Miscellaneous OB Flashcards
Potential causes of fetal bradycardia during labor:
- uteroplacental insufficiency
- acute onset maternal hypotension after epidural
- tachysystole
- rapid fetal descent or cervical dilation
- umbilical cord prolapse or prolonged cord compression
- placental abruption
- uterine rupture
Potential causes of fetal tachycardia during labor:
Maternal
- fever/infection
- medications (i.e. beta-agonist)
- hyperthyroidism
- anxiety
- dehydration
- anemia
Fetal
- congenital cardiac anomaly
- anemia
- early sign of hypoxia
- prolonged activity
- prematurity
When is SBE prophylaxis indicated and what is treatment (IV and PO option)?
Usually not indicated for vaginal or cesarean delivery unless patient has HIGH RISK cardiac disease including: CHD (congenital) with unprepared cyanotic cardiac disease or prosthetic valve or prior history of infectious endocarditis or cardiac transplant. Mitral valve prolapse is NOT an indication.
IV: ampicillin 2g IV: if allergy, cefazolin 1g IV or clindamycin 600 mg IV
PO: amoxicillin 2g oral x 1; if allergy, then clindamycin 600 mg oral x 1 or azithromycin 500mg oral x 1
NYHA classification of heart disease:
Class 1 (mild): asymptomatic with normal physical activity and functional status
2 (mild): mild symptoms with normal physical activity and minor limitation of functional status
3 (moderate): moderate symptoms with less than normal physical activity, comfortable only at rest with marked limitation in functional status
4 (severe): severe symptoms with features of heart failure with minimal physical activity and at rest with severe limitation in functional status
- all have cardiac disease
- symptoms refer to fatigue, palpitations, chest pain, dyspnea, syncope
How do you manage CIN1, CIN2, and CIN3 detected during pregnancy? What about CIS or cervical carcinoma Stage 1A1?
CIN1: expectant management, repeat cytology and colposcopy 4-6 weeks postpartum
CIN2/3 (no cancer suspected): repeat colposcopy every 12-24 weeks during pregnancy or defer to 4-6 weeks postpartum
CIS or Stage 1A1: if termination desired, subsequently treat as non pregnant patient; if GA >22 to 25 weeks, obtain tumor stage; if 1A1, no LVSI, defer to postpartum or definitive mgmt with conization; if 1AB to 1B1, no LVSI, conization or simple trachelectomy, if 1AB to 1B1, with LVSI or 1B1+, neoadjuvant chemo
Hemodynamic/CV changes in pregnancy: increase/decrease/unchanged
Cardiac output ____.
SVR ____.
Mean BP ____.
HR ___.
Equation for cardiac output:
List other hematologic changes:
Cardiac output increased
SVR decreased
Mean BP unchanged (slight increase maybe)
HR increased
CO = SVR x HR
●Expanded plasma volume (in excess of the increase in red blood cell mass) and resultant physiologic anemia
●Mild neutrophilia
●Mild thrombocytopenia
●Increased procoagulant factors and decreased natural anticoagulants
●Diminished fibrinolysis
Renal Changes in pregnancy (acid/base balance):
- ureteral dilation (more on R)
- GFR and renal plasma flow increase by 50%, which leads to increased Cr clearance (so lower Cr than baseline)
- hyperventilation and respiratory alkalosis (so PaC02 decreases to 27-32 mmHg)
- ## renal bicarb excretion increases (so bicarb decreases to 22 mmol/L
Respiratory Changes in pregnancy
Minute ventilation \_\_\_. Tidal volume \_\_\_. RR \_\_\_. VC \_\_\_. TLC \_\_\_. RV \_\_\_. FRC \_\_\_. PaO2/PaCO2/bicarb/pH
Calculation for minute ventilation:
Minute ventilation and TV increased.
RR, VC and TLC unchanged.
RV and FRC decreased.
paO2 increased/paCo2 decreased/bicarb decreased/pH high normal (due to hyperventilation and respiratory alkalosis)
Minute ventilation = TV x RR
Causes on congenital heart disease
- chromosome anomaly
- familial/genetics
- maternal diabetes on insulin
- alcohol use in pregnancy
- rubella infection in pregnancy
- IVF
- PKU
- SLE
- connective tissue disorder
- seizure disorder on high risk meds (i.e. valproate)
What 3h GTT criteria do you use? How much glucose? What are the lab cut offs?
