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
Pregestational diabetes
Poorly controlled DM: ↑R congen malfo, fetal loss, mater/fet morbi
ttt mom: assess end-org damage + strict glu control (fastin ≤95 and 2-h postprand <120)
ttt fetus: 16-24wks (quad screen, US); 32-34wks (NST, CST, BPP, US); deliv-postpart (IV insulin and glu/h in labor, early deliv if RF, C-sect* if >4500g, breastfeed)
Maternal complications of pregestational DM
DKA or hyperosm nonketotic coma Preeclampsia or eclampsia C-section Preterm labor Infection Polyhydramnios Postpartum hge Maternal mortality
Fetal complications of pregestational DM
Macrosomia or IUGR Cardiac and renal defects Neural tube defects Hypocalcemia Polycythemia Hyperbilirubinemia Hypoglycemia from hyperinsulinemia RDS Birth injury Perinatal mortality
Gestational and chronic hypertension
- Gestat HTN: at >20wks; proteinuria (<300); 25% dev preeclamp
- Chronic HTN: at <20wks and before concept*; till >12wks postpart; 33% dev preeclamp
ttt: close monitor BP
Antihypertens (methyldopa, labetalol, nifedipine)
!!! No ACEIs or diuretics
Preeclampsia and eclampsia
- Preeclam: new HTN (SBP≥140 or DBP≥90) + proteinuria (>300/d) at >20wks
- Eclam: new grand mal seiz + preeclam
-HELLP sd: Hemolyt anem, ↑LFTs, ↓plts
Vasospasm → hge + org necros; poor pg
Preeclampsia and eclampsia (PE, complications)
- Mild: asymp; edema
- Severe: BP>160/110; proteinuria (>5g/d) or oliguria; headac, somnol, blurred vis*, scotom, RUQ pain, HELLP
- Eclampsia: same as severe preeclam + seiz
Compl: prematur, fet distress, stillbirth, plac abrupt, seiz, DIC, cereb hge, retin detach, hypox enceph, thromboemb, fet/mat death
Preeclampsia and eclampsia (ttt)
Only cure: delivery
- Preecla: near term (induct*); far term (bed rest); labetal/hydral; continuous MgSulfate; seiz prophyl
- Sev preecla: same + induct* or C-section
-Eclam: !ABC; Mg; IV diazepam (if seiz); monito baby; contr BP; limit fluids+Foley; delivery if no seiz
!Seiz: antep/intrap/postpart till 48h
UTI and pyelonephritis during pregnancy
Asympt bacteriuria then UTI/pyelon if unttt
Persist unttt, ↑R for preterm labor, low birth weight, perinatal mortality
Dg: ⊕Cx (esp E coli)
ttt: asympt (3-7d nitrofur, cephalexin, amoxiclav)
Follow Cx at 1wk
Pyelon: admit, IV fluids, IV C3G, AB for rest of pgncy
Antepartum hemorrhage
Bleeding at >20wks
Esp placental abrupt* and placenta previa
Other: placenta accreta, ruptured uterus, genit tract les, trauma
!cervical cancer, cerv/vagin les, fetal bleeding
Placental abruption (RF, PE, dg, comlications)
Premature separat* of placenta
RF: HTN, trauma, tobacco/cocaine, previous abr, …
Painful dark bleed, uter hypertonicity, fetal distress
Dg: clinic, TA/TV US (retroplac clot; r/o previa)
Compl: hgic shock; DIC; recurr; fetal hypoxia
Placental abruption (ttt)
Mild: stabilize ptt w/ hospit, IV, fetal monito, bed rest
Mod-sev: immed delivery (vag if mom/baby stable; C-section if 1 in distress)
Placenta previa (RF, PE)
AbNl implantat*: total (covers os); marginal (margin of os); low lying (close to os)
