Second trimester · weeks 14–27 guide
Second trimester
Weeks 14 through 27
The second trimester spans weeks 14–27 — often called the "golden period." Nausea eases, energy returns, and the first felt movements arrive. Anatomy scan and glucose screening are the key milestones.
Months in this trimester
Key milestones
- Hearing develops at weeks 15–16; the fetus responds to outside sounds.
- Quickening (first felt movement) between weeks 18 and 22 — later in first pregnancies.
- Anatomy ultrasound (level II) at 18–22 weeks.
- Viability threshold reached at week 24.
- By the end of week 27: ~36.6 cm, ~875 g.
Recommended prenatal care
- Second-trimester screen (quad/integrated test) at 15–20 weeks.
- Anatomy ultrasound (level II) at 18–22 weeks.
- Amniocentesis, if indicated, at 16–20 weeks.
- Cervical length screening for preterm birth risk.
- Gestational diabetes screen (50 g glucose) at 24–28 weeks.
Frequently asked questions in this trimester
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When is the gestational diabetes screen done in the second trimester?
Most providers order the 50 g oral glucose challenge between 24 and 28 weeks as the first-line screen. If the result exceeds the cutoff (commonly 140 mg/dL), a 3-hour 100 g OGTT is typically used to confirm the diagnosis.
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Textbook averages. Individual variation is wide and this is not medical advice — confirm with your OB.