4 Months Pregnant
A look at weeks 13 through 16
Month 4 (weeks 13–16) begins the second trimester — the "golden period." Nausea fades and energy returns. Fetal sex becomes detectable.
Key changes this month
- Weeks 13–14: facial expressions form; the fetus can suck a thumb.
- Nausea generally resolves; appetite returns.
- Second-trimester screen (quad/integrated test) at 15–20 weeks.
Weeks in this month
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Textbook averages. Individual variation is wide and this is not medical advice — confirm with your OB.