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    16 weeks pregnant: Your guide to this week of your second trimester

    Updated 11 July 2023 |
    Published 24 February 2019
    Fact Checked
    Medically reviewed by Dr. Angela Jones, Obstetrician and gynecologist, attending physician, Jersey Shore University Medical Center, New Jersey, US
    Written by Kate Hollowood
    Edited by Sarah Biddlecombe
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    From appetite changes to constipation, here’s the lowdown on being 16 weeks pregnant.

    At 16 weeks, you’re officially four months pregnant and probably paying close attention to all the changes that are happening in your body. It’s an exciting time for you and your baby, who is now looking more and more like a mini human. 

    You may also be wondering what symptoms you should be looking out for at 16 weeks pregnant, and how your pregnancy hormones might be affecting you. From an increased appetite to feeling your baby move for the first time, here’s what you might experience this week, plus advice on navigating the changes from a Flo expert. 

    Your baby at 16 weeks pregnant

    Gaining facial expressions

    At 16 weeks, your baby is gaining facial expressions and pulling mini smiles and frowns at random. It’ll be a while before they can control their expressions, but by 37 weeks, they’ll be practicing smiling and frowning

    Developing a functioning nervous system

    As well as making random facial expressions, this week your baby will be able to start moving their arms and legs as their nervous system develops. Their tiny hands may even be able to form little fists and start punching around inside your belly. A critical system, the nervous system will be fully formed by 33 weeks and will affect everything from movement to memory. 

    How big is a baby at 16 weeks?

    Length (crown to heel): 18.6 cm or 7.3 in.

    Weight: 146 g or 5.2 oz. 

    Size: Equivalent to an avocado

    All measurements are approximate and vary within the normal range.

    Your body at 16 weeks pregnant

    Appetite changes

    Pickles and ice cream, anyone? You might notice those strange food cravings from the first trimester getting even stronger right around now. You may also find yourself feeling hungrier than usual, which could be due to your placenta producing extra amounts of a hormone called ghrelin. Known as the “hunger hormone,” ghrelin stimulates your hypothalamus (the area of the brain that controls hunger), increasing appetite. Not everyone will notice these symptoms, however, so don’t worry if your appetite feels the same as usual. 

    While you don’t need to eat for two, the average pregnant person does need up to 340 extra calories per day in the second trimester. This is the equivalent of one to two healthy snacks. Healthy snacks for pregnancy include hummus and pita bread, a small bowl of unsweetened breakfast cereal, and low-fat, lower-sugar yogurt. To find out more about the best foods to eat, read our guide to a healthy pregnancy diet


    Constipation is another common pregnancy symptom that you might experience at this stage. In fact, 16% to 39% of women experience constipation at some point in their pregnancy, thanks to all those hormonal changes. While it’s not dangerous for you or your baby, constipation can be very uncomfortable and annoying.

    “Constipation during pregnancy is likely related to increased progesterone levels, which lead to decreased bowel motility,” explains Dr. Jenna Beckham, obstetrician and gynecologist, WakeMed, North Carolina, US. “Constipation may also result from decreased physical activity, diets low in fiber, decreased water consumption, or taking iron supplements.” 

    And what can you do to try to get things moving again? “Pregnant people who experience constipation should increase dietary fiber and fluid intake and can use stool softeners or laxatives,” adds Dr. Beckham. Just remember to check with your health care provider before taking any new medication during pregnancy. 

    Your questions answered

    Can you feel the baby at 16 weeks?

    Excitingly, this week could mark an important milestone: the first time you feel your baby move! Sometimes called “quickening,” women tend to first feel these movements between 16 and 20 weeks of pregnancy. And what can you expect from these precious first movements? Well, they can feel like tiny pulses, fluttering, or bubbles in your tummy, and you’ll soon learn to recognize them. 

    It’s also worth noting that it’s normal to experience quickening for the first time a bit later, at around 20 to 24 weeks pregnant. This is especially true if this is your first baby. So if you haven’t felt anything yet, don’t panic. It’s still early days, and you’ve got that all to look forward to in the coming weeks and months. 

