The Upturned Superior Mesenteric Artery Sign for First-Trimester Detection of Congenital Diaphragmatic Hernia and Omphalocele

Detection of non-cardiac fetal abnormalities on ultrasound at 11-14 weeks: systematic review and meta-analysis

OBJECTIVES

To assess the diagnostic accuracy of two-dimensional ultrasound at 11-14 weeks' gestation as a screening test for individual fetal anomalies and to identify factors impacting on screening performance.

METHODS

This was a systematic review and meta-analysis that was developed and registered with PROSPERO (CRD42018111781). MEDLINE, EMBASE, Web of Science Core Collection and the Cochrane Library were searched for studies evaluating the diagnostic accuracy of screening for 16 predefined, non-cardiac, congenital anomalies considered to be of interest to the early anomaly scan. We included prospective and retrospective studies from any healthcare setting conducted in low-risk, mixed-risk and unselected populations. The reference standard was the detection of an anomaly on postnatal or postmortem examination. Data were extracted to populate 2 × 2 tables and a random-effects model was used to determine the diagnostic accuracy of screening for the predefined anomalies (individually and as a composite). Secondary analyses were performed to determine the impact on detection rates of imaging protocol, type of ultrasound modality, publication year and index of sonographer suspicion at the time of scanning. Post-hoc secondary analysis was conducted to assess performance among studies published during or after 2010. Risk of bias assessment and quality assessment were undertaken for included studies using the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

From 5684 citations, 202 papers underwent full-text review, resulting in the inclusion of 52 studies comprising 527 837 fetuses, of which 2399 were affected by one or more of the 16 predefined anomalies. Individual anomalies were not equally amenable to detection on first-trimester ultrasound: a high (> 80%) detection rate was reported for severe conditions, including acrania (98%), gastroschisis (96%), exomphalos (95%) and holoprosencephaly (88%); the detection rate was lower for open spina bifida (69%), lower urinary tract obstruction (66%), lethal skeletal dysplasias (57%) and limb-reduction defects (50%); and the detection rate was below 50% for facial clefts (43%), polydactyly (40%) and congenital diaphragmatic hernia (38%). Conditions with a low (< 30%) detection rate included bilateral renal agenesis (25%), closed spina bifida (21%), isolated cleft lip (14%) and talipes (11%). Specificity was > 99% for all anomalies. Secondary analysis showed that detection improved with advancing publication year, and that the use of imaging protocols had a statistically significant impact on screening performance (P < 0.0001).

CONCLUSIONS

The accurate detection of congenital anomalies using first-trimester ultrasound is feasible, although detection rates and false-positive rates depend on the type of anomaly. The use of a standardized protocol allows for diagnostic performance to be maximized, particularly for the detection of spina bifida, facial clefts and limb-reduction defects. Highlighting the types of anomalies amenable to diagnosis and determining factors enhancing screening performance can support the development of first-trimester anomaly screening programs. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

[Assessment of fetal superior mesenteric artery and vein by three-dimensional power Doppler sonography]

OBJECTIVE

To analyze the application of three-dimensional power Doppler sonography (3-DPDS) in evaluation of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in second-trimester fetus.

METHODS

Three-dimensional volume probe was used to collect the 3-DPDS blood flow images in 50 normal fetuses of 22⁺⁰-24⁺⁶ weeks and 50 fetuses of 30⁺⁰-32⁺⁶ weeks, respectively. The characteristics of three-dimensional ultrasound were analyzed. The clinical and imaging data of 4 fetuses of 26⁺³-32⁺¹ weeks with midgut volvulus were analyzed retrospectively.

RESULTS

The display rates of SMA and SMV were 93%in normal group by 3-DPDS and those in volvulus group were 4/4 and 3/4, respectively. The SMV trunk was parallel to and on the right side of the SMA in the normal group, while 3 cases in volvulus group showed the characteristic relationship of SMV swirling around SMA.

CONCLUSIONS

3-DPDS can be used to observe the spatial relationship of SMA and SMV visually in fetus during the second trimester and is of value to diagnose and predict the outcome of midgut volvulus.

Early prenatal ultrasound diagnosis of congenital thoracic malformations

Objectives: To evaluate and describe the spectrum and rate of congenital thoracic malformations (CTMs) diagnosed by early prenatal sonography (gestational age (GA) less than 16 weeks). Methods: A retrospective, cross-sectional analysis of prenatal ultrasound screening tests in a community-based clinic. Results: In 2001-2017, 31 261 prenatal ultrasound tests detected 31 CTMs at a gestational age of 15.2 (range, 11.6-16.0) weeks. The most common malformation was congenital pleural effusion (CPE) (15 fetuses, 0.48/1000), followed by congenital diaphragmatic hernia (CDH) (10 fetuses, 0.32/1000). Pulmonary hypoplasia (PH), congenital pulmonary airway malformation and broncho-pulmonary sequestration appeared in much smaller proportions (three, two and one fetuses, respectively). Most CTMs were associated with additional fetal lesions (15 fetuses, 48%). All early CDH (10 fetuses) and PH (three fetuses) and 6/15 with CPE had termination of pregnancy or missed abortions. Conclusions: Prenatal ultrasound before 16 GA was able to detect CTMs in 0.99/1000 of screening ultrasound (US) performed. Most CTMs tended to appear with multiple lesions and were associated with unfavorable outcomes. Earlier prenatal diagnosis may enable early termination of pregnancy in fetuses with lethal malformations.