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

By 20 weeks pregnant, you might have started to feel your bump developing. While some people “show” sooner than others, starting to see the physical signifiers of your pregnancy can be exciting but also a little daunting. You’re preparing for a major life change, after all. 

At 20 weeks pregnant, you may also feel a little bit more like yourself again. Symptoms like fatigue or nausea may have subsided. You might have heard pregnancy nausea referred to as morning sickness, but pregnancy sickness can strike at any time – morning, noon, or night. Alongside changes in your symptoms, you may also have your anatomy scan either this week or in the coming weeks, when you might be able to find out the sex of your baby. This can add a new level of excitement.

Although you’re about halfway through your pregnancy now (as pregnancy is considered to be full-term if your baby is born between 39 weeks and 40 weeks and 6 days), there may still be some new things to consider as your body continues to change and your baby grows. So, here are some of the things to think about at 20 weeks pregnant, with advice from a Flo expert. 

Your baby at 20 weeks pregnant

Producing antibodies

Around now, your baby is producing antibodies that will protect them from getting sick. The two types of antibodies that your baby is producing are called immunoglobulin G (IgG) and immunoglobulin M (IgM). This might sound science-heavy, but IgG and IgM have pretty simple jobs. IgG is responsible for fighting infections caused by bacteria and viruses, while IgMs are the first antibodies that your body produces after being exposed to new germs. Clever, right?

Developing lanugo

You may remember that at 19 weeks pregnant, your baby develops the vernix caseosa. This is a white, sticky layer (made of mostly water and proteins) that covers their skin to protect them from the amniotic fluid and help them to regulate their temperature. The vernix caseosa has to bind to your baby, and to help it do so, they develop lanugo at around 20 weeks. You can think of this as a soft, fine hair that covers your baby’s body. The lanugo helps to protect your baby and keep them warm. While many babies will shed these fine hairs before being born, some will be born with them. 

How big is a baby at 20 weeks?

Length (crown to rump): 25.7 cm or 10.1 in. 

Weight: 331 g or 11.7 oz

Size: Equivalent to a grapefruit

All measurements are approximate and vary within the normal range.

Your body at 20 weeks pregnant

By 20 weeks pregnant, you’ll have likely tracked lots of changes, both in the way you look and feel. Some people see big differences in their symptoms between their first and second trimesters, while others don’t. No two pregnancies are the same, so it can be hard to say what’s typical. You can learn more about the different second-trimester pregnancy symptoms that you might encounter by downloading an app like Flo.

Between your growing bump and changes to your discharge, there are a couple of other things you might want to keep an eye out for at 20 weeks. 

Sleep changes due to hormone fluctuations and your growing bump

You may have already realized that being pregnant can be pretty tiring for a multitude of reasons. During early pregnancy, hormone fluctuations can mean it’s more difficult to get a full night’s rest. Then, as your bump grows, it can be difficult to sleep in the positions you’re used to. 

“Sleep changes become common during pregnancy for multiple reasons,” explains Dr. Jenna Flanagan, academic generalist, obstetrician, and gynecologist at Beth Israel Deaconess Medical Center, Massachusetts, US. “People may notice more frequent awakenings during the night and more need to get up and go to the bathroom, which can be due to the hormonal changes of pregnancy as well as just the pressure of the uterus pushing on the bladder. Other issues that can be related to pregnancy hormones are experiencing more heartburn and restlessness.” 

Learning to adapt to your pregnancy symptoms can be tough, and you may feel pressure to get a full eight hours of sleep before your baby arrives. Luckily, there are some things you can do to help to combat sleep changes. Pillows can be a great way to support your bump in the night. You might want to try new sleep positions that may suit you better now that you’re pregnant. Similarly, using meditation techniques before bed may help to clear your mind and prepare you for sleep. 

Increased vaginal discharge

Around 20 weeks pregnant, you may also notice that your vaginal discharge has changed. Some people report having a more white-colored discharge called leukorrhea during their second trimester. Dr. Flanagan says this is very common and requires no further evaluation or treatment. “As long as there’s not a significant change in color, odor, pain, bleeding, or other symptoms like that, then discharge is pretty normal during pregnancy,” she says. 

Generally, discharge shouldn’t have a strong smell, should appear white or clear, and will be sticky or slippery in texture. If you notice a change in the smell, look, or consistency of your discharge, don’t hesitate to reach out to your doctor. 

Your questions answered

Are 20 weeks considered 5 months pregnant?

You might notice that some people measure their pregnancy in weeks, while others calculate how far along they are in months. You will generally hear your doctor use weeks as this is the best way to measure milestones in your pregnancy, but 20 weeks pregnant equates to around 5 months pregnant.

As a full-term pregnancy is considered to be anything between 39 weeks and 40 weeks and 6 days, you’re approaching the halfway mark. What a milestone!

What is my baby doing at 20 weeks in the uterus?

As you start to prepare for your baby’s arrival, you might be curious about what they’re up to in your uterus. Alongside developing antibodies and the lanugo, you may start to feel your baby’s movements more as you move through your second trimester. Generally speaking, most people find that their baby’s kicks feel stronger as their pregnancy progresses and their baby grows.

