Obstetrics Flashcards
0
Q
Parity
A
of pregnancies that led to a birth beyond 20 weeks’ gestational age or an infant weighing > 500 g
1
Q
Gravidity
A
of times a woman has been pregnant
2
Q
Developmental age
A
of weeks and days since fertilization
3
Q
Gestational age
A
of weeks and days measured from the 1st day of the LMP
4
Q
Determinants of gestational age
A
- Fundal height
- Fetal heart tones (Doppler)
- Quickening
- Ultrasound
5
Q
Fundal height measurement
A
Umbilicus - 20 weeks + 2-3 cm/weeks thereafter
6
Q
Fetal heart tones (Doppler)
A
Typically 10 - 12 weeks
7
Q
Quickening - appreciation of fetal movement
A
Usually heard 17 - 18 weeks
8
Q
Ultrasound
A
- Measures fetal crown-rup length: 6 - 12 weeks
2. Measures biparietal diameter, femure length, and abdominal circumference: 13 weeks
9
Q
Most reliable measurement of GA
A
Ultrasound
10
Q
Quantitative B-hCG
A
- Diagnose and follow ectopic pregnancy
- Monitor trophoblastic disease
- Screen for fetal aneuploidy
11
Q
B-hCG
A
- standard for diagnosing pregnancy
- produced by placenta
12
Q
Rate of B-hCG production
A
- reaches peak, 100,000mIU/ml by 10 weeks’ GA
- decreases throughout 2nd trimester and levels off by 3rd trimester
13
Q
Ultrasound
A
- used to confirm intrauterine prenancy
- gestational sac visible by 5 weeks GA
- B-hCG in range of 1000 - 1500 IU/ml
14
Q
Renal changes during pregnancy
A
- Renal flow increases 25-50%
- GFR increases early then plateaus
15
Q
Weight changes during normal pregnancy
A
- uterine weight increases from ~ 60 - 70 g to ~ 900 g - 1200g
16
Q
Weight gain recommendations during pregnancy
A
- 1.0 - 1.5kg/mo
17
Q
Weight gain guidelines by BMI
A
- undeweight: 12 - 18 kg
- acceptable: 11- 16 kg
- overweight: 7 - 11kg
- severely overweight: 7kg
18
Q
Folic acid supplementation
A
decreases neural tube defects for ALL reproductive age woman
- 0.4mg/day
- 4 mg/day for women w/ hx of neural tube defets in prior pregnancies
19
Q
CV changes during normal pregnancy
A
- HR gradually increases 20%
- BP gradually decreases by 10% by 34 wks, then increases to prepregnancy values
SV increases to maximum at 19 weeks then plateaus
CO rises rapidly by 20% then increases to addl 10% by 28 wk
20
Q
Pulm changes during pregnancy
A
- RR remains unchanged
- TV increases by 30 - 40%
- Expiratory reserve gradually decreases
- Vital capacity unchanged
- Resp minute volume increases by 40%
21
Q
Blood changes during normal pregnancy
A
- Blood volume increases by 50% in 2nd trimester
- Hct decreases slightly
- Fibrinogen increases
- Electrolytes remains unchanged
22
Q
GI changes during normal pregnancy
A
- sphincter tone decreases
- gastric emptying time increases
23
Q
Immunoglobulins that cross placenta
A
IgG
24
Organisms that can cross placenta (9)
1. Toxoplasmosis
2. Rubella
3. HIV
4. Parvovirus
5. CMV
6. Enterovirus
7. Treponema pallidum
8. Listeria monocytogenes
9. Parvovirus B19
25
Prenatal Visits
Wks 0 - 28: every 4 wks
Wks 29 - 35: every 2 wks
Wks 36 - birth: every wk
26
Heme Prenatal Dx Testing: initial visit
- CBC, Rh factor, type and screen
27
Infectious Dz prenatal testing: initial visit
- UA and cx
- Rubella Ab titer
- HBsg
- RPR/VRDL
- Cervical gonorrhea and chlamydia
- PPD
- HIV
- Pap smear (to check for dysplasia)
- Consider HCV and varicella based on hx
28
Genetic testing during initial visist
- HbA1c
- Sickle cell screening
- Tay-Sachs disease
- Cystic fibrosis
29
Prenatal Dx Testing: 9-14 wks
