Pregnancy Lecture Review
OB/GYN Prenatal Care: Comprehensive Study Notes
Aide mémoire for an initial OB intake and ongoing prenatal visits, incorporating common assessments, terminology, timelines, and practical guidance discussed in the transcript.
Demographics, Medical, and Surgical History (intake at first visit)
Collect basic patient demographics: age, race/ethnicity, marital status, etc. Example from case: age 37, Caucasian, married.
Past Medical History (PMH): migraines; asthma; hypothyroidism.
Past Surgical History (PSH): ACL reconstruction in right knee; laparoscopic myomectomy (2013) to remove uterine fibroids; cesarean section (C-section) in 2014; knee arthroscopy in 2020.
Current medications: levothyroxine (for thyroid); albuterol PRN (for asthma).
Allergies: stated as none in this example.
Last menstrual period (LMP) used for dating and due date calculations.
Immunization status is reviewed; vaccines administered in pregnancy are generally avoided if live vaccines would affect the fetus (e.g., MMR). Blood is drawn to assess rubella immunity.
Reproductive History: Gravida, Para, and Obstetric Details
Key acronyms:
Gravida: total number of pregnancies, including the current one. ext{Gravida} = ext{number of pregnancies including current}
Para: pregnancies that reached fetal viability beyond 20 weeks (not including miscarriages before 20 weeks). ext{Para} = ext{number of pregnancies beyond } 20 ext{ weeks}
Abortions/ miscarriages: included in the gravida count; life status of each pregnancy is tracked separately as part of the obstetric history.
Living: number of living children.
In the example, the patient had two prior pregnancies that reached viability and two living children, plus a current pregnancy:
Gravida: 3 (two prior pregnancies plus current one).
Para: 2 (two pregnancies beyond 20 weeks).
Individual pregnancy histories:
First pregnancy: bed rest at 24 weeks due to cervical dilation; delivery at 36 weeks with NICU stay of 2 weeks; fibroids noted to have grown during pregnancy; previous fibroids removed via myomectomy.
Second pregnancy: gestational diabetes; cesarean delivery at 39 weeks; no NICU stay.
Implications of fibroids (myomas) in pregnancy: fibroids can affect growth or placentation; monitoring may be more frequent.
Immunization and Infectious Disease Considerations
Immunization status is obtained and rubella immunity is checked via blood test. Live vaccines (e.g., MMR) are contraindicated during pregnancy; if non-immune, vaccination is deferred until postpartum.
GBS (Group B Streptococcus) prophylaxis planning begins late in pregnancy; not treated at the prenatal visit unless positive, but record is used to plan intrapartum antibiotics if positive at delivery.
Prenatal Care Timeline and Core Assessments
First prenatal visit (early pregnancy): establish dating, review history, confirm presumptive/probable signs, and perform objective testing to confirm pregnancy.
Urinalysis and blood work: confirm pregnancy; screen for infections and baseline labs; check for glucose/protein in urine (screen for gestational diabetes and preeclampsia risks).
Blood tests: HCG (to confirm pregnancy), CBC as baseline, blood type and antibody screen (type and screen) to prepare for potential Rh incompatibility management.
Ultrasound: confirm intrauterine pregnancy and viability; assess dating.
Education: discuss signs to report, lifestyle, nutrition, and safety during pregnancy.
Counseling on activities, medications, and avoidance of certain exposures (see safety section).
Early pregnancy potential signs (presumptive vs probable vs positive):
Presumptive signs (patient-reported): amenorrhea, nausea/vomiting, fatigue, breast changes, urinary frequency, baseline fatigue. These can have alternative explanations.
Probable signs (clinical or exam findings): cervical changes, uterine enlargement at palpation, pregnancy-related changes observed by clinician, positive home pregnancy test but not diagnostic.
Positive signs (definitive): fetal heartbeat detected by auscultation or Doppler; ultrasound visualization of embryo/fetus; fetal movement felt by clinician.
