# First Trimester for Dads: What's Happening and What to Do

> What happens in the first trimester for your partner and the baby, the appointments and tests to expect, the jobs that are yours, and when to tell people.

By Yoedhistiera, Bapak Life. Topic: Pregnancy. Published October 27, 2026.
Canonical: https://bapaklife.com/first-trimester-for-dads/

## Key takeaways

- The first trimester runs from the first day of her last period to the end of week 13. Pregnancy is counted from that date, so it starts about two weeks before conception.
- By the end of it, the baby is about 3 inches long and the heart has been beating in a regular rhythm since around weeks 6 to 7.
- Your jobs: go to appointments, bring your family health history, take over the cat litter, and help keep alcohol, smoke and risky foods out of her week.
- Early pregnancy loss happens in about 10 of 100 known pregnancies and is almost never anyone's fault. When to tell people is your call as a couple.

You just found out. Maybe you're thrilled, maybe you're terrified, probably both. The first trimester for dads is a strange stretch: nothing shows yet, your partner may feel awful, and most of what's happening is invisible. This guide covers what's going on with the baby and with her, the appointments and tests coming up, the jobs that are clearly yours, and the question everyone asks: when do we tell people?

## The short answer

- **How long is it?** From the first day of her last period to 13 weeks and 6 days.
- **What's happening?** The baby's brain, spine and heart form, and by the end the baby is about 3 inches long.
- **What's she going through?** Often exhaustion, nausea, tender breasts and mood swings.
- **What can you do?** Go to appointments, take over the cat litter and the smelly jobs, help her avoid alcohol, smoke and risky foods, and sort out insurance.

## How the first trimester is counted

The American College of Obstetricians and Gynecologists (ACOG) defines the first trimester as the first day of the last menstrual period (LMP) to 13 weeks and 6 days. Pregnancy is counted from that date, which means the first two weeks happen before conception. So when your partner is "6 weeks pregnant," the baby is about 4 weeks old.

The due date is calculated the same way, about 40 weeks from the LMP. Don't plan your life around it to the day: ACOG says only about 1 in 20 babies arrive on their due date.

## What's happening with the baby

- **Weeks 1 to 8:** the brain and spine begin to form, and heart tissue starts to develop (ACOG).
- **Around weeks 6 to 7:** the heart beats in a regular rhythm, which can be seen on a vaginal ultrasound (MedlinePlus). The heartbeat usually can't be seen or heard before then.
- **End of week 10:** the baby is no longer called an embryo but a fetus. The heartbeat may be picked up with a Doppler device.
- **Weeks 9 to 12:** eyelids form, the kidneys start making urine and fingernails form (ACOG).
- **Around week 12:** about 3 inches long and almost an ounce, according to the federal Office on Women's Health.

## What's happening with her

The Office on Women's Health lists these common first-trimester changes:

- Extreme tiredness
- Tender, swollen breasts
- Nausea, with or without vomiting
- Cravings, or suddenly hating certain foods
- Mood swings
- Needing to pee more often
- Headaches, heartburn and constipation

**Nausea** usually starts before 9 weeks and, for most women, goes away by 14 weeks, according to ACOG. It can hit at any time of day despite the name "morning sickness." ACOG's practical tips include using a fan when cooking and having someone else empty the trash. That someone is you.

## Appointments and tests to expect

**The first visit** should happen soon after she learns she's pregnant, according to MedlinePlus, with a visit about every month after that in the first trimester. Partners are welcome. Two things you can bring:

- **Your family health history.** The provider will ask whether either of you has genetic disorders or health problems that run in the family.
- **Questions.** Write them down; the visits can be quick.

**Tests in the first trimester** usually include blood tests (blood type, Rh factor, a blood count and screening for infections such as hepatitis B and HIV), a urine test, and an ultrasound to help set the due date.

