# Pregnancy Month by Month: What Happens Each Trimester

> What usually happens in each trimester, and the checkups along the way, from What to Expect.

Stage: pregnancy - Topic: Your pregnancy - Page: https://www.askcladle.com/guides/pregnancy/pregnancy-month-by-month

Grounded in: the month-by-month approach of Heidi Murkoff's *What to Expect When You're Expecting*, and standard prenatal-care guidance (for example from ACOG in the US). Paraphrased general information, not medical advice - the pregnant person's own practitioner decides.

## TLDR

- First trimester: tiredness and nausea are common; start prenatal care and a folic acid vitamin early.
- Second: more energy, an anatomy scan around 18-22 weeks, first kicks somewhere around 16-25 weeks, glucose test at 24-28.
- Third: aches, heartburn and practice contractions are normal, but a noticeable drop in the baby's movement means call right away.

## The approach

Knowing what is typical at each stage reduces worry, and anything unusual gets checked with the
practitioner (OB, midwife or family doctor) rather than looked up and guessed at. "Call your
practitioner" is a normal, encouraged step, not an overreaction.

## First trimester (weeks 1-13)

- Common: fatigue, nausea/vomiting ("morning sickness" can be any time of day), breast
  tenderness, frequent urination, mood swings, food aversions.
- Start prenatal care early; a prenatal vitamin with folic acid is standard advice.
- Severe, persistent vomiting (can't keep fluids down) needs a call to the practitioner.

## Second trimester (weeks 14-27)

- Often more energy and less nausea. The anatomy ultrasound usually happens around 18-22 weeks.
- First fetal movements are typically felt somewhere around 16-25 weeks (earlier in later
  pregnancies); timing varies widely.
- Glucose screening for gestational diabetes is commonly done around 24-28 weeks.

## Third trimester (weeks 28-40+)

- Common: backache, heartburn, swelling of feet/ankles, shortness of breath, trouble sleeping,
  Braxton Hicks (practice) contractions.
- Many practitioners suggest paying attention to the baby's usual movement pattern; a noticeable
  decrease is a reason to call right away, not to wait.
- Preparing: a birth plan (held loosely), a car seat installed before the birth, and support
  lined up for the postpartum weeks.
- Ask about vaccines in pregnancy: Tdap (usually 27–36 weeks) and the maternal RSV vaccine (32–36
  weeks, in RSV season) both pass protection to the baby.

## Emotional side

Anxiety, ambivalence and big feelings are common. Persistent sadness, hopelessness, or anxiety
that interferes with daily life can be perinatal depression or anxiety - treatable, and worth
raising with the practitioner.