Week 20 of Pregnancy: A Banana, Halfway There, and the Anomaly Scan
Key takeaways
- Week 20 is the halfway point of pregnancy, and the baby is now around 25.6cm long, roughly the size of a banana.
- This is typically when the anomaly scan happens, checking the baby's development, placenta, and blood flow in detail.
- The scan screens for 11 specific conditions, and also checks the placenta and uterine blood flow.
- Finding out the baby's sex is optional at this scan — you'll usually be asked if you want to know, not told automatically.
- It's common for this scan to show noticeably more detail than any earlier one, since the baby is so much bigger now.
Week 19 was quiet. Week 20 was not — this is the halfway mark of the whole pregnancy, and for us, it was also the week we found out we were having a daughter.
What’s actually happening in your body
The baby is now around 25.6cm long — measured head to heel from this point on rather than head to bottom — roughly the size of a banana. This week typically brings the anomaly scan, a detailed ultrasound that checks the baby’s development against 11 specific conditions, along with the placenta and blood flow in the uterus, according to NHS guidance on the 20-week scan. Finding out the baby’s sex isn’t part of the standard health checks — you’ll typically be asked at the start of the scan whether you’d like to know, rather than being told automatically, and it isn’t always possible to tell for certain depending on the baby’s position.
What I actually felt
The scan happened for us exactly during this week. We opted to find out the sex, and it was a girl — we were genuinely very happy in that moment. What struck me most was how much more we could actually make out this time compared to the earlier scan: we could identify individual body parts clearly, in a way that felt completely different from the vaguer shapes we’d seen before. It made the halfway point feel real in a way that just crossing a number on a calendar hadn’t.
If your scan lands at a different week, that’s normal too — anomaly scans are usually offered somewhere between 18 and 21 weeks, not always exactly at 20.
Nutrition focus this week
No changes from earlier weeks. Keep up with your prenatal vitamin and the general guidance in our foods and drinks to limit or avoid during pregnancy.
What to discuss with your doctor or midwife
If you haven’t had your anomaly scan yet, confirm when it’s scheduled. It’s also worth deciding in advance, as a couple, whether you want to know the baby’s sex — the sonographer will usually ask early in the appointment, so it helps to have already talked it through rather than deciding on the spot.
Frequently asked questions
What exactly does the anomaly scan check?
It screens for 11 specific conditions, including things like cleft lip, spina bifida, and certain heart or skeletal conditions, and also examines the placenta and blood flow in the uterus.
Can I always find out my baby’s sex at this scan?
Usually, but not always. It depends on the baby’s position during the scan and, in some cases, on hospital policy. The sonographer can’t be 100% certain either way.
Why does this scan often feel more detailed than earlier ones?
By week 20, the baby is significantly bigger and more developed than at the dating scan, so individual features and body parts are much easier to make out clearly.
Is week 20 really the halfway point?
Yes, based on a standard 40-week pregnancy, week 20 marks the midpoint, even though your baby is measured to have grown to about the size of a banana by now.
What if my anomaly scan isn’t at exactly week 20?
That’s completely normal — it’s typically offered somewhere between weeks 18 and 21, and timing depends on your provider’s scheduling.
References
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