Comprehensive Final Exam Flashcards
Which hormone begins follicle maturation?
- Follicular phase: days 1-14
- FSH causes maturation of the immature follicle
- There are also increased amounts of estrogen present
Which hormone is responsible for final maturation, and thus ovulation?
- LH is responsible for final maturation and ovulation
- Luteal phase: days 15-28, in a 28-day cycle
Estrogen
- hormones associated with “femaleness”
- Estrone, B-estradiol, estriol
- secreted by the ovaries, then placenta
- regenerates endometrial mucosa after menstruation
- inhibits FSH
- stimulates LH
- influences myometrium contractility, blood flow, and uterine mass
Progesterone
- secreted by corpus luteum, then placenta
- responsible for vaginal epithelium proliferation and thickening of cervical mucus
- hormone of pregnancy (relaces smooth muscle; maintains implantation; prevents rejection of the fetus)
Human Chorionic Gonadotropin (hCG)
- secreted by the trophoblast in early pregnancy
- stimulates progesterone and estrogen production by the corpus luteum to maintain the pregnancy until the placenta can take over
Human Placental Lactogen (hPL)
- also called human chorionic somatomammotropin
- produced by the syncytiotrophoblast
- An antagonist of insulin
- it increases the amount of circulating free fatty acids for maternal metabolic needs
- decreases maternal metabolism of glucose to favor fetal growth
Relaxin
- detectable in the serum of a pregnant woman by the time of the 1st missed period
- inhibits uterine activity
- diminishes strength of uterine contractions
- aids in the softening of the cervix
- has the long-term effect of remodeling collagen
- primary source is the corpus luteum, but small amounts are believed to be produced by the placenta and uterine decidua.
How long are ova and sperm viable/fertile?
Ova: fertile for 24 hours
Sperm: can survive for up to 72 hours; sperm can survive in the female reproductive tract for 48 to 72 hours, but are believed to be healthy and highly fertile for only about 24 hours.
Summarize the 3 shunts unique to fetal circulation
-Ductus venosus: fetal blood vessel that carries oxygenated blood between the umbilical vein and the inferior vena cava, bypassing the liver; it becomes a ligament after birth.
-Ductus arteriosus: a communication channel between the main pulmonary artery and the aorta of the fetus. It is obliterated after birth by rising PO2 and changes in intravascular pressure in the presence of normal pulmonary functioning. It normally becomes a ligament after birth but sometimes remains patent
Foramen ovale: special opening between the atria of the fetal heart. Normally, the opening closes shortly after birth; if it remains open, it can be repaired surgically.
Describe placental circulation
Maternal uteroplacental circulation:
-maternal BP via the endometrial arteries, spurts blood into the intervillous space
-maternal and fetal blood are very close facilitating gas exchange
-maternal blood bathes fetal chorionic villi
-maternal deoxygenated blood returns into maternal circulation via endometrial veins
Fetal placental circulation:
-fetal blood is well oxygenated from maternal “bathing” of O2
-it flows from the chorionic villi into the single large umbilical vein of the umbilical cord
-the umbilical cord vein takes the blood to the fetus
-the deoxygenated blood from the fetus is carried back to the placenta by 2 umbilical arteries
-these arteries divide into the arteriovenous system of the chorionic villi
-the maternal blood bathes the deoxygenated blood from the fetus and the process is started over
What is the venous structure of the umbilical cord?
2 arteries
1 vein
In the umbilical cord, what carries oxygenated blood and what carries deoxygenated blood?
Arteries carry deoxygenated blood
Vein carries oxygenated blood
What are some teratogens
Medication tobacco alcohol caffeine illicit drugs
When are teratogens most harmful and why?
Most harmful during the embryonic stage because “everything is forming.”
Subjective signs of pregnancy
- Presumptive
- amenorrhea, N/V, excessive fatigue, urinary frequency, changes in breasts, quickening (perception of fetal movement by mother)
Objective signs of pregnancy
- Probable
- changes in pelvic organs, enlargement of abdomen, Braxton Hicks contractions, changes in skin pigmentation, uterine soufflé, fetal outline, positive hCG
Diagnostic signs of pregnancy
- Positive
- Fetal HR, fetal movement, visualization of the fetus
What are expected maternal weight gains during pregnancy?
Underweight: BMI < 18; 24-80 lb gain
Normal weight: BMI 18.5-24.9; 25-35 lb gain
Overweight: BMI 25-29.9; 15-25 lb gain
Obese: BMI >30; 11-20 lb gain
Define gravida, para, and GTPAL
Gravida: number of pregnancies
Para: birth after 20 weeks gestation
GTPAL: Gravida, Term, Preterm, Abortion, Living
Gravida: number of pregnancies
Term: infants born 37-42 weeks
Preterm: infants born 20-36 weeks
Abortion: pregnancies ending in either spontaneous or therapeutic abortion
Living: number of living children
**Multiples: gravida/abortions refer to # of pregnancies and are counted as 1; term/preterm/living refers to the actual number of infants
What is GBS?
- Group B streptococcus
- found in the vagina or rectum of 10 to 30% of pregnant women
- GBS causes severe, invasive disease in infants
- Signs of illness include pneumonia, apnea, and shock
When is GBS test done?
35-37 weeks gestation
-rectal and vaginal swab of the mother
What does + GBS result mean?