RF: prior C-sec; multipar; adv age; multip gest; prior previa
Painless bright red bleed, stops in 1-2h; +/- contract*
No fetal distress
Placenta previa (dg, complications, ttt)
Dg: TA/TV US (abNl posit*)
Compl: ↑R placenta accreta; vasa previa; preterm; PROM; IUGR; congen anomal; recurr
ttt: NO vag exam; stabilize ptt; tocolytics; serial US; betamethasone (28-32wks, lung matur)
C-sect*: if labor, life-threat bld, fet distress, ⊕lung matur, 36wks GA
Vasa previa (RF, PE, dg)
Velamentous umb cord insert* +/or bilobed placenta
RF: multi gest, IVF, 1 umb artery, plac previa, low-lying plac
Painless bleed at rupture of membranes + fet bradycard
Dg: TV US w/ Doppler
Vasa previa (complications, ttt)
Compl: fetal exsanguinat*
ttt: acute bld = emerg C-sect*
If dg before bld: steroids at 28-32wks, hospit 30-32wks, close monito + C-sect* at 35wks
Ectopic pregnancy (PE, #dg)
dg: abort, ov tors, PID, ruptured ov cyst
Esp tubal
Abdo pain + vag bleed; or asympt
Ass w/ causes of scarring (Hx of PID, pelv surg, DES, endometriosis)
Ectopic pregnancy (dg, complications, ttt)
Dg: W of reprod-age + abdo pain = ruptured ectop pgncy until proven otherwise
⊕pgncy test, TV US (empty ut), serial B-hCG w/o doubling
Complic: tubal rupture, hemoperitoneum
ttt: methotrexate (if small + unruptured); surg is rupt or unstable (salpingectomy/salpingostomy w/ evacuat*)
Intrauterine growth restriction (RF, dg, complications)
EFW < 10th percentile for GA
RF: mat system ds w/ uteroplac insuff (An, HTN, ut inf); mat subst abuse; plac previa; multi gest
Dg: US (serial fundal height measur + EFW)
Compl: ↑perinatal morbi/morta
Intrauterine growth restriction (ttt)
Underl cause
If near term, give steroids (48h before delivery)
Fetal monito w/ NST, CST, BPP, umbil art Doppler
Fetal macrosomia
Birth weight > 95th percentile
Sequela of gest diabetes
Prenatal dg imprecise
Compl: ↑R should dystocia (brach plex injury + Erb-Duchenne palsy)
ttt: C-sect* if >5000g + no DM or if >4500g + DM
Polyhydramnios
AFI ≥25; asympt
Nl pgncy; fetal chromosom dev abNl
Causes: mat DM; multi gestat*; isoimmuniz; pulm abNl; fet anomalies; tw-twin transfu sd
Dg: fundal height > expect; US (fet anom); gluc; Rh
ttt: underl cause
Compl: preterm labor; fet malpresent; cord prolapse
Oligohydramnios
AFI <5; asympt or IUGR/fet distress
Causes: fet urin tract abNl; chron uteroplac insuff; ROM
Dg: US
ttt: r/o inaccur gest date; ttt underl cause
Compl: ass w/ ↑x40 perinat morta; MSK abNl; pulm hypopl; umbil cord compress*; IUGR
Rhesus isoimmunization (RF, dg, ttt)
Fetal RBCs leak to mat bld (Rh⊖) → mat form anti-Rh IgG → Ab cross plac + fet hemolysis (2nd pgncy)
↑R w/ prev SAB or TAB or delivery w/o RhoGAM
Dg: monito sensitized Rh⊖ moms w/ serial US + amniocent
ttt: sev (preterm deliv when lungs mature) +/- intraut bld transfu (if low fet Ht)
Rhesus isoimmunization (prevention, complications)
Prev: if mom Rh⊖ + dad ⊕/unk, give RhoGAM
If bb ⊕, give mom RhoGAM
If mom ⊖ and abort, Hx ectop pgncy, amniocent, vag bld, plac prev/abrup → type + screen + prev pgncy for 1y