- PAPP-A + nuchal transparency
| - free B-hCG +/- chorionic villus sampling
30
Prenatal Dx Testing: 15 - 22 wks
- Maternal serum alpha fetoprotein (MSAFP) or
- Quad screen
+/- amniocentesis
31
Prenatal Dx Testing: 18-20 wks
Ultrasound for full anatomic screen
32
Prenatal Dx Testing: 24- 28 wks
1 hr glucose challenge test for gestational diabetes screen
33
Prenatal Dx Testing: 28 - 30 wks
RhoGAM for Rh- women (after antibody screen)
34
Prenatal Dx Testing: 35- 40 wks
Group B Strep cx (GBS)
| - repeat CBC
35
Prenatal Dx Testing: 34 - 40 wks
- Cervical chlamydia and gonorrhea cx
- HIV
- RPR in high risk pts
36
Quad screening
1. MSAFP
2. Inhibin A
3. Estriol
4. B-hCG
37
Maternal serum alpha fetoprotein (MSAFP)
- produced by fetus and enters maternal circulation
- reported multiples of median (MoMs)
- measurement results depend on accurate gestational testing
- rarely tested alone, quad screening incr. sensitivity for chromosal abnormalities
38
Elevated MSAFP (> 2.5 MoMs) associated w/
- open neural tube defects (anencephaly, spina bifida)
- abdominal wall defects (gastrochisis, omphacele)
- multiple gestation
- incorrect gestational dating
- fetal death
39
Reduced MSAFP (< 0.5 MoM) is associated w/
- Trisomy 21 and 18
- Fetal demise
- Inaccurate gestational testing
40
Trisomy 18 via quad screening
* * Still UNDERage at 18**
- decreased AFP
- decreased estriol
- decreased B-hCG
- decreased inhibin A
41
Trisomy 21 via quad screening
* * 2 up and 2 down**
- decreased AFP, estrol
- increased B-hCG, inhibin A
42
Pregnancy-associated Plasma Protein A (PAPP-A)
- recommended at 9 - 14 wks
- PAPP-A + nuchal transparency + free B-hCG can detect 91% of Down's syndrome and 95% of cases of trisomy 18
- screen of low risk pregnant women (< 35 y/o)
- available earlier than CVS and less invasive than CVS
43
CVS
- done at 10 - 12 wks
- transcervical or transabdominal aspiration of placenta
- geneticall diagnostic/ available at earlier GA
44
Diasadvantages of CVS
- Risk of fetal loss is 1%
- Cannot detect open neural tube defects
- Limb defects are associated w/ CVS < 9 wks
45
Amniocentesis
- done at 15 - 20 wks
- transabdominal aspiration of aminiotic fluid using U/S needle
- genetically diagnostic
46
Disadvantages of CVS
At risk for:
- premature of membranes (PROM)
- chorioamniocentesis
- fetal maternal hemorrhage
47
Indications for amniocentesis
- in women > 35 yrs of age at time of delivery
- conjuction with abnormal quad screen
- in Rh-sensitized pregnancy to obtain fetal blood type or detect fetal hemolysis
- to eval lung maturity via lecithin to sphingomyelin ratio > 2.5
- detect presence of phosphatidylglycerol (during 3rd trimester)
48
ToRCHES pathogens
* organisms that can cross placenta
- Taxoplasmosis
- Other (Parvovirus, Varicella, Listeria, TB, malaria)
- Rubella
- CMV
- Herpes Simplex Virus
- Syphillis
49
Spontaneous abortion (SAB)
- loss of product of conception (POC) prior to 20 wk of pregnancy
- more than 80% occur in 1st trimester
50
Major factors that contribute to SAB
1. Chromosomal abnormalities
2. Maternal factors
3. Environmental factors
4. Fetal factors
51
Chromosomal abnormalities in SAB
- factor in 50% of SABs in 1st trimester
52
Maternal factors in SAB
Dx of Spontaneous Abortions
53
Dx of spontaneous abortions
- decreased levels of B-hCG
- U/S can identify:
- gestational sac 5-6 wks from LMP
- fetal pole at 6 wks
- fetal cardiac activity at 6-7 wks
