At 4 months pregnant, expect a small bump, steadier energy, and second-trimester screening choices while baby grows fast.
You’ve entered the second trimester. Nausea often fades, appetite returns, and a bump starts to show. The sections below cover month-four changes, tests, growth, and daily comfort.
4 Months Pregnant—What To Expect: Symptoms And Milestones
Month four covers weeks 14 through 18. Timing varies by cycle length and due-date math. Use these notes as a map, not a rigid clock.
| Task Or Topic | Why It Matters | Quick Action |
|---|---|---|
| Prenatal Visit | Track growth, blood pressure, and questions. | Schedule your month-four check. |
| Screening Options | Decide on blood tests and ultrasound timing. | Review choices before the visit. |
| Second-Trimester Ultrasound | Early anatomy review and due-date cross-check. | Book if offered this month. |
| Weight Gain Goals | Steady gain aids fetal growth. | Set a weekly range with your provider. |
| Food Safety | Lower risk from mercury and germs. | Pick low-mercury fish and reheat deli meats. |
| Exercise Routine | Helps sleep, mood, and back comfort. | Add walks, prenatal yoga, light strength. |
| Hydration | Prevents headaches and constipation. | Keep a bottle nearby; sip through the day. |
| Travel Plans | Many fly now while energy is better. | Check airline rules and seat comfort. |
| Warning Signs | Know when to call fast. | See the red-flag list below. |
Your Baby This Month
By month four, baby moves from lime to bell-pepper size. Weight rises quickly as organs mature and limbs lengthen. You may not feel movement yet, but tiny kicks start inside the uterus.
Week 14
Facial muscles practice. Lanugo—soft hair—begins to form. Genitals continue to differentiate.
Week 15
Ears move into place. Bones harden. Baby swallows fluid and makes simple breathing motions.
Week 16
Length is roughly 4–5 inches crown to rump. Eyes can make small movements behind lids. Some feel the first flutters.
Week 17
Fat stores start. The cord grows stronger. Limb motion picks up, though many still won’t feel kicks.
Week 18
Nerves gain myelin. Ears pick up sounds. An early anatomy scan may show heart chambers and spine.
Body Changes And Everyday Symptoms
A small bump shows as the uterus rises above the pelvis. Energy often rebounds. Skin and circulation shift too. Here’s what many notice and what helps.
Round Ligament Twinges
Short pulls on one or both sides, felt with quick moves or sneezes. They come from ligaments stretching with the uterus. Gentle stretching and slower position changes help.
Heartburn
Stomach acid backs up more easily. Eat smaller meals, avoid late plates, and talk to your clinician about safe antacids.
Constipation
Progesterone slows the gut. Add fiber, water, and movement. Ask before using any laxative.
Nasal Stuffiness
Extra blood flow swells nasal tissues. Saline rinses, humidifiers, and fluids bring relief.
Headaches
Often tied to dehydration or missed meals. Sip water and keep snacks handy. Check medicines with your clinician.
Back Ache
As posture shifts, aches pop up. Stable shoes, a warm shower, and a firm pillow between knees at night can ease strain.
Tests, Scans, And Screening Choices
Month four is a busy window for labs and scans. The items below cover the usual menu so you can choose with context.
Second-Trimester Blood Screening
Many clinics offer a quad test around weeks 15–22. It looks at four substances in your blood to estimate chances of certain conditions. Read about options on the ACOG prenatal screening page.
Nuchal Or Early Anatomy Ultrasound
Some clinics combine earlier first-trimester screening with this month’s ultrasound. Others schedule a targeted anatomy scan closer to 18–22 weeks.
Cell-Free DNA (If Offered)
Screening from a blood draw that reads small fragments of fetal DNA. It estimates chances for some chromosomal conditions and can report sex if you want to know. It’s still a screen, not a diagnosis.
Follow-Up Diagnostic Tests
When a screen flags higher risk, diagnostic options like chorionic villus sampling or amniocentesis may be offered. These carry risks and are optional. Your clinician can weigh the numbers with you.
Food, Supplements, And Safe Choice Basics
A steady pattern wins here. Aim for protein with each meal, calcium sources, iron-rich foods, and colorful produce. Keep the prenatal vitamin unless told otherwise.
