What are the essential components and investigations to be ordered during the first obstetrics (OB) visit?

Essential Components of First OB Visit

The first obstetric visit should include a comprehensive panel of laboratory tests, physical examination, risk assessment, and patient education to establish baseline maternal health and detect potential complications early.

History and Risk Assessment

• Complete medical, surgical, and obstetric history including:

  • Previous pregnancies and outcomes
  • Chronic medical conditions
  • Current medications and allergies
  • Family history of genetic disorders
  • Mental health screening for depression and anxiety 1
  • Domestic violence screening 1
  • Substance use assessment (smoking, alcohol, drugs) 1

• Social history:

  • Living situation
  • Support systems
  • Occupation and potential workplace hazards
  • Educational needs

Physical Examination

• Vital signs (blood pressure, heart rate, respiratory rate, temperature)
• Height and weight for BMI calculation
• Complete physical examination including:
  • Cardiovascular and respiratory assessment
  • Thyroid examination
  • Breast examination
  • Abdominal examination
  • Pelvic examination with cervical assessment 1

Laboratory Tests

• Blood tests:

  • Complete blood count (CBC) to assess for anemia 1
  • Blood type and Rh status 1
  • Antibody screen
  • Hepatitis B surface antigen (universal screening regardless of vaccination status) 1
  • HIV screening 1
  • Syphilis screening 1
  • Rubella immunity status 2
  • Thyroid-stimulating hormone (TSH) when indicated 2

• Urine tests:

  • Urinalysis for protein, glucose, and bacteria 1
  • Urine culture to screen for asymptomatic bacteriuria 1

• Cervical screening:

  • Gonorrhea and chlamydia testing 1
  • Pap smear if due according to screening guidelines 1

• Diabetes screening:

  • Random glucose, fasting glucose, or glucose challenge test based on risk factors 1

Ultrasound Assessment

• Dating ultrasound to confirm gestational age
• Assessment of fetal viability
• Evaluation for multiple gestation 2
• Nuchal translucency measurement when appropriate (typically 11-14 weeks) 2

Patient Education and Counseling

• Nutrition counseling:

  • Appropriate weight gain goals 1
  • Balanced diet recommendations
  • Food safety practices 1

• Supplements:

  • Folic acid (0.4 mg daily, or 4-5 mg if obese or diabetic) 1
  • Prenatal vitamins
  • Vitamin D if deficient 1
  • Calcium assessment and supplementation if needed 1

• Lifestyle modifications:

  • Exercise recommendations 1
  • Smoking cessation if applicable 1
  • Alcohol avoidance 1
  • Substance use cessation if applicable 1

• Medication review:

  • Evaluation of current medications for safety during pregnancy 1
  • Adjustment of potentially teratogenic medications 1

Follow-up Planning

• Schedule for subsequent prenatal visits
• Genetic counseling referral if indicated
• Specialist referrals based on risk assessment
• Discussion of prenatal screening options

Common Pitfalls to Avoid

1. Delayed first visit: Encourage patients to seek care as soon as pregnancy is confirmed to allow for early risk assessment and intervention.

2. Incomplete laboratory testing: Ensure all recommended screenings are completed to identify potential complications early.

3. Inadequate psychosocial assessment: Mental health issues and social determinants significantly impact pregnancy outcomes.

4. Missing medication review: Failure to identify potentially harmful medications can lead to preventable complications.

5. Insufficient patient education: Patients need clear information about warning signs, nutrition, and lifestyle modifications.

The first OB visit establishes the foundation for the entire pregnancy care plan. A thorough assessment allows for early identification of risk factors and appropriate interventions to optimize maternal and fetal outcomes 1, 3.