OB EXAM 4

What is the placenta?

the fetal support system. gives fetus nutrients and gas exchange.

What is the pathway of oxygen from the environment to fetus?

maternal lungs, heart, vasculature, uterus, placenta, umbilical cord

What effects fetal oxygenation?

Any interruption in the oxygen pathway at any point.

Ex: contractions, poor perfusion

What does adequate fetal oxygenation require?

sufficient maternal blood flow to placenta, normal maternal O2 sat, adequate placental exchange of O2 and CO2, open circulatory pathway through umbilical cord vessels, and normal fetal circulatory and O2 carrying functions.

what is uteroplacental circulation?

maternal blood flow into the intervillous space through spiral arteries.

How does maternal BP affect the flow of blood to fetus?

Maternal BP maintains flow of O2 and blood into uterus, placenta.

What is fetal placental circulation?

allows umbilical arteries to carry deoxygenated and nutrient depleted fetal blood from the fetus to the villous core fetal vessels.

Which vessels carry oxygenated blood to the fetus?

Umbilical vein

What is AVA?

2 arteries and 1 vein in the umbilical cord

How does the cardioregulatory center act as the source of FHR regulation?

SA/AV node, parasympathetic NS (decrease FHR baseline), Sympathetic NS (increases FHR baseline), baroreceptors (respond to BP changes), Chemoreceptors (respond to decrease in O2 and increase in CO2), maternal medications, placental abruption, hormone influences, miscellaneous factors (Ca, K)

What are the tools used to do intermittent auscultation of FHR?

doppler and fetoscope, only for LOW RISK moms

What is intermittent auscultation of FHR?

FHR checked in intervals, important to distinguish fetal HR from maternal.

What are the benefits and limitations of intermittent auscultation of FHR?

Benefits: moms can move freely around room

Limitations: does not provide documentation, significant events can occur when not listening

What is electronic fetal monitoring?

2 transducers are placed on mom and connected to monitor unit to provide continuous or intermittent monitoring of FHR. paper strips of FHR and contraction patterns are printed from machine.

What are the benefits of electrical fetal monitoring?

Benefits: non-invasive, constant knowledge, automatic documentation, baby and maternal VS shown on monitor.

Limitations: limits mom's movement, every time mom repositions transducers must be fixed, if mom has multiple fetuses it can be find every HR, can pick up maternal HR and mistake it for FHR

What is a fetal scalp electrode?

internal monitoring device that is placed superficially into fetus's scalp to monitor FHR.

When is a fetal scalp electrode contradicted?

unidentifiable presenting part of fetus, placenta previa, hemophilia, maternal HIV, visible genital herpes lesions, or prodromal lesion symptoms.

What is an intrauterine pressure catheter ?

internal monitoring device used to sense contractions and stays in place until baby is delivered.

Membranes must be ruptured, mom must be 2cm dilated.

What do thin light vertical lines represent in fetal monitor tracings?

10 second intervals

What do thick dark vertical lines represent in fetal monitoring tracing?

1 minute intervals

How is the baseline FHR determined?

FHR rounded in increments of 5 beats per minute during a 10 minute period excluding accelerations and decelerations

What is a normal FHR baseline?

110-160 bpm

What is fetal bradycardia?

below 110 bpm

What is fetal tachycardia?

above 160 bpm

What is variability?

Fluctuations in the baseline FHR that are irregular in amplitude and frequency. most critical indicator of good fetal oxygenation.

What is important to remember for absent and minimal (<5bpm) variability ?

They require intervention!

What is moderate variability?

6-25bpm this is best!

What are FHR accelerations?

abrupt increase in FHR when baby moves, these are good and predict fetal well being.

How do we know if there has been a fetal acceleration?

the peak of acceleration must be at least 15 bpm over the baseline and last at least 15 seconds or more from the onset to return 15x15 (in less than 32 weeks it is 10x10)

What is vibroacoustic stimulation?

tool placed on maternal abdomen that makes noise to wake up fetus

What is fetal scalp stimulation?

during vaginal exam nurse rubs head of baby to wake them up

What are fetal decelerations?

decrease in FHR, there are different kinds of decelerations

What are early fetal decelerations?

the peak of the deceleration occurs at the same time as the peak of the contraction (these are OKAY), these indicate head compression which is a normal part of labor

What are late fetal decelerations?

the onset of the deceleration to the peak is equal to or greater than 30 seconds and the peak of the deceleration occurs after the peak of the contraction. These indicate placental insufficiency and must be addressed

What are variable decelerations?

abrupt decrease from onset to peak of deceleration. This indicates cord compression

How do we identify a variable deceleration?

at least 15bpm below baseline, with decelerations lasting at least 15 seconds up to 2 minutes

What is a prolonged deceleration?

