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Flashcards in OB/GYN II Deck (196):

What are the three developmental stages of teratology

  1. Resistant period
    • Day 0-11
    • killed by the insult or survive unaffected
  2. Maximum susceptibility
    • day 11-57
  3. Lower Susceptibility
    • After 57 days
    • Growth retardation
    • Reduction in organ size


What are the categories of structural defects and what is the associated time period that they occur

  1. Malformations
    • 1st trimester
    • morphologic defect of a body part or organ
  2. Deformation
    • abnormal forms, shapes or positions of a body part
    • 2nd or 3rd trimester
  3. Disruptions
    • defects from interference with a normally developing organ system
    • 2nd or 3rd trimester


What is the effect of ionizing radiation

  1. Time of effect (susceptible period)
  2. Dose effect
    • Less than 10 rads (no effect)
    • 10-25 rads some adverse
    • greater than 25 classic fetal effects 


What are factors effecting access of a drug or medication to the fetus

  1. Maternal absorption
  2. drug metabolism
  3. protein binding and storage
  4. molecular size
  5. electrical charge
  6. lipid solubility


how much alcohol is needed to cause fetal alcohol syndrome

as little as one oz per day


Dose response:  the more drinks the more FAS that will present


What are the two most abused drugs in pregnancy

  1. Alcohol
  2. cocaine


What is a good predictor for fetal complications from maternal DM

Hemoglobin A1C


What are two types of malfomations found in the fetus of DM mothers

  1. Caudal regression syndrom with hypoplasia of the caudal spine and lower extremities
  2. CHD most commonly VSD


What is cretinism

the result of maternal, fetal, and neonatal thyroid hormone deficiency

usually in iodine poor areas


What is PKU


genetic d/o characterizeed by a deficiency of phenylalanine hydroxylase, a liver enzyme that catalyzes the conversion of phenylalanine to tyrosine.  the resulting high levels of phenylalanine in maternal serum result in high levels in the fetus.  


adverse effects:  

  1. mental retardation
  2. microcephaly
  3. CHD
  4. low birth weight


what is arrhenoblastoma

virilizing tumor


What are the common abnormalities associated with epilepsy

Clift lip

cleft palate



Valproic Acid caries a 1-2% risk of NTD


Some studies suggest that the frequency of seizures is correlated with the degree of abnormality


What is the #1 cause of death during pregnancy



What is the teratogenic effect of benzodiazepines

less than 1% risk of cleft anomalies


What are the effects of fetal warfarin syndrome

  1. Flattened nasal bridge
  2. stippled bony epiphyses
  3. birth weight less than 10th percentil
  4. ocular defects
  5. extremity hypoplasia
  6. developmental retardation
  7. seizures
  8. scoliosis
  9. deafness/hearing loss
  10. CHD
  11. death


What is used for the treatment of HIT (heparin induced thrombocytopenia)


Hirudin / bivalirudin


What are the problems with a 1st trimester infection of rubella

  1. Neuropathologic changes
    • microcephaly 
    • mental and motor retardation
    • meninogencephalitis
  2. Cardiovascular changes
    • PDA
    • pulmonary artery stenosis
    • Atrioventricular septal defects
  3. ocular defects
    • cataracts
    • microphthalmia
    • retinal changes
    1. blindness
  4. inner ear problems
  5. IUGR


What are the problems associated with an early pregnancy infection of CMV

  1. Microcephaly and hydrocephaly
  2. chorioretinits
  3. hepatosplenomegaly
  4. cerebral calcification
  5. mental ratardation
  6. heart block
  7. petechiae


What are the associated problems with a 1st trimester infection of HSV-2

  1. IUGR
  2. Microcephaly
  3. Chorioretinits
  4. cerebral calification
  5. microphthalmia encephalitis
  6. miscarriage


What are the associated problems with inutero infection of VZV during the 1st 20 weeks

Several organ systems are effected

  1. Cutaneous
  2. Musculoskeletal
  3. Neurologic


What is the problem with an enterovirus infection such as coxsachie B

Serious or fatal illness (40%) in the fetus


surviving infants may exhibit cardiac malformations; hepatitis, pneumonitis, or pancreatitis or adrenal necrosis


