OB/GYN Flashcards
What is gravidity
the number of times a woman has been pregnant
What is parity
The number of pregnancies that led to a birth beyond 20 weeks gestational age OR an infant weight > 500g
What is P####
(TPAL) the number of term deliveries, the number of preterm deliveries the number of abortuses the number of living children
What is the developmental age
the number of weeks and days since fertilization; usually unknown
What is gestational age
the number of weeks and days measured from the first day of the last menstrual period (LMP)
When is CRL considered
Crown Rump Length
6-12 weeks
When is BPD considered
Biparietal Diameter
After 13 weeks
What trimester is ultrasound measurement considered most accurate
1st
What is the standard of diagnosis for pregnancy
b-hCG
range of 1000-1500 IU/mL
Discuss b-hCG
Produced by the placenta
Peaks at 100,000 mIU/mL by 10 weeks GA
Decreases throughout the 2nd trimester, levels off during the 3rd
hCG levels double every 48 hours during early pregnancy
When is the gestational sac visible by ultrasound?
5 weeks GA
What happens to renal flow during the pregnancy
Increases 25-50%.
What happens to GFR during pregnancy
Increases early, then plateaus
What happens to uterine weight during pregnancy
Increases from about 60-70g to about 900-1200g
What is the average amount of weight gain for mothers during pregnancy
25 pounds (11-kg)
What happens to HR during pregnancy
increases gradually by 20%
What happens to BP during pregnancy
gradually decreases by 10% by 34 weeks, then increases to pregnancy values
What happens to stroke volume during pregnancy
Increases to a maximum at 19 weeks, then plateaus.
What happens to cardiac output during pregnancy
Rises rapidly by 20%, then gradually increases an additional 10% by 28 weeks
What happens with peripheral venous distention during pregnancy
Progressive increase to term
What happens to Peripheral vascular resistance during pregnancy
progressive decrease to term
What happens to respiratory rate during pregnancy
unchanged
What happens to tidal volume during pregnancy
increases by 30-40%
What happens to the expiratory reserve during pregnancy
gradual decrease
What happens to vital capacity during pregnancy
Unchanged
What happens to respiratory minute volume
Increases by 40%
What happens to blood during pregnancy
Increases by 50% in second trimester
What happens to hematocrit during pregnancy
decreases slightly
What happens to fibrinogen during pregnancy
increases
What happens to Electrolytes during pregnancy
unchanged
What happens to sphincter tone during pregnancy
decreases
What happens to gastric emptying time during pregnancy
Increases
What does the quad screen consist of
MSAFP (maternal serum a-Fetoprotein)
Inhibin A
Estriol
B-hCG
What is the unit MoM stand for
multiple of median
What is an elevated MSAFP (>2.5 MoM) associated with
Open neural tube defects Abdominal wall defects Multiple gestation Incorrect gestational dating Fetal death Placental abnormalities
What is reduced MSAFP (<0.5 MoM) associated with
Trisomy 21 and 18
Fetal demise
Inaccurate gestational dating
What is PAPP-A
Pregnancy associated plasma protein
What tests are needed to detect down syndrome
PAPP-A
Nuchal transparency
Free B-hCG
When conducted together can determine 91% of down’s and 95% of Trisomy 18
Using a quad screen what differentiates trisomy 21 from trisomy 18
Trisomy 18: all are decreased
Trisomy 21: MSAFP and Estriol are decreased while Inhibin A and B-hCG are increased
When is an amniocentesis indicated
- women >35 at time of delivery
- conjunction with abnormal quad screen
- Rh-sensitized pregnancy to obtain fetal blood type or to detect fetal hemolysis
- Evaluate fetal lung maturity
How do you evaluate fetal lung maturity using amniocentesis
lecithin-to-sphingomyelin ratio >2.5 or to detect the presence of phosphatidylglycerol
