- Congratulations! It’s the last week of your second trimester! Time to get ready for the grand-finale event. (Don’t worry, you still have time!)
- The not-so-glamorous symptoms of pregnancy are in full effect. You may have constipation and pregnancy hemorrhoids. Plus, baby is putting so much pressure on your bladder you may occasionally leak urine—especially when you cough or sneeze.
- Baby is practicing breathing in and out (it’s amniotic fluid, not air, but still pretty cool), developing lungs and even showing brain activity now.
As you look ahead to the third trimester, be prepared for some pretty embarrassing stuff (like having to pee all the time—and maybe even when you don’t mean to!). It’s all par for the late-pregnancy course and totally temporary. It’s time to head down the home stretch. Are you ready?
Inside your 27 weeks belly, baby is practicing inhaling and exhaling with their rapidly developing lungs. And it's official: Baby is showing brain activity! From here on out, baby’s brain will keep getting more complex, turning that 27-week fetus into a real smarty pants. Additionally, their whole nervous system—which is made up of the brain, spinal cord and nerves—is continuing to mature.
Baby’s hearing continues to improve, and they might start to recognize your voice and your partner’s voice. That said, the ears are covered with vernix, a thick, waxy coating that protects the skin from becoming chapped by amniotic fluid, so sounds might be a bit muffled.
Your cutie-pie will continue to gain fat, which will their skin look smoother and less wrinkly. Soon enough, baby will develop those chubby cheeks you’ll get to kiss in a few months!
How big is baby at 27 weeks?
At 27 weeks pregnant, baby is as big as a head of lettuce. The average 27-week fetus measures between 13 to 14.4 inches and weighs around 2 pounds. But baby isn’t just getting bigger, they’re also getting smarter.
What does a 27-week fetus look like?
If you could peek at baby at 27 weeks in the womb, you’d see your little 27-week-old fetus has continued to put on some fat and muscle with all that moving and dancing in your 27 weeks pregnant belly. Although baby at 27 weeks is just the size of a head of lettuce, they’re over a foot long now (whoa!) and basically a smaller, skinnier version of the baby you’ll meet when they’re born. Baby is learning to suck now too, so they might be sucking their thumb in utero right now! Awww.
27 weeks pregnant is how many months?
Find yourself wondering “how long is 27 weeks?” It may feel like the answer is “forever!” but 27 weeks pregnant in months is about six months pregnant.
27 week ultrasound
If your pregnancy has been uncomplicated so far, you probably won’t have a prenatal appointment or a 27 weeks pregnant ultrasound. Starting next week though, you’ll visit the doctor twice a month—or every two weeks. Maybe grab some magazines or download some new apps to make those future waiting room visits more enjoyable.
The annoying symptoms you’ve been having aren’t likely to go away anytime soon, but at least you’ve probably found some ways to deal with them—and hey, maybe you’re even used to them now. The most common 27 weeks pregnant symptoms are:
Leg cramps
Keep stretching those legs—flexing your feet can help—and drinking lots of water to prevent these ouchies.
Backaches
Gentle stretching can help your back pain too. Consider sleeping with one of those huge body pillows, which can ease some of the pressure on your hips and help you get into a comfy position for your back.
Constipation
If you’re stopped up and you’ve done all the usual prevention—eaten lots of fibrous foods, drunk lots of water and taken plenty of walks—ask your doctor if a fiber supplement or stool softener is safe to take.
Hemorrhoids
Straining to go to the bathroom and all the pressure baby is putting on your lower half can cause this not-so-pretty 27 weeks pregnancy symptom. Resolving constipation is essential to treating hemorrhoids.
Skin, hair and nail changes
Notch this one into the unpredictable pregnancy symptom category. Your skin, hair and nails might be thicker or grow faster (yay!) but they might also be more brittle (boo).
Snissing
This is what we call peeing when you sneeze. Baby is putting a ton of pressure on your bladder and there’s not much you can do about it except take frequent pit stops to empty your bladder, and maybe wear a pantiliner if you’re worried about an unexpected achoo.
What to expect at 27 weeks pregnant with twins
Women who are 27 weeks pregnant with twins are vulnerable to preterm labor, so if you notice any pregnancy symptoms that are out of the ordinary—such as bleeding, watery discharge, abdominal pains or consistent, repeated contractions, tell your OB right away. Many twin pregnancies are delivered by 37 weeks, but the longer you can keep those babies in there, the better for their development.
