How it's calculated
The WHO 2016 antenatal care model recommends a minimum of 8 contacts across pregnancy, timed at fixed gestational weeks from the last menstrual period. Each contact date is calculated as LMP + (gestational week × 7 days); the estimated due date (EDD) is LMP + 280 days.
The 8 ANC contacts
| Contact | Gestational age | Focus |
|---|---|---|
| 1 | Up to 12 weeks | Booking visit — history, exam, blood group & Rh, Hb, urine, infection screen, dating scan |
| 2 | 20 weeks | Anomaly scan window; fetal growth, BP, urine protein |
| 3 | 26 weeks | BP, urine protein, fundal height, fetal movements |
| 4 | 30 weeks | BP, urine protein, fundal height, repeat labs as indicated |
| 5 | 34 weeks | BP, urine protein, fundal height, fetal presentation |
| 6 | 36 weeks | BP, urine protein, fundal height, fetal presentation, birth planning |
| 7 | 38 weeks | BP, urine protein, fundal height, fetal presentation |
| 8 | 40 weeks | BP, urine protein, fetal wellbeing; discuss post-term management if undelivered |
Clinical use
- The WHO 2016 model increased the previously recommended minimum of 4 visits to 8 contacts, after evidence linked more frequent contact with reduced perinatal mortality and improved maternal experience of care.
- This schedule is a baseline for low-risk pregnancies. High-risk pregnancies — hypertensive disorders, diabetes, multiple gestation, prior adverse outcomes — need additional visits beyond this schedule per local protocol.
- Dates are calculated from LMP assuming a standard 280-day (40-week) gestation; adjust against an early dating scan if LMP dating and scan dating disagree significantly.
Frequently asked questions
Why did WHO increase ANC visits from 4 to 8?
The 2016 WHO ANC model was based on evidence that more frequent contact with a healthcare provider during pregnancy is associated with fewer perinatal deaths and a better overall experience of care for the mother, compared with the previously recommended 4-visit "focused" model.
What if the actual due date differs from LMP-based dating?
An early first-trimester ultrasound is generally the most accurate method for dating a pregnancy. If it differs significantly from LMP-based dating, gestational age and the visit schedule should be re-based on the scan rather than the LMP.
Do high-risk pregnancies follow this same schedule?
No — this is a minimum baseline for low-risk pregnancies. Conditions such as hypertensive disorders, gestational diabetes, multiple gestation, or a prior adverse obstetric outcome typically require more frequent visits, per local protocol.
References
- World Health Organization. WHO recommendations on antenatal care for a positive pregnancy experience. Geneva: WHO; 2016.