Pregnancy and Birth Risk Factors · 5 min read
Antenatal Factors and Maternal Health Status
Every mother-baby admission begins with the prenatal and birth record. The nurse reviews maternal history, laboratory results, medications, and labor events, then translates each finding into a postpartum risk (hemorrhage, infection, hypertension, VTE, mood disorder) and a newborn risk (hypoglycemia, sepsis, jaundice, withdrawal, birth injury).
Obstetric History: GTPAL
| Letter | Meaning | Counting rule |
|---|---|---|
| G (gravida) | Total number of pregnancies, including the current one | Twins count as one pregnancy |
| T (term) | Births at 37 0/7 weeks or later | Counted per pregnancy, not per infant |
| P (preterm) | Births from 20 0/7 through 36 6/7 weeks | Counted per pregnancy |
| A (abortions) | Pregnancy losses before 20 weeks, spontaneous or induced | Includes ectopic pregnancy |
| L (living) | Number of currently living children | Each twin counts separately |
Example: a patient who gave birth to twins at 35 weeks, later had one term birth, and has no losses is G2 T1 P1 A0 L3. Prior obstetric events predict recurrence: previous PPH, shoulder dystocia, preeclampsia, preterm birth, or a prior infant with GBS disease (which mandates intrapartum GBS prophylaxis regardless of current culture). A prior cesarean raises the risk of placenta previa, placenta accreta spectrum, and uterine rupture.
Maternal Age, Health Status, and Psychosocial Factors
| Group | Maternal risks | Newborn implications |
|---|---|---|
| Adolescent | Late prenatal care, anemia, preeclampsia, STIs, inadequate nutrition, IPV, interrupted education | Preterm birth, low birth weight; assess support system and readiness for infant care |
| Advanced maternal age (35 or older at delivery) | GDM, hypertensive disorders, previa, cesarean, PPH, stillbirth | Higher aneuploidy risk (trisomy 21); review prenatal screening and newborn exam for dysmorphic features |
- Prenatal genetic screening and diagnostic testing are offered to all pregnant patients regardless of age; age alone no longer defines who is offered testing.
- Preexisting conditions (diabetes, chronic hypertension, thyroid disease, seizure disorders, lupus, cardiac disease, mental health disorders) carry forward into the postpartum period and often require medication changes after birth.
- Psychosocial screening at intake and again postpartum: depression and anxiety, intimate partner violence (screen privately, without the partner present), substance use, housing and food insecurity, transportation, and social support. Positive screens trigger referral, not judgment.
- Cultural and religious considerations: use a qualified medical interpreter (never a family member or child for clinical teaching); ask about dietary customs, postpartum rest practices, modesty, and infant care traditions; plan in advance for a patient who declines blood products (for example, cell salvage, early uterotonics, and documented informed refusal).
Nutrition, Weight, and Bariatric Surgery
| Prepregnancy BMI (kg/m²) | Category | Total gain |
|---|---|---|
| Below 18.5 | Underweight | 28–40 lb |
| 18.5–24.9 | Normal weight | 25–35 lb |
| 25.0–29.9 | Overweight | 15–25 lb |
| 30 or higher | Obese | 11–20 lb |
- Additional energy need is about 340 kcal/day in the second trimester and about 450 kcal/day in the third; none in the first.
- Folic acid 400 mcg daily starting at least 1 month before conception prevents neural tube defects; 4 mg daily after a prior NTD-affected pregnancy. Iron need rises to 27 mg/day. Limit caffeine to under 200 mg/day; avoid high-mercury fish, unpasteurized dairy, and undercooked meat (Listeria, Toxoplasma).
- Obesity (BMI 30 or higher): GDM, preeclampsia, cesarean, wound infection, VTE, PPH, and delayed lactogenesis II. Newborn: macrosomia, birth injury, hypoglycemia, NTDs, stillbirth. Postpartum: early lactation support, wound checks, VTE prophylaxis, appropriately sized equipment.
- Bariatric surgery: pregnancy is usually deferred 12–24 months after surgery. Watch for deficiencies of iron, vitamin B₁₂, folate, vitamin D, and calcium. After gastric bypass, an oral glucose load can cause dumping syndrome, so GDM is screened with home glucose monitoring instead. Newborn: higher risk of SGA; maternal B₁₂ deficiency can affect a breastfed infant.
Infertility and Assisted Reproductive Technology
Pregnancies conceived with ART (ovulation induction, IVF) have higher rates of multiple gestation, preterm birth, low birth weight, preeclampsia, GDM, placenta previa and accreta spectrum, and cesarean birth, with a small increase in some congenital anomalies. Parents may have heightened anxiety and grief from prior losses; recognize this "precious pregnancy" dynamic, support bonding, and screen for postpartum mood disorders. Donor gametes or a gestational carrier raise legal and family-role questions addressed in Chapter 10.
Physiologic Changes of Pregnancy and Laboratory Values
| System or value | Change in pregnancy | Postpartum and exam relevance |
|---|---|---|
| Blood volume | Increases 40–50% (plasma more than red cells) | Allows tolerance of birth blood loss; signs of hemorrhage appear late |
| Hemoglobin / hematocrit | Dilutional (physiologic) anemia; anemia = Hgb below 11 g/dL (1st and 3rd trimesters) or below 10.5 g/dL (2nd) | Low predelivery Hgb reduces reserve for PPH |
| WBC | 5,000–15,000/µL; may reach 25,000/µL in labor and early postpartum | Leukocytosis alone does not prove infection |
| Platelets | Normal or mildly decreased (gestational thrombocytopenia) | Below 100,000/µL with hypertension suggests preeclampsia with severe features or HELLP |
| Fibrinogen and clotting factors | Fibrinogen rises (about 300–600 mg/dL); factors VII, VIII, X increase | Hypercoagulable state persists about 6 weeks: VTE risk. Low fibrinogen in hemorrhage signals DIC |
| Cardiac output / heart rate / BP | Cardiac output up 30–50%; HR up 10–20 beats/min; BP falls in the 2nd trimester, returns toward baseline by term | Supine hypotension from aortocaval compression: use lateral tilt |
| Respiratory | Tidal volume increases; PaCO₂ about 28–32 mm Hg (compensated respiratory alkalosis) | Lower buffering reserve; rapid desaturation with apnea |
| Renal | GFR up about 50%; creatinine and BUN fall (creatinine about 0.4–0.8 mg/dL) | A "normal" nonpregnant creatinine (1.0) may signal renal impairment |
| Hepatic | Alkaline phosphatase rises (placental); albumin falls; AST/ALT unchanged | Elevated transaminases are abnormal: think HELLP or acute fatty liver |
| Endocrine | Insulin resistance rises in the 2nd–3rd trimesters (hPL, cortisol); TSH slightly lower in the 1st trimester | Insulin needs fall sharply after placental delivery |
- GTPAL: twins count once for G and for T or P, but twice for L.
- Hypercoagulability and elevated WBC are normal in pregnancy and the early postpartum period.
- Transaminases do not rise in normal pregnancy; elevation suggests HELLP.
- Obesity delays lactogenesis II and raises PPH, wound infection, and VTE risk.
- After gastric bypass, avoid an oral glucose load for GDM screening (dumping syndrome).
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