Healthy weight gain at 27 weeks pregnant is around 15 to 30 pounds. If you’ve gained more weight than recommended, your OB may tell you to slow it down a bit. Sounds rough, but they can give you some tips on keeping the weight gain under control. On the other hand, insufficient weight gain may pose risks to baby. By sticking to pregnancy weight gain recommendations, you’re reducing your risk of pregnancy complications and preterm labor.
If you’re 27 weeks pregnant with twins, you’ve probably gained more weight—about 29 to 44 pounds. Still, your twins are growing and developing at about the same rate as singleton babies do, though one baby is probably a bit smaller than the other.
You’re probably feeling a ton of kicks inside that 27 weeks pregnant belly—twice as many if you’re 27 weeks pregnant with twins. You may even feel tiny hiccups, which are like patterns of little twitches. For now, sit back and enjoy the kicks and jabs. Next week, you should start counting kicks to make sure baby seems consistently active from day to day.
What trimester is 27 weeks?
At 27 weeks pregnant, you're now in the last week of your second trimester. Congrats, and get ready to enter the home stretch!
The closer you get to your due date, the more likely you are to spend time thinking about how you're going to get through the pain of labor. You've probably heard of the epidural, but there are lots of other methods, both medical and non-medical for pain relief. Nitrous oxide, or laughing gas, is a medical option that is self-administered during a contraction to help ease the anxiety and pain associated with labor… Some non-medical options include massage and heat, water immersion either in a shower or tub, and aromatherapy with essential oils.
Ready to feel great this week? Here are some steps to take.
Stay hydrated during the day
Focus on hydration during the day, but slow down as you get closer to bedtime so you’re not getting out of bed every two minutes to pee.
Get all the support you need
You probably need support in all kinds of ways right now, from a great bra to hold up those increasingly heavy boobs, to a good pregnancy pillow to support your belly at night. Don’t forget about the other kinds of support, though. As you get closer to your due date, you might find yourself getting more and more emotional. Make sure you have someone to talk to—whether that’s a partner, a friend or a therapist—so you can process all your feelings and get support when you need it.
Safety first
It’s time to get in a safety mindset by making sure you’re ready to keep baby safe at all times. Make sure any new baby gear meets current safety requirements, get started on baby proofing, take an infant safety and CPR class and get your vaccines. There’s a lot to think about, but it’s better to think about it now, before baby comes.
Sleep while you can
Your sleep may be interrupted by a wiggly 27-week fetus and trips to the bathroom, but get all the sleep you can while you can. It’ll get harder and harder to get the shut-eye you need as baby grows—and trust us, you want to be as rested as you can before baby arrives.
Frequently Asked Questions
Is eye twitching during pregnancy normal?
Dealing with eye twitching is always jarring—and distracting. But this can be a common issue during pregnancy. Some of the most common causes of eye twitching are fatigue and stress and, unfortunately, both can be common during pregnancy. Eye twitching should stop after a day or two, but if it extends beyond that and it’s bothering you, talk to your healthcare provider.
What is the TDAP vaccine in pregnancy? Who needs it?
The TDAP vaccine can prevent tetanus, diphtheria and pertussis, three potentially serious illnesses that you don’t want yourself—and you don’t want baby to get. It’s recommended that all pregnant people get a dose of the TDAP vaccine during every pregnancy and ideally during the early part of the third trimester to help protect baby from pertussis (aka whooping cough). Pertussis can cause severe, life-threatening complications in infants/
Why does my baby move so much at night?
If you’re feeling karate kicks from baby in the evening, it’s easy to assume that your little one is more active at night. While that’s possible, it’s more likely that nighttime is when you’re finally still and paying attention to what’s happening in your belly after a busy day. Just sit back and enjoy the love taps from your little one. They’ll settle down to rest soon enough.
When does my baby's immune system get stronger?
The cells that will become baby’s immune system start to develop as early as four weeks into your pregnancy. But while your 27-week baby’s immune system is getting stronger each day, the immunity that’s transferred from you to baby through the placenta becomes more solid after 22 weeks of pregnancy. When your little one is born, the tools are already in place to help them develop an immune response if they come into contact with germs or viruses.
Can gestational diabetes go away on its own?
