OB/GYN Registry Review Chapter 32 Fetal Environment And Maternal Complications
Placental Abruption
-abruptio placentae -premature separation of the placenta from the uterine wall before the birth of the fetus causing hemorrhage -complete (most severe), partial (only few cm of separation), marginal(subchorionic hemorrhage), or be defined by its location -complete abruption can lead to retroplacental hematoma which is located between the placenta and myometrium -marginal abruption lies at the edge of the placenta and is the most common placental hemorrhage identified with sonography -maternal conditions linked to this: hypertension, preeclampsia, cocaine use, cigarette smoking, poor nutrition, and trauma -sonography is not always effective -may present with vaginal bleeding, abdominal pain, uterine contraction, and uterine tenderness -can lead to fetal death from hypoxia and possibly death of the mother
The Placenta 2
-consists of three parts: 1. the chorionic plate 2.the placental substance 3. the basal layer or basal plate -the chorionic plate is the element of the placenta closest to the fetus -the basal layer is the area adjacent to the uterus -the placental substance contains the functional parts of the placenta and is located between the chorionic plate and the basal layer -normal variants: venous lakes (pools of blood, anechoic hypoechoic) -shape may vary too: bilobed placenta, succenturiate lobe, circumvallate placenta -calcifications may be noted within the placenta and indentations may be seen within the basal and chorionic plates with advancing gestation -grading of placenta has been performed in the past to predict fetal lung maturity by assessing these indentations and calcifications -thickness of the placenta should be evaluated -it should not exceed 4 cm -thick and large placenta: placentomegaly -think placenta are associated with maternal and/or fetal abnormalities
Possible Causes of a Thick Placenta
-diabetes mellitus -maternal anemia -infection -fetal hydrops -Rh isoimmunization -multiple gestation
Possible Causes of a Thin Placenta
-diabetes mellitus (long standing) -intrauterine growth restriction -placental insufficiency -polyhydramnios -preeclampsia -small for dates fetus
Functions of the Placenta
-gas transfer -excretory function -water balance -pH maintenance -hormone production -defensive barrier
Sonographic Findings of Vasa Previa
-identification of vessels over the internal os of the cervix with the use of color Doppler -velamentous cord insertion
Placenta Previa.
-implantation within the lower uterine segment -covers the internal os of cervix -common cause of painless vaginal bleeding in the 2nd and 3rd trimesters -discovered often in women with a history of multiparity, advanced maternal age, previous abortion, and prior c-section (correlation with uterine scar formation from surgery with the subsequent implantation of the next placenta in that area) -not routinely diagnosed until the late second or third trimester -secondary to the fact that because of the growth of the uterus, the placenta has potential to migrate away from the cervix (shifts with uterus growth doesn't move) -marginal and partial placental previa -fully distended bladder might produce a false positive -painless myometrial contractions can cause false positive -TV and translabial scanning can be helpful with advanced gestation -can be fatal during vaginal delivery so c-section is recommended
Clinical Findings of Placenta Previa
-previous c section or uterine surgery -painless vaginal bleeding -possibly asymptomatic
Vasa Previa.
