Movement: allows mvt of baby and mvt of cord; if nuchal cordx1 means cord was around the baby’s neck one time. Amniotic fluid does not have waste substances; baby can swallow it. Yolk sac-develops at about day 8 or 9 and forms primitive RBCs for baby until liver starts at 6 weeks Umbilical cord o formed from the amnion o 1 large vein, and 2 smaller arteries 2 vessels associated with congenital anomalies; send this baby for ultrasound (kidney; heart; something we can’t see); 2 vessels doesn’t cause it but it can be associated o Wharton’s jelly-a specialized connective tissue that surrounds the blood vessels in the umbilical cord; prevent compression/kinking of the umbilical cord; no sensory innervation o Central insertion in the placenta is considered normal When the cord is attached to the center, the vessels need to transverse the placenta in order to have optimum transport of nutrients. o Nuchal cord-when the cord encircles the fetal neck o Length of cord: avg. length of baby is 20” (18-22); cord length 20-22”; width is about 1”; large cords seen in GDM; moms who have suffered nutritionally or used drugs look weathered o vein brings oxygenated blood from mom to the baby; 2 arteries bring deoxygenated blood to the placenta b/c mom’s liver takes control of filtering blood in utero, taking care of bilirubin; baby should, therefore, not be born jaundiced; a baby that has been through a traumatic delivery (caput: blood under skin on skull) baby would be at increased risk of jaundice. Twins=2 questions Fraternal ( Dizygotic ) =arise from two separate eggs and 2 sperm; may not be the same gender; no more similar than siblings born separately; 2 placentas, 2 chorions, and 2 amnions o Studies indicate that dizygotic twins occur in certain families, possibly because of genetic factors that result in elevated serum gonadotropins and thus double ovulation o Occurrence increases which maternal age and then drops off after 35 yo Identical ( Monozygotic ) = develop from a single fertilized ovum (1 egg and 1 sperm); they will always be the same gender; something happens during the first eight days after fertilization and the cells divide and form two separate humans; identical twins usually have a common placenta Placental functions and fetal circulatory system=2 questions Placenta Develops at the site where the embryo attaches to the uterine wall during the third week of embryonic development means of metabolic and nutrient exchange btw baby and mom; no way a baby can survive w/o placenta; if it separates completely the baby may not survive o A woman who has had a miscarriage before 12 may be able to have miscarriage at home; however, if past 12 weeks placenta is fully developed, dilation and curretage may be the tx option of choice to make sure that no placental fragments are retained (which would be a risk for infection) Has two parts: a. maternal side (red and fleshy)/dirty dunkin: consists of the decidua basalis and its circulation; covered by the amnion, which gives it its shiny appearance b. fetal side (shiny)/shiny Schultz: consists of the chorionic villi and their circulation Placenta:
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