Up to 10 percent of pregnancies each year in the US are impacted by gestational diabetes.. If you develop gestational diabetes, it’s important to listen to your doctor’s recommendations and follow their treatment plan. That might include checking your blood sugar regularly, eating healthy foods at the right times, being active and taking medication. For most people, gestational diabetes goes away after giving birth. However, your doctor may want to monitor you for a period of time postpartum.
Later in pregnancy, I was struggling every night to sleep on my sore hips. Even our pillow-top mattress felt like a rock. In a middle-of-the-night exasperated online purchase, I bought a memory-foam mattress topper and my life was changed! We still use it to this day.
Please note: The Bump and the materials and information it contains are not intended to, and do not constitute, medical or other health advice or diagnosis and should not be used as such. You should always consult with a qualified physician or health professional about your specific circumstances.
American Pregnancy Association, Third Trimester of Pregnancy: Fetal Development
Cleveland Clinic, Pregnancy Constipation, October 2021
Cleveland Clinic, Pregnancy and Bladder Control, August 2023
Cleveland Clinic, Amniotic Fluid, June 2022
National Library of Medicine, Embryology, Pulmonary, August 2023
Environmental Health Perspectives, The Brain Before Birth, November 2018
Mayo Clinic, Pregnancy Week by Week: 3rd Trimester Pregnancy: What to Expect, March 2022
Proceedings of the National Academy of Science (PNAS), Development of Human White Matter Pathways in Utero Over the Second and Third Trimester, May 2021
American Pregnancy Association, 27 Weeks Pregnant
Mayo Clinic, Pregnancy Week by Week: Fetal Development: Second Trimester, June 2022
PLOS One, Development of Muscle Ultrasound Density in Healthy Fetuses and Infants, July 2020
Mount Sinai, Fetal Development
Cleveland Clinic, Ultrasound in Pregnancy, September 2022
March of Dimes, Prenatal Care Checkups, June 2017
Mayo Clinic, Pregnancy Week by Week: What Causes Leg Cramps During Pregnancy, and Can They be Prevented?, April 2023
Mayo Clinic, Pregnancy Week by Week: Back Pain During Pregnancy: 7 Tips for Relief, November 2021
Cleveland Clinic, Hemorrhoids During Pregnancy, July 2022
MedlinePlus, Skin and Hair Changes During Pregnancy, November 2022
UCSF Health, Recognizing Premature Labor
American College of Obstetricians and Gynecologists, How Much Weight Should I Gain During Pregnancy?, August 2021
Centers for Disease Control and Prevention, Weight Gain During Pregnancy, June 2022
American College of Obstetricians and Gynecologists, Weight Gain During Pregnancy, 2023
American Pregnancy Association, Weight Gain With Twins
UCSF Health, Fetal Development: Unequal Placental Sharing
American Pregnancy Association, Counting Baby Kicks
Neurourology and Urodynamics, Association Between Pregnancy and Nocturia: A National Health and Nutrition Examination Survey Analysis, August 2022
Sleep Foundation, How to Sleep Better While Pregnant, March 2023
American Pregnancy Association, Breast Changes During Pregnancy
University of Pennsylvania Health System, How to Get Sleep During Pregnancy
March of Dimes, Take Care of Your Mental Health During Pregnancy, July 2022
Centers for Disease Control and Prevention, Vaccines and Pregnancy: 9 Things You Need to Know, September 2023
U.S. Consumer Product Safety Commission, Childproofing Your Home–Several Safety Devices to Help Protect Your Children from Home Hazards
Stanford Medicine Children’s Health, Fetal Movement Counting
Christine Greves, MD, an ob-gyn at the Winnie Palmer Hospital for Women and Babies in Orlando. She earned her medical degree from the University Of South Florida College Of Medicine.
Mount Sinai, Eyelid Twitch
Hussain T, Murtaza G, Kalhoro DH, Kalhoro MS, Yin Y, Chughtai MI, Tan B, Yaseen A, Rehman ZU. Understanding the Immune System in Fetal Protection and Maternal Infections during Pregnancy, 2022
Children’s Hospital of Philadelphia, Development of the Immune System
Centers for Disease Control and Prevention (CDC), Gestational Diabetes
Nemours Kids’ Health, Week 27
Mayo Clinic, Fetal development: The 2nd trimester](https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/fetal-development/art-20046151))
Learn how we ensure the accuracy of our content through our editorial and medical review process.
Navigate forward to interact with the calendar and select a date. Press the question mark key to get the keyboard shortcuts for changing dates.