-the complication of fetal vessels resting over the internal os of the cervix -these vessels are prone to rupture as the cervix dilates which can lead to exsanguination -often associated with velamentous cord insertion and possibly a succenturiate lobe
The Placenta 1
-vital organ to the fetus during pregnancy -normally weighs around 450-550 grams and has a diameter of 16-20cm -the decidua basalis, maternal contribution, is the endometrium beneath the developing placenta -the chorion frondosum, the portion derived from the blastocyst and containing the chorionic villi is the fetal contribution -consists of approx. 10-30 cotyledons, groups/lobes of chorionic villi -produces hCG, estrogen, and progesterone taking over the function of the corpus luteum -one major function is to act as an excretory organ for the fetus, performing imperative exchanges of waste products and gases with valuable nutrients and oxygen from the mother -effectively becomes the means of respiration for the fetus -identified around 10-12 weeks as an echogenic thickening structure part of the gestational sac -as pregnancy progresses the placenta becomes more define
Hemangioma
a benign tumor composed of blood vessels
Leiomyoma (Uterine)
a benign, smooth muscle tumor of the uterus; AKA fibroid or uterine myoma
Gestational Trophoblastic Disease
a disease associated with an abnormal proliferation of the trophoblastic cells during pregnancy; may also be referred to as molar pregnancy
Diethylstilbestrol (DES)
a drug administered to pregnant women from the 1940s to the 1970s to treat threatened abortions and premature labor that has been linked with uterine malformation in the exposed fetus
Multicystic Dysplastic Kidney Disease
a fetal renal disease thought to be caused by an early renal obstruction; leads to the development of multiple noncommunicating cysts of varying sizes in the renal fossa
Intrauterine Growth Restriction (IUGR)
a fetus that is below the 10th percentile for gestational age (small for gestational age) and whose growth is impeded for some reason
Neural Tube Defects
a group of development abnormalities that involve the brain and spine
Oligohydramnios
a lower-than-normal amount of amniotic fluid for the gestational age
Cystic Adenomatoid Malformation
a mass consisting of abnormal bronchial and lung tissue that develops within the fetal chest
Mirror Syndrome
a rare disorder in which the mother suffers from edema and fluid buildup similar to her hydropic fetus
Hypoxia
a shortage of oxygen or decreased oxygen in the blood
Marginal Cord Insertion
abnormal cord insertion at the edge of the placenta
TORCH
acronym that stands for toxoplasmosis, other infections, rubella, cytomegalovirus, and herpes simplex virus
Fetal Hydrops
an abnormal accumulation of fluid in at least two fetal body cavities
Circumvallate Placenta
an abnormally shaped placenta caused by the membranes inserting inward from the edge of the placenta, producing a curled up placental shap
Succenturiate Lobe
an accessory lobe of the placenta
Omphalocele
an anterior abdominal wall defect where there is herniation of the fetal bowel and other abdominal organ into the base of the umbilical cord
Macrosomia
an estimated fetal weight of greater than the 90th percentile or the neonate that measures more than 4,500 g
Polyhydramnios
an excessive amount of amniotic fluid for gestational age
Infantile Polycystic Kidney Disease
an inherited renal disease that results in bilateral enlargement of the fetal kidneys and microscopic renal cysts; AKA autosomal recessive polycystic kidney disease
Two Vessel Cord
an umbilical cord with one artery and one vein, could possibly be associated with other fetal abnormalities and intrauterine growth restriction
Erythroblastosis Fetalis
condition in which there is an incompatibility between the fetal and maternal red blood cells
Nuchal Cord
condition of having the umbilical cord wrapped completely around the fetal neck
Esophageal Atresia
congenital absence of part of the esophagus
Duodenal Atresia
congenital maldevelopment or absence of the duodenum
Allantoic Cyst
cyst found within the umbilical cord
Gestational Diabetes
diabetes acquired as a result of pregnancy
Anasarca
diffuse edema
Placentomegaly
enlargement of the placenta
Immune Hydrops
fetal hydrops caused by Rh incompatibility
Nonimmune Hydrops
fetal hydrops caused by congenital fetal anomalies and infections
Meconium
fetal stool that is composed of fetal skin, hair, amniotic fluid, and bile
Vasa Previa
fetal vessels resting over the internal os of the cervix
Chorionic Villi
fingerlike projections of gestational tissue that attach to the decidualized endometrium and allow the transfer of nutrients from the mother to the fetus
Umbilical Vein Varix
focal dilatation of the intra-abdominal portion of the umbilical vein
Cesarean Section
form of childbirth in which a surgical incision is made through the maternal abdomen to deliver the fetus
Idiopathic
