large retrospective study involving 59,063 sequential unselected pregnancies. Scans at 11 to 13+6 weeks were performed in a single center during a 7-year span. All fetuses were examined following a predefined protocol for standardized views. RESULTS: From October 2008 to December 2015, first-trimester scans were performed in 53,349 pregnant women with available outcome. Of these, there were 1578 (3%) pregnancies that presented with at least 1 fetal structural abnormality. The detection rate for first-trimester screening was 43.1% (95% confidence interval, 40.6%-45.5%). Routine first-trimester scans detected 95.6% of abdominal wall defects, 66.3% of nervous system defects, 33.8% of limbs and skeleton malformations, 30.8% of facial abnormalities, 21.2% of urogenital abnormalities, 18.4% of thoracic and lung abnormalities, and 4.1% of gastrointestinal tract abnormalities. During the first trimester, 37.7% of cardiac defects were identified and included 57.9% of major cardiac defects and 2.6% of mild cardiac defects. A robust high detection rate for anencephaly, exencephaly, cephalocele, holoprosencephaly, exomphalos, gastroschisis, Pentalogy of Cantrell, sirenomelia, and body stalk anomaly was achieved during routine first-trimester scans. CONCLUSION: A standardized anatomic protocol is advised when performing routine first-trimester ultrasound screening. It is recommended that screening for severe structural abnormalities should be extended to the first trimester.

Congenital abnormalities of the aortic arch: revisiting the 1964 Stewart classification.

The traditional classification of congenital aortic arch abnormalities was described by James Stewart and colleagues in 1964. Since that time, advances in diagnostic imaging technology have led to better delineation of the vasculature anatomy and the identification of previously unrecognized and unclassified anomalies. In this manuscript, we review the existing literature and propose a series of modifications to the original Stewart classification of congenital aortic arch abnormalities to incorporate this new knowledge. In brief, we propose the following modifications: (1) In Group I, we further divide subgroup B into left arch atretic and right arch atretic; (2) In Group II, we add three more subgroups, including aberrant right innominate artery, "isolated" right innominate artery (RIA), "isolated" right carotid artery with aberrant right subclavian artery; (3) In Groups I, II, and III, we add a subgroup of absence of both ductus arteriosus; and (4) In Group IV, we add three subgroups, including circumflex retro-esophageal aorta arch, persistent V aortic arch, and anomalous origin of pulmonary artery from ascending aorta.

Routine screening for fetal limb abnormalities in the first trimester.

OBJECTIVE: We aim to determine the accuracy of first-trimester ultrasonography in detecting fetal limb abnormalities. METHODS: This is a retrospective study of all women undergoing fetal nuchal translucency (NT) assessment and detailed fetal anatomic survey in the first trimester at a single tertiary-care referral center in China. Fetal anatomy scans were repeated in the second trimester. Detection of fetal limb abnormalities was compared between first and second trimester anatomy scans and confirmed at delivery or at autopsy. RESULTS: Analyzed were 9438 fetuses from 9197 women (241 twin pairs). The incidence of fetal limb abnormalities was 0.38% (36/9438). Of these, 28 (77.8%) were diagnosed prenatally: 23 (63.9%) on first trimester scan and 5 (13.9%) on second trimester scan. Limb reduction defects (usually transverse limb deficiencies) were the most common limb defects identified in the first trimester (n = 12), followed by clubfoot (n = 4), skeletal dysplasia (n = 3), sirenomelia (n = 1), limb dysplasia (n = 1), malposition (n = 1), and syndactyly (n = 1). Nine fetuses with isolated limb abnormalities had normal NT, while 74.1% (20/27) of limb abnormalities that were associated with other abnormalities had increased NT. CONCLUSIONS: This study demonstrates that the majority of limb abnormalities detected prenatally [23/28 (82%)] can be identified in the first trimester, especially major limb defects; however, our numbers are small and still need larger cases for further investigation.

Prenatal diagnosis and perinatal outcome of congenital dacryocystocele: a large case series.

OBJECTIVE: To describe the incidence, prenatal diagnosis, and perinatal outcome in fetuses with congenital dacryocystocele. METHODS: All cases of congenital dacryocystocele diagnosed by prenatal ultrasound were identified using an established perinatal database. Prenatal ultrasound images were reviewed, and perinatal outcome was abstracted from the medical records. The correlation between the cyst size, gestational age, and prenatal and neonatal outcome was analyzed. RESULTS: The overall incidence of fetal dacryocystocele was 0.016% (75/456,202). Fifty-three cases (70.7%) had unilateral, and 22 (29.3%) had bilateral lesions. Lesions were seen more commonly among female fetuses with a female : male ratio 1.48 : 1. The average diameter of cysts size was 6.9 ± 1.9 mm (3.3-11 mm). There was a direct correlation between cyst size and gestational age. Among the 75 cases, 8 were lost to follow-up, 3 underwent elective termination of pregnancy. 58 resolved spontaneously before birth, and 6 were confirmed at birth. Two developed neonatal infection requiring antibiotic treatment. All 6 cases confirmed at birth resolved without surgical resection. CONCLUSIONS: Congenital dacryocystocele can be diagnosed by prenatal ultrasound. Such lesions typically resolve spontaneously in utero or in the early neonatal period. Thus, it should be considered as a developmental variant rather than a structural birth defect.