What is substance use

involves taking low, infrequent doses of illicit substances fro experimentation or social reasons.  damaging consequences are rare or minor


what is substance abuse

is the persistent or repeated use of a psychoactive substance for more than 1 month, despite the persistence or recurrence of adverse social, occupational, psychological or physical effects


what is substance dependence

WITHDraw IT mneumonic


what is the pharmacologic effect of cocaine

blocks dopamine and norepinephrine reuptake at the postsynaptic junction, thereby increasing CNS irritability

this leads to maternal and fetal vasoconstriction and tachycardia, as well as stimulation of uterine contractions

tocolytic agent of choice: Mag sulfate

Mag Sulfate can also be used to treat seizures


What are the effects of marijuana during pregnancy 

no increase in congenital malformations


What are the fetal effects of heroin during pregnancy

no increase in congenital malformations





Increased perinatal death


What are the fetal effects associated with methadone

no increase in congenital abnormalities


associated with low birth weight


What are the fetal effects of tobacco

spontaneous abortion

abruptio placentae


preterm delivery

lower birth weight


What is placenta previa

implantation of the placenta over the cervical os


What are the three types of placenta previa

  1. Total placenta previa: placenta completely cover the internal os.  Associated with the greatest risk and largest amount of blood loss
  2. Partial previa: placenta partially covers the os
  3. marginal previa: the placenta extends to the margin of the internal cervical os


What are the factors thought to cause placenta previa

  1. Previous placenta previa
  2. Previous C section
  3. Multiparity
  4. Advanced maternal age
  5. Smoking
  6. Asian and african descent
  7. Previous D & C


Placenta previa is associated with painful or painless bleeding

Painless bleeding


70% occurs at rest


Should you do a manual exam to determine placenta previa


unless you are in the OR ready for emergency C section


Confirm placenta previa via ultrasound


What are the complication of PPH (post partum hemorrhage)

  1. renal damage from prolonged hypotension
  2. Pituitary necrosis (sheehans syndrome)
  3. DIC


What is placenta accreta 

growth of the placenta into the myometrium or any of its variations due to the asence of decidua basalis


Placenta accreta should always be considered in the presence of placenta previa


What are the 3 types of placenta accreta

  1. Placenta Accreta: placenta is attached directly to the myometrium
  2. Placenta Increta: placenta invades the myometrium
  3. Placenta Percreta: placenta penetrates completely through the myometrium


What is abruptio placentae

premature separation of a normally implanted placenta after 20 weeks gestation.


It is initiated by bleeding into the decidua basalis, the bleeding splits the decidua, and the hematoma that forms causes further splitting.  The process may be self limiting


What is the common triad of presenting symptoms associated with placenta previa

vaginal bleeding

uterine or back pain

fetal distress


What necessitates an immediate delivery with a placentae previa

  1. fetal heart rate tracing is nonreassuring and the gestational age is greater than 24 weeks
  2. maternal condition deteriorate regardless of gestational age


What is an Apt test

determination of a vasa previa

  1. blood from the vagina
  2. adding a small amount of tap water
  3. centrifuging the sample
  4. adding the pink supernatant to 1mL of NAOH solution
  5. Reading the treated sample in 2 minutes
    • Pink color: presence of fetal hemoglobin
    • Yellow-brown color: presence of adult hemoglobin



How does oxytocin effect labor

Levels of oxytocin increase with labor, but there is not a surge.


The greatest increase is in the number of oxytocin receptors

  1. Six fold increase in weeks 13-17 gestation
  2. 80 fold increase at term
  3. preterm labor has 2-3 times as many receptors than would be expected


How do prostaglandins assist in labor

Labor is associated with an increase in prostaglandins.  this is likely the result of inflammation and not labor itself.

However, prostaglandins are believed to be important stimulatros of gap junctions


How is labor characterized

contractions that occur with increasing frequency and intensity, causing dilation of the cervix


What is the role of gap junctions in pregnancy

important cell-cell contacts that facilitate communication between cells via electrical or metabolic coupling


myometrial gap junctions, which are virtually absent during pregnancy increase in size and number before and during labor

Progesterone prevents gap junctions

Estrogen stimulates gap junctions


What are tocolysis agents and what is their functino

pharmacologic inhibition of uterine activity

  1. Antiprostaglandin agents
    • indomethacin
    • acetylsalicylic acid
  2. Calcium channel blockers
    • nifedipine
    • magnesium sulfate
  3. B-mimetic agents
    • terbutaline