**Genetic screening** is offered to all pregnant women, according to ACOG:

- **First-trimester screening:** a blood test and an ultrasound, usually done together between 10 and 13 weeks.
- **Cell-free DNA screening:** a blood test that can be done from 10 weeks, with results in about a week.
- A positive screening result doesn't mean the baby definitely has a condition; it means more testing may be offered. ACOG is clear that there's no right or wrong answer about whether to have these tests. Decide together.

## The jobs that are yours

**The cat litter.** The CDC says that if someone in the house is pregnant, another household member should clean the litter box. Cat feces can carry a parasite that, if she's infected during pregnancy, can pass to the baby and cause birth defects. Wear disposable gloves, and change it daily.

**A smoke-free home.** The CDC says there is no safe level of exposure to secondhand smoke, and women exposed to it during pregnancy are more likely to have babies with lower birth weight. If you smoke, this is the moment to quit, and never smoke inside the house or car.

**No alcohol for her.** The CDC says there is no known safe amount of alcohol during pregnancy, and no safe time to drink. Going alcohol-free alongside her makes it easier.

**Food safety.** Listeria is rare but dangerous in pregnancy. The CDC's list of foods to avoid includes:

- Unheated deli meats, cold cuts and hot dogs (heat them to 165°F or until steaming hot instead)
- Unheated queso fresco and similar soft cheeses
- Refrigerated smoked fish
- Raw or lightly cooked sprouts
- Raw (unpasteurized) milk, yogurt and ice cream
- Cut melon left out for more than 2 hours

If you do the cooking, this is an easy one to own.

**Folic acid.** The CDC recommends 400 micrograms of folic acid daily for anyone who could become pregnant, because neural tube defects happen in the first few weeks, often before a woman knows she's pregnant. Her provider will likely recommend a prenatal vitamin; help her remember it.

## When to tell people

There's no rule. What's useful to know is how common early loss is, so the decision is an informed one:

- **It's common.** ACOG says early pregnancy loss, before 13 completed weeks, happens in about 10 of 100 known pregnancies. About half are caused by the embryo not developing properly, often because of an abnormal number of chromosomes.
- **It's almost never anyone's fault.** ACOG says that in almost every case, a miscarriage is not a woman's fault. Working, exercising, stress, arguments and sex don't cause it.
- **It usually doesn't happen again.** Most women who have an early loss go on to have successful pregnancies.

Some couples wait until after the first trimester to tell anyone. Others tell close family or friends early, so they'd have support either way. Both are reasonable. Agree on it together, and on who tells whom.

## What might happen to you

Some expectant dads get symptoms of their own. In a classic 1982 study at a US health plan, about 22.5% of expectant fathers sought medical care for pregnancy-like symptoms such as nausea and abdominal pain, a pattern called couvade syndrome. Later studies report very different rates, and there's no agreed way to define or measure it, so take any single number loosely.

Your hormones may shift too. A small study of 29 first-time couples found that expectant fathers' testosterone fell during the pregnancy. In another small study, dads whose testosterone dropped more reported more investment and commitment after the birth.

## Money and insurance

Sort this out early:

- **Coverage:** all Marketplace and Medicaid plans cover pregnancy and childbirth, even if the pregnancy began before the coverage started, according to HealthCare.gov. If your coverage comes through a large employer that self-insures, check your plan, because those plans don't have to cover the same essential benefits.
- **Enrollment:** being pregnant doesn't qualify you for a Special Enrollment Period on the Marketplace, but the birth does. Add the baby within 60 days of the birth, and coverage can start on the day the baby was born.
- **Medicaid:** you can apply any time of year. If she has Medicaid when she gives birth, the baby is automatically enrolled and stays eligible for at least a year.
- **Leave:** start looking at your own options for time off after the birth. FMLA and state paid leave both have notice rules; see our guide to [paternity leave in the US](/paternity-leave-in-the-us/).

