Congrats! You and your partner are past the first trimester. Take a moment to pat yourselves (and your pregnant partner) on the back for making it through what is literally the most nauseating part of pregnancy, and get ready for what most consider the most enjoyable trimester.

Here is what you need to know about the second trimester:

Toddler hugging moms pregnant belly

Pregnancy wellness

How to take the very best care of your changing self through this amazing transformation.

When does the second trimester start?

The second trimester starts at the beginning of week 13 and ends at 27 weeks and 6 days.

What’s happening with baby in the second trimester?

While all your baby’s major organ systems were formed during the first trimester, the second trimester hosts some major milestones for your growing little human. At the start of the second trimester, your baby is the size of a lemon and has closed eyelids—but their eyes are already able to sense light.

By 17 weeks: Your kiddo’s arms and legs are starting to move regularly as they explore the womb.

By 18 weeks: The genitals are developed. Soon you’ll be able to discover if you’re having a little boy or girl!

By 20 weeks: Around this time your baby is able to hear and has started to grow fine hair on their tiny head.

By 24 weeks : One of the biggest pregnancy milestones occurs. Your baby reaches viability, meaning if they were born at this point they might survive with proper NICU support.

By the end of the second trimester: Your baby’s eyes are open, they are developing a sense of smell and taste, they have regular sleep and wake cycles and they weigh nearly 2 pounds.

Psst: For week-by-week updates on what your sweet baby is up to throughout pregnancy, check out The Motherly Guide to Becoming Mama.

What’s happening with mama during the second trimester?

The second trimester is often a welcome relief for a lot of mamas. Around this time, those exhausting early pregnancy symptoms start to disappear, or at least greatly wane. Your partner will hopefully have much less nausea and increased energy, and will likely start feeling more like herself again.

This is also the trimester where the physical changes really start to kick in, and you will start to notice that adorable baby bump.

At around the 17 week mark, your partner may feel the baby move for the first time—but reassure her that most first-time moms often don’t feel any movement until 20 to 23 weeks. Your partner may be noticing her breasts are getting bigger, as well as her waist size.

How to support your partner during the second trimester

This is a really fun and exciting trimester for both you and the mama-to-be, filled with opportunities for you to shine as a supportive partner. Here are a few ways to show her how much you appreciate all that she’s doing for your growing family:

1. As your partner’s energy starts returning, offer to exercise with her and encourage healthy food choices as her appetite returns to normal.

2. When her pants start to get too tight, reassure her that she is beautiful and send her on a shopping spree for some new maternity clothes.

3. Get a couple of books to read to your baby, as they can now hear your voice!

4. Plan a few extra date nights or even a weekend away to soak in these moments together.

You’ve been doing a great job at being the supportive partner that she needs you to be. This is a great trimester in which to celebrate the two of you and your little one on the way.