Discuss the stages of labor

  1. Stage 1
    • Entails effacement and dilation.  it begins when uterine contractions become sufficiently frquent, intense and long to initiate obvious effacement and dilation of the cervix
  2. Stage 2
    • involves the expulsion of the fetus.  it begins with complete dilation of the cervix and ends when the infant is delivered
  3. Stage 3
    • involves the separation and expulsion of the placenta.  It begins with the delivery of the infant and ends with the delivery of the placenta


What do contractions do to the uterus

upper segment of the uterus becomes thicker and as labor progresses and contracts down with a force that expels the fetus with each contraction


lower segment of the uterus passively thins out with the contractions of the upper segment, promoting efacement fo the cervix


What is effacement of the cervix

the shortening of the cervical canal from a structure of approximately 2 cm in length to one in which the canal is repalced by a more circlar orifice with almost paper thin edges

effacement occurs as the muscle fibers near tthe internal os are pulled upward into the lower uterine segment


What is the dilation of the cervix

involves the gradual widening of the verival os.  must dilate to 10 cm to be considered completley dilated


What are the types of vertex presentations regarding position

Postion is named based on the occiput with in the birth canal (R or L and A or P) in an oblique fashion or 

Occiput transverse or  

Occiput anterior/posterior



What are the stations of engagement

Station 0 is the level of the ischial spine

Above the ischial spine in cm is the negative station

below the ischial spine in cm is the positive stations



+3 the presenting part is on the perineum


What does it mean if the fetal head is floating

when the fetal head is not engaged at the onset of labor and the fetal head is freely movable above the pelvic inlet


What are the 7 cardinal movements of labor and delivery

  1. Engagement
  2. Descent
  3. Flexion
  4. Internal rotation
  5. Extension of the fetal head
  6. External rotation
  7. Expulsion


What is engagement

the biparietal diameter of the fetal head, the greatest transverse diameter of the head in occiput presentations, passes through the pelvic inlet


What is associated with an increased risk of infection from ruptured membranes


greater than 24 hours regardless if labor has begun


On average how long should the first stage of labor last

12 hours primigravida

7 hours multigravida


What are the 2 phases of the 1st stage of labor


  • Prolonged is greater than 20 hours for primi or 14 hours multiparous


  • prolonged is dlation less than 1.2cm/hour in primi or 1.5 cm/hour in multiparous


On average how long does the second stage of labor last

50 minutes in primigravida 

20 minutes in multigravida


still common to last up to 2 hours


What is crowning

encirclement of the largest diameter of the fetal head by the vulvar ring


What are the two types of episiotomy




episiotomy is easier to repair and heals better than a tear, shortens the second stage of labor, and spares the infants head from prolonged pounding again the perineum


On average how long is the 3rd stage of labor

5 minutes


What are the signs of placental separation

uterus becomes globular and firm

often a sudden gush of blood

umbilical cord protrudes farther out of the vagina


What is the main control of uterine hemostasis

vasoconstricion produced by a well contracted myometrium


May be assisted  after the placenta has been delivered by:



prostaglandin F2a


Discuss the degrees of lacerations associated with birth

1st degree: invovle the fourchette, perineal skin and vaginal mucosa.  

2nd degree: involve the skin, mucosa, fascia and muscles of the perineal body

3rd degree: extend throught the skin, mucosa, and perineal body and involve the anal sphincter

4th degree: are exensions of the third degree tear through the rectal mucosa to expose the lumen of the rectum.


What are the 2 types of fetal heart monitoring

External ultrasound device

Fetal scalp electrode


What is baseline fetal HR

the heart rate that occurs between contractions regardless of accelerations or decelerations

normal FHR is 110-160 and decreases gradually after 16 weeks gestation as the parasympathetic system develops


What are the causes of baseline fetal tachy

FHR greater 160

  1. hypoxia
  2. maternal fever
  3. chorioamnionitis
  4. prematurity
  5. drugs
  6. fetal stimulation
  7. fetal arrhythmias
  8. maternal anxiety
  9. maternal thyrotoxicosis


what are the causes of fetal bradycardia

FHR less than 110

  1. hypoxia
  2. drugs
  3. autonomic mediated reflex
  4. arrhthmias
  5. hypothermia
  6. maternal hypotension


is baseline FHR variability normal


one of the best indicators of intact integration between the fetal CNS and the heart


