OBGYN Crash Course Flashcards
How long do pregnancy usually last?
37 - 42 weeks since LMP (median 40 weeks)
(around 9 months)
Which weeks are the trimesters divided into?
- 1st: weeks 0 - 13
- 2nd: weeks 14 - 26
- 3rd: weeks 27 - 40 (depends on term date)
How do we decide term date? Which rule do we use and what do we do in cases where the rule doesn’t apply?
We use Naegele’s rule for 28-day menstrual cycle:
Date of LMP - 3 months + 7 days + 1 year = Term date
OBS! If patient has a menstrual cycle longer or shorter than 28 days, remember to add or substract the difference in days.
Best way of determining term date for sure?
USG in the 1st trimester!
How long is the menstrual cycle? Can it vary? And what 2 parts do we divide it into?
- The menstrual cycle is on average 28 days long. But can also vary between being 21 - 35 days long for many.
- It’s divided into 2 phases called the Follicular phase and the Luteal phase.
- The Luteal phase alway comes after the follicular phase. No matter how long or short the menstrual cycle is ALWAYS 14 days
- The follicular phase is on average 14 days, but may vary. In people with 21 day cycle, the follicular phase is for example 7 days (remember, the luteal phase is always 14d)
When does ovulation happen?
Ovulation happen is on average the first 24h of the Luteal phase
What kind of significant OBGYN monitoring is epecially used for women in labor?
CTG: CardioTokography
Measures 2 things:
- Fetal HR (normal 110 - 160)
- Contractions (per 10min)
B-hCG: what is normal (no pregancy), what lvl causes a pausitive pregnancy test? When does it peak?
- Negative pregancy test: B-hCG < 5
- Positive pregancy test: B-hCG > 25 (may already show 8-9 days after ovulation)
- Peaks between week 8 - 12
Explain the TPAL system
System of classifications used in patient history of pregnant women:
- G (gravidity): number of times patient has been pregnant
- T(term): number of term pregnancies (>37 weeks)
- P(parity): number of pre-term pregnancies (between weeks 20 - 37)
- A (abortions): number spontanous abortions (<20 weeks)
- L (live births): number of live births in the past
Hematlogic changes due to pregnancy (6)
- Blood volume increase by upto 50%, mostly being plasma
- RBC also increase, but because the plasma increases so much more, we se decreased Hct on blood tests
- Hypercoagulative state: increased coagulation factors (5x risk of DVT)
- WBC increase, especially plasma cells –> hypergammaglobulinemia (immunglobulin lvl is raised so some can diffuse over to baby and protect it until it can make its own Ig’s), causes also increased ESR
- Iron deficiency –> Iron-def anemia (give iron sulfate)
- Folate deficiency –> megaloblastic anemia (give folate)
Endocrine changes due to pregnancy? (11)
Everything pretty much increases, these are just a few….
- High estrogen and progesterone lvls with progesterone being much higher than estrogen
- Hyperaldosteronism
- Hypercortisolism
- Hyperparathyroidism
- Hyperthyroidism
- Hyperprolactinemia
- Increase in Relaxin
- Increased Insulin-intolerance –> hyperglycemia
- Increased MSH –> hyperpigmentation
- Increased HPL
- Incresed size of thyroid and pituitary gland
Cardiovascular changes during pregnancy? (6)
- HR increased by 20bpm
- Increased Stroke Volume
- Decreased SVR (progesterone is a vasodilator)
- Increased pressure in lower veins (uterus press down on IVC)
- Ventricualr hypertrophy (changes the PMI)
- Midsystolic murmur
Respiratory changes during pregnancy? (3)
- Decreased RV (cause uterus presses on diaphragm)
- Increased TV and Minute-Volume due to increased ligament elasticity from Relaxin release(more movement in ribs and costal ligaments)
- Increased RR (causes mild resp-alkalosis, good for the infant as this means more pCO2 can diffuse from placenta to mother)
Renal changes during pregnancy? (8)
- 100% Kidney-size increase
- 50% GFR increase –> low BUN, creatinine, urea
- Decreased BUN (makes up for resp alk)
- Increased urin glucose (due to hyperglycemia)
- Small increase in blood PH within normal values (resp alk)
- Incontinence in 3rd trimester (lightening effect)
- Proteinuria (though blood albumin lvl is usually increased)
- Increased chance of UTI and pyelonephritis due to the high pressures on bladder and kidney causing congestion
Gastric changes due to pregnancy? (4)
- Decreased gastric motility (constipation) and prolonged emptying time
- Decreased LES muscle tone (GERD)
- Nausea and Vomiting (can be very severe causing weight loss, Afipran helps nausea and can even increase motility)
- Hemorrhoids (remember, uterus presses on IVC)
