What is the management for an 18-year-old pregnant patient at 20 weeks gestation?

Management of 18-Year-Old at 20 Weeks Gestation

For an 18-year-old patient at 20 weeks gestation, management should include regular prenatal visits with appropriate screening for pre-eclampsia risk factors, blood pressure monitoring, and assessment for signs of complications at each visit. 1

Risk Assessment for Pre-eclampsia

First, assess for pre-eclampsia risk factors:

• First pregnancy (nulliparity increases risk 2.91 times) 1
• Age (though 18 is not a high-risk age; ≥40 years increases risk)
• Body mass index (≥35 increases risk)
• Family history of pre-eclampsia (mother or sister increases risk 2.90 times)
• Booking diastolic blood pressure (≥80 mm Hg increases risk)
• Proteinuria at booking
• Multiple pregnancy (increases risk 2.93 times)
• Pre-existing medical conditions

Referral Criteria

Refer for specialist input before 20 weeks if any of these are present:

• Previous pre-eclampsia
• Multiple pregnancy
• Pre-existing hypertension or booking diastolic BP ≥90 mm Hg
• Pre-existing renal disease or booking proteinuria
• Pre-existing diabetes
• Presence of antiphospholipid antibodies
• Any two other pre-eclampsia risk factors 1

Visit Schedule

Based on risk assessment:

1. If no risk factors present (Level 1):

   • Follow standard prenatal care schedule for low-risk patients
   • NICE recommends assessments at weeks 16,28,34,36,38,40, and 41 1

2. If one risk factor present (Level 2):

   • More frequent monitoring:
   • From 20-32 weeks: visits at least every 3 weeks
   • From 32 weeks to delivery: visits at least every 2 weeks 1

3. If multiple risk factors or medical conditions:

   • Follow specialist recommendations for more intensive monitoring

Research supports that reduced-visit models (8-9 visits) can be effective and safe when enhanced with appropriate monitoring, showing higher patient satisfaction and lower prenatal stress compared to traditional 12-14 visit schedules 2, 3.

Content of Each Visit After 20 Weeks

At every assessment, evaluate for:

1. Blood pressure measurement:

   • Critical to measure accurately as errors have been implicated in maternal deaths
   • Monitor for new hypertension (diastolic ≥90 mm Hg)
   • BP patterns after 20 weeks are important - normally BP should have decreased until 20 weeks and then begins a gradual increase 4

2. Urine testing:

   • Check for new proteinuria (≥+ on dipstick)

3. Symptom assessment:

   • Headache or visual disturbance
   • Epigastric pain or vomiting
   • Reduced fetal movements

4. Fetal growth assessment:

   • Monitor for small for gestational age 1

5. Nutritional supplementation:

   • Continue folic acid supplementation (but not exceeding 0.4 mg daily unless specifically indicated) 5

Action Plan Based on Findings

For new hypertension without proteinuria:

• Diastolic 90-99 mm Hg: Refer for hospital assessment within 48 hours
• Diastolic 90-99 mm Hg with symptoms: Same-day hospital assessment
• Systolic ≥160 mm Hg: Same-day hospital assessment
• Diastolic ≥100 mm Hg: Same-day hospital assessment 1

For new hypertension with proteinuria:

• Diastolic ≥90 mm Hg and new proteinuria ≥+: Same-day hospital assessment
• Diastolic ≥110 mm Hg and new proteinuria ≥+: Immediate admission
• Systolic ≥170 mm Hg and new proteinuria ≥+: Immediate admission
• Diastolic ≥90 mm Hg, new proteinuria ≥+ and symptoms: Immediate admission 1

For new proteinuria without hypertension:

• • on dipstick: Repeat assessment within one week
• ≥++ on dipstick: Hospital assessment within 48 hours
• ≥+ with symptoms: Same-day hospital assessment 1

Patient Education

Educate the patient that:

• Pre-eclampsia can develop between antenatal visits
• She should be aware of warning symptoms (headache, visual changes, epigastric pain)
• She should know how to contact healthcare providers at all times 1

Important Considerations

• Recent research shows that even elevated BP (120-129/< 80 mm Hg) or stage 1 hypertension (130-139/80-89 mm Hg) after 20 weeks is associated with increased risk of hypertensive disorders of pregnancy, fetal growth restriction, and placental abruption 6
• For patients presenting late to care, ultrasound measurement combining head circumference and femur length can provide reasonable gestational age estimation in the second trimester 7
• Ensure accurate dating of the pregnancy to properly time assessments and interventions

By following this structured approach to prenatal care for an 18-year-old at 20 weeks gestation, you can optimize maternal and fetal outcomes while efficiently using healthcare resources.