What about 1h GTT?
Carpenter and Coustan
100g
Fasting 95 mg/dL
1h 180
2h 155
3h 140
50g
1h 135
Neonatal complications of diabetes in pregnancy:
- hypoglycemia
- low serum calcium, magnesium
- hypothermia
- respiratory distress
- polycythemia
- hyperbilirubinemia
Risks of meth use in pregnancy (fetal/maternal):
Fetal
- SGA, GFR
- neonatal withdrawal syndrome
Maternal
- labile hypertension, placental abruption, PPROM, preterm labor/delivery
- depression, violent behavior
Vertical transmission rate for HIV in pregnancy with or without treatment?
with treatment: 1-2% (zidovudine + CS or viral load <1000 copies/mL and no CS); 8% with zidovudine only (no CS)
without treatment: 24%
Differential diagnosis for hyperemesis:
- pregnancy related: high estrogen level, multifetal gestation, molar pregnancy
- GI related: gastroenteritis, appendicitis, cholecystitis, pancreatitis, SBO, peptic ulcer disease
- GU related: nephrolithiasis, UTI/pyelonephritis
- Endo related: hyperthyroidism (Grave’s), DKA
- Neuro related: benign intracranial hypertension, migrane
What is a Coombs antibody test? What are the 2 types?
Checks blood for antibodies that attack red blood cells. Type types of tests, direct and indirect.
Direct looks for antibodies attached to blood cells
Indirect look for antibodies that are free in serum
Summarize clinical pelvimetry:
Pelvic inlet: diagonal conjugate measured from pubic symphysis to sacral promontory; OB conjugate is diagonal conjugate - 2. Value >10cm is favorable.
Midpelvis: AP diameter between symphysis in sacrum >11.5 cm is favored. Distance between ischial spines >10 cm is favored.
APGAR score
Activity (muscle tone) flaccid, mild flexion, active motion
Pulse (HR) absent, <100, >100
Grimace (reflex) no response, grimace, vigorous cry
Appearance (color) blue/pale, pink/ext blue, all pink
Respiration (RR) absent, irregular, good
* all 0, 1, or 2 points
Management of cord prolapse:
- get help!
- if not complete cervical dilation and multip: elevate fetal head (to take pressure off cord), knee-chest or elevate hips, place moist lap over prolapsed cord (keep moist and avoid manipulation to avoid cord spasm), notify anesthesia/NICU/OR staff and get to OR quickly; ensure adequate IV access, consent for emergent CS, possible terb if needed to stop contractions and not yet able to deliver. Reassess cervix dilation in OR prior to CS (in case fully dilated, multip, and could have assisted vaginal delivery)
Congenital rubella syndrome
- characteristics
- how long after rubella vaccine should one wait to get pregnant
Characteristics: blueberry muffin rash, low birth weight, deafness, hepatosplenomegaly, developmental delay
How long wait after vaccine: 1 month
Lamotrigine therapeutic serum level?
Levatiracitam (Keppra) therapeutic serum level?
Lamotrigine: 3-14 mcg/mL
Keppra: 5-30 mcg/mL
Which medications for SLE are contraindicated in pregnancy?
What medications for SLE are acceptable in pregnancy?
Contraindicated:
- cyclophosphamide
- mycophenolyate mefotil
- methotrexate
Indicated:
- hydoxychloroquine
- azathioprine
- tacrolimus
- low dose corticosteroids
Hyperthyroidism in pregnancy
- what is PTU (propylthiouracil) dosing?
- what is methimazole dosing?
- what is proponalol dosing? why is it used?
- what is treatment goal?
PTU: 100-600 mg daily divided in 3 doses; typical dose is 200-400 mg daily in 3 doses
Methimazole: 5-30 mg daily divided into 2 doses (or 1 dose for maintenance therapy)
Proponalol is used for symptomatic palpitations: 10-40 mg taken three to four times daily
- Goal is to maintain free T4 slightly above or high-normal range regardless of TSH
Twinning process timeline for:
- di-di
- mono-di
- mono-mono
Di-di: 0-4 days
Mono-di: 4-8 days
Mono-mono: 8-12 days
Which muscles are cut during episiotomy?