What is the teratogenic defect associated with ACE I
fetal renal tubular dysplasia neonatal renal failure oligohydramnios intrauterine growth restriction (IUGR) Lack of cranial ossification
What is the teratogenic defect associated with Alcohol
Fetal alcohol syndrome
>6 drinks per day has 40% risk
What are the deficits with fetal alcohol syndrome
growth restriction before and after birth metal retardation midfacial hypoplasia renal defect cardiac defects
What is the teratogenic defect associated with androgens
virilization of females
advanced genital development in males
What is the teratogenic defect associated with carbamazepine
neural tube defects fingernail hypoplasia microcephaly developmental delay IUGR
What is the teratogenic defect associated with cocaine
bowel atresias congentital malformation of the heart limbs, face, and GU Microcephaly IUGR Cerebral infarcts
What is the teratogenic defect associated with Diethylstilbestrol (DES)
Clear cell adenocarcinoma of the vagina ro cervix, vaginal adenosis, abnormalities of the cervix and uterus or testes, possible infertility
What is the teratogenic defect associated with Lead
increased spontaneous abortion (SAB) rate
stillbirths
What is the teratogenic defect associated with Lithium
Congenital heart disease (Ebsteins anomaly)
What is the teratogenic defect associated with methotrexate
Increased SAB
What is the teratogenic defect associated with organic mercury
Cerebral atrophy microcephaly mental retardation spasticity seizures blindness
What is the teratogenic defect associated with phenytoin
IUGR Mental retardation microcephaly dysmorphic craniofacial features cardiac defects fingernail hypoplasia
What is the teratogenic defect associated with radiation
microcephaly
mental retardation
medical diagnostic radiation delivering < 0.05 Gy to the fetus has no teratogenic risk
What is the teratogenic defect associated with Streptomycin and kanamycin
hearing loss
CN VIII damage
What is the teratogenic defect associated with tetracycline
permanent yellow brown discoloration of deciduous teeth
hypoplasia of tooth enamel
What is the teratogenic defect associated with Thalidomide
bilateral limb deficiencies
anotia and microtia
cardiac and GI abnormalities
What is the teratogenic defect associated with trimethadione and paramethadione
cleft lip or cleft palate
cardiac defects
microcephaly
mental retardation
What is the teratogenic defect associated with Valproic acid
neural tube defects
minor craniofacial defects
What is the teratogenic defect associated with vitamin A and derivatives
Increased SAB mircotia thymic agenesis cardiovascular defects craniofacial dysmorphism microphthalmia cleft lip or cleft palate mental retardation
What is the teratogenic defect associated with Warfarin
Nasal hypoplasia and stippled bone epiphyses
developmental delay
IUGR
ophthalmologic abnormalities
When does a fetus’s endocrine structures begin to function
as early as the 11th week of pregnancy
What are the effects of an increased amount of circulating estrogens
- increase the maternal hepatic procution of binding proteins such as thyroid binding globulin (TBG) and cortisol binding globulin (CBG)
- Inhibit maternal pituitary gonadotropin synthesis and release
- Enjance placental production of 11B-hydroxysteroid dehydrogenase
What forms hCG
alpha and beta subunits non covalently linked
alpha is similar to alpha subunit in the pituitary gonadotropins (FSH, LH, TSH)
Where is hCG produced
exclusively the product of the trophoblast, specifically the syncytiotrophoblast
When will hCG begin to be produced
as early as 6-8 days post conception
what is the significance of abnormally low levels of hCG
miscarriage
ectopic pregnancy: (value exceeds 2000 mIU/mL and intrauterine pregnancy not visual on ultrasound.