How is FHR variability characterized

absent: undectable amplitude

minimal: detectable amplitude less than 5 bpm

moderate: amplitude of 6-25

marked: amplitude of more than 25 bpm


what are the two ways to measure contractions and there associated limitations

tocodynamometer: only determines the frequency and NOT intensity or strength

intrauterine pressure catheter (IUPC): measures both frequency and intensity


What define FHR accelerations

before 32 weeks: a peak of at least 10 bpm above baseline lasting 10 seconds or more

after 32 weeks: a peak of at least 15 bpm above baseline between 15 seconds and 2 minutes


what are the 3 types of FHR decelerations

1. Early decelerations

2. Variable decelerations

3. Late decelerations



What determines if a deceleration is prolonged

decreases from baseline of 15 BPM or more and last 2-10 minutes

caused by vagus nerve discharge or fetal hypoxia


define early decelerations

begin with the onset of uterine contractions, reach their lowest point (never below 100 bpm) at the PEAK of contraction and return to baseline as the contraction ends

thought to be caused by local changes in cerebral blood flow which results in stimulation of the vagal centers

these decelerations are physiologic


define variable decelerations

abrupt decreases in fhr with a rapid reurn to baseline (onset of deceleration to nadir less than 30 seconds) that may occur before, during, or after contration

generally are caused by compression of the umbilical cord


What are the types of variable decelerations

mild: duration less than 30 seconds

moderate: Two types
1. Nadir of 70-80 with duration of more than 60 seconds
2. Nadir less than 70 duration 30-60 seconds

severe: nadir less than 70 with duration greater than 60 seconds


define late decelerations

gradual decreases and returns to baseline with uterine contractions (onset to nadir greater than 30 seconds)

the nadir occurs after the peak of contraction

associated mechanisms

  1. normal variant
  2. direct myocardial depression
  3. uteroplacental insufficency


What are some nonreassuring FHR patterns

  1. repetitive decelerations
  2. abnormal baseline FHR
  3. absence of accelerations
  4. loss of variability
  5. repetitive late decelerations


What position should the mother avoid to avoid decreased uterine blood flow


in the supine position, the uterus blocks blood flow through the aorta and the inferior vena cava, potentially leading to decreased placental perfusion

placement in a lateral recumbent position during labor causes the uterus to fall away from the great vessels which should improve fetal oxygenation


what is the fetal scalp stimulation test

the examiner rubs the fetal scalp during a digital examination.  an acceleration is usually seen in the FHR tracing of the uncompromised, nonacidotic fetus.  The presence of an acceleration is associated wiht an intact ANS and a fetal scalp blood pH greater than 7.2

Fetal scalp pH greater than 7.2 isis reassurance that the fetus is not acidotic 


what is normal fetal oxygen saturation

between 35 and 75%

if the fetal oxygen sat remains above 30% during labor there appears to be no risk of fetal metabolic acidosis


What is dystocia

abnormal progression of labor.  Used an indication for cesarean section


What are the major causes of perinatal morbidity and mortality

low birth weight

congenital abnormalities


What are the indications for a cesarean section

  1. contraindication to labor
  2. Dystocia and failed induction of labor
  3. Emergent conditions that warrant immediate delivery


What are the contraindications to labor

  1. Placenta previa
  2. vasa previa
  3. previous classic cesarean
  4. previous myomectomy with entrance into uterine cavity
  5. previous uterine reconstruction
  6. malpresentations of the fetus
  7. active genital herpes infection
  8. previous cesarean section and patient declines trial of labor


What are the types of cesarean sections

  1. Low transverse (Kerr)
    • is made in the noncontractile portion of the uterus 
    • Lowest potential of blood loss
  2. Low verical (sellheim or kronig)
    • used when more room is needed to remove the fetus
  3. Classic incision (Sanger)
    • Simplest and quickest procedure to perform
    • uterine closure is more difficult