Movements might feel like bubbles or butterflies initially, before feeling like more pronounced kicks and turns. Many people report feeling their baby move for the first time around 16 to 24 weeks, but if you haven’t yet, try not to worry. There are lots of reasons why you might start feeling your baby move at different times. One reason is that your placenta placement can have an impact on how you feel your baby’s movements. This can be worrying, so if you have any questions about your baby’s movements, don’t be afraid to reach out to your doctor. 

Plus, along with becoming more active every day, your baby is also developing sweat glands underneath their skin, and they’re continuing to gain weight. 

Is a 20-week baby fully developed?

Although your baby is growing in leaps and bounds, their crucial organs and systems will continue to develop, and they will gain weight throughout the rest of the second and third trimesters. As we’ve seen, you won’t be considered to be full term until between 39 weeks and 40 weeks and six days. A baby born between 37 weeks and 38 weeks and six days is considered to be early term. Babies born before 37 weeks are considered to be preterm and have an increased risk of developing health complications. 

20 weeks pregnant checklist

Looking into vaccines

Keeping on top of your vaccinations is incredibly important for both your health and that of your baby, too. While Dr. Flanagan explains that it is best to start thinking about this before pregnancy — as some vaccines, such as varicella and rubella, are live and cannot be injected while you are expecting — others are perfectly fine to have while your baby is growing. 

“In pregnancy, an inactivated vaccine or a non-live vaccine is going to be safe, and people will be offered things like the flu or COVID-19 immunizations,” she explains. “I would recommend both of those because those illnesses can be quite dangerous to pregnant women.” 

Having sex

Coping with your growing bump and mood changes during pregnancy can be a big learning curve, and you might find that it’s impacted your sex drive. Your libido can change for several reasons, and it’s important not to pressure yourself into doing something you don’t want to do. However, Dr. Flanagan says that if you do want to have sex, it’s perfectly fine and safe for both you and your baby. 

“People worry that they’re going to hurt the baby, cause their water to break, or go into early labor if they have sex while pregnant, but that’s not likely to happen,” she says. Your baby isn’t going to be poked or harmed. 

However, Dr. Flannagan explains that there are some times when your doctor may recommend “pelvic rest.” “This would be if someone had an issue where the cervix was short or dilated or there was a worry about preterm labor,” she explains. “There are also some conditions related to the location of the placenta where, again, we would recommend pelvic rest. But for the most part, sex is fine and a healthy part of life, pregnant or not, so we don’t restrict it unless necessary.” If you have any concerns or questions, be sure to reach out to your health care provider for clarity.

Start thinking about baby names and the kind of birth you would like to have

As you reach 20 weeks pregnant, you may want to start thinking about the kind of birth you’d like to have. While a lot of people choose to have their baby in a hospital, some opt to deliver in a birth center or have a home birth. There are also decisions to be made about what kind of pain relief you would prefer — if any — and if you would like to use a birthing pool. 

Having a birth plan in place may help to keep you calm when the big day comes, but remember, you can change your mind at any point in your pregnancy, and you may choose not to have a birth plan at all. Your doctor may suggest you reconsider your birth plan as your pregnancy progresses, or you may change your mind, or complications may mean you amend it on the day. Nothing is set in stone, so don’t worry too much about making the wrong choices. It’s just good to know what your options are. 

Alongside researching the merits of hypnobirthing and pain relief, you might also want to start thinking about names for your child. Whether you decide to find out the sex of your baby or not, making a list of potential names may help to build excitement in the countdown to meeting your little one. And if you’re choosing with a partner, you can whittle down your long list to names you both agree on. This isn’t always an easy feat!

When to consult a doctor at 20 weeks pregnant

You don’t need to wait until your appointments if you have any concerns or questions about your pregnancy. However, at 20 weeks pregnant, you should contact your doctor immediately if you experience: 

• Severe cramping
• Vaginal bleeding
• Changes in vaginal discharge
• Fever
• Dizziness and fainting
• Severe vomiting
• Severe headaches or blurry vision
• Intense heartburn
• A loss of liquid from your vagina or watery/mucus-like discharge (This could be a sign of premature labor.)

This isn’t an exhaustive list but just some examples 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 worried about any other symptoms you experience during pregnancy, don’t hesitate to reach out to your health care provider. 

20-week ultrasound scan 

You might have heard the 20-week ultrasound scan referred to as the mid pregnancy or anatomy scan. You might have yours between 18 and 21 weeks pregnant. According to Dr. Flanagan, this is when your health care provider will examine your child’s bones, heart, brain, spinal cord, face, kidneys, and abdomen, as well as your placenta. They may be able to tell you the sex of the baby, too!

It’s advised that you attend this 30-minute appointment as the sonographer will be able to check for birth defects and ensure that your baby’s growth is on track. You’ll also be able to take a picture of the scan home with you. 

20 weeks pregnant: The takeaway 

At 20 weeks pregnant, you'll be experiencing some pretty exciting milestones. You may have an ultrasound scan this week, and if you’re curious to know, this could be the week you find out your baby’s sex (if you haven’t already through fetal DNA testing, a blood test that looks at your baby’s chromosomes.) 

You might have seen your symptoms change during your second trimester and still be adapting to new sleep positions with your growing bump and learning which vaccinations may benefit you and your baby.  

You might also want to start thinking about the type of birth you’d like to have. The most important thing to remember is that any decisions you make about where you’d like to give birth or what kind of assistance you’d like to use aren’t set in stone. You can change your mind at any time, and doing research into all of your options may help you feel more in control and calmer about your birth.