What is the time difference for sensitivity for detecting hCG in the blood versuses serum
blood is 6-8 days of ovulation
urine is 14 days of ovulation
ONLY after implantation
how long after a pregnancy can hCG be detected
4 weeks for normal pregnancy
10 weeks for first trimester abortion or elective early termination
What are the biologic functions of hCG
- maintain the corpus luteum and continue progesterone production
- regulate fetal testicular testosterone production
- TSH like properties
- Clinical uses
When is hPL formed
as early as 3 weeks post conception and secreted from the synctiotrophoblast
Detectable in maternal serum after 6 weeks
What is the biologic function of hPL
- induces lipolysis and increases maternal free fatty acids, ketones, and glycerol, which provide energy for the mother
- increased insulin levels
What are the 3 potential sources of prolactin
- anterior lobe of the maternal pituitary gland
- anterior lobe of the fetal pituitary gland
- decidual tissue of the uterous
What is the biologic function of prolactin
- preparing the mammary glands for lactation
a. stimulates growth of mammilary tissue
b. lactation does not occur during pregnancy because estrogen inhibits the action of prolactin on the breast - Decidual prolactin regulates fluid and electrolytes of the amniotic fluid
Where is progesterone produced in the pregnant state
- corpus luteum until the 7th week
2. Placenta after the 8th week
What is the biologic function of progesterone
- prepares the endometrium for implantation of the embryo
- relaxes the myometrium
- prevents rejection of the fetus by the maternal immune system
What is a progesterone receptor antagonist
mifepristone
used as as an abortifacient in the first trimester
What are the 3 estrogens and what is the production ratio
- estrone (14%) - 1 OH
- estradiol (5%) - 2 OH
- Estriol (81%) - 3 OH
later in the pregnancy estriol is produced almost exclusively by the placenta
Can estrogens be produced in the placenta
NO
due to a lack of the enzyme necessary to confer pregnenolone to androgen precursors
What is do low levels of estrogen signify
- fetal demise
- anencephaly
- Maternal ingestion of corticosteroids
- placental sulfatase deficiency
What are the biologic activities of estrogen
- stimulate receptor mediated LDL uptake by the placenta
- Increases blood flow to the uterous
- Regulates end-of-gestation events
Estrogen stimulates epithelial cell proliferation in human breast tissue. However, milk release is delayed until estrogen levels decrease after delivery
What increases myometrial gap formation
Estriol
What suppresses maternal lympohocyte activity
Progesterone
What is necessary fro development of male external genitalia
hCG
What is the most sensitive marker for abnormal karyotype
hCG
What elevates ketone levels
hPL
What hormone is produced by the uterus
prolactin
What inhibits lactation during pregnancy
Estriol
Lack of this hormone can cause spontaneous abortion in the first trimester
Progesterone
Lack of this hormone is associated with an enzyme deficiency in the placenta
Estriol
Elevated levels of this hormone are associated with twin pregnancy
hCG
Anencephaly causes ack of production of this hormone
Estriol
Where are gases and nutrients exchanged between mother and fetus
The villi of the placenta
What is the function of the placenta
- Mother to fetus transfer of nutrients
- Gas exchange
- Secretion of proteins and steroids
a. Progesterone is produced by the placenta from maternal cholesterol
b. Estrogen is converted from circulating fetal androgens produced in the fetal adrenal glands
How does the placenta immunologically protect itself from the mother
Invadinging placental cells express a unique antigen, HLA-G which is not recognized as a “foreign” antigen by the mother
What forms the umbilical cord
Two umbilical arteries originate from the fetal aorta
one umbilical vein returns nutrient rich, oxygen rich blood to the fetus
What are the amniotic membranes
Amnion: a single layer of epithelial cells surrounding the fetus and containing the amniotic fluids
Chorion: lies adjacent to the uterine endometrium, is exterior and fused to the amnion
Where is amniotic fluid derived
primarily from the fetal urine. It is important for the successful development of the bronchial tree
What are the requirements for fetal metabolism
- oxygen
- glucose
- amino acids
What is the rate of fetal oxygen metabolism
8 ml/kg/min
normal adult is 3 ml/kg/min
Where does the umbilical vein give branches
to the liver and becomes the ductus venosus
What is the function of the ductus venosus
mixes maternal oxygenated blood with fetal deoxygenated blood and flows into the IVC
What is the foramen ovale
a right to left intracardiac (atrial) shunt
What promotes closure of a PDA