- mother is positive
- given antibiotic prophylaxis at the onset of labor or the rupture of membranes
Describe the 5 variables of the biophysical profile (BPP)
- fetal breathing movements
- fetal movements of body/limbs
- fetal tone (extension/flexion of extremities)
- Amniotic fluid volume
- Reactive NST
How is each section of the BPP scored?
- Normal scored 2; abnormal scored as 0
- 8-10 reassuring (cannot be related to abnormal volumes of amniotic fluid)
- 6 equivocal; term-deliver; preterm-reassess in 24 hrs
- 4 or less; consider delivery
What would be the expected management with a reassuring, equivocal or non-reassuring BPP score?
Reassuring: continue pregnancy; reevaluate PRN
Equivocal: term-deliver; preterm-reassess in 24 hours
Non-reassuring: deliver the baby
Describe the prenatal screening of maternal serum alpha-fetoprotein (MSAFP/AFP)
- this is a screening tool; NOT diagnostic
- may be collected as part of the quad screen
- measures specific hormones and proteins in the maternal serum to help detect NTD or chromosomal abnormalities (trisomy 18/21)
- AFP is produced by the fetal liver
- most accurate if performed between 15-20 wks
- important to know accurate dates
- obtain hCG level
Nuchal translucency testing (NTT)
- also referred to as nuchal testing (NT) or nuchal fold testing (NFT)
- performed between 11- 13 6/7 weeks gestation
- used to screen for chromosomal abnormalities
- ultrasound scanning is used to observe the back of the fetal neck
What do altered levels suggest with MSAFP/AFP and NTT?
MSAFP/AFP: high levels of AFP may suggest NTD; low levels of AFP may indicate trisomy 18 or 21 (down synd)
NTT: 3mm or greater are at risk for trisomy disorder
Define gestational diabetes
A form of diabetes of variable severity with onset or first recognition during pregnancy
What 2 ways should GDM be screened/diagnosed?
- Screening: 1st prenatal visit to asses risk and again via OGTT at 24 to 28 weeks gestation
- Diagnosis: 50g 1 hr OGTT: 50g oral solution given at any time of day; glucose levels are obtained 1 hour later; levels increased more than 130-140 mg/dL require 3 hr OGTT. 100g 3 hr OGTT: 100g oral solution following 8 hours of fasting; diagnosed if any of the following are exceeded: Fasting 93 mg/dL, 1 hr 180 mg/dL, 2 hour 155 mg/dL, 3 hour 140 mg/dL
Summarize insulin needs during pregnancy & postpartum.
- 1st trimester decreased
- 2nd/3rd trimester increased
- Postpartum decreased
Define preeclampsia
Toxemia of pregnancy, characterized by hypertension, albuminuria, and edema; diagnosis is increased blood pressure equal to or greater than 140/90, that is first noted in pregnancy, after 20 weeks gestation, with an absence of proteinuria.
What defines preeclampsia without severe features?
BP greater than or equal to 160 SBP and/or 110 DPB
What defines preeclampsia with severe features?
Thrombocytopenia < 100,000
Impaired liver function (increased liver enzymes)
Renal insufficiency (serum creatinint > 1.1 mg/dL)
Pulmonary edema
cerebral/visual disturbances (HA, clonus, increased DTR)
Describe the process of Rh alloimmunization
It occurs when an Rh negative mother carries an Rh positive fetus and red blood cells from the RH+ fetus enter the circulation of an Rh- mother, antibodies are formed. Most commonly, blood mixes at birth; 1st infant usually not affected
What would be the blood type of the mother and fetus with Rh alloimmunization?
Mother Rh -
Fetus Rh +
What medication is given to prevent Rh alloimmunization?
RhoGAM
Describe the steps of Leopold’s maneuver.
1- palpate the fundus. The fetal head is firm, hard and round, the buttocks is softer and has bony prominences. Should be able to start feeling at about 30 weeks gestation.
2- Determine location of fetal back. The fetal back will feel firm and smooth; the fetal extremities will feel small and knobby.
3- determine which fetal part is lying in the pelvic outlet. Grasp abdomen just above the symphysis pubis, should confirm opposite what was found with 1st maneuver.
4- attempt to locate the cephalic prominence. A fetal head that is well flexed, will have the cephalic prominence on the opposite side of the back.
Since most infants are in the cephalic/vertex presentation, what would you feel if the infant is LOA, ROA, LOP, ROP?
LOA: head down, face down (toward mom’s spine), back of head in mom’s left side of pelvis
ROA: head down, face down (toward mom’s spine), back of head in mom’s right side of pelvis
LOP: head down, face up (toward mom’s tummy), back of head in mom’s left side of pelvis
ROP: head down, face up (toward mom’s tummy), back of head in mom’s right side of pelvis
Explain FHR baseline
The baseline rate refers to the average FHR rounded in increments of 5 beats/minute observed during a 10-minute period of monitoring. This excludes periodic or episodic changes, periods of marked variability, and segments of the baseline that differ by more than 25 beats/minute. You need at least 2 minutes w/in the 10 minutes and they do not need to be consecutive. Normal FHR ranges from 110-160.
Explain FHR variability
-The amplitudes of peak and trough in bpm are defined as:
Absent- amplitude undetectable
Minimal- amplitude detectable but less than 5 bpm
Moderate (normal)- amplitude 6 to 25 bpm <– desired
Marked- amplitude greater than 25 bpm
**Reduced variability is the best single predictor for determining fetal compromise. Fetal acidosis and subsequent hypoxia are highest in fetuses that have absent or minimal variability.