Obstetrics Flashcards
What is gravity?
Number of times a woman has been pregnant
What is parity
Number of pregnancies that led to a birth at or beyond 20 weeks
What is considered term?
Born after 37 weeks
What is considered preterm?
Born after 20 weeks but before 37 weeks
What is abortion?
All pregnancy losses prior to 20 weeks
What is living?
Any infant who lives beyond 30 days of life
Define nulligravida
A woman who is not pregnant and has never been pregnant
Define primigravida
A woman who currently is pregnant and has never been pregnant before
Define multigravida
A woman who currently is pregnant and who has been pregnant before
Define primipara
A woman who has delivered only once of a fetus or fetuses born alive or dead with an estimated length of gestation >20 weeks
Define multipara
A woman who has completed 2 or more pregnancies to 20 weeks gestation or more
What is considered the first trimester?
Until 14 weeks gestation
What is considered the second trimester?
From 15 weeks until 28 weeks
What is considered the 3rd trimester?
From 29 weeks until 42 weeks
What is the goal of pre-conceptional care?
- Identify and modify biomedical, behavioral, and social risks to woman’s health or pregnancy outcome throuhg prevention and management
What percentage of all pregnancies are unplanned?
Up to half
What are symptoms of pregnancy?
- Amenorrhea (not reliable until 10 days after expected menses)
- Breast tenderness and paresthesias
- Maternal perception of fetal movement (20 weeks primigravida or 16-18 weeks multigravida)
What are signs of pregnancy?
- Chadwick sign
- Cervical softening
- Change in cervical mucus due to progesterone
- Uterine isthmus softening –> hegar sign
- Increase in breast size and nipple size
- Breasts produce colostrum
- Areola becomes more deeply pigmented
- Increased pigmentation and visual changes in abdominal striae
What are tests for pregnancy?
- BhCG
- Ultrasound
What is bhCG?
- heterodimer with similar subunit to LH, FSH, and TSH
- Produced by syncytiotrophoblasts after implantation
- Detected in blood and urine approx 8-9 days after ovulation
- Prevents involution of corpus luteum (supports pregnancy)
What are causes of false positive b hCG?
- Circulating serum factors ie heterophilic antibodies bind to hCG, urine would be negative still
- Exogenous hCG injection for weight loss
- Renal failure with impaired hCG clearance
- Physiological pituitary hCG
- hCG producing tumors of GI tract, ovary, bladder, or lung
How should the bhCG value change over the course of early pregnancy?
Should double every 1.4-2 days
What is seen on a transvaginal ultrasound?
- Gestational sac –> anechoic fluid collection within endometrial cavity
- Yolk sac –> echogenic ring with anechoic center
- Fetal pole/embryo after 6 weeks
- Crown rump length –> head to butt at 6-12 weeks
What is the first sonographic evidence of pregnancy seen around 4-5 weeks gestation?
Gestational sac
Why would it be reassuring to see a yolk sac?
Confirms intrauterine location
When is yolk sac first seen? Fetal pole/embryo?
Yolk sac: 5-6 weeks
Fetal pole/embryo: after 6 weeks
When would you measure crown rump length?
6-12 weeks
Used up to 12 weeks to predict due date
Accurate within 4 days
What are ways that you can estimate date of delivery?
- Naegele’s rule
- Ultrasound (first trimester crown rump length)
Crown rump length is most accurate tool for gestational age assessment
What is Naegele’s rule?
LMP + 7 days - 3 months = EDD
Assumes pregnancy to have begun 2 weeks before ovulation
What are components of the initial prenatal visit?
- History and physical
- Lab testing
- Patient education
- Routine care
What are important historical components of the initial prenatal visit?
- Obstetrical history: prior pregnancies (C section or vaginal), prior complications, infertility
- Menstrual history: interval between menses, contraceptive use
- Psychosocial history: depression/anxiety, violence/abuse, tobacco/alcohol/drugs
What are components of the initial prenatal physical exam?
- General physical –> heart, lungs, etc
Pelvic exam
* Speculum exam: pap smear (if >21) and chlamydia and gonorrhea testing
* Bimanual exam: uterine size, cervical dilation, length, consistency, and bony pelvic architecture
What size uterus is a small orange? Large orange? Grapefruit?
- 6 weeks
- 8 weeks
- 12 weeks
What lab testing is done at the first prenatal visit?