Bulbospongiosis and
Risks of grand multiparity
PPROM, preterm labor, abnormal placentation, dysfunctional labor, malpresentation, macrosomia, preclampsia, gestational diabetes, cesarean delivery, PPH
What is Surgicel?
Oxidized regenerated cellulose
What is scant prenatal care?
<4 prenatal visits or prenatal care starting during 3rd trimester
How do you diagnose Intraamniotic infection?
- fetal tachycardia
- foul smelling purulent copious vaginal discharge
- maternal leukocytosis
- fever > 38-38.6 C (100.4-101.4) with 1 other feature above or fever > 39.0 (102.2)
Mechanism of action of betamethasone?
Stimulates synthesis of surfactant by Type 2 pneumocytes to lubricate lungs and facilitate fetal breathing
Why is tocolysis in the setting of Preterm PROM controversial?
Tocolysis can prolong labor but is also associated with increased risk of chorioamnionitis; limited data available on whether or not there is neonatal benefit
Tocolytic drug name examples, side effects, and contraindications for:
- calcium channel blockers
- NSAID (dose?)
- beta adrenergic against
- mag sulfate
- calcium channel blocker (nifedipine): dizziness, flushing, hypotension; avoid in preload dependent patient such as aortic insuffiency); nifedipine 10/10/20 loading dose then 20 mg q6 hours
- NSAID (indomethacin): gastritis, reflux, N/V; risk of premature closure of ductus arterioles, oligohydramnios, NEC; avoid in patients with platelet disorder, liver problems, peptic ulcer disease; do not use after 32 weeks; indomethacin is 50 mg loading dose f/b 25mg q6h x 48 hours max
- Beta adrenergic agonist (terbutaline): tachycardia, hypotension, palpitation, tremors, hypokalemia, hypoglycemia, fetal tachycardia; avoid in tachycardia sensitive heart or poorly controlled DM
- Mag sulfate: flushing, diaphoresis, nausea; risk of neonatal depression; avoid in myasthenia gravid or renal disease
Different indications for cerclage
- History indicated
- previously diagnosed cervical insufficiency or prior cerclage for same diagnosis should be recommended for cerclage at 13-14 weeks in next pregnancy - Ultrasound indicated
- transvaginal cervical length <25mm in patient with prior history of preterm birth
- transvaginal cervical lengh <10mm in patient without prior history of preterm birth may be considered - Exam indicated
- dilated cervix by digital or speculum exam between 16-23w6d
- NOTE: in addition to discussing the maternal risks and potential neonatal benefits, it is important to note that although there may be an extension of the pregnancy, it may extend the pregnancy just to periviability or just past viability, committing the pregnancy to an early preterm birth as opposed to a pregnancy loss - Rescue
- when the fetal membranes are visible at or past the external cervical os in the absence of PPROM, labor, abruption, or infection
Risk factors associated with AMA during pregnancy
- SAB
- chromosome abnormality
- gestational diabetes
- preeclampsia or other hypertensive disease of pregnancy
- placenta previa/abruption
- preterm birth
- low birth weight
- stillbirth
Risks associated with late term/postterm delivery (maternal and fetus)
maternal:
- severe perineal lac
- infection
- PPH
- CS
- maternal anxiety
fetus:
- neonatal seizure
- meconium aspiration
- stillbirth (odds ratio increases from 1.5 to 1.8 between 41 weeks to 42 weeks; to 2.9 by 43 weeks)
- low 5 min Apgar
- postmaturity syndrome (decreased SC fat, lack vernix/lanugo, mec staining)
- postterm also associate with significant increased rate of neonatal ICU admission
- 2x risk fetal macrosomia
Would you offer earlier IOL to AMA > 40 and why?
Yes; risk of stillbirth at 39 weeks for AMA > 40 approaches risk of stillbirth at 41 weeks for age 20s
MoA of misoprostol and dosing?