prostaglandin inhibitors
What is the function of the ductus arteriosus
connects the left pulmonary artery to the arch of the aorta
What maintains the patency of the ductus arteriosus
Prostaglandin E
What does the fetal umbilical vein become in the neonate
ligamentum teres
The intra abdominal portion of the umbilical arteries of the fetus become what in a neonate
lateral umbilical ligaments
What is the normal fetal HR
120-160
What is the cardiac output of a normal fetal heart
200 mL/kg/min
normal adult is 70 mL/kg/min
when do fetal lungs begin to produce surfactant
34 weeks
from type II pneumocytes
What is the function of surfactant
lowers the surface tension in the alveoli and prevents collapse
How is fetal hepatic conjugation of bilirubin
deficient, and a mild hyperbilirubinemia may be seen for the first few days of life
Where does hematopoiesis occur
2 weeks: yolk sac
5 weeks: spleen and liver
11 weeks: bone marrow
What composes fetal hemoglobin
Fetus: 2 alpha and 2 gamma
Adult: 2 alpha and 2 beta
At term about 70% hemoglobin is fetal
What is the function of the thyroid in fetal development
important for normal neurological development
What is the most common immunoglobulin found in the fetus
IgG
Only IgG can cross the placenta
What are some presumptive symptoms of pregnancy
- amenorrhea
- breast changes
- Nausea (morning sickness)
- Disturbances in urination
- Fatigue
- Sensation of fetal movement
What is quickening
the sensation of fetal movement. Usually between the 16th and 20th week
What is hegar’s sign
Softening between the cervix and the uterine fundus causes a sensation of separateness between these two structures
what is chadwicks sign
the vaginal mucosa has a bluish color within the first 6-8 weeks of pregnancy
How is pregnancy confirmed
Only two ways
- Identification of fetal heart beat (120-160)
- Ultrasonographic representation of a fetus
How is EDC (estimated date of confinement) determined
9 calendar months plus 7 days from FDLMP
or
counting back 3 calendar months and adding 7 days to the FDLMP
What is the viability of life if birth occurs in the end of the second trimester
80-90%
What is lightening regarding pregnancy
the descent of the fetal head to or even through the pelvic inlet due to the development of a well formed lower uterine segment and a reduction in the volume of amniotic fluid
Regarding pregnancy what is a bloody show
a discharge of a combination of blood and mucus caused by thinning and stretching of the cervix, is a sure sign of the approach of labor
What is placenta previa
The placenta developing in the lower uterine segment an completely or partially covering the internal os.
Usually painLESS heavy bleeding
What is abruptio placenta
premature separation of the normal implanted placenta.
usually painful bleeding
What is normal fetus weight at 26, 36, and 40 weeks respectively
1000g (more than lbs)
2500g (5.5 lbs)
3300g (7-7.5 lbs)
What are good indications of fetal lung maturation with reduced risk of RDS
Leithin-to-sphingomyelin (L/S) Ratio of or greater than 2:1
A greater indicator is presence of phosphatidylglycerol
What accelerates fetal lung maturation
Glucocorticoids.
Stress will increase fetal cortisol production.
Administration of maternal glucocorticoids
What are the types of fetal presentation
- Cephalic
a. Vertex (chin in) (95%)
b. Face (Neck extended)
c. Brow (slightly extended but will convert to a vertex or a face during labor) - Breech presentation
a. Complete
b. Incomplete
c. Frank
What is a complete breech presentation
both the legs and the hips are flexed
What is an incomplete breech presentation
one hip is not flexed, and on foot or knee lies below the breech
What is a frank breech
the hips are flexed and the legs are extended
What is puerperium
period of 4-6 weeks and starts immediately after delivery and ends when the reproductive tract has returned to its nonpregnant condition
How does breast feeding accelerate involution of the uterus
stimulation of the nipples releases oxytocin from the neurohypophysis; the resulting contractions of the myometrium facilitate the involution of the uterus
What is lochia
uterine discharge that follows delivery and last for 3-4 weeks. Foul smelling lochia suggests:
- lochia rubra: blood stained fluid last for the first 3-4 days
- lochia serosa: discharge appears 3-4 days after delivery. It is paler than lochia rubra because it is admixed with serum
- Lochia alba: after the 10 day, because of admixture with leukocytes, the lochia assumes a white or yellow-white color
What kind of contraception can lactating mothers use
Progesterone only oral contraceptions as soon as their milk supply is established.
Progesterone only contraceptives do not appear to have adverse effects on lactation.
