Welcome to week 27. This is the last week of the second trimester. 13 weeks to go!

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Your baby that was the size of a zucchini is growing to the size of a cabbage. This week, your baby measures 14.4 inches (36.6 cm) and weighs 2.3 pounds (1.1 kg).

Your baby’s immune system is gearing up for life outside the womb. They have also likely discovered thumb sucking, which can help strengthen their cheeks and jaw.

At this point, you should be able to feel when your baby has hiccups. These tend to feel like spasms in your belly and end relatively quickly. Even if this happens often, you don’t need to worry about hiccups; it is perfectly normal.


At 27 weeks, your uterus is still expanding and is now the size of a basketball. Enjoy showing off that bump; you only have a few months left of pregnancy.

Pregnancy brain is a term used to describe forgetfulness during pregnancy, inability to focus, or brain fog. This can also extend to after birth, and you may have heard people blame mommy brain or momnesia. Anecdotally, pregnancy brain and mom brain are very common. The standard answer to why this happens is that you are short on sleep, have a lot going on, and are dealing with additional stress. This is all true, but it may not fully explain why we get pregnancy brain from a scientific standpoint.

It is well-documented that hormones alter our brain structure and function. During pregnancy, your progesterone increases 10 to 15-fold. You have more estrogen during pregnancy than during your entire non-pregnant life. These high hormone levels contribute to your short- and long-term brain structure and function changes. What if we viewed pregnancy brain as a trade-off with a long-term benefit instead of a loss? Caring for an infant and raising a child requires a shift in your thinking as you step into becoming a parent. This episode examines the science behind pregnancy brain and explores some evidence that it may make you a better parent.

In the United States, the CDC and ACOG recommend the TDap vaccine in your third trimester between 27-36 weeks. The antibodies your body creates are highest two weeks after you receive the vaccine. The goal of having the vaccine by week 36 is to pass antibodies to your baby before they are born. Tdap provides immunity for tetanus, diphtheria, and pertussis (whooping cough). It can be challenging to sift through the vaccine evidence, especially during pregnancy. See this episode that is a deep dive into evidence on the Tdap vaccine.

Vaccines are a very controversial and complex topic. The choice to get vaccinated is a decision you should make with your doctor or midwife. If you have questions or concerns about any vaccine, I urge you to bring them up with your care provider.

As you head into the third trimester you may want to give more thought to your birth plan. This is much more than a piece of paper you hand to your care provider. It is the process you go through to prepare for the birth experience you want. When done right, you plan for the scenario in which everything goes as planned and what should happen if things do not. The end result is that you are more prepared and confident going into your birth.

The Pregnancy Podcast has several resources to help you create your birth plan:

Guide to Creating Your Birth Plan

Get a copy of Vanessa’s birth plan

Your Birth Plan book (FREE for Premium Members)

Tip for Dads and Partners

Find out if your significant other wants to take maternity photos or photos of the two of you while they are pregnant. Even if you aren’t super into the idea, it may be important to them. It would be helpful to find possible photographers, price out package options, and scope out some photoshoot locations.

Want more evidence-based information to navigate your pregnancy and birth?

20% OFF Pregnancy Podcast Premium with the code 40WEEKS. With a Premium membership, you get access to the private podcast feed (in your favorite podcast app) with every episode ad-free. Exclusive access to all episodes, articles, and resources on the website. Plus, a digital copy of the Your Birth Plan book. Your step-by-step guide to creating the birth experience you want. Including sample plans and a master template you can customize. Become a Pregnancy Podcast Premium Member.