Bapak Life

Second Trimester for Dads: What's Happening and What to Do

What happens to the baby and your partner in weeks 14 to 27, the scans and tests to expect, and the to-do list that's yours, from classes to the car seat.

By Dad of Two kids and Beautiful Wife
Published 8 min read
A dad kneeling by the sofa with his hand on his pregnant partner's bump, both smiling as if he just felt the baby move
In this guide
  1. The short answer
  2. How the second trimester is counted
  3. What’s happening with the baby
  4. What’s happening with her
  5. Appointments and tests
  6. Your second-trimester to-do list
  7. Travel, exercise, sex and sleep
  8. When to call her provider
  9. Why showing up matters
  10. FAQ
  11. Sources

The second trimester for dads is when the pregnancy starts to feel real. The nausea usually fades, the bump shows, the baby starts to move, and you get to see a lot more of them on the big ultrasound. It’s also the best window to get your own list done before the third trimester gets busy. This guide covers what’s happening with the baby and with your partner, the appointments to expect, and the jobs that are yours.

If you’re earlier along, start with the first trimester for dads.

The short answer

  • When is it? Weeks 14 to 27, according to ACOG.
  • What’s new? Energy usually returns, the bump shows, and she’ll start to feel the baby move, typically around 20 weeks.
  • Big appointments: the anatomy ultrasound (18 to 22 weeks) and the glucose screening (24 to 28 weeks).
  • Your list: childbirth class, hospital tour, pediatrician shortlist, your vaccines, the car seat, and a trip if you want one.

How the second trimester is counted

The American College of Obstetricians and Gynecologists (ACOG) defines the second trimester as 14 weeks and 0 days to 27 weeks and 6 days. Other government health sites draw the line a week earlier or later, so don’t worry if an app says something slightly different.

What’s happening with the baby

From ACOG’s week-by-week guide:

  • Week 18: the baby can hear sounds. This is your cue to start talking, reading or singing to the bump.
  • Weeks 21 to 24: kicks and turns get stronger.
  • Weeks 25 to 28: the baby can respond with movement to familiar sounds, such as a parent’s voice. Loud sounds may make the baby pull in their arms and legs.

How big?

By the end ofLengthWeight
Week 20More than 6 inchesLess than 11 ounces
Week 24About 12 inchesAbout 1½ pounds
Week 28Nearly 15 inchesAbout 2½ pounds

When will you feel a kick? ACOG says your partner will typically start to feel the baby move at about 20 weeks, though it can be earlier or later. There’s no official week for when you’ll feel it from the outside, so ask her to grab your hand when the baby is active.

What’s happening with her

ACOG’s guide for partners says the second trimester may be the time your partner feels the best: energy usually improves and morning sickness usually goes away. Other changes ACOG and MedlinePlus describe:

  • A bigger appetite, and less nausea and tiredness.
  • Aches on one side of the belly or in the groin, as the ligaments supporting the uterus stretch. MedlinePlus calls this round ligament pain and says it’s most common between 18 and 24 weeks. Moving slowly or changing position helps.
  • Back pain. ACOG says to call her ob-gyn if it’s severe or lasts more than two weeks, because back pain can also be a sign of preterm labor.
  • Itchy, tight skin and stretch marks, and swelling in the feet and ankles.

Two easy wins for you: do the heavy lifting (ACOG’s advice to her is to squat with a straight back, but better that you carry it), and offer a back rub. MedlinePlus suggests having someone massage the sore part of her back.

Appointments and tests

Monthly visits. MedlinePlus says prenatal visits are usually every month in the second trimester, and partners are welcome.

The anatomy ultrasound, 18 to 22 weeks. ACOG says every pregnancy should have at least one standard ultrasound, usually at 18 to 22 weeks. It checks the baby’s physical development, screens for major birth defects and estimates the baby’s age. If the baby is in a good position, it may also show the sex. Decide together beforehand whether you want to know, and tell the provider and the ultrasound team ahead of time, as MedlinePlus suggests.

The glucose screening, 24 to 28 weeks. ACOG says all pregnant women should be screened for gestational diabetes, usually between 24 and 28 weeks (earlier if she has risk factors). MedlinePlus describes the test: she drinks a sweet liquid and has blood drawn an hour later, with a longer test if the result is abnormal.

If she’s Rh-negative, MedlinePlus says she may get a shot called RhoGAM around 28 weeks.