What are the types of abdominal incisions used to conduct a cesarean section

  1. Midline
  2. Paramedian
  3. Pfannenstiel:  most common, but requires more time to perform

A transperotoneal approach is used almost exclusively today


What are the complications of a cesarean section

  1. Endomyometritis
  2. UTI
  3. Wound infection
  4. Thromboembolic disorder
  5. Cesarean hysterectomy
  6. Uterine rupture in future pregnancy
  7. Uterine rupture in future pregnancy


What are the 2 types of episiotomy's




What are the indications for an operative vaginal delivery

  1. Nonreassuring fetal status
  2. Prolonged second stage of labor
  3. Certain maternal illness
  4. Poor voluntary expulsion efforts


What is a prolonged second stage of labor

  1. Nulliparous: more than 3 hours with regional or 2 hours with out regional
  2. Multiparous: more than 2 hours with regional or 1 hour without regional


What are the prereqs for instrumental vaginal delivery

  1. Cervix must be fully dilated
  2. membranes must be ruptured
  3. position and station must beknown, and the head must be engaged (0, station)
  4. maternal pelvis must be judged adequate size for delivery
  5. bladder should be empty
  6. skilled operator present
  7. adequate anesthesia is needed before forceps or vaccum applications


When are classic forceps indicated

primarily for traction when there is to be little or no rotation


What are the classic forceps

  1. simpson
  2. elliot
  3. tucker-McLean


What are the  specialized forceps

  1. Kielland (for rotation)
  2. Barton (for rotation)
  3. Piper (for the aftercoming head in breech deliveries)


Name the vaccum extractors

  1. Mamstrom vacuum extractor
  2. Plastic cup extractor (more widely used in US)


What is cervical cerclage

A sututre is placed in the cervix to treat cervical incompetence


What are the types of cerclage

  1. Shirodkar technique
  2. McDonald Technique: Less trauma and is a simple purse string
  3. Abdominal Placement: less common but used for short or amputated cervix


When is a cerclage performed

Usually performed between the 12th and 16th week but can be done as late as the 24th week.  It is generally removed at the 38th week.


Elective or prophylactic cerclage has a much lower risk of infection compared to waiting until the cervix is dialated


What is a spontaneous abortion

expulsion of the products of conception without medical intervention


what are the types of spontaneous abortion

  1. Threateed abortion
  2. Inevitable abortion
  3. Incomplete abortion
  4. Missed abortion
  5. Recurrent pregnancy loss


Discuss a threatened abortion

traditionally used when bleeding occurs in the first half of gestation without cervical dilation or passage of tissue


What is an inevitable abortion

pregnancy loss is diagnosed when bleeding or rupture of membranes occurs with cramping and dilation of the cervix


What is an incomplete abortion

progenancy loss occurs when there has been partial but incomplete expulsion of the products of conception from the uterine cavity


What is a missed abortion

Death of the fetus or embryo may occur without the onset of labor or passage of tissue for a prolonged period


How late can an elective induced abortion be performed

24 weeks in most states


What is a therapeutic abortion

terminations of pregnancy that are performed when maternal risk is associated with continuation of the pregnancy or fetal abnormalities are associated with genetic, chomosomal or structural defects.


What are the techniques used to terminate a pregnancy

  1. Surgical evacuation:
    1. Suction curetage (before 12 weeks)
    2. Dilation and Extraction (after 12 weeks).  After 16 weeks forceps are required for extraction
  2. Induction of labor


What are the medical means for inducing labor

  1. Prostaglandins
  2. Urea or hypertonic saline: injected directly into uterine cavity
  3. Progesterone antagonist: Mifepristone (effectiveness is often increased by administering with prostaglandin E)


How are future pregnancies effected by a suction curetage

incidences of infertility, spontaneous abortion, and ectopic pregnancy do not increase after uncomplicated suction curetage procedures


Normal parturients are less responsive to vasopressors and chronotorpic agents such as ephedrine or phenylephrine.  Why is this

decrease in response may be related to down regulation of alpha and beta receptors


How is the uterus effected by blood pressure

As blood pressure decreases so do uterine perfusion


What happens to the diaphragm with a gravid uterus

The diaphragm elevates 4 cm

causes a 20% decrease in FRC



Breathing of complete O2 will denitrogenate the lungs.  How will this benefit a patient and how is it effected by during pregnancy.

