Prenatal Care, Pregnancy Physiology & GTPAL

Prepared for Pass the Shift (owner: Kristina, RN). Always follow your facility’s protocols, provider orders, and current references.

1. Overview and Physiology

Pregnancy changes nearly every body system so the parent can grow and perfuse a fetus and survive blood loss at birth. Many “abnormal” adult findings are expected in pregnancy, and some normal-looking values are actually concerning. Knowing the baseline is how you spot trouble.

System	Expected change	Why it matters to the nurse
Cardiovascular	Blood volume rises ~40–50%; cardiac output up ~30–50%; HR up ~10–20/min; BP dips in the 2nd trimester then returns toward baseline	A pregnant patient can lose a lot of blood before BP drops. Tachycardia is an early hemorrhage clue
Blood	Plasma rises more than red cells → physiologic anemia; clotting factors and fibrinogen rise; WBC rises	Higher clot risk (VTE). Normal fibrinogen for a nonpregnant adult may be low for late pregnancy
Supine position	The uterus compresses the vena cava → supine hypotensive syndrome	Position on the side (left lateral tilt); never lie flat on the back in later pregnancy
Respiratory	Tidal volume up, mild respiratory alkalosis, diaphragm pushed up	Shortness of breath with exertion is common; true distress is not
Renal	GFR rises ~50%; frequency; ureters dilate	Lower normal creatinine; higher UTI and pyelonephritis risk
GI	Progesterone slows motility; sphincter relaxes	Nausea, heartburn, constipation, gallstones
Endocrine	Placental hormones (hPL) raise insulin resistance in the 2nd–3rd trimester	Basis of gestational diabetes screening at 24–28 weeks
Skin / MSK	Linea nigra, chloasma, striae; lordosis, joint laxity (relaxin)	Back pain, fall risk

Signs of pregnancy

• Presumptive (felt by the patient): missed period, nausea, breast tenderness, fatigue, urinary frequency, quickening (~16–20 weeks)
• Probable (seen by the examiner): positive hCG test, Goodell (soft cervix), Chadwick (bluish cervix), Hegar (soft lower uterus), ballottement, Braxton Hicks contractions
• Positive (only the fetus causes it): fetal heart tones, fetus seen on ultrasound, fetal movement felt by the examiner

2. Pregnancy Math: Due Date and GTPAL

Naegele’s rule: first day of the last menstrual period (LMP) − 3 months + 7 days (+ 1 year). Example: LMP June 10 → due date March 17. Early ultrasound dating is more accurate when they differ.

Fundal height: at ~20 weeks the fundus is at the umbilicus. From ~20–36 weeks, height in cm ≈ weeks of gestation (±2 cm).

GTPAL (the obstetric history):

Letter	Means	Counts
G — Gravida	Number of pregnancies, including the current one	Twins = 1 pregnancy
T — Term	Births at 37 weeks 0 days or later	Twins born at term = 1
P — Preterm	Births 20 weeks 0 days to 36 weeks 6 days
A — Abortions	Pregnancy losses before 20 weeks (spontaneous or induced, incl. ectopic)
L — Living	Number of children currently alive	Twins = 2

Example: Pregnant now; one son born at 39 weeks; twins born at 34 weeks (both alive); one miscarriage at 8 weeks → G4 T1 P1 A1 L3.

Gestational terms: early term 37 0/7–38 6/7; full term 39 0/7–40 6/7; late term 41 0/7–41 6/7; post-term ≥ 42 0/7 weeks.

3. Prenatal Visits and Screening

Typical pattern (varies by risk and practice): monthly to 28 weeks, every 2 weeks to 36 weeks, then weekly. Each visit: weight, BP, urine (protein/glucose per practice), fundal height, fetal heart tones (Doppler from ~10–12 weeks), fetal movement, edema, and danger-sign review.

