Obstetrics Flashcards
Gestational age (GA)
From day of last menstrual petiod
- Fundal height: umbil-20wks +2-3cm/wk
- Fetal heart tones: 10-12wks
- Appreciat fetal mvt: 17-18wks
- US: CRL 6-12wks; BPD/FL/AC 13wks; measur of GA most reliable in 1st trim
Diagnosis of pregnancy
Beta-hCG: by placenta; peak at 100K by 10wksGA
↓2nd trim
Double every 48h in early pgncy; ectopic if abNl doubling
US: confirm intraUt pgncy
Gestational sac on transvag US, by 5wksGA + B-hCG 1000-1500
Normal physiology of pregnancy
↑ then ↓: renal flow
↓ then ↑: BP
↑ then plateaus: GFR, SV, TV
↑: weight, HR, CO, periph venal distens*, bld volume, fibrinogen, gastric emptying time
↓: periph vasc resist, expirat reserve, Ht, sphincter tone
Unchanged: RR, vital capac, e-
Prenatal care (weight, nutrition, exercise)
-Weight gain: 1-1.5kg/mo
-Prepgncy BMI: 19.8-26 w/ gain of 11-16kg
-Nutrition: add 100-300kcal/d; add 500/day if breastfd
Folic ac 0.4mg/d; Iron 30mg/d; Calcium 1000mg/d; VitD 400IU/d; VitB12 2ug/d
-Exercise: moderate 30min/d
Prenatal diagnostic testing
Wks 0-28: /4wks
Wks 29-35: /2wks
Wks 36-birth: /1wk
CBC, ABO, Rh, UA+Cx, rubella, HBV, syphilis, gono/chlam, TB, HIV, Pap smear, HCV, varicella, …
Quad screening
MSAFP, estriol, B-hCG, inhibin A
MSAFP >2.5xNl ass w/ neural tub def, abdo wall def, multi gestat*, incorrect date, fetal death, placent abNl
MSAFP <0.5xNl ass w/ trisomy 21/18, fetal demise, incorrect date
Pregnancy-associated plasma protein A
Recomm at 9-14wks
PAPP-A + nuchal transp + free B-hCG detect trisomy 21/18
- Screen of pgnt women (>35yo)
- Available before CVS + less invasive
Chorionic villus sampling vs Amniocentesis
CVS: 10-12wks; transcerv/transabdo apirat of placental T.; genetic dg; earlier GA; ↑R fetal loss; limb defect if <9wks
Amniocentesis: 15-20wks; transabdo aspirat of amniot fluid; genetic dg; PROM; chorioamnionitis; fetal-maternal hge
Cell-free fetal DNA
10wks
Fetal DNA from bld of mother
Noninvasive
Limited bcz low concentration of DNA in mom
Amniocentesis (indications)
In women >35yo
If abNl quad screen
In Rh-sensitized pgncy
Eval fetal lung maturity (L/S ≥2.5)
Toxoplasmosis congenital infection
Transplacental Hydroceph, intracran calcif, chorioret, ring les* (MRI) Dg: serology ttt: pyrimethamine + sulfadiazine Prophyl: spiramycin in 3rd trim Prev: avoid cat feces
Rubella congenital infection
Transplacental (1st trim)
Blueb muff rash, cataract, mental retard, hear loss, PDA
Dg: serology
ttt: sympt
Prevent: immunize before pgncy; vaccin mom if ⊖ serol
CMV congenital infection
Transplacental Petechial rash, periventric calcif Dg: urin Cx, PCR of amniot fluid Postpartum ganciclovir No prevention
HSV congenital infection
Intrapartum if active les* Skin, eye, mouth; life-treat CNS/systemic Dg: serology ttt: acyclovir Prevent: C-section if active les*
HIV congenital infection
In utero, at delivery, via breast milk
Often asympt; failure to thrive; bact inf; up/low resp ds
Dg: ELISA, Western blot
ttt: HAART (mom); prophyl AZT (baby)
Prevent: AZT or nevirapine in pgnt W; C-section if viral >1000; No breastfeed
Syphilis congenital infection
Intrapartum, transplacental Maculopap rash, LNpathy, HMG, snuffles, osteitis, late congen (saber shins, saddle nose, CNS, Hutchinson teeth, deafness) Dg: dark-field, VDRL/RPR, FTA-ABS ttt: penicillin Prevent: penicillin if pgnt W is ⊕
Spontaneous abortion (RF)
<20wks; esp 1st trim
-Chrom abNl: 1st/2nd/3rd trim
-Maternal fact: inherited thrombophilias, immuno, anatomic, endocrino, other (trauma/↑age/inf/diet)
-Environm: tobacco, alcoh, caffeine, toxin, drug, radiat*
-Fetal fact: anatom malfo
-Recurr SAB: ≥2 consecut or 3SAB/1y; for cause, karyotype parents, hypercoag labs mom, uterin anatom
(<12wks esp chrom abNl) (12-20wks esp hypercoag)