Nonpregnat patients will be able to tolerate 9 minutes of apnea before oxygen sat drops below 90%.  The parturient will only be able to tolerate 2-3 minutes


How does progeesterone effect the GI system

Decrease motility and food absorbtion


For general anesthesia, how is MAC (minimum alveolar concentration) effected during pregnancy

decreased up to 40 %


What is the pain asscoiated with the first stage of labor

distention and stretching associated with the dialation of the cervix

Sensory nerves enter the spinal cord at T10 - L1


What is the pain associated with the second stage of labor

stretching and tearig of fascia, skin, subcutaneous tissue, and other somatic structures

Derived primarily from S2-S4


Discuss the chemical structure of local anesthetics

weak bases that have a 3 part sturcture

  1. lipophyilic aromatic rin
  2. intermediate chain
  3. hydrophilic carbon chain bearing an amino group

The intermediate chain determines which classification a local anesthetic belongs:  

  • esters have COO
  • amides have NHCO


What is the mechanism of local anesthetics

prevent impulse generation in the nerve and propagation by gaining access to the sodium channel abd blocking permeability to sodium ions


What are the common risks associated with epidural 

hypotension and postdural headace

may prolong the duration of labor by 30-120 minutes


The hypotension is generally not related to a sympathetic blockade, but a removal of pain


What is the most common epidural combination

Fentanyl (25 micrograms)

sobaric bupivacaine (0.25%, 1mL)


What are some contraindications to epidurals

Clotting disorders


previous spinal surgery


Consider using PCA (IV - patient control anesthesia)


What is used to reverse the effects of opiods



When is antenatal test started and what does it include

started twice weekly between 41 and 42 weeks gestation.  

It includes:

  1. Nonstress test (NST)
  2. Contraction stress test (CST)
  3. Biophysical profile (BPP)



Discuss the non stress test

a noninvasive test of fetal activity that correlates with fetal well being.  FHR accelerations are boserved during fetal movement.  An external monitor is used to receorthe FHR, and the mother participates by indicating fetal movements

  • Reactive test requires 2 fetal heart rate accelerations of at least 15 beats amplitude of 15 seconds duration in a 20 minute period
  • If a test is nonreactive after 40 minutes, a CST is performed


Discuss the contraction stress test

a test of FHR that indirectly measures placental function in response to uterine contractions

An IV infusion of oxytocin is used to stimulate uterine contractions

It is used when the NST is nonreactive


What consists of a negative CST and postive CST

Negative CST:
3 uterine contractions of moderate intensity lasting 40-60 seconds over a 10 minute period with no late decelerations in the FHR tracing

Positive CST: 
has late decelerations associated with more than 50% of the uterine contractions.

A CST with inconsistent late decelerations are considered suspect


What is preterm birth

infants born before 37 weeks gestation

before 32 weeks have the greatest risk of poor health outcome and death

75% of preterm births occur after preterm labor and PPROM



What are the risk factors for preterm birth

  1. low socioeconomic class
  2. African American
  3. less than 18 or over 40,
  4. tobacco
  5. cocaine
  6. Previous premature birth

Maternal medical and obstetric conditions

  1. Mullerian malformations
  2. Cervical insufficiency
  3. Uterine over distention
  4. Obstetric conditions: Pre-eclampsia, Placenta Abruptio/previa, IUGR, PROM



What may be done for women that have a history of preterm birth

administration of progesterone showed to reduce risk of recurrent preterm birth


If a patient presents with vaginal bleeding, what must be done before a digital exam is performed?

ULTRASOUND to rule out placenta previa


What is the benefit of using tocolytics

They will not reduce the rate of preterm birth, however, they will often delay birth for 48 hours and reduce the associated complications


What are tocolytic options currently available

  1. Magnesium sulfate
  2. B-mimetics
  3. Indomethacin
  4. Nifedipine


What is the mechanism of magnesium sulfate

inhibits uterine contractility. 

acts by competitive inhibition of calcium at the motor end plate or the cell membrane, thereby decreasing calcium influx into the cell


What are the complications associated with magnesium sulfate

  1. Nausea vomiting
  2. flushing and headache
  3. muscle weakness
  4. pulmonary edema
  5. cardiopulmonary arrest


what are some contraindications to using magnessium sulfate

  1. renal failure
  2. myasthenia gravis 
  3. hypocalcemia


What is the only FDA approved B-mimetic used as a tocolytic



What is the major problem with using indomethacin as a tocolytic 

Neonatal side effects  is constriction of the ductus arteriosus: Do not use after 32 weeks


pulmonary hypertension

nectrotizing enterocolitis


What is the mechanism of Indomethacin

nonsteroidal anti-inflammatory which inhibits the synthesis of prostaglandins, which are involved in the biochemical process of labor


