Flashcards in Normal Pregnancy from Fertilization--> Labor: OP Deck (32)
Where does fertilization actually occur?
Ampulla of fallopian tube
Which phase of the oocyte cell cycle is completed after fertilization?
The first cute little bundle of cells that forms after fertilization is called:
Describe the time frame, post conception.
a morula- a mullberry shaped embryo of a dozen or so cells
Roughly around day 4 post conception.
The morula cavitates to form a:
Describe the two components of this structure and their differing fates.
Describe the time frame, post conception.
Blastocyst (imagine a ball with a tumor on the inside surface)
Inner cell mass becomes fetus
Outer cell mass becomes trophoblast
Roughly around day 5 post conception, around same time the blastocyst enters the uterine cavity.
When does implantation occur (how many days after conception)?
Day 8-9 post conception
The decidualization (glycogen and lipid rich buildup of endometrium) is promoted by this hormone. The hormone is produced where?
Progesterone. Produced by the corpus luteum.
What component of the blastocyst invades the decidua?
By week 5, the Beta subunit of this hormone, produced by the trophoblastic cells, can be detected in a urinary pregnancy test to confirm pregnancy.
human chorionic gonadotropin (hCG)
How do you calculate the estimated due date?
Count back 3 months from the last menstrual period and add 7 days.
A fetus is considered preterm when delivered before week ____.
Postterm when delivered after week ____.
Fetus is considered viable if delivered after week ___.
pre-term = before 37wk
post-term = 42wk or later
Viable after 23 weeks gestation.
An abortion is the loss of a pregnancy before _____ weeks or when the fetus is less than ____ grams.
Organogenesis occurs between weeks ___ and ___ of gestation.
The G's and P's. What are they all about?
G3- has been pregnant 3 times (including this one)
P- pregnant now*
1- 1 full-term birth*
0- No preterm births
1- 1 abortion*
1- I child living
* count towards the 'G'
List some symptoms that a female may experience if they are pregnant but did not suspect so until now.
Perceived fetal movement (G0 @ 18 wks, G>0 @ 16 wks)
To Dx a pregnancy purely based off of physical examination (no hCG testing) look for:
::Uterus soft @ 6-7 wks gestation
::Cervix is bluish from blood engorgement
::Uterus enlarged by 7-8 wks
::Hear fetal heart tones w/ doppler @ 10 wks
Describe the physical landmarks for uterine growth based on weeks of gestation.
Uterus palpable at pelvic brim @ 12 wks
Palpable at umbilicus @ 20 wks
Beyond 20 wks, 1 cm from pubic bone for every wk.
What is the most common type of antigen-antibody rxn in pregnancy?
Is it bad when the mother is + or - for this antigen?
Describe the problem.
Describe the solution.
RH factor (anti-D abs)
Found on chr. 1. Autosomal dominant inheritance
Problem arises when mom is RH negative.
In 1st RH+ preg., mom will develop abs to RH factor. If she has a 2nd RH+ fetus, her anti-D IgG abs will cross the placenta and raise hell in the fetus.
Antigen-ab complexes will form on fetal RBC, distorting RBC, which will then get lysed in fetal liver, bone and spleen. Fetus will be anemic.
Tx: intrauterine transfusion can be done or baby can be delivered early.
Around what weeks of gestation would it be appropriate to perform ultrasound to look for anatomical defects such as a malformed heart or limbs?
When do we administer Rhogam and screen for diabetes (in gestational weeks)?
Describe how Rhogam works.
Rhogam is a synthetic anti-D ab. Administering it to mom will act as a surrogate for her immune system, binding up all the fetal D+ (RH) RBCs, causing them to be destroyed before mom mounts an immune response that would harm the fetus more.
36 weeks is a benchmark to retest for these:
STIs. CDC recommends testing in high risk communities
Culture for Group B strep. Group B strep kills babies born healthy.
Signs of labor?
Describe the phases of labor.
From not in labor to 4 cm dilation of cervix.
When contractions become regular, painful and cervical dilation picks up.
May be 18 hrs in a primigravada; may be very rapid in multigravada.
From this moment (4-5cm dilated), to delivery of infant.
Should progress 0.8cm/hr in primigravada; 1.3cm/hr in multigravada.
Describe the 3 stages of the active phase of labor and delivery.
Stage 1: From 4cm to completely dilated
Stage 2: From completely dilated to delivery of baby
Stage 3: From delivery of baby to delivery of placenta
Briefly describe the cardinal movements of delivery that a baby goes through.
1) head floating before engagement (nothing is happening)
2) engagement; flexion, descent (chin to chest, pushes down to efface and dilate cervix)
3) Further descent, internal rotation (baby's chest faces laterally, head is rotating to face posteriorly)
4) Complete rotation, beginning extension (baby faces posteriorly with chest lateral, beginning to extend head as if to look up)
5) Complete extension
6) External rotation (baby faces same direction as chest, laterally) head has breached mother's external vaginal opening
::Then one shoulder is delivered at a time
Ms. L is concerned about excessive alcohol use over NYE. The first day of her LMP was Dec 6. When is her due date? What is your advice?
EDD is Sept 13th.
She should be reassured. The embryo was likely just at an implantations stage where a teratogen would have no affect on organdevelopment. Organogenesis occurs between weeks 2-8 (4-10 wks since LMP). The exception to the rule is Accutane, a fat soluble acne (Vit. A) drug that is stored in blood and is released slowly over time.
Ms. F presents with vag. spotting. The first day of her LMP was 5 wks ago. hCG level is 938 mlu. Transvag. ultrasound shows no gestational sac.
Can you tell if she is pregnant?
She is too early. You may not see fetus even within TVU window (3-4wks). Go by your objective evidence (hCG 1000mlu-2000mlu).
Ms. J is a 28 y/o G3P1011 at 16 wks for a new OB visit. Her blood type is O-. The ab screen is pos.; anti-D with a titer of 1:4 (low titer). Your next step?
She recalls receiving Rhogam with her previous baby.
This is a new partner. If he is RH-, there is nothing to be concerned about.
**titer is of Anti-D in mom's blood**
Titer explained: The greater the ratio, the greater the immune response, because if you have diluted mom's blood 1:256 and you're still picking up anti-D in the titer, then she is REALLY mounting an immune response and the baby is fooked.
A 1:4 titer is not very strong. 1:32 is a cause for concern (8-fold increase).
(prev. question continued) Ms. J's new partner is RH+ on his blood donation card. The pt is now 17 weeks. What is the next step?
Repeat the titer in one month. If it is 1:32 or greater, the fetus may be at risk.
(Prev. question continued) The titer is repeated at 20 weeks, but is stable. At 28 weeks, it is found to be 1:64. The next step?
The mom's immune system is having an amnestic response and is recognizing the fetus as foreign. Ultrasound and fetal cord blood sampling is indicated.
**titer needs to go up 8-fold for your to be concerned**
Ms. K is found to be Hep. B surface antigen pos. on third trimester labs. She was not tested earlier. What is the next step?
This will be an issue to discuss with the neonatal team. The baby will get immunoglobulin at birth. It will also be vaccinated early.
Ms. O presents in early labor at term. She has bot been to the clinic for the past 6 months. Her initial labs, including HIV, were negative. What is the appropriate next step?
Rapid HIV is drawn and if pos., AZT is begun.
*remember, we want to routinely screen for STIs at 36 weeks* pt doesn't always comply.