Spontaneous abortion (types)
Complete Threatened Incomplete Inevitable Missed Septic Intrauterine fetal demise
Spontaneous abortion (dg, ttt)
Nonviable pgncy: gestat sac >25mm w/o fetal pole of card activ
Clinic, speculum, US, serum B-hCG
US
Give RhoGAM if mom Rh⊖
Elective termination of pregnancy
Depend on GA and ptt
-First (90%): medical mngmt (mifepristone, misoprostol, methotrexate) up to 59d; surgical mngmt (MUA, D&C) up to 13wks
-Second (10%): obstetric mngmt (induct* labor w/ prostagl, oxytocin); surgical mngmt (D&E) up to 13-24wks
Normal obstetric examination
Leopold maneuvers: fetal lie + presentation
Cervical exam: dilat*, effacem, consist, station of fetal head relative to ischial spines, …
Sterile speculum exam if ROM suspected
Stages of labor
1st latent: 3-4cm dilation, 6-11h (primip), 4-8h (multip), prolong w/ excess sedation
1st active: 4-10cm dilation, 4-6h (primip), 2-3h (multip), prolong w/ cephalopelvic disprop
2nd: 10cm to deliv of NN, 0.5-3h (primip), 5-30min (multip), NN through all cardinal mvts
3rd: deliv of NN to deliv placenta, 0-30min (primip/multip), uterus contr + hemostasis
Recommendations for fetal heart rate monitoring
Electrode to fetal scalp or external monit Doppler US
- Ptts w/o complic: 1st stage /30min; 2nd stage /15min
- Ptts w/ complic: 1st stage /15min; 2nd stage /5min
Components of fetal heart rate evaluation
Rate (110-160bpm):
- Brady (<110): congen heart malfo, severe hypox
- Tachy (>160): hypox, mom fever, fetal anemia
Variability (6-25bpm):
-Absent (sev fet distress); minimal (<6; fet hypox, sleep, opioid); marked (>25; fel hypox, before ↓variab); sinusoidal (serious fet anem)
FHR: accelerations vs decelerations
Accelerations (↑>15 beats abov baseline in <30sec): reassuring
Decelerations:
- Early (gradual ↓FHR to nadir in >30sec, then baseline): head compress by Ut contrac (Nl)
- Late (gradual ↓FHR to nadir in >30sec, then baseline): begins after end of Ut contrac, uteroplac insuff + fet hypoxemia
- Variable (abrupt ↓FHR 15 below baseline for ≥15sec + <2min, to nadir in <30sec): umbil cord compress
Antepartum fetal surveillance
In pgncy w/ ↑R of antepart fet demise Tests at 32-34wks -Fetal mvt assessment -Nonstress test -Contraction stress test -Biophysical profile -Amniotic fluid index -Modified biophysical profile -Umbilical artery Doppler velocimetry
Obstetric analgesia and anesthesia
- Visceral pain (T10-L1): ut contrac + cerv dilat*
- Somatic pain (pudend N, S2-S4): press on vagina+perineum
Absolute CI to regional anesthesia: maternal: refract hypoTN, coagulop, LMWH in 12h, unttt bacteremia, ↑ICP
Hyperemesis gravidarum (PE)
Persist vomit (#morning sickn that is wks 4-16) Acute starvat*; ↓weight (≥5% of preprgncy)
Esp first pgncy, multiple gest, molar pgncy
↑B-hCG, ↑estradiol
Hyperemesis gravidarum (dg, ttt)
Dg: B-hCG; US; R/o molar pgncy
Ketones, Na, K, metab alkal, liv enz, bili, amyl/lipa
ttt: VitB6, doxylamine, promethazine/dimenhydrinate
If sev: metoclopra, ondenset, prochlorpera, promethaz
If dehydr: IV fluids, nutrit supplem, dimenhydrinate
Diabetes in pregnancy
-Gestational DM: during pgncy
>50% dev glu intol +/- DM2 later in life; always screen
-Pregestational: before pgncy
If RF for DM, screen w/ HbA1c or fasting glu
Gestational diabetes mellitus (PE, dg)
Usual dg 24-28wks
Asympt; may have edema, polyhydram, large infant (>90th percentile)
Dg: 1-h 50g glu chall test at 24-28wks (abNl if ≥140)
Confirm w/ 3-h 100g glu toler test (3h >140)
Gestational diabetes mellitus (ttt)
ADA diet, regular exo, strict glu monito (4/d)
Tight glu control
Insulin if diet insuff (+ intrapartum insulin+dextrose)
Periodic US + NST (fetal growth/health)
If poor glyc control, induce labor 39-40wks