PGE1 synthetic analogue
50 mcg oral or 25 mcg vaginal every 6 hours x max 6 doses
MoA of dinoprostone
PGE2
aka Cervidil
Vaginal insert 10 mg @ rate of 0.3 mg/h
5% associated rate of uterine tachysystole
Risks of obesity in pregnancy
*preconception counseling, weight loss very important
antepartum risks: SAB, structural congenital anomaly (due to limited US), gestational diabetes, excessive weight gain, preeclampsia, DVT, PPROM, preterm labor, dysfunctional labor, stillbirth, fetal macrosomia, shoulder dystocia, CS
postpartum risks: wound infection or complications, DVT
Definition of second stage arrest (same as arrest of descent)
For nullip:
completely dilated cervix with 4 hours no fetal descent with epidural or 3 hours without epidural
For multip:
3 hours no fetal descent with epidural or 2 hours without epidural
Definition of active phase arrest
At least 6 cm dilated cervix with no cervical change despite 4 hours of adequate contractions or 6 hours of inadequate contractions; IUPC required for contraction adequacy
Definition of latent phase arrest
<6 cm cervical dilation with no cervical change despite at least 12-24 hours of pitocin with ruptured membranes; aka failed IOL
Causes for FGR:
Maternal - chronic disease (cHTN, diabetes, seizure disorder on antiepileptics), smoker or other drug use, nutritional deficiency Fetal - constitutional - chromosome abnormality or congenital anomaly Placental - uteroplacental insufficiency - vasa previa, single umbilical artery
External cephalic version
- contraindications
- factors associated with success
- factors associated with less success
Contraindications:
- any CI to vaginal delivery
- congenital uterine anomaly
- anhydramnios or ruptured membranes
- active labor
- non reassuring FHT
- placental abruption
- twin gestation prior to delivery of Twin A
Success assoc with
- oblique/transverse lie
- posterior placenta
- complete breech
Failure assoc with
- nulliparity
- anterior placenta
- low AFI
- FGR
- deep pelvic breech
- obesity
- posterior fetal spine
- tense uterus
- head not palpable or extended
Causes of polyhydramnios. What are associated increased risks during pregnancy?
Causes:
- infection
- maternal diabetes
- fetal CNS/swallowing problem (congenital anomaly)
- multiple gestation
- infection
- isoimmunization
Risks:
- PPROM
- placental abruption
- preterm labor
- cord prolapse
- macrosomia
- malpresentation
- uterine atony, PPH
- CS
- NICU admission
Describe IOL for second trimester loss
Misoprostol 400mcg loading dose then 200-400 mcg q6 hours for max dose (2400g)
How do you diagnose retained placenta in 18 week SAB
No delivery of placenta after 4 hours of uterotonics such as pitocin, methergine, hemabate
Stillbirth evaluation
- causes
- labs
- what is risk of recurrence?
- how would you manage next pregnancy?
Causes:
- chronic dx
- drug use
- infection
- placental abruption
- FGR
- multiple gestation
- post dates
- oligohydramnios
- cholestasis
- maternal hx of prior stillbirth
- extremes of age
- ethnicity
- ART
- obesity
Labs:
complete external evaluation, placenta pathology, karyotype, offer autopsy, APS testing, tox screen
Recurrence risk:
Up to 10 fold!
Management next pregnancy:
Antepartum surveillance 1-2 weeks before last stillbirth gestation or at 32 weeks; offer delivery at 39 weeks (or case by case basis at 37-38 weeks in case of severe maternal anxiety)
General risks of twin pregnancy
- how about risks unique to monochorionic pregnancies?
general:
- hyperemesis
- gestational diabetes
- gestational HTN, earlier risk of preeclampsia
- anemia
- hemorrhage
- CS
- postpartum depression
monochorionic
- higher frequency of neonatal morbidity/mortality
- anomalies
- prematurity
- FGR
- twin twin transfusion, TRAP
- single fetal death
- mo mo risk of cord entanglement
start antepartum surveillance earliest 24-8wk, latest 32wk
Risks of IVF
- multifetal gestation
- SAB
- gestational diabetes
- preeclampsia
- FHR/low birth weight
- perinatal mortality
- CS
- congenital anomaly (higher risk with ICSI)
- placenta previa/abruption
Recommended delivery timing for:
- di-di twins
- mo-di twins
- mo-mo twins
Di di: 38w0d - 38w6
Mo di: 34w0 - 37w0d
Mo mo: 32w0d - 34w0d (by CS)
Contraindications to TXA
- active or history of thromboembolism (in pregnancy)
- history of thrombophilia
- active intravascular clotting
- known allergy to TXA
