Key terms Flashcards
Indications for 1st trimester exams
Confirm presence of intrauterine pregnancy evaluate suspected ectopic pregnancy difine cause of vaginal bleeding evaluate pelvic pain estimate gestational age diagnose or evaluate multiple pregnancy confirm cardia activity an adjunct to chorionic villous sampling, embryo transfer or localilzation and removal of an IUD assess for certain fetal anomalies such as anencephaly in patients that are high risk evaluate maternal pelvic or adenexal masses or uterine anomalies screen for fetal aneuploidy evaluate suspectede hydatidiform mole
Indications for 2nd & 3rd trimesters
gestational age fetal growth vaginal bleeding cervical insuficiency abdominal and pelvic pain determine fetal presentation eval suspected multiple gestatoin adjunct to amniocentesis or other procedure discrepancy between uterine size and clinical dates pelvic mass suspected hydatidiform mole adjunct to cervical cerlage placement suspected ectopic pregnancy suspected fetal death suspected uterine abnormality fetal well being suspected amniotic fluid abnormalities suspected placental abruption adjunct to external cephalic version premature rupture of membranes and or premature labor abnormal biochemical markers follow up fetal anomaly follow up placental locatoin for suspect placenta previa history of previous congenital anomaly fetal condition in late registrants for prenatal care assessment of findings that may increase the risk of aneuploidy screening for fetal anomalies
Types of OB exams
standard limited repeat specialty first trimester first trimester risk assessment
Patient history
key information that the sonographer must know before eamination
Nageles rule
calulating the EDD
add 7 days from last known mestrual period,
subtract 3 months
add 1 year
Maternal risk factors
increaed maternal age serum biochem values increased nuchal translucency maternal disease uterince cavity that is too small or too large previous births with congenital disorders
Fetal anatomy
chromosomal disorders downs syndrome neural tube defects
Morality and ethics in OB sonography
reflection and analysis of morality right and wrong conduct and character assessment follow code of ethics for the profession of DMS
Nonmaleficence
do no harm attain and maintain appropirate education and clinical skills to ensure competence in performing required tasks
Conceptual age
embryologic age conceptoin as the first day pf pregnancy
Menstrual age
gestational age first day of last period as the beginning date of gestation
Embryonic age
conception as first day of pregnancy
Zygote stage from conception through implantation
fertilization zygote marula blastocyte implantation
Maternal serum biochemistry
maternal chemical levels that are used as both correlations of events and indicatoins of abnormalities and pregression of pregnancy
Decidua basalis
the myometrial or burrowing side of the conceptus
Decidua capsularis
the villi covering the developing embryo
Double decidual sac sign
interface between the decidua capsularis and the echogenic decidua on the opposite wall of the endometrial cavity
Features of a normal gestational sac
shape position countour wall internal landmarks growth
Yolk sac
earlist gestational anatomy seen normally seen at 5 weeks gestatoin
Embryo
start of 5th week the bilaminar embryonic disk undergoes gastrulatoin and is converted into the trilaminar embryonic disk at this point organogenesis begins
Rhomboencephalon
primary part of brain divides into two segments the cephalic portion or metancephalon and the caudal component or myelencephalon
HCG levels in 1st trimester
correlate with gestational sac size during normal pregnancy lower levels with an ectopic pregnancy rise until about the 9th week then plateau and subsequently decline wile gestation continues
Limb development
limb buds become recognizable during the 6th week of gestatoin upper for first then lower
Skeletal ossification
calcification of the clavicle begins at approx 8 weeks
Physiologic herniation of bowel
the midgut elongates faster than the embryo is growing causing the midgut to herniate into the base of the umbilical cord at approx 11 weekis it descends into the fetal abdomen
Gestational sac size
mean sac size correlates closely with menstrual age during early pregnancy remains accurate through first 8 weeks of gestatoin
Crown rump length
measurement used as a determinant of first trimester gestatoinal dates produces dates plus or minus 5 to 7 days most accurate method through 12 weeks gestation
Nuchal translucency
normal first trimester popcket of fluid along the fetal back measruement of this space is a component of first trimester risk assessment