What is the mechanism of nifedipine

calcium channel blocker decreases smooth muscle contraction


What is the mechanism for ritodrine

smooth muscle relaxation


What are the abolute contraindications to tocolytic therapy

  1. Severe preeclampsia
  2. nonreassuring fetal heart rate
  3. significant antepartum bleed
  4. clinical chorioamnionitis


What is the leading cause of PPROM 

Intramniotic infection


What is used to determine a rupture of membranes

Nitrazine paper turns blue with a pH above 6.0 to 6.5

Amniotic fluid produces a fernlike pattern on a microscope slide when allowed to dry


What is chronic hypertension of pregnancy and what are the associate classifications

Persistent blood pressure greater than 140/90 mmHg before the 20th week of pregnancy

  • Mild: over 140/90
  • Moderate: 150/100 -170/110
  • Severe: over 170/110 

Hypertension can be initially diagnosed if it persists longer than 12 weeks postpartum


What is PIH

Pregnancy induced hypertension

  • Hypertension onset after 20 weeks gestation
  • Absolute MAP of 105
  • Absolute BP of 140/90 twice over 6 hours, without prior comparison
  • BP returns to normal 12 weeks post partum


What is preeclampsia

Gestataional hypertension with proteinuria

  • Proteinuria: 30mg/dL on dipstick or 300 mg on 24 urine


What is HELLP

Variant of severe preeclampsia
  • Hemolysis
  • elevated liver enzymes
  • Low Platelets


What is the effect of the placenta from hypertension

4 - 8 times more likely in pregnancy to develope abruptio placenta

IUGR because of decreased uterine blood flow


Perinatal mortality increase 25%


What are the antihypertensive medications that are used in the treatment during pregnancy

  1. Hydralazine (reduces afterload but compensates with an increase in HR)
  2. Alpha methyldopa
  3. labetalol
  4. nifedipine
  5. B-antagonist


What are the pathophysiological changes seen with preeclampsia

  1. Increased total Peripheral vascular resistance
  2. Preeclamptic endothelial cells generate less prostacyclin (vasodilator) than normal endothelial cells
  3. Coagulation system: DIC 10%
  4. Renal Function: GFR decreased
  5. Tubular changes: Decreased uric acid clearance is observed prior to a GFR disturbance
  6. RAAS


What are the clinical manifestations of preeclampsia


edema (related to Na retention)



What is the management of preeclampsia

Delievery is the only known treatment (at 37 weeks is recomended)

With severe preeclampsia before 24 weeks, termination should be offered.  Before 32 weeks delivery is a legitimate choice.


What is used for seizure prophylaxis for preeclampsia

Magnesium sulfate


What can be used to reverse Magnesium sulfate toxicity

1 gm calcium gluconate


What are the indications for antihypertensive medications

  1. Persistent diastolic blood pressure of over 105 mmHg
  2. Isolated diastolic BP over 110 mmHg


What is the effect of pregnancy on glucose metaolism

increased insulin secretion occurs as a result of B-cell hyperplasia from the increased levels of estrogen and progesterone

Insulin antagonism results from the increase in human somatomammotropin


Does insulin cross the placenta




How does fetal glucose relate to maternal glucose

directly proportional


What are the effects of pre existing diabetes on pregancy

Maternal complications

  • Preeclampsia
  • DKA
  • nephropathy
  • retinopayth
  • infection
  • polyhydraminos
  • Cesarean delivery
  • postpartum hemorrahge
  • mortality

Fetal complications

  • Miscarriage
  • Stillbirth
  • Perinatal mortality
  • Congenital malformations


What are the congenital malformations associated with a preexisting DM during pregnancy


spina bifida


Situs Inversus

Sacral Agenesis (Caudal Regression)


  • the risk of congenital abnormalities increases with higher hemoglobin A1C values