54
Fetal defects: ACEis
- fetal renal tubular dysplasia and neonatal renal failure
- oligohydramnios
- intrauterine growth restriction (IUGR)
- lack of cranial ossification
55
Alcohol: fetal defects
- Fetal alcohol syndrome (growth restriction before and after birth)
- Mental retardation
- Midfacial hypoplasia
- Renal and cardiac defects
- Consumption of > 6 wks per day is associated w/ 40% risk of FAS
56
Androgens: fetal defect
- virilization of females
| - advanced genital development in males
57
Carbamazepine
- neural tube defects
- fingernail hypoplasia
- microcephaly
- developmental delay
- IUGR
58
Cocaine: fetal defects
- Bowel atresias
- Congenital malformations of the heart, limbs, face, and GU tract
- Microcephaly
- IUGR
- Cerebral infarctions
59
Diethylstilbestrol (DES): fetal defects
- Clear cell adenoma of vagina or cervix
- Vaginal adenosis
- Abnormalities of cervix and uterus or testes
- Possible infertility
60
Lead: fetal defects
- increased risk of SAB
| - stillbirths
61
Lithium: fetal defects
Congenital heart disease (Ebstein's anomaly)
62
Methotrexate: fetal defects
increased SAB rate
63
Organic mercury: fetal defects
```
Cerebral atrophy
Microcephaly
Mental retardation
Spasticity
Seizures
Blindness
```
64
Phenytoin: fetal defects
- IUGR
- Mental retardation
- Microcephaly
- Dysmorphic craniofacial features
- Cardiac defects
- Fingernail hypoplasia
65
Radiation: fetal defects
- Microcephaly
- Mental retardation
- Medical diagnostic radiation delivering < 0.05 Gy to the fetus has no diagnostic risk
66
Streptomycin and kanamycin: fetal defects
- Hearing loss
| - CN VIII damage
67
Tetracycline: fetal defects
- Permanent yellow-brown discoloration of deciduous teeth
| - Hypoplasia of tooth enamel
68
Thalidomide: fetal defects
- Bilateral limb deficiencies
- Anotia and microtia
- Cardiac and GI abnormalities
69
Trimethadone and paramethadone: fetal defects
- Cleft lip palate
- Cardiac defects
- Microcephaly
- Mental retardation
70
Valproic acid: fetal defects
- Neural tube defects (spina bifida)
| - Minor craniofacial defects
71
Vitamin A derivatives: fetal defects
- increased SAB rate
- Microtia
- Thymic agenesis
- CV defects
- Craniofacial dysmorphism
- Microphthalmia
- Cleft lip or cleft palate
- Mental retardation
72
Warfarin: fetal defects
| ** wages WAR on the fetus**
- Natal hypoplasia and stippled bone epiphyses
- Developmental delay
- IUGR
- Ophthalmologic abnormalities
73
Toxoplasmosis: transmission
- transplacental
| - primary infxn via consumption of raw meat or contact w/ cat feces
74
Toxplasmosis: Sx and Dx
```
Sx:
- hydrocephalus
- intracranial calcifications
- chorioretinitis
- ring enhancing lesions on MRI
Dx:
- serum testing
```
75
Toxoplasmosis: Dx and Tx
Dx: serologic testing
Tx: pyrimethamine + sulfadiazine
76
Toxoplasmosis: Prevention
- Avoid exposure to cat feces during pregnancy
| - Spiramycin prophylaxis for 3rd trimester
77
Rubella: Transmission
- transplacental in the 1st trimester
78
Rubella: Sx
- purpuric "blueberry muffin"rash
- cataracts
- mental retardation
- hearing loss
- patent ductus arteriosus (PDA)
79
Rubella: Dx and Tx
Dx: serologic testing
Tx: symptomatic
80
Rubella: prevention
- immunize before pregnancy
| - vaccinate the mother after delivery if serologic titers remain negative
81
CMV: transmission
- primarily transplacental
82
CMV: Sx
- petechial rash
| - periventricular calcifications
