No relevant finding
Planned follow-up continues, while recognising ultrasound limitations.
Around 20 weeks
The anomaly scan: a systematic review of fetal anatomy
This is one of the main examinations in pregnancy. It reviews fetal structures systematically, but cannot rule out every anomaly or predict all later development.
- Obstetric consultation
- Advanced ultrasound
- Laboratory and screening
- Late-pregnancy monitoring
- Nutrition
Complementary follow-upAskabide + Osakidetza · birth at the reference hospital
Areas that may be reviewed
- Head and intracranial structures.
- Face and profile when position permits.
- Spine.
- Chest, heart and great vessels according to protocol.
- Abdomen, abdominal wall, stomach, kidneys and bladder.
- Limbs.
- Placenta, cord, amniotic fluid and biometry.
- Cervix or other parameters when indicated.
Image quality depends on several factors
Fetal position, movement, gestational age, maternal tissue and other conditions influence visualisation. If a structure cannot be assessed adequately, completion at another time may be recommended.
Poor visualisation is not the same as detecting an anomaly.
Possible outcomes
Incomplete examination
A review is arranged for structures not adequately seen.
Finding requiring further assessment
The result is explained and additional study or hospital referral is organised.
After the anomaly scan
Follow-up continues with maternal checks, blood tests, gestational diabetes screening and later growth/third-trimester assessment according to the individual plan.
Second trimester
See the other checks in this stage.
Open information
Third trimester
How follow-up changes towards the end.
Open informationClinical sources
General information only. It does not replace an individual medical assessment or recommendation.
Reviewed 19 August 2026