How many months are you at 13 weeks pregnant

On this page

• Your baby
• Your body
• Things to remember
• Related information on Australian websites

Your baby

Your baby is now fully formed and looks much more like a human being. They are about 7.5 cm long — about the size of a peach — and weigh about 30g. They are moving about vigorously in your uterus and they can move their arms and legs, suck their thumb and form a fist.

Their organs, including the liver and pancreas, are starting to function. The vocal cords are beginning to develop, and they have soft hair on their eyebrows and head. They are growing a penis or clitoris, but these are too small to be seen during an ultrasound.

The kidneys produce urine, which becomes amniotic fluid. The baby practises breathing and swallowing the fluid.

Your baby at 13 weeks

Your body

At 13 weeks, you have officially entered the second trimester of pregnancy. If morning sickness is still a problem, talk to your doctor or midwife about how to manage it.

Your bump might start to show and you might feel the ligaments stretching in your tummy and groin.

You may notice more visible veins, especially in your breasts. You may also be tired, have food cravings or food aversions, or have heartburn, indigestion or constipation.

Things to remember

The chances of having a miscarriage decrease once you enter the second trimester. Many people therefore decide to share the news of their pregnancy at this time. Chat with your partner about how you want to do this, and be prepared in case people don’t react in the way you hope for.

You don’t have to tell your employer that you’re pregnant. If you want to take maternity leave, however, you will need to give your employer 10 weeks’ notice. It’s worth thinking early about how you will manage life with a baby. If you haven’t already, now is a good time to find out more about your parental rights and entitlements.

If you haven’t already had prenatal screening or diagnostic tests, now is also the time to organise appointments them if you want to. At 13 weeks you can have a nuchal translucency scan (an ultrasound) or chorionic villus sampling (CVS) if there are any concerns that your baby may have Down syndrome or some other genetic disorders.

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13 Weeks Pregnant: Your Baby’s Development

This week, your little one’s organs are fully formed and are hard at work! The kidneys are starting to produce urine and release it into the amniotic fluid, and the spleen is busy producing red blood cells, which carry oxygen throughout the body. Your baby's intestines have moved back into the abdomen from the umbilical cord, now that there’s enough room to accommodate them, and some of the larger bones, including those of the skull, are beginning to harden. What else is happening with your baby? Even though you won’t hear those tiny coos and cries until after you give birth, your baby’s little vocal cords have already started to develop. If you’re 13 weeks pregnant with twins, read more about your babies’ development in our weekly twin pregnancy overview.

The Size of the Fetus at 13 Weeks Pregnant

At 13 weeks, your fetus is about the size of a large plum or a small peach. It can be hard to imagine exactly what’s going on inside your belly. Check out the visual below to get an idea of how your little one is looking.

Mom’s Body at 13 Weeks Pregnant

You’ve just about made it to your second trimester, which many moms-to-be describe as the honeymoon period of pregnancy. The discomforts you may have experienced in the first trimester — fatigue, nausea, and frequent urination — often ease up a bit, and you may even feel a surge of energy during this trimester. By this stage, your blood supply and flow are fully linked to the placenta, which will continue to grow as your pregnancy progresses. By the time you give birth, the placenta may weigh about one and a half pounds. At your upcoming prenatal appointments, your healthcare provider may monitor your fundal height -- the distance from your pubic bone to the top of your uterus (the fundus). This measurement helps your provider determine how your baby is doing by measuring the size of your growing uterus. Breast tenderness may continue on and off, and other issues like constipation, bloating, and heartburn are normal at this stage, too, as your increased hormone levels can slow down digestion. Learn more about prenatal health, fitness, nutrition, and more in our downloadable Pregnancy Guide.

13 Weeks Pregnant: Your Symptoms

At 13 weeks pregnant, here are some of the symptoms you may be experiencing:

• Vaginal discharge. A clear to milky-colored discharge known as leukorrhea may increase around this point in your pregnancy. You might be surprised to learn that this discharge has a unique purpose: It helps keep your vagina and birth canal clear of infection and irritation. If it gets a little messy, panty liners can be a big help.

