Obstetric

Physiological Changes in Pregnancy

• Heart
  • – VERY Increased Preload
  • – Increased HR
  • – Decreased SVR
• Pulmonary
  • – Increased total volume
  • – Decreased functional residual capacity
• Clotting
  • – Increased adhesion (due to increased vWf)
  • – Increase in factors 7,8,and 10
  • – Decrease in protein C and S
• Renal
  • – Increased GFR
  • – Decreased Creatitine
  • – Obstructive uropathy usually occurs at pelvic brim
• Gastrointestinal
  • – GERD
  • – Nausea
  • – Constipation
  • – Iron Deficiency
  • – Gallbladder dx

Weight gain during pregnancy

• BMI <18 = 1lb/wk = 28-40 lbs
  
• BMI 18.5-25 = 0.75lbs/wk = 25-35lbs
  
• BMI 25-30 = 0.5lbs/wk = 15-25lbs
  
• BMI > 30 = 0.25lbs/wk = 10-20lbs

Aneuploidy

• Path:
  • Down’s 21 (Drinking age is 21)
    
  • Edwards 18 (Election age is 18)
    
  • Patau’s 13 (Pg-13)
    
  • Risk Increases with increased maternal age (35yrs)
    
  • Prevalence = younger woman
    
• Pt:
  • Asx screen
    
  • Increased maternal age
    
  • Aneuploidy
    
• Dx:
  • Screening Tool (Non-invassive)
    
  • Confirm Test (Invasive)
    
• Tx:
  • Termination

!st trimester testing

• U/S nucal translucency <3mm
  
• PAPP-A
  
• hCG

2nd trimester testing

• Downs = Increased HCG, inhibits A, decreased AFT and estriol
  
• Edwards = Decreased HCG, Inhibit A, AFT, and estriol
  
• Patua = none

Combined vs Sequential screening

• Combined Screen = 1st + 2nd trimester
  
  • – Increased sensitivity
    
  • – Decreased options

• Sequential Screen = 1st trimester then straight to invasive
  
  • – Increased invasiveness = increased fetal loss
    
  • – Increased options

Alloimmunization

• Path: Mom = Rh-Ag (-) had baby with Rh (+)
  
  • Then if she has another baby that is Rh (+) then the mom will attack it with her Rh-Ab (+) and cause fetal anemia
    
• Pt: Rh-Ag (-) mom
  
• Dx: Rh-Ab (-) mom + Baby Rh-Ag (+) = tx with Rh-D immune globulin at 18 weeks and within 72 hrs of delivery

Gestational DM

• Path: DM > 20 weeks
  
• Pt: BMI > 30, GDM hx, pre-DM
  
• Dx: 1hr glucose tolerance test if greater than 140 then get 3 hr glucose tolerance test
  
  • – Fasting > 90
    
  • – 1 hr test > 180
    
  • – 2hr test > 155
    
  • – 3 hr test > 140
    
  • *2 must be + to diagnose
    
• Tx: Insulin –> post-prandial

Lochia

• Etiology:
  • a vaginal discharge that is a normal part of recovery during the postpartum period. 
  • starts out thick and red, becomes thin and pink, then finally white to yellow
• Management:
  • resolves 6-8 weeks after delivery

Maternal Anemia

• Path: Normal raio (drop of Hgb) = 10/30 (hub/hct)
  
  • … if lower than 10 then probably iron deficiency
    
• Pt: Axs = 28 weeks
  
• Dx: Hgb <10, iron studies
  
• Tx: Iron

Seizures

• Path: ALL antiepileptic drugs are teratogens
  
• Pt: Dx of epilepsy
  
• Dx: Clinical
  
• Tx: Leviteracetam = lamotrigine
  
  • No phenytoin, carbamazepine, valproate, balance benefits/risk
    
• f/u: If she does have a seizure use phenobarbital, it is safe in pregnancy (give folic acid)

Thyroid

• Path: Hyper: Fetal demise, Hypo: Cretinism
• Pt: Hyper: Increased, Hypo: Decreased
• Dx: Hyper: Increased T4 with Decreased TSH
• Hypo: Decreased T4 with Increased TSH
• Tx: Hyper: PTU pregnancy, 2nd trimester pregnancy for surgery if absolutely necessary
• Hypo: Levothyroxine f/u TSH q 4 weeks
• f/u: Increased TBG, increased levothyroxine (need more T 4 in pregnancy by 25%)

OB Operating Room

Anesthesia

• Benefits:
  • Opiates (anytime)
    
  • Epidural
    
  • Paracervical block
    
  • Pudendal nerve block

• Risks:
  
  • Prolonged latent phase … baby needs naloxone
    
  • Tocometer, pushing coach…hypotension/ death
    
  • Stage I: dilation… fetal bradycardia
    
  • Stage II: Delivery

C-section

• Benefits:
  
  • 1) elective
    
    • – breach
      
    • – desired
      
  • 2) Urgent
    
    • – prolonged labor
      
    • – arrest of labor
      
    • – eclampsia
      
  • 3) Emergent
    
    • – Hemodynamic instability
      
    • – Fetal distress
      
• Risk: VBAC, scar, permanent sterilization (bilateral tubal ligation)

Vacuum + Forceps

• Benefits:
  • Fetal distress/prolonged/ arrest of labor
    
  • + full effacement, + 2+ station,

• Risk:
  • Denuding vagina, cephalohematoma, bell’s palsy

Episiotomy (lacerations)

• Benefits: Macosomic + 1st-time moms
  
• Risk: Lacerations + Postpartum hemorrhage
• Bonus: Laceration grading
  
  • – Grade I = vagina only
    
  • – Grade II = perineal body
    
  • – Grade III = sphincter
    
  • – Grade IV = Mucosa