Compl: hydrops fetalis if bb Hb <7; fet hypox + acidosis, kernict, prematur, death
Gestational trophoblastic disease (benign vs malignant)
-Benign: complete (sperm+empty ov; 46XX; no fet tiss) or incomplete (Nl ov+2 sperm; 69XXY; fet tiss) molar pgncy
-Malign: molar pgncy progr to invasive mole or choriocarcinoma
W/ complic: pulm or CNS meta, trophobl pulm emboli
Gestational trophoblastic disease (PE, dg)
1st trim ut bleed; hyperem gravid; preecl/ecl <24wks; ↑ut size
RF: <20 or >40yo; def folate or B-carotene
Dg: no heartbeat; large ovaries; grapelike molar in vagina
↑↑B-hCG (>100K); US (snowstorm, no gest sac/fetus); CXR (lung meta)
Gestational trophoblastic disease (ttt)
Evacuate uterus + follow B-hCG/week
Malign: methotrexate or dactinomycin (chemoth)
Residual: hysterectomy
Meta: chemoth + irradiation
Multiple gestations
Monozy (ident) or dizygot (fratern)
Rapid ut growth; excess ↑weight; palpat* of ≥3 large fet parts
Dg: US; B-hCG; human plac lactogen; MSAFP (all ↑)
ttt: surveill for IUGR
Compl: hospit ↑x6; ↑R plac prev + C-sect*; tw-twin transfu sd; IUGR; preterm; ↑R congen malfo
Shoulder dystocia
RF: obes, DM, macrosomic bb, Hx of prior dystocia
Dg: prolong 2nd stage of labor, recoil of perineum, No spontan restitut*
ttt: HELPER (Help reposit, Episiotomy, Leg elevat, Pressure suprapub, Enter vagina+rotation, Reach fetal arm
Failure to progess with labor/delivery (dg, complications)
Ass w/ chorioamnionitis, occiput post posit*, nullipar, ↑birth weight
- 1st stage: fail adequate progr cervic chang
- 2nd stage: arrest fetal descent
Compl: chorioamnionitis, fet inf, permanent injury, postpart hge, lacerat*
Failure to progess with labor/delivery (ttt)
- 1st stage: latent (parenteral analgesia, oxytocin, amniotomy, cervical ripening); active (amniotomy, oxytocin, C-sect*)
- 2nd stage: observ w/ ↓epidural rate and oxytocin; assisted vagin deliv (forceps/vacuum); C-sect*
Rupture of membranes (4 types)
- Spontan: after or at onset of labor
- Premat: >1h before onset of labor
- Preterm premat: <37wks gest
- Prolong: >18h before deliv
Rupture of membranes (dg, ttt, complications)
Dg: sterile spec exam; nitrazine paper test (blue); fern test; US
No digit vag exam (if no plan for labor)
Monito fetal HR, mat T*C, WBCs, ut tendern
ttt: dep on GA+lung matur (rest or induct)
AB (prophyl or ttt); CS (betameth or dexameth x48h
Compl: perterm, chorioamnionitis, plac abrupt, cord prolapse
Preterm labor (RF, PE)
Labor betw/ 20-37wks gestat* #1 cause of neonat morbi/morta
RF: multi gest; inf; PROM; ut anomalies; prev preterm; polyhydram; plac abrupt; poor mat nutrit*; low SES
PE: cramps, low back pain, pelv press, new vag disch/bld
Preterm labor (dg)
Dg: regular ut contrac (≥3 each 30sec over 30min) AND concurr cerv chang at <37wks
- CI tocolysis: inf, nonreassu fet test, plac abrupt
- Sterile spec: r/o PROM
- US: r/o anomalies, verigy GA, fet present, fluid volume
- Cx chlam/gororr/GBS; UA, ur Cx
Preterm labor (ttt, complications)
ttt: hydrat* + bed rest; tocolyt unless CI; steroids; GBS prophyl (peni/ampic)
Compl: RDS; intravent hge; PDA; necrot enterocolitis; retinopathy; bronchopulm dyspl; death