[An approach to screen fetal agenesis of the corpus callosum at 11-13(+6) weeks].

OBJECTIVE: To detect structural changes in the brain in fetuses with agenesis of the corpus callosum (ACC) and holoprosencephaly (HPE) in the first trimester. METHODS: The ultrasound data were analyzed retrospectively in 620 normal singleton fetuses between 11 and 13(+6) gestational weeks, 5 fetuses diagnosed to have ACC, and 13 fetuses with HPE. The midbrain diameter (MD) and falx diameter (FD) were measured and their ratio (MD/FD) was calculated for comparative analysis. RESULTS: No significant difference was found in the MD, FD, and MD/FD ratio between fetuses with ACC and HPE (P>0.05). Compared to the normal fetuses, all the fetuses with ACC and HPE showed significantly increased mean MD and MD/FD ratio (P<0.05); 4 (80%) fetuses with ACC and 11 (84.6%) with HPE had a reduced FD. All the fetuses with ACC and HPE had MD/FD ratios greater than 1, which were below 1 in all the normal fetuses. CONCLUSION: In the first trimester, fetuses with ACC and HPE have measurable abnormalities in the midbrain and falx area of the brain, and these changes, represented by abnormal midsagittal MD, FD and their ratio, can be of value in detecting ACC or HPE in fetuses in the first trimester.

[Ultrasound measurement of fetal posterior fossa at 11 to 13⁺6 gestational weeks for screening open spina bifida].

OBJECTIVE: To establish the normal reference ranges of transabdominal ultrasound measurements of the posterior fossa structure in fetuses at 11 to 13⁺6 gestational weeks and explore their clinical value in screening open spina bifida (OSB). METHODS: Between January, 2013 and September, 541 randomly selected normal fetuses underwent nuchal translucency at the gestational age 11 to 13⁺6 weeks. The parameters of the posterior fossa were measured in mid-sagittal view of the fetal face and the axial view of the transverse cerebellum insonated through the anterior fontanel by transabdominal ultrasound to establish the normal reference ranges. The measurements were obtained from 3 fetuses with OSB for comparison with the reference ranges. RESULTS: In normal fetuses, the parameters of the posterior fossa measured in the two views showed no significant differences (P>0.05). Two high echogenic lines were observed in normal fetuses, as compared with one in fetuses with OSB representing the posterior border of the brain stem and the anterior border of the fourth ventricle. The line between the posterior border of the fourth ventricle and the anterior border of the cisterna magna was not displayed in fetuses with OSB. The anteroposterior diameters of the brain stem, the fourth ventricle, and cisterna magna all increased in positive correlation with the crown-lump length in normal fetuses. In the 3 OSB fetuses, the anteroposterior diameter of the brain stem exceeded the 95th percentile and the anteroposterior diameter of fourth ventrical-cisterner magena was below the 5th percentile of the reference range for CRL; the brain stem to fourth ventrical-cisterner magena anteroposterior diameter ratio was increased to above 1. CONCLUSION: The established normal reference ranges of the parameters of fetal posterior fossa may provide assistance in early OSB detection. The absence of the posterior border of the fourth ventricle and the anterior border of the cisterna magna and a brainstem to fourth ventrical-cisterner magena anteroposterior diameter ratio greater than 1 can be indicative of OSB at 11 to 13⁺6 gestational weeks.

Prenatal diagnosis of congenital vascular rings and slings: sonographic features and perinatal outcome in 81 consecutive cases.

OBJECTIVE: To describe the sonographic features and perinatal outcome of congenital vascular rings diagnosed prenatally at a single tertiary care institution. METHODS: All cases of congenital vascular rings diagnosed by prenatal ultrasound between July 2005 and December 2009 were identified at a single referral center using an established perinatal database. The diagnosis was confirmed by postnatal echocardiography for live-born infants or autopsy for terminated cases. RESULTS: The overall incidence of vascular ring during this 5-year period was 0.086% (81 cases among 94 321 women undergoing perinatal ultrasound examination). Forty-four cases had complete O-shaped (n = 3) or U-shaped (n = 41) vascular rings, and 37 cases had incomplete C-shaped vascular rings (vascular slings). The most common type of vascular ring seen in 50.6% (41/81) of cases was a right aortic arch with aberrant left subclavian artery. The second most common type was a left aortic arch with an aberrant right subclavian artery [39.5% (32/81)]. Chromosomal analysis was performed prenatally in 46 pregnancies, and six cases (13.0%) of fetal aneuploidy were identified. CONCLUSIONS: Congenital vascular rings can be diagnosed with prenatal ultrasound using the three-vessel trachea view and subsequent fetal echocardiography with particular attention to the relationship of the aortic arches, ductal arches, and the trachea.