What is the most common cause of postpartum hemorrhage
- Uterine atony (most common)
a. general anesthesia
b. multiple fetuses
c. prolonged labor
d. rapid labor
e. high parity
f. vigorously stimulated with oxytocin - Retention of of placental tissue
What are some uterine contracting agents
Oxytocin
methylergonovine
Prostaglandin F(2a)
What is a puerperal infection
infection of the GU tract during the puerperium accompanied by a temperature of 100.4 or higher that occurs for at least of the first 10 days after postpartum EXCLUSIVE of the first 24 hours
How is milk production stimulated
Prolactin which is released from the anterior pituitary gland
Continuous production is controlled by a stimulus of the breast that curtails the release of prolactin-inhibiting factor from the hypothalamus
What is responsible for milk let down
Oxytocin released from the posterior pituitary
What kind of drugs or excreted in high concentrations in breast milk
lipid soluble drugs
What are the two phases of the menstrual cycle and how do they differ in duration
Follicular is the 1st half and is variable in length.
Secretory phase is the second half and is fixed at 12-16 days
How is EDC determined
EDC is determined by using naegele’s rule.
When FDLMP is uncertain, ultrasound can be used.
Use LMP unless
- Ultrasound dating in 1st trimester differs by more than 7-10 days
- Ultrasound dating in 2nd trimester differs by more than 14 days
- Ultrasound dating in 3rd trimester differs by more than 21 days.
Foamy white vaginal liquid with a strawberry discoloration of the cervix is suggestive of what
Trichomonas
White curdy vaginal discharge is suggestive of what
candida
Foul-smelling, gray discharge may indicate what
bacterial vaginosis
What is the diagonal conjugate
measured from the sacral promontory to the anterior inferior pubic symphysis. can be measured on on pelvic examination
what is the obstetric conjugate
the length from the sacral promontory to the posterior pubic symphysis. Measurement is determined by subtracting 1.5 to 2 cm from the diagonal conjugate.
The obstetric conjugate is the shortest anterior posterior diameter through which the fetal head must pass.
What are the for pelvic types
Android
gynecoid
platypelloid
anthropoid
Describe the gynecoid pelvis
Most common type (50%) Overall shape is round posterior sagittal diameter of the inlet is only slightly shorter than the anterior sagittal diameter. Ishial spines are not prominent Wide pubic arch
Describe the android pelvis
overall shape is heart like
posterior sagittal diameter of the inlet is much shorter than anterior sagittal, limiting the space for the fetal head
ischial spines are prominent
Narrow pubic arch
Describe the anthropoid pelvis
Overall shape is long and oval
Anteriorposterior diameter is greater than the transverse
prominent ischial spines
narrow pubic arch
Describe the platypelloid pelvis
Least frequent
flattened shaped with short anterioposterior diameter and wide transverse diameter
What women should be offered genetic testing
All women.
Women over the age of 35 should be offered genetic testing through chorionic villous sampling or amniocentesis
When is the quad screening performed
15-21 weeks
What is the difference between integrated and sequential screening
sequential screening: the results of the first trimester screenings are released to the patient and the provider
Integrated screening: the result of the first trimester test is withheld and incorporated into a final overall risk assessment
What is the frequent of prenatal visits
every 4 weeks until 24-28 weeks
every 2 weeks until 36 weeks
weekly until delivery
What amount of weight should be gained during pregnancy
Normal BMI: 25-35 lbs
less than 19 BMI: 28-40 lbs
more than 29 BMI: 15 lbs
How many calories should be taken in during pregnancy
2500
What food items should be avoided during pregnancy
unpasteurized cheeses
raw shellfish
fish that have high mercury levels
What is the effects of caffeine during pregnancy
greater than 5 cups per day has been associated with an increased risk of spontaneous abortion
Are whites or black mothers a greater risk during pregnancy
Blacks:
4X higher maternal mortality
2X perinatal mortality
What is the perinatal period
20 weeks gestation - 28 days after birth
What are some items that increase risk in pregnant patients
Low socioeconomic status Maternal age Less than 20 Maternal age greater than 35 Substance abuse Domestic Violence
How is a short cervical discovered and what are the associated complications
Cervical length less than 2.5 cm
Determined by ultrasound at 20-24 weeks.
associated with risk of preterm birth
What are the contraindications for a vaginal birth after cesarean
Classical uterine incision
Active herpes infection
Myomectomy
Placenta previa
What is eisenmengers syndrome
he process in which a left-to-right shunt caused by a congenital heart defect causes increased flow through the pulmonary vasculature, causing pulmonary hypertension,[1][2] which in turn causes increased pressures in the right side of the heart and reversal of the shunt into a right-to-left shunt.