Fetal malpresentation
Other than vertex
RF: premat; prior breech deliv; ut anomal; poly/oligohydr; multi gest; PPROM; hydroceph; anenceph; plac previa
Esp breech (LE/butt) ttt: 75% chang by wk38; external vers*; C-sect*
Indications for cesarean section
- Mat fact: prior C-sec; activ gen herpes; cerv carcinoma; mat trauma; HIV
- Fet + mat fact: cephalopelvic disprop; plac previa/abrupt; failed vag deliv; postterm pgncy
- Fet fact: malposit*; distress; cord compr/prolap; erythroblastosis fetalis (Rh incomp)
Episiotomy
Median or mediolateral
Compl: extens* to anal sphinct or rectum; bleed; inf; dyspareunia; rectovag fistula; mat death
Postpartum hemorrhage (complications, ttt)
> 500mL for vag deliv or >1000mL for C-sect*
Before, during, after deliv of placenta
Compl: acute bld loss (fatal); chronic loss (anemia, ↑R inf); Sheehan sd
ttt: if severe, uter art emboliz
Uterine atony
RF: ut overdist (multi gest, macrosom, polyhydr); exhausted myomet (prolong labor, oxytocin); ut inf; condit* interfer w/ contrac (anesth, myoma, MgSO4)
Dg: soft enlarg boggy ut; #1 cause of postpart hge
ttt: biman ut massage; oxytocin; methergine if no HTN; PGF2a
Genital tract trauma
RF: precipit labor; operat vag deliv; large bb; inadeq episiot repair
Dg: manual/visual inspect* of lacerat* >2cm; postpart hge
ttt: surg repair
Retained placental tissue
RF: plac accr/incr/percreta/previa; ut leiomyoma; preterm deliv; previous C-sec/curett
Dg: manual/visual inspect* of cotyled; US
ttt: manual removal; curettage w/ suct*
Postpartum infections (PE, RF)
≥38*C for ≥2 of the first 10 days postpart (w/o first 24h)
Ut tendern, malodor lochia
RF for endometritis: emerg C-sec; PROM; prolong labor; multi intrapart vag exams; intraut manip; deliv; low SES; young W; prolong rupt membr; bact coloniz; CS
Postpartum infections (ttt, complications)
ttt: broad AB IV (clinda/genta) until afeb x48h; add ampi if complic
Compl: septic pelvic thrombophlebitis (abdo/back pain; fev up to 41*C; bld Cx; CT (absc); ttt w/ broad AB and anticoag heparin x7-10d)
Sheehan syndrome (postpartum pituitary necrosis)
Massive obstet hge/shock → pituit ischem + necros → ant pit insuff (#1 in adult W)
PE: esp failure to lactate (↓ prolact); other sympt
Dg: provocative hormo test, MRI of hypoth/pitui (r/o other cause)
ttt: replac all def hormo
7 W’s of postpartum fever (10 days)
Womb (endometritis) Wind (atelectasis, pneumonia) Water (UTI) Walk (DVT, PE) Wound (incision, episiotomy) Weaning (breast engorgement, abscess, mastitis) Wonder drugs (drug fever)
Lactation and breastfeeding
In pgncy: ↑estro+progest → brst hypertrop + inhib prolact
After deliv: ↓hormo, prolac stimul alveol epith cells (↑milk)
Periodic suckling: ↑prolact/oxytocin → milk eject*
Colostrum: prot, fat, secret IgA, minerals
In 1wk: mature milk w/ prot, fat, lactose, water
Lactation and breastfeeding (benefits, CI)
↓ incid of allergies
↓ incid of early URIs and GI inf
Facilit mom-bb bonding
Maternal weight loss
CI: HIV; active HBV and HCV; medic (tetracyc, chloramph)