Timing (approx.)	Common tests	Nursing notes
First visit	Blood type and Rh, antibody screen, CBC, rubella and varicella immunity, hepatitis B, HIV, syphilis, urine culture; other infections/risk-based tests	Rh-negative + unsensitized → Rh immune globulin plan
10–13 weeks	First-trimester/cell-free DNA genetic screening options	Screening is not diagnosis; diagnosis needs CVS or amniocentesis
15–22 weeks	Quad screen (if chosen), anatomy ultrasound (~18–22 weeks)	Elevated AFP → neural tube defect concern
24–28 weeks	Glucose screen; repeat CBC; antibody screen if Rh-negative	Rh immune globulin ~28 weeks if Rh-negative and unsensitized
36–37 weeks	Group B strep (GBS) culture	Positive → IV antibiotics in labor
Any time	Nonstress test, biophysical profile, as indicated	See the fetal monitoring guide

Vaccines commonly recommended in pregnancy: influenza (inactivated) in season, Tdap each pregnancy (often 27–36 weeks), and per current guidance RSV (seasonal, at a set gestational window) and COVID-19. Live vaccines (MMR, varicella) are avoided in pregnancy. Check the current CDC/ACOG schedule.

Nutrition and lifestyle: folic acid (commonly 400 mcg daily before and during early pregnancy; higher for some risk factors); iron as ordered; avoid alcohol, tobacco, and drugs; limit high-mercury fish; avoid raw/undercooked meat, unpasteurized dairy, and deli meats unless heated (listeria); cat litter precautions (toxoplasmosis). Extra calories mainly in the 2nd–3rd trimesters (~300–450 kcal/day).

4. Priority Nursing Assessments

1. BP every visit — ≥ 140/90 on two readings 4 hours apart after 20 weeks needs workup (see the hypertensive disorders guide)
2. Bleeding, fluid leaking, contractions, fetal movement
3. Weight trend — sudden gain plus edema of face/hands is a red flag
4. Urine — protein, glucose, UTI symptoms
5. Mental health and safety — screen for depression, anxiety, substance use, and intimate partner violence (ask privately)
6. Social needs — food, housing, transportation, insurance, health literacy

5. Common Discomforts and Teaching

Discomfort	Teaching
Nausea/vomiting	Small frequent dry meals, avoid empty stomach, ginger; vitamin B6 ± doxylamine if prescribed. Can’t keep fluids down for > 8–12 h → call (hyperemesis gravidarum risk)
Heartburn	Small meals, stay upright after eating, antacids as approved
Constipation/hemorrhoids	Fluids, fiber, activity
Back pain	Posture, pelvic tilts, supportive shoes
Leg cramps	Stretch with dorsiflexion (point toes toward the knee)
Ankle edema / varicosities	Elevate legs, avoid long standing, side-lying rest
Supine dizziness	Lie on the side

6. Danger Signs — Teach “Call Now”

• Vaginal bleeding; fluid gushing or leaking
• Severe headache, vision changes, RUQ/epigastric pain, sudden swelling of face/hands (preeclampsia)
• Decreased fetal movement
• Regular contractions or pelvic pressure before 37 weeks
• Fever ≥ 100.4 °F (38 °C), painful urination, flank pain
• Chest pain, trouble breathing, one-sided leg swelling (VTE)
• Thoughts of harming self or baby

7. Medications and Safety

• Prenatal vitamin, folic acid, iron (take iron with vitamin C, not with milk/antacids; dark stools expected, constipation common)
• Acetaminophen is generally the preferred OTC analgesic; avoid NSAIDs unless prescribed (especially after ~20 weeks: fetal kidney and ductus effects)
• Teratogens to recognize: isotretinoin, warfarin, ACE inhibitors/ARBs, valproate, methotrexate, tetracyclines, alcohol. Always ask “Could you be pregnant?” before meds and imaging
• Rh(D) immune globulin for Rh-negative, unsensitized patients (~28 weeks, after events like bleeding/trauma/procedures, and within 72 h after birth of an Rh-positive infant)

8. Emergencies in Early Pregnancy

• Ectopic pregnancy: missed period, one-sided pelvic pain, spotting; rupture → sudden severe pain, shoulder pain (referred from blood under the diaphragm), signs of shock. Priority: IV access, type and crossmatch, prepare for surgery. Methotrexate is an option for unruptured cases (teach no folic acid, alcohol, or NSAIDs during treatment, per prescriber)
• Spontaneous abortion (miscarriage): bleeding and cramping before 20 weeks; count pads, save tissue per protocol, Rh status, emotional support
• Hyperemesis: dehydration, weight loss, ketones, low K⁺ → IV fluids with electrolytes and thiamine as ordered, antiemetics