In adults, the most common causes of cyanotic congenital heart disease are Eisenmenger syndrome and tetralogy of Fallot. Eisenmenger’s syndrome specifically refers to the combination of systemic-to-pulmonary communication, pulmonary vascular disease, and cyanosis.
What happens to clotting factors during pregnancy
Increased production of clotting factors by the liver.
Increases the risk of thromboembolic events
What congenital abnormality in the fetus is associated with maternal Rho and La antibodies
associated with greater risk of congenital hear blocks
What is consanguinity
marriage between close relatives
What effect may the use of Paxil (paroxetine) have on fetal development
greater risk for fetal cardiac malformations
When is a gestational diabetes screen completed
24-28 weeks with a 1 hour 50g glucose test
What can be used to reduce incidence of neural tube defects
0.4 mg folic acid daily reduces incidence in the general population by 50%
4 mg daily in patients with previous NTD pregnancies will reduce risk by 70%
What is the most common cause of inherited mental retardation
Fragile X
What is the inherritance pattern of fragile x
X linked recessive
When are serum markers drawn during pregnancy
First trimester ( 10weeks 4 days - 13 weeks 6 days) Included are: MSAFP B-hCG PAPP-A
Second trimester (15-22 weeks) Included are: MSAFP B-hCG Estriol Inhibin A
What invasive testing is done in the first trimester
CVS (Chorionic Villus Sampling)
done in weeks 10-12
Risk of fetal loss is 1%
Rh negative women who are not sensitized receive Rho(D) immune globulin after the procedure
What invasive testing is done in the second trimester
Amniocentesis
Risk of loss is 0.25 - 0.5%
If conducted in the 3rd trimester, the risk of preterm delivery is 1-2%
Rh negative women who are not sensitized receive Rho(D) immune globulin after the procedure
An increase in NT (nuchal translucency) is suggest what
Trisomy 18 or Trisomy 21
Estriol is increased with 18
Estriol is decreased with 21
What is the most common inherited disorder in caucasions
Cystic fibrosis
Carrier rate is 1 in 25
What is the most common mutation associated with CF
Delta F508
There are 23 mutations that are tested in genetic screens which accounts for 80% of cases
It is an autosomal recessive trait
What are the 3 types of normal hemoglobin
Hemoglobin A: 2 alpha and 2 Beta chains (95%)
Hemoglobin A2: 2 Alpha and 2 delta
Hemoglobin F: 2 alpha and 2 Gama
What is the most common inherited trait in african americans
Sickle Cell
Frequency of trait is 1 in 12
Autosomal recessive inheritance
What is Tay Sachs disease
the congenital absence of the enzyme hexosaminidase A, which results in an over accumulation of GM2 gangliosides, leading to severe progressive neurologic disease causing death in early childhood
Carrier rate in Ashkenazi Jews is 1 in 30
Autosomal recessive inheritance
What is an ultrasound
low energy high frequency sound wave
Frequencies between 3.5 and 5 MHz
What are the determining factors for amniotic fluid on ultrasound
Measurement of the deepest single pocket of amniotic fluid
8cm polyhydramnios
How is fetal well being measured during a 3rd trimester ultrasound
Biophysical profile
- Amniotic Fluid
- Fetal Tone
- Fetal Movements
- Fetal breathing
- Nonstress test
score of 2 is normal 0 is abnormal for each section. Total score of 8-10 is normal
When is fetal echocardiography indicated
Risk factors for CHD (congenital heart disease) suspected CHD's on ultrasound suspected fetal arrhythmia other congenital abnormality nonimmune hydrops fetalis