I’ve been asked this question several times.
1. Generally at your first antenatal visit, your midwife will do a risk assessment to decide if you are low or high risk.
2. Doctors start measuring your tummy from 24-28W to assess the growth of your baby.
3. Decline in the babies growth is often associated with fetal Ill health and stillbirth.
4. Low risk women will generally have measurements as a way of assessing the baby’s growth. They will therefore have 2-3 very important scans in their pregnancy. One to date and assess the neck thickness, one to do a detailed assessment for anomalies and sometimes a last one to reassure growth. The rest of the time, the midwife will just measure the tummy.
5. High risk women will primarily need scans to assess the baby’s growth because the baby is at increased risk of poor growth. Examples are women with hypertension, a previous stillbirth etc. If your pregnancy is high risk, you will be offered a dating scan, an anomaly scan and growth scans at 28,31,34,37,40 weeks. That’s every 3-4 weeks.
6. There are women who have no risks but are unsuitable for measuring. These include women with BMI > 35 (Plus size women), those with huge fibroids and those carrying twins. In these women, scans will be the primary tool for measuring growth.
7. Measuring baby’s growth is one of the main reasons for antenatal care since poor growth often precedes stillbirth.
8. Doing many poor quality scans has no benefit. The detailed dating scan, detailed Anomaly scans and detailed growth scans are only offered by trained professionals.
9. A low risk pregnancy may only need 3 good scans. A dating scan, an anomaly scan and a growth scan.
10. Sometimes when you see your doctor, he/she may use the ultrasound machine to check the baby’s heartbeat. This should not be construed to mean he has done a full scan unless he/she specifically says so.
11. A pregnancy may start out as low risk but can become high risk along the way.
12. If in doubt, always talk to a professional midwife or a doctor.