Your second-trimester to-do list

  1. Sign up for a childbirth class. ACOG notes many couples take one at the hospital where they plan to have the baby, and classes teach you how to support her during labor.
  2. Tour the hospital. ACOG suggests asking who can be in the room, whether you can stay overnight, whether you can take photos or video, and where to park and check in.
  3. Shortlist pediatricians. The American Academy of Pediatrics recommends that parents-to-be visit a pediatrician during the third trimester, and suggests both parents go to the interviews if possible. Making the list now gives you time.
  4. Get your own shots. ACOG’s guide for partners says you need a Tdap shot at least 2 weeks before the baby is born if you haven’t had one, plus a flu shot if it’s flu season (October to May).
  5. Buy the car seat. ACOG is blunt: you can’t take the baby home without an infant car seat. Get a rear-facing one well before the due date and make sure it’s installed correctly.
  6. Look into leave. FMLA and state paid leave have notice rules. See our guide to paternity leave in the US.
  7. Plan a trip, if you want one. ACOG says the best time to travel during pregnancy is mid-pregnancy (14 to 28 weeks), when her energy is back and she can still get around easily. See the travel notes below.

Travel, exercise, sex and sleep

Travel. From ACOG:

  • She should have a prenatal check-up 4 to 6 weeks before you leave.
  • Any trip of 4 hours or more (car, train, bus or plane) doubles the risk of blood clots, and pregnancy adds to that risk. Make frequent stops to move around, and share the driving.
  • The seat belt goes low on her hip bones, below the belly.
  • Check the CDC’s travel health notices for your destination.

Exercise together. ACOG recommends at least 150 minutes a week of moderate activity for most pregnant women, like brisk walking, and says physical activity doesn’t increase the risk of miscarriage, low birth weight or early delivery. Moderate means she can still talk normally, but not sing. An evening walk together counts.

Sex. ACOG’s guide for partners says that unless her ob-gyn has said otherwise, you can have sex throughout pregnancy. You may need to try new positions as the belly grows, and it may be uncomfortable for her at times, so talk about what feels right.

Sleep. ACOG says that in the second and third trimesters, lying on her back may press on a major blood vessel to the uterus. Sleeping on her side with knees bent, a pillow between her knees and another under her belly, or a full-length body pillow, may be best. A good pregnancy pillow makes an easy gift.

When to call her provider

Call her ob-gyn or midwife for:

  • Any bleeding. ACOG says bleeding later in pregnancy can be more serious and can signal preterm labor.
  • Signs of preterm labor: cramps, a change in discharge, pressure low in the belly, a constant dull backache, or regular tightening, which ACOG says is often painless.
  • Fever, chills or pain when urinating, and moderate or severe cramping, according to MedlinePlus.
  • Urgent warning signs from the CDC, like a headache that won’t go away, vision changes, sudden swelling of the hands or face, trouble breathing, or the baby moving less.

For more on preterm signs and when to go in, see when to go to the hospital for labor.

Why showing up matters

ACOG’s guide for partners says that if you’re involved and supportive, your partner may be less anxious and less stressed in the weeks after the birth, and notes research suggesting lower rates of preterm birth and growth problems in babies of mothers with supportive partners. A US study of more than 5,000 women found those whose partners were involved in the pregnancy were 1.5 times more likely to start prenatal care in the first trimester. These studies show links, not proof, but the direction is consistent.

The practical version: go to the appointments you can, learn what’s coming, and take things off her plate. And if the mood at home gets rough, see our guide to a pregnant partner who’s angry or exhausted.

FAQ

What should dads do during the second trimester?

Go to the anatomy scan, sign up for a childbirth class, tour the hospital, shortlist pediatricians, get your own Tdap and flu shots, buy and install the car seat, and look into paternity leave. If you want a trip, ACOG says mid-pregnancy (14 to 28 weeks) is the best time.

When can dad feel the baby kick?

There’s no official week. Your partner will typically feel movement from about 20 weeks, according to ACOG, and kicks get stronger in weeks 21 to 24. Ask her to put your hand on her belly when the baby is active.

Can the baby hear dad’s voice in the womb?

ACOG says the baby can hear sounds by week 18, and by weeks 25 to 28 can respond with movement to familiar sounds, such as a parent’s voice.

Is the second trimester the easiest?

For many women, yes. ACOG says it may be the time your partner feels the best, with more energy and less morning sickness.

Is it safe to have sex in the second trimester?

ACOG says that unless her ob-gyn has said otherwise, you can have sex throughout pregnancy, though you may need to try new positions as her belly grows.

Sources