Your baby at 21 weeks
Your baby is moving a lot and starting to have sleeping and waking patterns.
Hair and eyebrows are growing, and your baby can hear noises and voices outside the womb.
Your body at 21 weeks
You may feel unsteady as your centre of gravity shifts and your joints loosen.
Backache, piles, leg cramps and heartburn are all common.
Babies are often most active just as you lie down. It's not personal.
Your to-do list at 21 weeks
- Tell your midwife as soon as possible if you have a fall.
- Speak to your midwife or GP if you haven't had your whooping cough vaccine.
When to call your midwife
Contact your midwife or maternity unit straight away if you have bleeding, fluid leaking, severe tummy pain, a bad headache with vision problems or swelling, or, once you're feeling them, your baby's movements slow down or stop.
How big is my baby at 21 weeks pregnant?
At 21 weeks, your baby is about 26.7cm from head to heel.
How many months is 21 weeks pregnant?
21 weeks pregnant is around 5 months, in the second trimester.
What should I do at 21 weeks pregnant?
Tell your midwife as soon as possible if you have a fall.
Keep reading
- Pregnancy week by week: the complete guide
- Due date calculator: when is my baby due?
- Your rights when you're pregnant in the UK: the 2026 guide
- The baby name games every couple ends up playing
This guide is general information based on NHS week-by-week guidance, not medical advice. Every pregnancy is different, and baby sizes are averages. If you're worried about anything, contact your midwife, GP or maternity unit. See the NHS week-by-week guide.
If you’re trying to conceive (TTC), you probably know that there are certain foods and nutrients that become especially important once you’re pregnant. But nutrition plays a vital role even when trying to conceive, much like laying a strong foundation before constructing a house.
Certain nutrients create that foundation by supporting egg and sperm health (yes, nutrition matters for both partners), hormone balance and creating a hospitable environment for a fertilized egg to implant. In fact, studies show that certain nutrients can help increase fertility and improve success rates for both natural conception and fertility treatments.
In other words, nutrition is a key player in the TTC journey, but getting the right nutrients in the right quantities can be tricky. That’s where supplements come in. Just as you’d take a multivitamin to fill in nutritional gaps for optimal health, fertility supplements can give you that extra nutrient boost.
Choosing supplements for your fertility journey
When choosing a supplement to support your fertility journey, look for science-backed, high-quality ingredients. Our editors are careful to select and partner with brands that use ingredients that have been clinically studied to support fertility. Eu Natural® (pronounced you) covers all those bases and more. We love knowing that Eu Natural® products contain zero artificial additives, binders, or fillers and are lab-tested to ensure purity and potency.
When choosing a supplement to support your fertility journey, look for science-backed, high-quality ingredients. Our editors are careful to select and partner with brands that use ingredients that have been clinically studied to support fertility. Eu Natural® (pronounced you) covers all those bases and more. We love knowing that Eu Natural® products contain zero artificial additives, binders, or fillers and are lab-tested to ensure purity and potency.
.jpeg)