Nasal bone
absence of nasal bone in late first trimester associated with trisomy 21 is an indicator of Down Syndrome
Subchorionic hemorrhage
most common type of first trimester bleeding result from the implantation of the fertilized ovum into the endometrial wcavity and myometrial wall
Incomplete abortion
loss of pregnancy with products of conception remaining in the uterus
Missed abortion
a miscariage that is missed when a fetus dies, but the body does not recognize the pregnancy loss or expel the pregnancy tissue
Anembryonic pregnancy
blighted ovum gestatoinal sac in which the embryo fails to develop or stops developing at such an early stage that it is imperceptible by ultrasound
Molar pregnancy
abnormal proliferation of trophoblastic cells
Gestational trophoblastic disease
proliferative disease of the trophoblast that occurs after normal conception it represents a spectrum of disease from relatively benign form called hydatidiform mole to a more malignat form called invasive mole or choriocarcinoma
Normal cardiac activity
heart rate between 90 and 170 bpm
Bradycardia
heartbeat less than 90 bpm
Tachycardia
heartbeat more than 170 bpm
Oligohydramnios
insufficient amount of amnionic fluid in the sac
Growth restriction
growth delay of the embryo or gestational sac chromosome abnormalites such as triploid have been associtated with this
Ectopic pregnancy
pregnancy that occurs outside of the uterine cavity
Pseudogestational sac
gestatoinal sac that appears along with an ectopic pregnancy
Heteroectopic
one pregnancy in the uterus and another outside of the uterus
Interstitial pregnancy
pregnancy that occurs right where the fallopian tube attaches at the cornua of the uterus very dangerous situation could rupture and cause mother to bleed out
Cervical pregnancy
a pregnancy that occurs in the cervix 1 in 16000
Ovarian pregnancy
very rare pregnancy that occurs in the ovary itself
Acrania
partial or complete absence of the cranium
Anencephaly
congenital absence of the brain and cranial vault with the cerebral hemispheres missing or reduced to small masses
Cephalocele
midline cranial defect in which there is herniation of the brain and meninges
Iniencephaly
rare lethal anomaly of cranial development whoe primary abnormalites include 1 a defect in the occiput involving the foramen magnum 2 retroflexoin of the spine where the fetus looks upward with its occipital cranium directed toward the lumbar spine 3 open spinal dects
Ventriculomegaly
dilatoin of the ventricular system without enlargment of the cranium
Holoprosencephaly
malformatoin sequence that results from failure of the prosencephalon to differentiate into cerebral hemispheres and lateral ventricles between 4 8 weeks gestation
Dandy-walker malformation
cystic dilation of the 4th ventricle with dysgenesis of complete agenesis of the cerebellar vermis and frequently hydrocephaly
Spina bifida
occurs when neural tube fails to close after 6 weeks gestatoin appearacne includes spinal irregularitesor bulging within the posterior contour of the fetal spine
Abdominal wall defects
omphalocele gastroschisis limb body wall complex
Obstructive uropathy
results in a large urinary bladder that may extend out of the pelvis and into the fetal abdomen
Cystic hygroma
most common abnormalites seen sonographically in the first trimester seen early in fetal life have a high association with chromosomal abnormalities
Turners syndrome
most common karyotype abnormality non lethal endochrine disorder cause by failure of the ovaries to respond to pituitary hormone
Umbilical cord cysts
cysts ranging in size from 2 to 7.5 mm found between weeks 8 and 12 gestation
Corpus luteum cyst
most common ovarian mass secrete progesterone necessary to preserve the embryo measure less than 5cm and does not contain septations
Uterine fibroids
common throughout pregnancy may increase in size throughout first trimester and early 2nd because of estrogen stimulatoin
Diamnitoic
multiple pregnancies with two anmiotic sacs
Dichorionic
multiple pregnancies with two chorionic sacs
Monoamniotic
multiple pregnancies with one anmiotic sacs
Monochorionic
multiple pregnancies with one chorionic sacs
Zygote
the fertilized ovum is called this before implantation occurs
Chorionic villi sampling
invasive diagnostic genetic testing that involves sampling zygotic tissue cells from developing placental tissue
Hematopoiesis
the formation of RBC’s starts in the yolk sac and then moves to the liver
IUP
Intra Uterine Pregnancy
MSD
Mean Sac Dimension
Gastroschesis
born with abdomenal contents outside the body without a membrane
Omphalocele
born with abdomenal contents outside the body with a membrane
