16 weeks pregnant: Pregnancy Symptoms & Baby Development

Pregnant woman feeling sick

Explore pregnancy stages week by week

quick explanation

Read Aptaclub's guide to being 16 weeks pregnant. Learn what your baby can do at this stage and your cravings




reading time



16 weeks pregnant is how many months?

Month 6 (Trimester 2)


Baby development at 16 weeks

Your baby’s moving around more and you may feel light flutters in your belly.. 


What’s happening in your body?

By week 16, you may have a visible pregnancy bump.


Vitamin D

Why you and your baby need plenty of Vitamin D.

Baby development at 16 weeks

Expectant mother feeling bump

How big is my baby? And what does my baby look like?

Your baby is now the size of an avocado, and around 11.6cm in length. He or she will weigh around 100g1. The circulatory system is now starting to run, and can pump over 28 litres of blood a day.

Around now, your baby may start flexing their arms and fingers. Their hands may even be able to meet, form a fist, and hold each other2. As your baby’s nervous system continues to develop, their range of movements will also progress2.

Your baby may also be able to recognise your voice. Studies have shown that babies who hear a song while in the womb react to the same song when it’s sung after they’re born. Choose your lullabies wisely3.

While they’re beginning to make facial expressions, they can’t control them yet2. More importantly, your baby is gearing up for a tremendous growth spurt, more than doubling in weight over the next few weeks4.

Pregnancy at 16 weeks (second trimester)

Body changes

You may not be able to hide your pregnancy any more. That said, baby bumps at 16 weeks are different. Some women may not be showing much at all, while others have visible bumps. Everyone’s different, so don’t worry or waste time comparing your belly to anyone else’s.

The extra hormones in your body are also increasing blood flow to your mucus membranes, so you may feel more congested. Don’t be surprised if you experience the occasional nosebleed due to this, too. Saline sprays and nasal strips are safe to help you ease congestion3.

Hormones can also cause your veins to stretch. Together with increased blood flow, varicose veins may appear. Don’t worry too much - they shrink after you give birth5.

Even if your back is aching from carrying a growing baby, after week 16 only lie or exercise on your back for short periods of time as it can cause low blood pressure and dizziness6.

Pregnancy symptoms at 16 weeks

By now most mums-to-be are free of the unpleasant pregnancy symptoms of their first trimester. However, there are still uncomfortable symptoms that you can experience at 16 weeks, including:

  • Continued breast growth and sensitivity
  • Constipation Increased vaginal discharge
  • Bleeding gums
  • Varicose veins
  • Back ache

Focus on Vitamin D

Pregnant women have an increased risk of vitamin D deficiency and need to pay special attention to getting adequate levels7. Taking a daily supplement protects your own health, as well as your baby’s.

If you have dark skin, your increased pigment affects your skin’s ability to generate vitamin D, making a daily supplement even more important. Women of South Asian, African, Caribbean and Middle Eastern descent who live in the UK are particularly at risk7.

Sunlight creates vitamin D naturally, although take great care not to over-expose yourself to the sun. Between October and April, the body uses reserves left over from summer8.

A few foods provide vitamin D, but these are limited. Oily fish, egg yolks and fortified foods are among the few dietary sources. In the UK many people find it difficult to get significant amounts from food alone8.

Because of this, it’s recommended that all pregnant and breastfeeding women take a vitamin D supplement of 10mcg per day. This amount will provide enough for your own needs and help to build the stores your baby needs for the first 6 months of life8.

The science behind Vitamin D, powered by Nutricia

Your baby is hungry for vitamin D as it’s essential to help bone development by regulating calcium and phosphate in the body7. A lack of vitamin D can lead to conditions like rickets in children, and osteomalacia (bone pain) in adults7. The good news is that, from early spring to the end of September, you should be able to get plenty of vitamin D from sunlight.

How much weight should I gain during pregnancy?

Weight gain during pregnancy depends on your pre-pregnancy weight, and varies a great deal from mother to mother. Most women gain between 10kg and 12.5kg (22–28lb) while pregnant, some of which is the weight of the growing baby9. Learn everything you need to know about weight gain in pregnancy.

Your baby's future health begins here

At Aptaclub, we believe that experience helps to build resilience; and that each new encounter, whether in pregnancy or after birth, can shape your baby’s future development. With our scientific expertise and one-to-one round the clock support, we can help you and your baby embrace tomorrow.

mom and baby

Get in touch with our Careline experts

Our nutritionists and feeding advisors are always on hand to talk about feeding your baby. So if you have a question, just get in touch

  1. NHS Start 4 Life. 2nd trimester, week 16. [Online]. Available at: https://www.nhs.uk/start4life/pregnancy/week-by-week/2nd-trimester/week-16/#anchor-tabs [Accessed October 2019].
  2. NHS. You and your baby at 13-16 weeks pregnant [Online]. Available at: www.nhs.uk/conditions/pregnancy-and-baby/pages/pregnancy-weeks-13-14-15-16.aspx Page last reviewed: 17 July 2018. Next review due: 17 July 2021.
  3. What to expect. 16 Weeks Pregnant [Online]. Available at: https://www.whattoexpect.com/pregnancy/week-by-week/week-16.aspx Reviewed October 2019.
  4. Baby Centre. 16 weeks pregnant: fetal development. Available at: https://www.babycentre.co.uk/16-weeks-pregnant Last reviewed: November 2016.
  5. What to expect. Varicose Veins During Pregnancy [Online] Available at: https://www.whattoexpect.com/pregnancy/symptoms-and-solutions/varicose-veins.aspx Reviewed January 2018.
  6. Tommy’s. 16 weeks pregnant - all you need to know [Online]. Available at: https://www.tommys.org/pregnancy-week-by-week/16-weeks-pregnant-whats-happening Last reviewed: June 25th, 2018. Next review: June 25th, 2021.
  7. NHS. Vitamin D [Online]. Available at: https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/ Reviewed March 2017. Page last reviewed: 3 March 2017. Next review due: 3 March 2020.
  8. NHS. How to get vitamin D from sunlight [Online]. Available at: www.nhs.uk/Livewell/Summerhealth/Pages/vitamin-D-sunlight.aspx Page last reviewed: 31 August 2018. Next review due: 31 August 2021.
  9. NHS choices. How much weight will I put on during my pregnancy? [Online]. Available at: https://www.nhs.uk/chq/Pages/2311.aspx?CategoryID=54 Page last reviewed: 18 October 2018. Next review due: 18 October 2021.

Last reviewed: 04th December 2019
Reviewed by Nutricia’s Medical and Scientific Affairs Team

Share this article