Prenatal L&D Flashcards
What is fertilization and when does it occur?
- Egg moved fallopian tube by fimbriae, remains in ampulla for 24 hrs, destroyed if not fertilized
- occurs when viable sperm penetrate zona pellucida→ fertilized egg remain in fallopian tube for 72 hrs
What are 3 processes of implantation?
o Apposition→ blastocyte differentiates into embryo (inner cell mass) and placenta (trophectoderm) o Adhesion→ binds to endometrium o Invasion(migration) trophoblast cells invade endometrium, establish blood supply
What occurs in the first 7-9 weeks after fertilization?
Progesterone produced by corpus luteum
o If there is a corpus luteum cyst; leave it alone, they are common and the corpus leutem is providing stabilization of the pregnancy so mustn’t be disturbed
What happens to the HcG levels during pregnancy
o Amnt of hCG doubles every 2 days until 10 weeks
o If values are not doubling→ pregnancy could be compromised
o If you don’t have a good timing on the pregnancy it can be hard to interpret the hCG levels acutately
4 functions of the placenta?
• Exchange of oxygen and CO2, Waste removal, nutrients, produces hCG
What are some GI changes that can occur during pregnancy?
slowed gastric emptying=constipation
o Increased acidity, increased reflux
What are some renal changes that can occur during pregnancy
GFR increased by 50% because amnt of fluid sent to kidney has increased
o BUN & CR→ decrease d/t hemodilution
o Hydronephosis (swelling in urine d/t build up of urine) late in pregnancy and trace glucose in urine
What are some cardiac changes that can occur during pregnancy
o Blood volume incr. by 50% (if pt has valve problem you will hear murmur as preg. Progresses)
o HCT falls until wk 28 (d/t hemodilution)
o WBC increase (5,000- 12,000)
o In clotting factors (risk of DVT)
o 40% in CO, SV , decreased diastolic by 10mmHg
Gestation & Naegele’s Rule includes?
• Start of gestation is based on last normal menstrual period (LNMP), 2 wkes before ovulation
o Developmental/Fetal Age
o Menstrual Gestational Age→ calc. at 280 days/40 completed weeks
o Estimated Due Date
how to estimate due date
add 7 days to first day of last menstrual period, subtract 3 month, add 1 year (aka add 9 months
What is the development/ fetal age
age of conception calculated from time of implantation (4-6 days after ovulation is completed)
When is the first trimester? and what 2 phases occur during that time?
• Trimester 1: 1-12 weeks
o Embryonic
o Fetal Period
Embryonic phase
fertilization (2-10 wks), organogenesis—embryo most sensitive to teratogens
Fetal period is what?
8 wks after fertilization, or 10 wks after onset of last menstrual period
When are the second and third trimesters?
- Trimester 2: 13-27 weeks
* Trimester 3: 28-40 wks
What is the difference between a fetus and an embryo?
Embryo→ 1-8 wks
Fetus = after 8 weeks
What does fetal viability mean?
23 -24 weeks gestational age weight of 600 gm or more (600g=1.25 lbs)
What does term refer to in relation to pregnancy?
refers to 37 weeks or beyond
what does abortion mean?
elective or spontaneous
• Pregnancy loss
Less than 500 gm, Less than 20 week
What does preterm and premature refer to?
Preterm→ birth before 37 weeks
Premature→birth between 28 – 37 weeks, Weight 1000 - 2500 gm
What does post mature mean?
at or > 42 weeks → most are induced at this point
What does parity mean?
passing child through/actual births of over 20 wks gestational age, infants over 500g
What does gravity mean
of pregnancies, live or dead (elderly primigravida- 1st pregnancy > 35)
what is considered a low birth weight and macrosomia?
Low birth weight - full term but < 2500 gm
Macrosomia – large baby weighing > 4500 gm