Weeks 14–27 are widely considered the most comfortable stretch of pregnancy: nausea fades, energy returns, the bump appears, and those first flutters arrive.
The second trimester spans weeks 14–27. The baby grows from lemon to head-of-cabbage size, develops hearing and sleep-wake cycles, and reaches viability around week 24. Highlights: the anatomy scan at 18–22 weeks, first movements between weeks 18 and 22, and glucose screening at 24–28 weeks.
18–22 wks
Typical window for the detailed anatomy ultrasound
~24 wks
Viability milestone, when lungs can work with medical support
24–28 wks
When glucose screening for gestational diabetes is done
~875 g
Approximate fetal weight by the end of week 27
Why the Second Trimester Is Called the Golden Period
Ask parents to name their favorite trimester and the second wins by a landslide: hCG levels plateau and fall, the placenta takes over hormone production more smoothly, energy resurfaces, and appetite returns.
It is also when pregnancy starts to feel real in joyful ways: the uterus rises out of the pelvis, a visible bump appears — usually between weeks 14 and 20 — and partners can eventually feel kicks from the outside.
“Golden” does not mean symptom-free. New sensations replace the old ones: backaches, leg cramps, heartburn, and vivid dreams commonly debut now. The difference is that most second trimester discomforts are manageable annoyances rather than all-consuming nausea — a trade most people gladly accept.
Baby Development: Weeks 14–27
With every organ system built in the first trimester, the second is about growth, refinement, and the senses switching on — the fetus roughly triples in length.
Weeks 14–17: The senses awaken
The neck lengthens and the head sits more upright. Taste buds form, light sensitivity begins, the skeleton hardens from cartilage to bone, and a waxy coating called vernix covers the skin.
Weeks 18–22: Anatomy scan window
The inner ear bones harden enough for hearing to begin, eyebrows and eyelashes appear, and the grip reflex develops. By week 22 the fetus weighs about a pound.
Weeks 23–27: Viability and brain growth
The lungs develop the structures needed for gas exchange, pushing the fetus toward viability around week 24. The brain forms its folds, eyelids open around week 26, and REM sleep appears by week 27.
How Your Body Changes
Your body in the second trimester is visibly, unmistakably pregnant. The uterus grows from lemon to cabbage size, rising toward the belly button by week 20, and blood volume increases by up to 50 percent.
Aches, pains, and new sensations
Round ligament pain — brief, sharp twinges in the lower belly or groin when you move suddenly — is the most common new ache. Lower back pain follows as your center of gravity shifts, and leg cramps often strike at night; gentle stretching before bed helps.
Skin, hair, and digestion
Increased blood flow can bring the famous “pregnancy glow,” though hormones also trigger acne or dark facial patches (melasma) — all temporary. The growing uterus crowds the stomach, so heartburn and constipation often replace first trimester nausea.
Feeling Your Baby Move: Quickening
Quickening — the first perception of fetal movement — is famously hard to describe until you have felt it: bubbles popping, a fish swishing, light taps low in the abdomen. Many people initially mistake it for gas. Then the pattern repeats, and you know.
First-time parents typically notice movement between weeks 18 and 22; those previously pregnant often recognize it earlier. An anterior placenta can delay when you feel movements. By weeks 24–26, kicks, rolls, and hiccups strengthen enough for partners to feel.
Movement is still irregular now — the baby sleeps a lot — so providers do not usually ask you to count kicks until the third trimester. But if regular movement suddenly stops or drops off sharply, call your provider the same day.
The Anatomy Scan at 18–22 Weeks
The anatomy scan is the most comprehensive look at your baby before birth: a sonographer examines the brain, face, heart, spine, kidneys, and limbs, measuring growth. It usually takes 30–45 minutes — longer if the baby is camera-shy.
The scan also evaluates the pregnancy itself: placental location, amniotic fluid volume, and cord vessels. If you want to know the sex, this is typically when it is confirmed. Many parents leave with printed images that suddenly make the baby feel very real.
Occasionally the scan flags something needing a closer look — an incomplete heart view or a measurement outside the typical range. Most such findings resolve on follow-up, but the wait can be anxious. Ask exactly what was seen, what it could mean, and what the next step is.
Glucose Screening and Other Tests
The headline test of late second trimester is glucose screening for gestational diabetes — high blood sugar that develops during pregnancy and affects roughly 6–9 percent of pregnancies. The one-hour glucose challenge test, done between weeks 24 and 28, involves drinking a sweet solution and having blood drawn an hour later.
A result above the lab's threshold leads to the three-hour glucose tolerance test, which requires fasting. Needing the longer test does not mean you have gestational diabetes — many people pass it. If diagnosed, it is managed with diet, activity, monitoring, and sometimes medication, and it usually resolves after delivery.
Other routine checks include repeat blood work for anemia, an antibody screen for Rh-negative parents, and blood pressure and urine checks at every visit, plus the recommended Tdap vaccine. Your estimated due date is also reviewed against scan measurements.
Week-by-Week: Weeks 14–27
From first flutters to the viability milestone, every week of the second trimester has something worth knowing. Pick your current week below.
The second trimester is generally smooth sailing, but certain symptoms always merit a prompt call: vaginal bleeding, fluid leaking from the vagina, regular painful contractions before 37 weeks, severe headache, vision changes, sudden swelling of the face or hands, severe abdominal pain, fever, or a sudden decrease in fetal movement.
Regular, timeable contractions before 37 weeks can signal preterm labor — which can sometimes be slowed when caught early, so calling quickly matters. When in doubt, call. No provider has ever wished a patient waited longer with concerning symptoms.
Medical disclaimer: This calculator provides estimates for educational purposes and is not medical advice. Always confirm with your healthcare provider.
Frequently Asked Questions
Common questions answered by our medical team
First-time parents usually notice quickening — the first faint flutters — between weeks 18 and 22. Those previously pregnant may recognize it as early as weeks 14–16. Early movements feel like bubbles or gentle taps, becoming unmistakable kicks and rolls by the mid-20s weeks.