Typical visits through the trimesters:
1st trimester: confirm dating; assess history; screen for infections; baseline labs; plan for continued care.
2nd trimester (weeks ~13–27): frequent visits with fetal heart tones at each visit; fundal height checks; urine tests (glucose/protein); anatomy scan around 18–22 weeks; possible genetic testing; ongoing counseling.
3rd trimester (weeks ~28–40): increased visit frequency; glucose tolerance testing (GTT) around 24–28 weeks; fetal movement checks; ongoing fundal height tracking; ultrasound as indicated; monitoring for preterm labor signs; Group B Strep testing around 35–36 weeks; routine vital signs; discussion of labor signs and when to call or go to OB; Rhogam administration if indicated; planning for delivery and postpartum care.
Estimated due date (EDD): calculated from LMP using a standard rule; ultrasound dating may adjust the EDD if measurements are outside the expected range.
Example process: input last menstrual period into an EDD calculator; result provides an estimated due date. If an ultrasound measures differently, date adjustment is made only if the clinician is confident in the accuracy.
Fundal height measurements:
The clinician uses a measuring tape (like a sewing tape) to measure from the top of the uterus (fundus) to the pubic bone.
The resulting measurement in centimeters roughly corresponds to gestational age in weeks (with some normal variance).
Example: a fundal height of 15 cm roughly corresponds to 15 weeks of gestation.
Anatomy scan and fetal measurements:
A comprehensive anatomy ultrasound is performed (often around 18–22 weeks) and includes: femur length, multiple fetal measurements, and assessment of major organ structures.
Doppler color flow assessment to evaluate fetal cardiac blood flow (red/blue imaging for oxygenated vs deoxygenated blood).
The scan helps assess growth and rule out major anomalies.
Urine testing at each visit:
Check for glucose and protein to screen for gestational diabetes and preeclampsia risk, respectively.
Movement and activity monitoring in the third trimester:
Expect to assess fetal movement; describe patterns and advise on how to elicit movement if needed (e.g., caffeine or sugar intake to stimulate activity if needed).
Group B Strep (GBS) screening:
Performed around 35–36 weeks.
If positive, intrapartum antibiotics are administered during labor (with timing preference to maximize effectiveness, typically within about 2 hours before delivery).
A negative GBS test reduces risk but monitoring continues as pregnancy progresses.
Rh status and Rho(D) immune globulin (Rhogam):
If mother is Rh-negative and baby is Rh-positive, administration of Rhogam is indicated to prevent maternal antibody formation.
Rhogam is typically given in the third trimester if indicated and a second dose is given postpartum if the baby is Rh-positive.
If both parents are negative or both positive, management considerations differ accordingly.
Signs and Symptom Management in Pregnancy (Practical Advice from Transcript)
Nausea and vomiting in the first trimester:
Common strategies discussed: small, frequent meals; dry crackers before getting out of bed; hydration; ginger-containing products (e.g., ginger candy or ginger ale); peppermint; aroma considerations; aromatherapy around heightened sense of smell.
If vomiting is severe, antiemetics like Zofran may be used after trying non-pharmacologic options; doctors will balance benefits and safety.
If vomiting is persistent, consider nighttime prenatal vitamin if daytime GI upset persists; prenatal vitamins often contain iron which can worsen GI symptoms.
Dietary guidance during pregnancy:
Avoid raw or undercooked foods (e.g., raw fish/sushi) and potentially risky deli meats unless properly heated; avoid cat litter exposure to reduce toxoplasmosis risk.
Ensure adequate caloric intake for fetal growth; focus on nutrient-rich foods and hydration.
Use “safe medication list” and avoid NSAIDs (e.g., ibuprofen, naproxen) unless advised by a clinician.
If a headache occurs, acetaminophen (Tylenol) is typically preferred; other medications require clinician guidance.