- CBC
- Blood type and Rh factor
- Antibody screening
- Pap smear
- Urine protein and culture
- Rubella serology
- Syphilis serology
- Gonococcal screening
- Chlamydial screening
- Hepatitis B and C serology
- HIV serology
- Varicella serology- if needed
- Hgba1c
What are you assessing on the prenatal CBC?
- WBC, hemoglobin, hematocrit, platelet count
- Monitor anemia, thrombocytopenia
What are you looking for with Rh status?
- Lacking Rh or D antigen
If a mom is lacking Rh or D antigen, what would you do?
- Give RhoGAM at 28 weeks to prevent Rh alloimmunization
- Give RhoGAM if vaginal bleeding in trauma prior to this time
- Give postpartum if infant is Rh positive
What is Kleihauer Betke?
- Tests amount of fetal red blood cells in maternal circulation
- Can test if trauma or abruption and administer additional RhoGAM
Why is rubella important to screen for in pregnancy?
- Cause of fetal growth restriction
- Infection in 1st trimester can cause abortion and severe congenital malformations
- Fetal effects: eye defects, congenital heart defects, sensorineural deafness, CNS defects (microcephaly, developmental delay, mental retardation), hepatosplenomegaly and jaundice, pigmentary retinopathy
How is rubella diagnosed?
Serology
How do you treat/prevent rubella?
- Treatment: no specific treatment
- Prevention with MMR vaccine for non-pregnant women of childbearing age, avoid 1 month before or during pregnancy (live virus)
What does maternal syphilis lead to?
- Preterm labor
- Fetal death
- Fetal growth restriction
- Neonatal infection
How is syphilis diagnosed?
- Venereal Disease Research Laboratory (VLDR)
- Rapid Plasma Reagin
What is the treatment for syphilis?
- Penicillin G
- Women with allergy should have oral penicillin dose challenge or skin testing and penicillin desensitization if confirmed allergy
What counseling should be provided to patients prenatal regarding vitamins, occupation, and weight?
- Prenatal vitamin with 400 ug of folic acid
- Can work until onset of labor, depending on type of work (some increase pregnancy complications)
- Weight gain of 1 lb/week in 2nd/3rd trimester if normal weight or underweight and .6 lb/week if overweight, .5 lb/week if obese
What are risks of obesity during pregnancy?
- Gestational hypertension
- Preeclampsia
- Gestational diabetes
- Macrosomia- big babies hard to deliver
- Cesarean delivery
How much weight gain in obese women has the lowest rate of complications?
Less than 15 lbs
What is counseling regarding diet to provide to patients prenatally?
- Require additional 100-300 kcal per day
- avoid fish and shellfish
- Definitely avoid shark, swordfish, king mackerel, tile fish (high mercury levels)
- No more than 6 oz albacore or white tuna in a day
When would you do lead testing prenatal?
If risk factor identified
* Recent immigrant
* Living near lead source
* Using lead glazed pottery
* Eating non-food substances (pica)
* Using imported cosmetics
* Remodeling home with lead hazards
* Consuming lead contaminated drinking water
* Living with someone identified with an elevated lead level
How should a patient wear a seat belt while pregnant?
- Place lap belt under abdomen and across upper thighs
How should a patient be counseled prenatal on air travel? Dental treatment? Sexual intercourse?
- Air travel: can safely fly up to 35 weeks but should ambulate hourly or consider wearing TED hos
- Dental treatment: can still receive dental treatment and dental radiographs
- Sexual intercourse: usually not harmful. If threatened abortion, placenta previa, or preterm labor should be avoided
How should a patient be counciled prenatally on caffeine?
- Heavy intake (>5 cups of coffee) increases abortion risk
- Moderate consumption of caffeine (less than 200 mg per day/10 oz coffee) does not seem to be associated with miscarriage or preterm birth
What are guidelines for exercise during pregnancy?
- Healthy pregnant women do not need to limit
- Do not recommend if significant health issues or obstetric complications
- Encourage regular, moderate intensity physical activity for 30 mins a day
- Avoid activities with high risk of falling or abdominal trauma
- Avoid scuba diving due to decompression sickness
What is recommended regarding smoking during pregnancy?
Quit smoking
Person to person counseling is most successful
1. Ask about tobacco use
2. Advise to quit
3. Assess willingness to quit
4. Assist in quit attempt
5. Arrange follow up
Who is most likely to drink while pregnant?
- White
- 35-44 yo
- College graduates
- Employed