9. Memory Aids

• GTPAL: “Get The Pregnancy All Listed.” Twins count once for G/T/P but twice for L
• Naegele: “Minus 3, plus 7, plus 1”
• Signs: “I think (presumptive) → you see it (probable) → only baby causes it (positive)”
• 20 at the belly button: fundus at the umbilicus at ~20 weeks
• Key weeks: 24–28 glucose and RhoGAM; 36–37 GBS

10. NCLEX-Style Practice Questions

1. A client is pregnant. She has a 4-year-old born at 38 weeks, lost a pregnancy at 10 weeks, and delivered twins at 35 weeks who are both alive. What is her GTPAL?

A. G3 T1 P1 A1 L3
B. G4 T1 P1 A1 L3
C. G4 T1 P2 A1 L3
D. G5 T1 P2 A1 L3

Answer: B. Pregnancies: current + 38-week birth + 10-week loss + twin pregnancy = 4. Term = 1 (38 weeks). Preterm = 1 (twins count as one birth event). Abortion = 1 (loss before 20 weeks). Living = 3 (the 4-year-old plus twins). C counts twins twice for preterm; A misses the current pregnancy.

2. The first day of a client’s LMP was August 20. Using Naegele’s rule, what is the estimated due date?

A. May 13
B. May 27
C. June 27
D. November 27

Answer: B. August 20 − 3 months = May 20; + 7 days = May 27 of the next year.

3. A client at 32 weeks becomes dizzy and pale while lying flat for a fundal height check. BP has dropped from 118/72 to 92/58. What should the nurse do first?

A. Raise the head of the bed to 90 degrees
B. Turn the client onto her left side
C. Start an IV fluid bolus
D. Check a fingerstick glucose

Answer: B. This is supine hypotensive syndrome: the uterus compresses the vena cava and reduces venous return. Lateral positioning relieves the compression immediately. The other actions don’t fix the cause.

4. Which findings should a client at 30 weeks report immediately? Select all that apply.

A. Persistent headache with blurred vision
B. Mild ankle swelling at the end of the day
C. Fewer fetal movements than usual
D. Heartburn after large meals
E. Clear fluid leaking from the vagina
F. Upper abdominal pain under the right ribs

Answer: A, C, E, F. Headache with visual change and RUQ/epigastric pain suggest preeclampsia with severe features; decreased fetal movement can signal fetal compromise; leaking fluid suggests rupture of membranes. Dependent ankle edema (B) and heartburn (D) are common discomforts.

5. A client who is Rh-negative with a negative antibody screen is at 28 weeks. The nurse anticipates which order?

A. Rh immune globulin IM
B. Rh immune globulin only if the baby is Rh-positive at birth, and not before
C. Rubella vaccine
D. No action; Rh issues affect only a second pregnancy

Answer: A. Antenatal Rh immune globulin around 28 weeks prevents sensitization from small fetal-to-maternal bleeds late in pregnancy. A postpartum dose is also given within 72 h if the newborn is Rh-positive, so B is incomplete. Rubella (live) vaccine is not given during pregnancy (C). Prevention must happen now to protect future pregnancies (D).

References

American College of Obstetricians and Gynecologists. (n.d.). Prenatal care [Patient FAQ]. Retrieved October 15, 2026, from https://www.acog.org/womens-health/faqs/prenatal-care

Centers for Disease Control and Prevention. (2024). Urgent maternal warning signs and symptoms. HEAR HER Campaign. https://www.cdc.gov/hearher/maternal-warning-signs/index.html

Maines, J., & Langaker, M. D. (2025). Prenatal genetic screening. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK557702/

National Council of State Boards of Nursing. (2026). 2026 NCLEX-RN test plan. https://www.nclex.com/test-plans.page

Pascual, Z. N., & Langaker, M. D. (2023). Physiology, pregnancy. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK559304/