Chapters authored
Fetal Abdominal Wall Defects
Abdominal wall defects (AWDs) represent a group of congenital anomalies that can be diagnosed early during pregnancy even at the time of the first trimester assessment, with direct impact on pre- and postnatal fetal prognosis and management decisions. The most frequent anomalies in this group are gastroschisis and omphalocele. The key method available, that allows the detection of any deviation from the physiologic midgut herniation, is the ultrasound (US) assessment. A precise algorithmic scan approach is imposed not only for an accurate detection of any abdominal wall defect, but also for a proper location of the defect and of the spatial relation to the umbilical cord insertion, fundamentally important in differentiating among various malformations. Other structural or chromosomal anomalies should be excluded. Suitable multidisciplinary counseling should be considered. Unfortunately, in utero surgery, in these cases, has not been yet successful. Postnatal early interventions are usually required in specialized pediatric centers.
Part of the book: Congenital Anomalies
Congenital Abnormalities of the Fetal Face
Even at the early stages of gestation, the fetal face can be examined. There have been observations of the normal anatomy, such as orbits and the forehead, starting with the 12th week of gestation. However, nowadays, ultrasound equipment still cannot distinguish the soft tissues of the face, which are too thin. Yet, after the age of 14 weeks, we can easily examine the forehead, orbits, nose, lips, and ears. Recently, three-dimensional ultrasound (3D) images of the fetus can also be obtained. However, two-dimensional (2D) ultrasonographic (US) images are more easily, rapidly, efficiently, and accurately obtained. At the first stage of embryogenesis, the main part in the development of the fetal face is taken by the genetic factors. Later, the influence of the environment becomes more important. It is known that the outcome of chromosomal aberrations and of teratogenic factors is the facial malformation. Therefore, examining the facial dimorphism may get us useful hints in revealing chromosomal or genetic abnormalities. This chapter focuses on the fetal face anomalies more frequently found while performing the prenatal diagnosis. It is divided into anomalies of the orbits, nose, lip, palate, and mandible.
Part of the book: Congenital Anomalies
Abnormalities of the Placenta
The placenta is considered an important organ that evolves with the implantation of the blastocyst throughout the pregnancy. The placenta has an essential role in functions such as nutrition, excretion, and immunologic and endocrine function. The normal placenta is a round- or oval-shaped organ that attaches to the uterine wall and has roughly 22 cm in diameter and a thickness of about 2–2.5 cm and weighs about one sixth of the fetal birth weight. Thus, a normal development of the placenta is important for an uneventful embryonic and fetal development. Consequently, the placenta abnormalities can range from structural anomalies, to function disorders, to site of implantation abnormalities.
Part of the book: Congenital Anomalies
The Hepatic Fetal Venous System
The vascular architecture of the human liver is established at the end of the 10th week of gestation as a result of a complex process. Recent developments in ultrasonographic imaging facilitate the prenatal evaluation of this system. However, many of the involved mechanisms are poorly understood. The hepatic primordium is in contact with the vitelline veins and the umbilical veins, and by the end of the 6th week, the afferent venous system of the liver is acquired giving rise to the portal vein, the portal sinus, and the ductus venosus. The only afferent vein of the liver that remains open at birth is the portal vein. Also, the efferent venous system of the liver is formed and emerges from the vitelline veins.
Part of the book: Embryology Update