Obstetrics Flashcards
(280 cards)
Antenatal visit frequency
> 28/40: monthly
28-36: biweekly
36: weekly
Medications that cross the placenta so should be changed in pregnancy are
Medical conditions advised AGAINST getting pregnant
Anti-epileptic drugs
Warfarin (swap for LMW hep)
Pulm HTN Renal failure (until on dialysis or receive a transplant)
SX of pregnancy
Nausea
Tender breasts
Missed period
Urinary frequency
Naegle’s rule
Date of conception is first day of last normal period + 9 months and 7 days
- When does the uterus first become palpable?
2. When do fetal movements first become noticeable?
- 12 weeks
2. ~20 weeks
What supplements should pregnant women be taking?
Folate
Vitamin D
Iron
Ca
Routine bloods at first antenatal visit (12 weeks)
FBE Blood group and antibody screen (ABO, Rh) HIV, HBV, HCV, syphilis Rubella immunity MSU for MCS (?asymptomatic bacteriuria)
+/- VZV immunity
+/- Down syndrome serum screen (free betaHCG, PAPP-A)
Components of combined down syndrome serum screen
12 week ultrasound - gestational age and nuchal translucency
Serum free bHCG + PAPP-A
OR as an alternative, non-invasive pre-natal screen for cell-free DNA from 9 weeks. tests for aneuploidies. 99% NPV. If pos, refer for invasive testing. Takes 3 days but costs $450.
IF a women’s combined serum screen comes back as high risk, what is the next step in investigations for diagnosis?
Refer her for diagnostic invasive testing (chorionic villus sampling at 10-13 weeks or amniocentesis at 15-18 weeks) anti-D if mum is Rh neg
+ FISH and full karyotype
when do routine USS in low-risk pregnancies typically occur.
Ultrasound @ 12 weeks: gestational age and down syndrome screen
18-20weeks: morphology and wellbeing
What bloods get done in the second trimester and when?
28 week bloods:
- FBE
- Oral glucose challenge
- AB screen in Rh neg women (will need anti-D injections if no Anti-D detected)
Who needs anti-D injections and when are these given?
Rh neg women who are negative for anti-D antibodies
Given at 28 and 36 weeks
To Rh(neg) women with M/C, invasive procedures, abruption, trauma etc
What 2 medical conditions do we screen for every visit and how do we do this?
Placental insufficiency - ask about fetal movements + SFH
Pre-Eclampsia - HTN (BP), proteinuria (urine dipstick) , oedema (exam/Hx)
When should women stop working?
34 weeks onwards
What routine Inx get done in the third trimester and when?
36 weeks:
- FBE
- AB screen in Rh neg women (will need anti-D injections if no Anti-D detected)
- GBS swab! (lower vaginal)
Physiological changes in third trimester
Breast enlargement, colostrum production
Uterine contractions/tightenings, painless at first and becoming more painful closer to labour
Cervical ripening (effacement and dilation), evidenced by incr loss of D/C or mucus plug
Advise to women in third trimester as to when to come to hospital
Contractions are regular and painful, occurring ~1x5min (2:10) OR:
- DFM
- Bleeding
- SROM
- Psychological distress
When does the GBS swab get done?
36 weeks, lower vaginal and anal swab
When does the oral glucose challenge test get done?
28 weeks
How do you assess fetal wellbeing antenatally (5)
- fetal movements
- maternal SFH
- USS
- Infection screen +/- karyotype (aneuploidy screen)
- CTG
Assessing fetal wellbeing in labour
- CTG
- fetal movement
- Doppler
- Fetal scalp blood sampling
At what gestation does the uterus sit at the
- umbi
- xiphisternum
- 20 weeks
2. 38 weeks
Causes of:
- Oligohydramnios
- Polyhydramnios
- Decr fetal urine production (kidney or urinary tract problems) or ruptured/leaking membranes
- Placental insufficiency
- Post-date pregnancy
- Maternal problems (HTN, PE, dehydration, GDM) - Fetal inability to swallow or excess amniotic fluid production (polyuria in GDM)
What arteries does the doppler measure blood flow in and what is the clinical significance of each?
Umbilical arteries: fetal blood flow to placenta. Placental resistance to flow should be low and cardiac activity high so good flow in diastole.
Placental insufficiency or cardiac impairment can lead to absent or reversed diastole flow and high resistance to flow.
MCA: blood from circle of willis to brain. Resistance to flow should be HIGH. Fetal hypoxia -> MCA dilates -> reduces resistance to flow.
Uterine arteries: reflects maternal perfusion of uterus and normal placental implantation. Resistance should start high and reduce after 23 weeks.