from an unknown origin
Wharton Jelly
gelatinous material that is located within the umbilical cord around the umbilical vessels
Cotyledons
groups or lobes of chorionic villi
Multiparity
having had several pregnancies
Sonographic Findings of Placental Abruption
hematoma located either at the edge of the placenta or between the placenta and the myometrium
Gastroschisis
herniation of abdominal contents through a right-sided, periumbilical abdominal wall defect
Placenta Increta
invasion of the placenta within the myometrium
Posterior Urethral Valves
irregular thin membranes of tissue located within the male posterior urethra that does not allow urine to exit the urethra
Biophysical Profile
method of fetal monitoring with sonography to produce a numerical scoring system that predicts fetal well-being
Grade 2
moderate indentations in the chorionic plate with "comma-like" calcification in the placental substance
Nongravid
not pregnant
Placenta Percreta
penetration of the placenta through the uterine serosa and possibly into adjacent pelvic organs
Complete (Total) Previa
placenta covers the internal os completely
Partial Previa
placenta partially covers the internal os
Bilobed Placenta
placenta that consists of two separate discs of equal size
Abruptio Placentae
placental abruption
Low-Lying Previa
placental edge extends into the lower uterine segment but ends more than 2 cm away from the internal os
Marginal Previa
placental lies at the edge of the internal os
Venous Lakes
pools of maternal blood within the placental substance
Preeclampsia
pregnancy-induced maternal high blood pressure and excess protein in the urine after 20 weeks' gestation
Grade 3
prominent indentation in the chorionic plate that extends to the basal layer with diffuse echogenic and anechoic areas noted within the placental substance
Vernix
protective fetal skin covering
Proteinuria
protein in the urine
Twin-Twin Transfusion Syndrome
shunting of venous or arterial blood from one twin to another through placental circulation
Microcephaly
small head
Grade 1
subtle indentations on the chorionic plate, with some small calcifications within the placental substance
Placenta Accreta
the abnormal adherence of the placenta to the myometrium in an area where the decidua is either absent or minimal
Velamentous Cord Insertion
the abnormal insertion of the umbilical cord into the membranes beyond the placental edge
Amniotic Fluid Index
the amount of amniotic fluid surrounding the fetus; the sum of four quadrant measurements of amniotic fluid
Anemia
the condition of having a deficient number of red blood cells
Hydronephrosis
the dilation of the renal collecting system resulting from the obstruction of the flow of urine from the kidney(s) to the bladder; AKA pelvocaliectasis or pelvicaliectasis
Decidua Basalis
the endometrial tissue at the implantation site, and the maternal contribution of the placenta
Bilateral Renal Agenesis
the failure of both kidneys to develop in the fetus
Estimated Fetal Weight
the fetal weight based on sonographic measurements
Neonatal Period
the first 28 days of life
Diaphragmatic Hernia
the herniation of the abdominal contents into the chest cavity through a defect in the diaphragm
Cervical Incompetence
the painless dilation of the cervix in the second or early third trimester
Chorion Frondosum
the part of the chorion, covered by chorionic villi, that is the fetal contribution of the placenta
Cerclage
the placement of sutures within the cervix to keep it closed
Funneling (cervical)
the results of the premature opening of the internal os and the subsequent bulging of the membranes into the dilated cervix
Premature Rupture of Membranes
the rupture of the amniotic sac prior to the onset of labor
Blastocyst
the stage of the conceptus that implants within the decidualized endometrium
Vitelline Duct
the structure that connects the developing embryo to the secondary yolk sac
Lower Uterine Segment
the term used for the isthmus during pregnancy
Philtrum
the vertical groove seen between the upper lip and the nasal septum
Umbilical Vein
the vessel of the umbilical cord that carries oxygenated blood from the placenta to the fetus
Postpartum
time directly after giving birth and extending to about 6 weeks
Exsanguination
total blood loss; to bleed out
Umbilical Arteries
two vessels of the umbilical cord that carry deoxygenated blood from the fetus to the placenta
Grade 0
uninterrupted chorionic plate and homogenous placental substance
Retained Products of Conception
when additional placental tissue remains within the uterus after the bulk of the placenta has been delivered
Placenta Previa
when the placenta covers or nearly covers the internal os of the cervix
Shoulder Dystocia
when the shoulder of the fetus cannot pass through the birth canal during pregnancy
Clinical Finding of Placental Abruption
-abdominal pain (often sudden onset) -possible vaginal bleeding -uterine contractions -uterine tenderness