Decrease in FHR that lasts a minimum of 2 minutes or up to 10 minutes. This indicated an interruption of oxygen

What is considered category 1 FHR?

normal FHR baseline, moderate variability, accelerations present or absent, variable or late decelerations absent, early decelerations can be present or absent

What is considered category 3 FHR?

Absent variability WITH recurrent late decelerations OR recurrent variable decelerations OR bradycardia. Need to expedite delivery- use of vacuum, forceps or c section

What is considered category 2 FHR?

anything that is not category 1 or 3

What is the ABCD approach?

Assess oxygen pathway and identify the cause of FHR changes

Begin corrective measures

Clear obstacles to delivery

Determine a delivery plan

What is uterine activity?

number of contractions in a 10 minute window of time averaged over 30 minutes

What is contraction frequency?

period from beginning of 1 contraction to beginning of next

What is contraction duration?

beginning of one contraction to the end of the same contraction

What is contraction intensity?

strength of contraction (mild, moderate, strong)

What is resting tone?

The tone of uterus at rest. assessed by palpation

What is relaxation time?

how long from the end of 1 contraction to the beginning of next. This is when the baby is getting blood and nutrients.

What are normal contractions?

five or fewer contractions in 10 minutes, averaged over a 30 minute period

What is tachysytole?

More than 5 contraction s in 10 minutes, averaged over a 30 minute period but may also include contractions lasting 2 minutes or longer, contractions with less than 1 minute of resting time between, or failure of the uterus to return to resting tone between contractions

What is external version?

procedure used to change fetal presentation from breech to cephalic

What are the contradictions for external version?

uterine malformation, previous c/s or abdominal surgeries, placental abnormalities, 3rd trimester bleeding, large fetus, multiple gestations, Oligohydramnios, ROM, or nuchal cord, uteroplacental insufficiency, engagement of head into pelvis

What are the risks for the fetus in external version?

entanglement in cord, placental abruption, mixing maternal/fetal blood

What is induction?

initiating labor before spontaneous onset

What is augmentation?

labor has already spontaneously started; however, progress is inadequate

What are the medical indications for induction?

hostile intrauterine environment, SROM, post-term pregnancy, Chorioamnionitis, HTN, placental abruption, fetal demise

What is bishop scoring?

Used to estimate how easily a woman's labor can be induced. Higher scores are associated with a greater likelihood of successful induction because the cervix has undergone prelabor changes, 'ripening.'

What are the contradictions to induction/augmentation?

placenta previa, vasa previa, umbilical cord prolapse, abnormal fetal presentation, active genital herpes, previous uterine surgery

What is the individual evaluation for induction/augmentation?

one or more previous low transverse CS, breech presentation, overdistended uterus, severe maternal disease, fetal presenting part above the pelvic inlet, Inability to adequately monitor fetus, or indeterminate or abnormal FHR

What are the risk of induction/augmentation?

hypertonic uterine activity, uterine rupture, maternal water intoxication, Greater risk for chorioamnionits, greatest risk for C section, postpartum hemorrhage

What are the two prostaglandin gels and what are they used for?

Dinoprostone and Prepidil. these are used to soften (ripen) the uterus

What is Dinoprostone (cervidil)?

vaginally inserted prostaglandin gel used for cervical ripening. Can be removed in the event of tachysystole

What is Misprostol (Cytotec) used for?

pill taken to soften the cervix

What is membrane stripping?

Dr manually inserts finger and "sweeps" the amniotic sac

What is oxytocin?

Used to achieve adequate contraction pattern, comes diluted in an isotonic solution and is regulated with an IV pump

What should be done prior to oxytocin administration?

monitor UA/FHR for at least 20 minutes to determine baseline and fetal wellbeing. vaginal exa to assess dilation and verify presentation

What are the contradictions for forceps or vacuum extraction?

breech/face/brow presentation, CPD, unengaged fetal head, incompletely dilated cervix, bleeding disorder, premature infant

What are the risks of forceps or vacuum extraction?

maternal: soft tissue injury

Fetal: ecchymosis, facial and scalp lacerations/abrasions, facial nerve injury, cephalhematoma, subgaleal hemorrhage, intracranial hemorrhage

When are forceps or vacuums used?

