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