When the first trimester gets rough at home, see our guide to [a pregnant partner who's angry or exhausted](/pregnant-wife-angry-and-exhausted/). Next up: [the second trimester for dads](/second-trimester-for-dads/). Later on: [what dads do during labor](/what-dads-do-during-labor/) and [everything in Pregnancy](/category/pregnancy/).

## FAQ

### What should a dad do in the first trimester?

Go to the first prenatal visit with your family health history, take over the cat litter and any cooking smells, help keep alcohol, smoke and high-risk foods out of the house, and check your insurance and leave options.

### When can you hear the baby's heartbeat?

The heart beats in a regular rhythm from around weeks 6 to 7, which can be seen on a vaginal ultrasound. With a Doppler device, heart tones may be picked up from around the end of week 10, according to MedlinePlus.

### How common is miscarriage in the first trimester?

ACOG says early pregnancy loss happens in about 10 of 100 known pregnancies. It's usually a random event and almost never caused by anything either parent did.

### Can dads get pregnancy symptoms?

Some do. Couvade syndrome describes expectant fathers seeking care for pregnancy-like symptoms such as nausea or stomach pain. Studies report very different rates and there's no agreed definition, but it's a recognized pattern.

### Should we tell people before 12 weeks?

It's your choice as a couple. Some wait until the first trimester is over; others tell a few close people early so they have support either way.

## Sources

- [How Your Fetus Grows During Pregnancy](https://www.acog.org/womens-health/faqs/how-your-fetus-grows-during-pregnancy), [Early Pregnancy Loss](https://www.acog.org/womens-health/faqs/early-pregnancy-loss), [Prenatal Genetic Screening Tests](https://www.acog.org/womens-health/faqs/prenatal-genetic-screening-tests), [Routine Tests During Pregnancy](https://www.acog.org/womens-health/faqs/routine-tests-during-pregnancy) and [Morning Sickness: Nausea and Vomiting of Pregnancy](https://www.acog.org/womens-health/faqs/morning-sickness-nausea-and-vomiting-of-pregnancy), American College of Obstetricians and Gynecologists
- [Prenatal care in your first trimester](https://medlineplus.gov/ency/patientinstructions/000544.htm) and [Fetal development](https://medlineplus.gov/ency/article/002398.htm), MedlinePlus (National Library of Medicine)
- [Stages of pregnancy](https://womenshealth.gov/pregnancy/youre-pregnant-now-what/stages-pregnancy), Office on Women's Health (HHS)
- [About Cleaning and Disinfecting Pet Supplies](https://www.cdc.gov/healthy-pets/about/cleaning-and-disinfecting-pet-supplies.html), [Health Problems Caused by Secondhand Smoke](https://www.cdc.gov/tobacco/secondhand-smoke/health.html), [About Alcohol Use During Pregnancy](https://www.cdc.gov/alcohol-pregnancy/about/index.html), [Preventing Listeria Infection](https://www.cdc.gov/listeria/prevention/index.html) and [About Folic Acid](https://www.cdc.gov/folic-acid/about/index.html), Centers for Disease Control and Prevention
- [Health coverage if you're pregnant, plan to get pregnant, or recently gave birth](https://www.healthcare.gov/what-if-im-pregnant-or-plan-to-get-pregnant/) and [What Marketplace health insurance plans cover](https://www.healthcare.gov/coverage/what-marketplace-plans-cover/), HealthCare.gov
- [The couvade syndrome: an epidemiologic study](https://pubmed.ncbi.nlm.nih.gov/7199885/), Lipkin and Lamb, *Annals of Internal Medicine*, 1982
- [Prenatal hormones in first-time expectant parents: longitudinal changes and within-couple correlations](https://pubmed.ncbi.nlm.nih.gov/25504668/), Edelstein et al., *American Journal of Human Biology*, 2015
- [Fathers' decline in testosterone and synchrony with partner testosterone during pregnancy predicts greater postpartum relationship investment](https://pubmed.ncbi.nlm.nih.gov/27469070/), Saxbe et al., *Hormones and Behavior*, 2017