done in second stage of labor if mom isn't pushing effectively, abnormal FHR during pushing, labor needs to be quickened

What is an episiotomy?

surgical incision of the perineal to get baby out

When is an episiotomy done?

fetal shoulder dystocia, vacuum/forceps assisted birth, occiput posterior position, breech delivery, macrocosmic fetus

What are the risks of episiotomy?

infection, pain

What can be done to prevent episiotomy?

upright positioning while pushing, delayed pushing, "laboring down", perineal massage and stretching

What are the indications for a C section?

dystocia, cephalopelvic disproportion, HTN, maternal diseases, active genital herpes, previous uterine surgical procedures, persistent/non reassuring FHR patterns, prolapsed umbilical cord, fetal malpresentation, hemorrhagic conditions, maternal request

What are the contradictions for a C section?

fetal death, immature fetus, maternal coagulation defects

What are the maternal risks for a C section?

infection, hemorrhage, UTI, thromboembolism, thrombophlebitis, paralytic ileus, atelectasis, anesthesia complications

What are the fetal risks for a C section?

inadvertent preterm birth, transient tachypnea, persistent pulmonary HTN, traumatic injury, lung immaturity is the greatest risk if fetus is premature

What is the prep for a C section?

labs, fetal surveillance, skin prep, meds, anesthesia, position on operating table, foley insertion, pad, SCDs, "time out", sterile skin prep

What are the meds given for a C section?

famotidine, bicitra, prophylactic antibiotics

What are the two incisions made for a C section?

abdominal and uterine (transverse, vertical, classical)

What are the nursing considerations for a C section?

Provide emotional support, education, promote safety, provide post op care

What can cause ineffective contractions?

anxiety/fear can stall labor, maternal inactivity, baby not pushing on cervix

How can ineffective maternal pushing be corrected?

labor down, upright positions add gravity to the woman's pushing efforts, education about fetal descent, coaching through contractions if the woman can't feel them, encourage to rest and push only when she feels the urge to push or push with every other contractions

How could the passenger cause labor dysfunction?

fetal size, fetal presentation or position, multifetal pregnancy, fetal anomalies

What is shoulder dystocia?

delayed or difficult birth of the shoulders may occur as they become impacted above the maternal symphysis pubis

What are the possible problems of prolonged labor?

maternal infection, neonatal infection, maternal exhaustion, higher levels of anxiety for next delivery

What are the possible problems of precipitous (short) labor?

birth occurs within 3 hrs of its onset, intense contractions, may lead to precipitous birth(provider not present)

What is placenta accreta ?

placenta is implanted into the uterine wall (all or part)

What is placenta incretra?

chorionic villi invade the myometrium

What is placenta percreta?

complete perforation through the uterine musculature and onto the adjacent organs such as the bladder

What is a prolapsed umbilical cord?

cord slips downward after the ROM subjecting it to compression between the fetus and pelvis

What are the risks for prolapsed umbilical cord?

fetus that remains at a high station, very small or preterm fetus, breech presentation, transverse lie, hydramnios

What are the signs of cord prolapse?

complete with cord visible at vaginal opening, or cord not visible but can be palpated during vaginal exam or occult prolapse

What is the therapeutic management of a prolapsed cord?

relieve pressure on the cord to improve umbilical blood flow until delivery, do not remove hand from vagina if you find it, get help, positioning, administer O2

What is a uterine rupture?

tear in the wall of the uterus because the uterus cannot withstand the pressure being exerted against it

What are the 3 variations of uterine rupture?

complete rupture, incomplete rupture, dehiscence

What are the causes of uterine rupture?

rare and normally associated with a previous uterine surgery, risks for rupture greater in a woman with a classical incision as opposed to a low transverse incision, rupture of an unscarred uterus more likely for women of high parity with a thin uterine wall or women having intense contractions

What are the signs of uterine rupture?

abdominal pain and tenderness, chest or shoulder pain, pain between scapulae, or pain on inspiration, hypovolemic shock caused by hemorrhage, signs of impaired fetal oxygenation, absent fetal heart activity, cessation of uterine contractions, palpation of the fetus outside of the uterus

What is uterine inversion?

occurs when the uterus completely or partly turns inside out, usually during the third stage of labor

What are the signs of uterine inversion?

uterus is absent from the abdomen or a depression in the fundal area is present, interior of the uterus may be seen through the cervix or protruding into the vagina appearing as a red beefy mass, hemorrhage, shock, pain

What is the management of uterine inversion?

physician tries to replace the uterus through the vagina into a normal position