Medically Reviewed by: Dr Ayanthi Gunasekera
So, you're 12 weeks pregnant—how exciting! Did you know that your little one has more than doubled in size over the last few weeks? It’s incredible to think how much change is happening in there. And let’s be honest, your body is doing some pretty amazing things right now!
We had a chat with Consultant Obstetrician and Gynaecologist Dr. Ayanthi Gunasekera to fill you in on everything you need to know about week 12 of your pregnancy. From what to expect during your 12-week scan to all the changes happening as you head into the second trimester, we’ve got you covered!
Your baby at 12 weeks pregnant
Size and growth
"At 12 weeks pregnant, your baby is approximately the size of a plum," says Dr. Ayanthi. "The length from the crown (top of the head) to the rump (bottom) is typically around 5.4cm."
Organ development
"Most major organs are fully formed, and they continue to mature and function," says Dr. Ayanthi. The intestines have moved into place in their abdomen, and the umbilical cord is now fully functional, providing your baby with oxygen and nutrients.
Digestive system
Your baby’s digestive system is starting to practise functioning, and their bone marrow is busy making white blood cells.
Reflexes and movement
"Your unborn baby will have developed the startle reflex, also known as the Moro reflex," says Dr. Ayanthi. They’ll react to sounds by opening and closing their arms and legs. Though you won’t feel it yet, your baby is moving around, and you’ll start feeling those little kicks later in the second trimester.
Exciting milestone – 12-week scan
This week, you’ll likely have your 12-week scan and hear your baby’s heartbeat for the first time!
Your body at 12 weeks pregnant
Uterus and baby bump
As your uterus moves from the bottom of your pelvis to the front of your abdomen, the constant need to pee may subside! Yay! But you might start feeling a bit dizzy as your blood vessels relax and widen due to progesterone, increasing blood flow to your baby.
Dizziness and fainting
Dizziness is a common symptom during pregnancy, particularly in the first trimester, and it can occur around 12 weeks. This can be triggered by hormonal changes, low blood sugar, or overheating.
Dr. Ayanthi recommends, “If you feel dizzy, lie down with your head between your knees, take deep breaths, and keep snacking to help maintain your blood sugar levels.”
Skin, hair & nails
You may start noticing the "pregnancy glow" or changes like darkening of your skin in certain areas. Plus, your hair and nails may grow faster and become stronger due to hormonal changes.
12 weeks pregnant belly
Your pregnancy won't be showing just yet, but that's okay. It’ll push itself above your pelvic bone soon, so expect the first vague outlines of a baby belly. On that note, your jeans, trousers and skirts are probably becoming quite snug, so it might be time to invest in some comfy maternity clothes.
12 weeks pregnant symptoms
Morning sickness
"For many women, morning sickness may begin to decrease or subside by the 12th week," says Dr. Ayanthi. However you may still be experiencing morning sickness at 12 weeks pregnant and if so, keep eating little and often and stay hydrated. Hopefully, it won't be long until this unpleasant symptom eases and you may start to notice a difference by week 13 of pregnancy.
Headaches
Headaches are another very normal symptom of pregnancy, caused by low blood sugar levels. Remember to keep snacking, drink plenty of water and ask your doctor for any pregnancy-safe painkillers should you need.
Breast tenderness
Hormones can cause your breasts to become sore, which often happens before you’re due your period as well. But good news! "Some women find relief from the symptoms experienced in the first trimester," says Dr. Ayanthi.
After week 12 breast tenderness should reduce as hormone levels start to become normal again.
Fatigue
You’re nearing the end of your first trimester, but your body may still be exhausted from growing your baby. That said, "you might experience an increase in energy levels as you enter the second trimester", says Dr. Ayanthi.
If this isn't you, don't fret, just rest up when you can, and get ready for that energy burst that’s expected during trimester two!
Stomach cramps
Cramping is normal during early pregnancy, especially around week 12. A lot of women report feeling sharp pains on one or both sides of their groin as they stand up or twist. This is normal and is caused by the ligaments supporting your womb stretching as it grows.
12 weeks pregnant ultrasound
The 12 week scan is usually pretty exciting, as it will probably be the first time you see your baby. It typically lasts around 15 to 30 minutes, and the sonographer will listen for a heartbeat, check your baby's development and measure them for the first time - which will give everyone a better idea of how old your baby is, and work out your due date. Here's a look at a 12-week pregnancy scan so you can know what to expect.
What to do at 12 weeks pregnant
Announce your pregnancy
If you haven't already, you may be considering sharing the news of your pregnancy with friends, family, and colleagues. Some parents choose to wait until after the first trimester due to a lower risk of miscarriage. There are lots of adorable announcement ideas to choose from.
Keep an eye on your health
Focus on continuing to maintain a healthy and balanced diet. Ensure you are getting essential nutrients, including folic acid, iron, and calcium. You should continue to take your pregnancy vitamins.
Gender guessing
At this time, it's usually too early to work out whether you're having a boy or a girl, so you'll have to wait until your 20-week scan to find out the gender of your baby. That said, some people believe in nub theory, which is where you determine the sex from the first ultrasound photo or there's even the Chinese gender predictor.
Start those pelvic floor exercises
Pelvic floor exercises are so important (trust us!) Squeeze for up to 10 seconds, for 10 times and 10 quick squeezes, for 10 times. Not only can these muscles help during childbirth but they also reduce your chances of bladder issues and can help with postpartum symptoms. There are several pregnancy apps for fitness that you can download to help you.
Keep an eye out out
If you have painful cramps, bleeding or are feeling particularly lonely or sad, call the midwife or your doctor if you're having any concerns.
12 weeks pregnant: Facts and FAQs
Should I have a baby bump at 12 weeks?
At 12 weeks, your bump might be just starting to show, or it might still be hiding. Every pregnancy is different, so don’t worry if you’re not quite there yet. Your body’s still adjusting and it’ll pop when it’s ready!
Can you feel your baby at 12 weeks?
At this stage, it’s still too early to feel the baby move. But hang tight—by week 16-20, those little flutters will become noticeable!
How do I know my baby is safe at 12 weeks?
You’ll likely be offered your first dating scan soon. This is a huge milestone as you’ll get to see your little one and check on their growth. Many women feel more confident telling their employer after the 12-week scan, once the risk of miscarriage reduces.
What are some fun facts about babies at 12 weeks?
Your baby may be tiny, but they're now fully formed! About the size of a plum, they’ve got all their major features, and the placenta is fully formed, too, although it’ll keep growing throughout your pregnancy. So exciting!
About the expert
Consultant Obstetrician and Gynaecologist Ms Ayanthi Gunasekera is the Medical information lead at London Gynaecology
About the author
A journalist since 2015, Emily Gilbert is the Features & Reviews Editor for Mother&Baby and has written for the website and previously the magazine for seven years. Emily writes about everything from the top baby products to pregnancy, fertility and maternal mental health. Specialising in product reviews, Emily is the first to know about all the exciting new releases in the parenting industry.