    What should I be feeling at 16 weeks pregnant?

    Good news: Second trimester symptoms can come with a sense of well-being, which is why it’s sometimes described as the “honeymoon period” of pregnancy. At 16 weeks pregnant, you may no longer be getting severe nausea or feeling quite as tired as you did in the first trimester. Phew!

    With a new wave of energy, you might feel like adding more activity into your daily routine. This is a great instinct. Staying fit can help you adjust to your changing body shape and cope better with labor in a few months’ time. 

    However, it’s important not to exhaust yourself. To give you an idea of what overdoing it feels like, you should be able to hold a conversation as you exercise when pregnant. 

    And, particularly from 16 weeks onward, it’s best to avoid any activities that involve lying flat on your back for long periods. This is because the weight of your pregnant belly can press on a main blood vessel to your heart and make you feel faint. Check with your doctor if you’re not sure about taking up a particular activity or sport. 

    At 16 weeks pregnant, it’s also perfectly normal to be getting the same symptoms you had in the earlier weeks, from nausea and mood swings to strange food cravings. So don’t worry if you’re not experiencing the “glowing” pregnancy stereotype just yet. It doesn’t mean that anything is wrong or that you won’t start to feel better in a few weeks’ time. Noting your symptoms in an app like Flo can be a comforting and useful way to track your progress. 

    Where is your baby located at 16 weeks?

    This can actually vary from woman to woman. At 12 weeks pregnant, the uterus tends to be located low in the pelvis. By 20 weeks, the top of your uterus tends to reach the belly button. “In most patients, at 16 weeks pregnant the fetus is still below the belly button,” says Dr. Beckham. 

    This means that you’re unlikely to feel your baby’s movements much higher than the belly button until you’re more than 20 weeks pregnant. However, “each person experiences the feeling very differently,” adds Dr. Beckham. 

    The size of your baby bump is individual too, with no two pregnant bellies looking quite the same. That’s why it’s really important not to compare yourself to others too much and know that your baby is growing at their own sweet pace. 

    Want to know more?

    Download the Flo app for tailored insights throughout your pregnancy

    16 weeks pregnant checklist

    Eat B1-rich foods

    Vitamin B1, or thiamine, helps to turn food into energy and keeps your nervous system healthy. Your body needs more vitamin B1 in pregnancy to support your growing baby, but you should be able to get all the B1 you need through your diet without having to take supplements. Examples of B1-rich foods include:

    • Pork 
    • Fish 
    • Whole grains 
    • Beans and lentils
    • Green peas
    • Sunflower seeds
    • Yogurt 

    When to consult a doctor at 16 weeks pregnant

    Throughout your second trimester, you may have prenatal appointments every four weeks. However, this will depend on where you live and what you and your doctor decide is right for you and your baby. These checkups will give you a chance to ask any questions you have, as well as make sure your vitals are on track, like your blood pressure and weight

    Remember that you don’t need to wait until your appointment if you have any concerns or questions about your pregnancy. However, at 16 weeks pregnant, you should contact your doctor immediately if you experience: 

    This isn’t an exhaustive list and just an example of some of the changes you should look out for. Some of these can be a sign of miscarriage or other health complications, so it’s essential that you speak to your doctor about the best next step for you. And if you’re ever worried about any other symptoms you experience during pregnancy, then don’t hesitate to reach out to your health care provider. 

    16 weeks pregnant: The takeaway

    With your second trimester well under way, you may have fewer of those pesky early pregnancy symptoms and a new spring in your step. But don’t worry if you’re still not feeling great, or if you haven’t reached other milestones like feeling your baby move yet. Remember, every pregnancy is different, and yours will unfold in its own unique way. 


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    History of updates

    Current version (11 July 2023)

    Medically reviewed by Dr. Angela Jones, Obstetrician and gynecologist, attending physician, Jersey Shore University Medical Center, New Jersey, US
    Written by Kate Hollowood
    Edited by Sarah Biddlecombe

    Published (24 February 2019)

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