Adverse perinatal outcomes following the prenatal diagnosis of isolated single umbilical artery in singleton pregnancies: a systematic review and meta-analysis

Objectives A systematic review and meta-analysis was conducted to quantitatively synthesize the current evidence on the association of prenatally diagnosed isolated single umbilical artery (iSUA) in singleton pregnancies with small for gestational age (SGA) neonates and other perinatal outcomes. Methods A search of PubMed/Medline, Scopus and The Cochrane Library was conducted, from inception to February 2021, in order to identify studies comparing the risk of SGA and other perinatal adverse outcomes in prenatally diagnosed iSUA singleton pregnancies vs. those with a 3-vessel cord (3VC). The quality of eligible studies was assessed according to the improved Newcastle–Ottawa Scale (NOS). The heterogeneity of results across the studies was tested using the I2 test. Funnel plots and Egger’s test were used to assess the possibility of publication bias. Prospero RN: CRD42020182586. Results The electronic search identified 7,605 studies, of which 11 were selected, including three retrospective cohort and eight retrospective case control studies, overall reporting on 1,533 iSUA cases. The risk of delivering SGA neonates was increased in cases with iSUA (OR: 2.90; 95% CI: 2.02–4.18; p<0.00001; I2=71%). Similarly, iSUA was associated with an increased risk of pregnancy-induced hypertension (PIH) (OR: 2.23; 95% CI: 1.41–3.54; p<0.000; I2=1%), intrauterine death (IUD) (OR: 2.62; 95% CI: 1.43–4.79; p=0.002; I2=0%), preterm birth (PTB) (OR: 2.48; 95% CI: 1.73–3.56; p<0.00001; I2=56%), cesarean section (CS) (OR: 1.64; 95% CI: 1.11–2.41; p=0.01; I2=78%) and admission to neonatal intensive care unit (NICU) (OR: 2.28; 95% CI: 1.52–3.44; p<0.000001; I2=73%). Conclusions In prenatally diagnosed iSUA there is a higher risk of SGA, PIH, IUD, PTB, CS and NICU admission. These findings support the value of prenatal diagnosis of iSUA, which may subsequently intensify surveillance for the detection of specific pregnancy complications.

Prenatal and neonatal outcomes of pregnancies diagnosed with fetal single umbilical artery

Objective To investigate the associated anomalies and outcomes of fetuses diagnosed as having a single umbilical artery (SUA) which were reported inconsistently in previous studies. Methods The data of 82 pregnancies with fetal SUA, 35 of which were complex, and 47 isolated SUA (iSUA) and 100 pregnancies with fetal double umbilical arteries (DUA) between June 2018 and July 2020 were retrieved. We compared the maternal characteristics, and pregnancy and fetal outcomes of the three groups (iSUA, SUA, and DUA). Results Of 82 fetuses with SUA, 35 had 64 major structural abnormalities. 20 of these 35 fetuses (57.1%) had cardiovascular malformations, 12 (34.2%) had central nervous, 10 (28.5%) had genitourinary, and eight (22.8%) had gastrointestinal system malformations. Isolated SUA was present in SUA. Compared with the 100 DUA fetuses, SUA was a risk for intrauterine growth restriction (IUGR), preterm delivery, Apgar scores of <7, and admission to the neonatal intensive care unit. Having fetal chromosomal or structural abnormalities, was a risk for amnion fluid abnormality, pregnancy termination, intrauterine fetal death, early neonatal death, and a low live birth ratio in SUA cases. Conclusion SUA has an increased rate of fetal structural and chromosomal abnormalities. Among them, the most detected one is cardiac and the second most common one is central nervous system malformations. Pregnancies with fetal SUA have increased risk for IUGR, preterm delivery, low Apgar scores, and admission to the neonatal intensive care unit. The presence of additional structural or chromosomal malformations increases the rate of these adverse pregnancy risks. Thus, these cases warrant dedicated fetal ultrasonographic organ screening and close prenatal follow-up.

The missing umbilical artery – A case report

Single umbilical artery (SUA) is a condition where one umbilical artery exists. Normally, the umbilical artery contains two umbilical artery and one umbilical vein. The incidence of SUA varies from 0.2% to 0.8%. We present a case of SUA in a term baby with birth weight of 1.7kg delivered by a 28-year-old mother. SUA is a condition which must be kept in mind during histopathological examination since it helps in improving the neonatal and maternal care.

To Estimate the Importance of Wharton’s Jelly in the Growth of the Foetus – A Light Microscopic Study

BACKGROUND Human umbilical cord contains two arteries and one vein with their tunica intima and tunica media layers. The role of tunica adventitia is fulfilled by Wharton’s jelly, a mucoid connective tissue. The function of Wharton’s jelly is to prevent the vessels from compression and torsion which is essential for foetal development. The purpose of the study was to estimate the importance of Wharton’s jelly in the growth of the foetus. METHODS Umbilical cord tissue collected from each case was immediately put in 10 % formalin for fixation. Slides were then stained with Haematoxylin and Eosin. These slides were then read under light microscopy and measurements were taken using a photomicrograph. Wharton’s jelly area was calculated by subtracting the total vessel area from the umbilical cord area. RESULTS The histological measurements of umbilical vessels include the external diameter, lumen diameter, wall thickness, thickness of tunica intima and tunica media, and the area. The mean area of the umbilical cord was 35.73 ±23.04 mm2 (Mean ± SD) and the mean area of the Wharton’s jelly was 29.74 ± 19.26 mm2. There was a significant difference in the external diameter and wall thickness of the umbilical artery. Analyses showed that there was a significantly (P < 0.01) increased external diameter and wall thickness of umbilical artery in normal cases, compared to single umbilical artery cases. CONCLUSIONS There was a significant positive correlation between the gestational age and the external diameter of the umbilical cord. There was a significant difference in the external diameter of the umbilical cord between SUA cases (4.45 mm) and the other foetuses with normal umbilical cord (6.53 mm). There was a significantly increased external diameter, lumen diameter, wall thickness and area of umbilical vein in normal cases, compared to single umbilical artery cases. There was a significantly increased area of umbilical cord and area of Wharton’s jelly in normal umbilical cord foetuses than foetuses with a single umbilical artery. KEY WORDS Foetus, Umbilical Cord, Wharton’s Jelly, Umbilical Artery, Umbilical Vein, Light Microscopy

A case report of sirenomelia with two umbilical arteries: an unusual finding in a rare case

Sirenomelia also known as Mermaid syndrome is a rarely encountered fusion anomaly of the caudal region of body often associated with Potter’s facies, single umbilical artery and various visceral abnormalities which make it irreconcilable with life. Here we report a case of sirenomelia delivered in our tertiary care hospital by lower segment cesarean section to a 24 year old third gravida with no previous live issues. No high risk factors could be identified with the mother including diabetes mellitus. Baby was born alive with Potter’s facies. Both the lower limbs were merging into each other like a mermaid’s tail (hence called mermaid syndrome). Sex of the baby could not be identified and the urogenital and anal orifices were absent. Umbilical cord stump had two umbilical arteries. The baby died after 20 hours of life. There appears to be no definitive modality for diagnosing sirenomelia in the antenatal period. However, if a patient has consistently low AFI without any history of leaking per vaginum, high resolution USG or colour Doppler should be done at the earliest to look for the cause.