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Fetal Growth Restriction
Published in Vincenzo Berghella, Maternal-Fetal Evidence Based Guidelines, 2022
Juliana Gevaerd Martins, Alfred Abuhamad
Doppler waveforms can be obtained from any segment along the umbilical cord as the variation is minimal and does not impact clinical decision-making [5]. Doppler measurements of both umbilical arteries also do not improve predictive value for adverse perinatal outcomes since the two umbilical arteries show good agreement in terms of their PI values [132].
Placental transport and metabolism
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Placental growth and function also depend upon adequate blood flow. This requires normal trophoblast invasion and remodeling of the spiral arteries, achieved by vasculogenesis, new blood vessel formation from endothelial precursor cells, and angiogenesis, new vessel formation from those already present. Deficient conversion of the spiral arteries leads to impaired villous perfusion and hypoxia, which itself can have a pejorative effect on vascular remodeling by limiting proliferation and growth of fetal vessels (7,8). This results in increased resistance to blood flow in the umbilical arteries, which is reflected in abnormal flow velocity waveforms using Doppler ultrasound. Growth of the placenta, its blood vessels, and its blood supply are intertwined such that, under normal circumstances, fetoplacental growth correlates with the ability to provide oxygen and nutrients to the placenta for subsequent transfer to the fetus.
Vascular access
Published in Mark Davenport, James D. Geiger, Nigel J. Hall, Steven S. Rothenberg, Operative Pediatric Surgery, 2020
Marcus D. Jarboe, Ronald B. Hirschl
White tape under moderate tension is applied to control the cord at its base. The cord is cut with a no. 15 scalpel about 1 cm from skin level. The two thick-walled umbilical arteries and the one thin-walled vein are identified. A fine non-toothed forceps is introduced closed into the selected artery and opened gently to achieve dilatation. A preprepared and flushed catheter is grasped close to the tip using another pair of forceps and advanced into the umbilical artery, gently but firmly in a caudal direction. The catheter is thereby guided into the aorta via an internal iliac artery. Ready bleeding should be seen and a predetermined position aimed for and confirmed radiologically. In the “low position” the catheter tip is just above the aortic bifurcation, while in the “high position” it is just above the level of the diaphragm (Figure 1.8e).
The Allantois and Urachus: Histological Study Using Human Embryo and Fetuses
Published in Fetal and Pediatric Pathology, 2022
Xuelai Liu, Xianghui Xie, Zhe-Wu Jin, Huan Wang, Yanbiao Song, Peng Zhao, Long Li
During development, the urogenital sinus is divided into three parts: a cranial part that is continuous with the allantois, a middle pelvic part that becomes the urethra in the bladder neck and the prostatic portion of the urethra in males or the entire urethra in females, and a caudal part that grows toward the genital tubercle [2]. The urinary bladder develops mainly from the cranial part of the urogenital sinus, which is called the allantois. The allantois soon becomes a thick fibrous cord known as the urachus and extends from the apex of the bladder to the umbilicus. The urinary bladder enters the pelvic cavity at about GA 6 weeks, subsequently extending posteriorly along the posterior surface of the anterior abdominal wall and becoming the fibrous remnant of the urachus. In adults, the urachus is represented by a median umbilical ligament, the fibrous remnant of the umbilical arteries [3–5]. In the clinical setting, about 50% of urachal anomalies in infants are present in the inferior part of the urachus, and its lumen is continuous with the cavity of the urinary bladder. This may give rise to urachal sinuses, urachal cysts in children with umbilical recurrent infection and moisture, and patent urachus in children with urine leakage from the urinary bladder to the umbilical orifice. However, the exact anatomical location of allantois/urachus and its correlation with the abdominal wall remain unknown, as is histological information about the allantois/urachus during early phases of normal human development.
Comparative study of umbilical cord cross-sectional area in foetuses with isolated single umbilical artery and normal umbilical artery
Published in Journal of Obstetrics and Gynaecology, 2022
Tian-Gang Li, Chong-Li Guan, Jian Wang, Mei-Juan Peng
A normal foetal umbilical cord includes two umbilical arteries (UAs) and one umbilical vein (UV). In the umbilical cord of a foetus with the condition single umbilical artery (SUA), only one UA is found (Murphy-Kaulbeck et al. 2010; Voskamp et al. 2013; Arslan et al. 2019). SUA is one of the most common prenatal diagnoses with foetal abnormalities, and the incidence is approximately 0.5%–5% (Gornall et al. 2003; Hua et al. 2010). Metabolic diseases, smoking, reproductive technology-assisted pregnancy, early pregnancy, primiparity, advanced age and multiple births are high-risk factors for SUA (Friebe-Hoffmann et al. 2019). SUA is a soft marker for foetal chromosomal abnormalities, congenital malformations and premature birth (Dagklis et al. 2010; Wang et al. 2019). Approximately >80% of SUA cases involve isolated SUAs (Martinez-Payo et al 2005; Chetty-John et al. 2010), which are not related to foetal malformations or chromosomal abnormalities. However, isolated SUA often leads to the development of certain obstetric complications, such as increased perinatal mortality and foetal growth retardation (Horton et al. 2010; Luo et al. 2017).
Abnormal Umblical Artery Doppler is Utilized for Fetuses with Intrauterine Growth Restriction Birth at 280/7–336/7 Gestational Weeks
Published in Fetal and Pediatric Pathology, 2020
Emre Baser, Istemi Han Celik, Melek Bilge, Taner Kasapoglu, Dilek Ulubas Isik, Ethem Serdar Yalvac, Omer Lutfi Tapisiz, Safak Ozdemirci
The utilization of umbilical artery Doppler (UAD) is useful, easy, and a noninvasive method by which to assess the association of intrauterine growth restriction (IUGR) with placental insufficiency in order to diminish adverse perinatal mortality and morbidity [1–4]. Abnormal umbilical artery flow is strongly associated with placental insufficiency [1, 2], which is characterized as a histopathological finding of the obliteration or narrowing of arteries in the tertiary stem villi of the placental pathology [5]. UAD conveys information about the circulation and vascular structure of placental villi [3]. More than 70% of occluded umbilical arteries are strongly associated with worsened circumstances, leading to absent or reversal of end‐diastolic flow (AREDF) [1]. AREDF produces a detrimental risk factor for neonatal mortality and morbidities [6], such as preterm birth, IUGR, intraventricular hemorrhage (IVH), respiratory distress syndrome (RDS), necrotizing enterocolitis (NEC), and neonatal sepsis [1–3]. In the literature, there is a paucity of evidence regarding the effects of AREDF on perinatal outcomes of preterm births between 280 and 336 gestational weeks. The aim of this study is to compare the perinatal outcomes of preterm births (280–336 gestational weeks) with IUGR according to UAD characteristics of AREDF to those with normal end-diastolic umbilical artery blood flow (NEDF). Our hypothesis is that AREDF may be directly and indirectly associated with detrimental perinatal outcomes in preterm birth with early IUGR when compared to those of NEDF.