What are the glucose goals during pregnancy for preexisting DM

fasting glucose less than 95

2 hour post prandial less than 120


what is a complication of delivering a fetus greater 4000 grams

shoulder dystocia


What is the effect of gestational diabetes on pregnancy

increased risk of macrosomia

increased risk of preeclampsia

increased rate of still birth if fasting glucose is elevated




What is the standard for screening for gestational diabetes and what are the parameters

3 hour Glucose tolerance test

  • Fasting value: 95 mg/dL
  • 1-hour: 180 mg/dL
  • 2 hour: 155 mg/dL
  • 3 hour: 140 mg/dL

Diagnosis is given if any two of the parameters are met or exceeded


What is the effects of the thyroid during pregnancy

plasma inorganic iodine concentration decreases because of increased renal excretion and increased glomerular filtration


What are the treatment options for hyper thyoidism

PTU (propylthiouracil)


Beta blockers


What is the mechanism of PTU

prevents both the snthesis of thyroid gland and the peripheral conversion of T4 to T3


What is teh mechanism for methimazole

prevents only the release of thyroid hormone and has been associated aplasa cutis (a reversible but developmental disorder of the fetal scalp)


What are the effects of hypothroidism on the fetus during pregnancy

Deceased performance on IQ tests


What are the common bugs for acute urethritis in pregnancy

E Coli

Chlamydia Trachomatis

Neisseria gonorrheae


What is the most common cause of cystitis in pregnancy

E coli 90%

Usually there is NO fever


What is the most common cause of acute pyelonephritis in pregnancy


e coli (90%)

Preisposing factors unique to pregnancy:

  • Ureteral compression at the pelvic brim
  • decreased tone and peristalsis of the ureters resulting from increased progesterone levels
  • Decreased bladder sensitivity


How is anemia define in pregnancy

Hemoglobin concentration less than:

First trimester: 11g/dL

Second trimester: 10.5 g/dL

Third trimester: 11 g/dL


How much additional iron is needed during pregnancy

1000 mg elemental iron


What happens to hematocrit during pregnancy

decreases during the second trimester


What are the pregnancy complications associated with maternal heart disease



Preterm Deliver

Intrauterin demise

Highest risk is associated with pulmonary hypertension, and other conditions with aorta involvement


What treatment options are available during pregnancy against tuberculosis



Streptomycin and Rifampin should be avoided in pregnancy


What is the leading cause of death in pregnant and post partum women

thromboembolic disease


What abnormalities increase the risk of thromboembolic disease

Factor V leiden mutation

prothrombin mutation

antiphospholipid antibody

potein c or protein s deficiency

antithrombin III deficiency



What causes increased clotting factors during pregnancy



venous stasis from a gravid uterus compressing the IVC and pelvic veins also plays a significant role


How is a DVT diagnosed

real time ultrasonography is the procedure of choice

the gold standard is a venography (Invasive and expensive)


What are the findings associated with a PE



pleuritic pain






How is a PE diagnosed

Arterial blood gas less than 80 mmHg

Ventilation Perfusion abnormality

Pulmonary angiogram (gold standard)

Spiral CT tomography


What are the anticoagulants used for thromboembolic disease

heparin or SQ low molecular wight heparin (neither cross the placenta


Warfarin is teratogenic


What are the teratogenic effects of carbamazepine


Craniofacial defects

nail hypoplasia



What are the teratogenic effects of phenytoin


dysmorphic facies



What are the teratogenic effects of trimethadone

multiple malformations 

mental retardation


What are the teratogenic effects of valproic acid



What is the crierion for developing an Rh isoimmunization

All 3 must be met in an Rh-negative pregnant woman

  1. Fetus must be Rh positive
  2. Enough fetal cells must reach the maternal circulation (fetomaternal breech)
  3. The mother must make antibody to D antigen (as many as 30% are non responders)


How is Rh isoimmunization prevented?

300 micrograms Anti D immunoglobulin (RhoGAM) can protect a mother from up to 30mL of fetal blood


How can assess the degree of hemolysis and risk for fetal death with Rh Isoimmunization pregnancies


  • Bilirubin in amniotic fluid (byproduct of fetal hemolysis)
  • Spectrophotometry:  degree of shift at 450nm
    • Zone I mild anemia
    • Zone II mild to severe anemia
    • Zone III severe to death


When should a fetal transfussion be indicated

hematocrit below 30% with Rh isoimmunization pregnancy