• Changing sex drive. It's perfectly normal for you and your partner to feel an increase or a decrease in sexual desire at various times during pregnancy. If your pregnancy is normal and both of you feel the urge, go ahead and enjoy the intimacy. Don't worry — your baby will be safe! Your uterus and the amniotic sac provide protection for your baby. Talk to your healthcare provider if you’re worried or have questions about this or anything else. Note that your provider might advise you to abstain from sex if you have complications including a history of miscarriage or if you are at risk of preterm labor. Read more about sex during pregnancy.

• Heartburn. Heartburn and indigestion can come and go throughout your pregnancy as your baby moves from one position to the next, and as your growing uterus puts pressure on your stomach. Pregnancy hormones also cause the muscle at the top of your stomach to relax, allowing stomach acid to travel up into the esophagus, which causes heartburn; this is more likely to happen if you lie down after having just eaten a large meal. You can reduce the discomfort by sitting upright after eating and avoiding potential triggers such as chocolate, citrus fruits, and fried or spicy foods.

• Constipation. Hormones strike again! Progesterone and estrogen play an important role in pregnancy, but right now they might be causing your digestive system to work more slowly than usual. This means that you may be feeling a bit backed up. Adding more fruits, vegetables, and whole-grain foods to your diet increases your fiber intake and helps keep things moving along. Drinking prune juice might also help, as can drinking lots of water and doing regular exercise.

• Leaking colostrum. You may start to notice a thick, yellow fluid leaking from your breasts right about now. This is called colostrum, and it’s the milk that appears for the first few days after you give birth. It is completely normal, but you may want to try using disposable or cotton breast pads (without plastic liners) to help absorb any leaking fluid.

13 Weeks Pregnant: Things to Consider

• Have you shared the good news with your family and friends? The beginning of your second trimester is a great time to do this, because the risk of miscarriage is lower after the first three months. Of course, the decision about when to start spreading the word is totally up to you! Get inspired with our creative pregnancy announcement ideas.

• If you work, plan when you'll let your boss know that you’re expecting. Start to think about how you will share the news, and when. You’ll want to keep your employer and colleagues in the loop so they can make plans for accommodating your absence during your maternity leave. You might even like to have a little fun with announcing your pregnancy to co-workers.

• Working out? If yes, keep it up! If not, consider talking to your healthcare provider about starting a basic fitness routine. If your provider gives you the all-clear, it could include things like walking, swimming, and maybe yoga. Your muscles will thank you – both during the last six months of your pregnancy, and during your new baby’s first few months, when increased fitness will help you deal with all the extra stress that’s placed on your body.

• If you are doing abdominal exercises that have you lying flat on your back, you may want to look for alternatives during pregnancy, since the weight from your uterus can cause less blood to return to your heart when you're in that position. Ask your healthcare provider for alternatives.

• While we’re on the topic of exercise – it’s worth mentioning the pelvic floor muscles as well. The benefits of strengthening these muscles include improved bladder control and increased pelvic organ support. (The pelvic organs include the bladder, uterus, small intestine, and rectum.) You can strengthen the pelvic floor by doing an exercise known as Kegels. Basically it involves squeezing and relaxing the muscles in the pelvic and genital area. You can do the clenches in different timings, for example hold for three, relax for three, or a succession of quick contract and releases.

• You might be experiencing some unusual things now that you’re pregnant, perhaps you’re having more intense dreams or perhaps you’re feeling a little “spaced out” or having trouble concentrating. You’re not alone! Read up on the so-called “pregnancy brain” and why you may be experiencing more vivid dreams.

13 Weeks Pregnant: Ask Your Doctor

• Why do I sometimes feel pain in my pelvic area? (Some pelvic pain may be associated with round ligament pain resulting from things like your growing uterus, but ask your healthcare provider about what’s normal and what isn’t.)

• Am I gaining the right amount of weight? If not, what changes can I make to get on the right track?

• Is chorionic villus sampling recommended?

• How is a twin pregnancy different?

13 Weeks Pregnant: Your Checklist

• Start doing research into your childcare options. You can ask friends, neighbors, or coworkers for recommendations for in-home care or childcare centers.

• If you work, find out about your maternity leave rights and options, including how many weeks you may have, and how much of that time might be paid. You can also ask if your employer offers any additional benefits.

• Plan how to share your big news with your wider circle of family and friends.

• Start making a shortlist of possible names for your little one with the help of our Baby Name Generator.

• As you enter the second trimester, read up on the trimesters of pregnancy for an overview of what’s to come.

• Sign up for even more pregnancy tips here:

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