Exercise and activity:
If pre-pregnancy activity was regular, continue with modification as pregnancy progresses (avoid lying flat on the back in later stages; adjust weights and intensity; avoid crunches; modify to uprights or elevated positions).
If not previously active, start with walking or light activity rather than starting intense new workouts.
Sleep and posture:
Side sleeping preferred, particularly left side to optimize uteroplacental blood flow; pillow support can help with comfort.
Insomnia and increased daytime fatigue are common; environmental adjustments may help with sleep quality.
Bathing, bathing safety, and home safety:
Showers preferred to baths as pregnancy progresses; baths may be used for relief (e.g., sciatic pain) but should not be a daily routine.
Sexual activity:
Generally safe unless restricted by obstetrician; if there was prior cervical dilation or other complications, activity may be restricted as advised by clinician.
Medications and safety planning:
Prepare a safe medication list to share with providers.
Avoid substances that could harm the fetus; discuss any current medications with the health care team.
Practical obstetric scenarios and clinician notes (from the transcript)
A patient with a history of fibroids and prior C-section may have additional monitoring during pregnancy due to potential growth of fibroids and prior uterine scarring.
The patient’s prior gestational diabetes is a risk factor that requires glucose screening in late 2nd trimester and possible dietary management strategies.
The patient’s neonatal history (first baby spent 2 weeks in NICU) is important for counseling and monitoring of potential recurrence risk and perinatal planning.
The patient’s family planning and partner’s health history are considered in broader risk evaluation, but in OB visits the focus during intake is primarily maternal health, with partner history often collected separately for genetic or heritable concerns.
Key Terms and Quick References (glossary)
Gravida: ext{Gravida} = ext{# of pregnancies including current}
Para: ext{Para} = ext{# of pregnancies beyond }20 ext{ weeks}
Living: number of living children.
Uterus anatomy terms: fundus – the top part of the uterus; fundal height is measured with a tape from the pubic symphysis to the top of the uterus.
Anatomy scan: comprehensive ultrasound around 18–22 weeks to assess fetal structures, growth, and amniotic fluid; includes head-to-toe organ assessment and fetal blood flow via Doppler.
GBS: Group B Streptococcus; screening at 35–36 weeks; intrapartum antibiotics if positive.
Rhogam: Rh immune globulin given to Rh-negative mothers to prevent alloimmunization; typically given at 28 weeks and postpartum if baby is Rh-positive; additional doses may be given after events with potential fetal-maternal blood mixing.
Nausea management strategies: small meals, crackers before rising, ginger, peppermint, aromatherapy considerations.
Glucose testing:
1-hour glucose tolerance test (screen) in the third trimester or late second trimester.
If abnormal, a 3-hour glucose tolerance test confirms gestational diabetes.
Safety and lifestyle reminders:
Avoid raw seafood and unpasteurized foods; avoid alcohol; avoid cat litter exposure; warm deli meats; avoid NSAIDs; use acetaminophen for headaches as advised.
Exercise continuation with modification is acceptable if previously active; sleeping on the side; monitor fetal movement; call if movement decreases or contractions occur.
Connections to Foundational Principles and Real-World Relevance
Evidence-based screening and management: rubella immunity testing, GBS screening, glucose tolerance screening, and Rh incompatibility management are standard components of prenatal care that reduce maternal and neonatal morbidity.
Patient education and shared decision-making: guidelines cover lifestyle, diet, exercise, and safety to empower patients to participate in their care decisions.
Ethical considerations: avoidance of live vaccines during pregnancy and balancing medication safety for the mother and fetus reflect risk-benefit assessments in obstetric care.
Practical clinical workflow: structuring a first visit with history, physicals, labs, and ultrasound, followed by trimester-specific assessments (FHR, fundal height, urine tests), mirrors typical OB clinic protocols.
If you need, I can convert these notes into a compact study sheet or expand any section with more examples or practice questions (e.g., sample patient scenarios to test recognition of presumptive/probable/positive signs, or calculating due dates from different LMP examples).