Fish And Mercury
Pick lower-mercury fish two to three times a week and skip high-mercury choices like king mackerel or shark. See the FDA–EPA chart in Advice About Eating Fish for brand-safe picks.
Deli Meats And Cheese
Reheat deli meats until steaming. Choose pasteurized dairy. These steps reduce listeria risk.
Caffeine
Many clinicians cap at about 200 mg per day. That’s roughly one 12-ounce coffee, depending on brew strength.
Hydration And Electrolytes
Water needs rise. Sip through the day. On hot days or after a workout, add a light electrolyte drink.
Work, Travel, And Movement
Month four suits gentle travel. Pack snacks, carry water, and walk the aisle on flights. On long drives, stop to stretch.
Exercise That Feels Good
Think brisk walks, stationary cycling, swimming, and prenatal yoga. Skip contact sports and deep-twist positions. If dizziness or bleeding shows up, stop and call.
Sleep Position
Many start side-sleeping now. A pillow under the belly or between knees can ease hip and back pressure.
When To Call Your Clinician
Call right away for any of the following. Trust your instincts; you know your body best.
- Vaginal bleeding, leaking fluid, or strong cramps
- Severe headache, vision changes, or sudden swelling
- Fever, chills, or painful urination
- Fainting, chest pain, or shortness of breath
- Reduced movement later in the month after you’ve felt regular flutters
Month 4 Symptom Relief Table
| Symptom | What It Feels Like | What Helps |
|---|---|---|
| Nausea Lingering | Waves, often mornings | Small meals, ginger, vitamin B6 if cleared |
| Heartburn | Burning after meals | Smaller meals, upright after eating, safe antacids |
| Constipation | Hard stools, strain | Fiber, fluids, prune snacks, clinician-approved aids |
| Back Ache | Low back pull | Heat in short bursts, pillow placement, short walks |
| Round Ligament Pain | Quick stab with moves | Slow transitions, light stretches |
| Nose Congestion | Stuffy nose | Saline rinse, humidifier, extra fluids |
| Leg Cramps | Night calf tightness | Gentle calf stretch, magnesium if cleared |
| Headache | Dull, dehydration-linked | Water, regular snacks, rest, safe meds if advised |
| Sleep Trouble | Hard to get comfy | Side-sleep with pillows, cool room, calm routine |
| Skin Changes | Darkening line or patches | Sun protection, gentle cleansers, moisturizer |
Mood, Sex, And Relationships
Hormones settle for many in month four, and mood steadies. Some feel lighter and more social; some feel flat or worried. Both patterns are common. If low mood lingers for weeks, bring it up at your visit. Short screeners exist, and early care helps. Sex is usually safe in a low-risk pregnancy. Pick positions that feel comfortable and stop if you feel pain, bleeding, or leaking fluid.
Partners help by joining visits when possible, sharing chores, and listening. A quick nightly check-in keeps you connected. Ask about local groups or virtual classes if stress builds.
Comfort Gear Worth Considering
You don’t need a cart full of gadgets. A few items bring real comfort and value across month four:
- Maternity band for gentle belly band on walks
- Soft, breathable bras as ribcage size changes
- Body pillow or two firm pillows for side-sleeping
Keep receipts and test gear for a week. Return what doesn’t help.
Budget, Work, And Paperwork
A little planning now saves stress later. Review insurance coverage for the anatomy scan and delivery site. Ask about lactation visits and breast pump coverage. Note claim steps and phone numbers in one place. For work, check leave policies and needed forms. If you stand all day, ask about stools or short breaks. If you sit all day, adjust chair height and keep feet flat with a box or rest.
Start a simple budget for vitamins, co-pays, a few clothing basics, and a small class fund. Many clinics offer free or low-cost classes. Build a baby list when you’re ready.
Common Worries And Straight Facts
“I don’t feel movement yet.” Many don’t until 18–22 weeks, and later with a first pregnancy or an anterior placenta. “I’m not showing.” Bump size varies by body type, muscle tone, and how you carry. “My weight is up and down.” Day-to-day swings reflect salt and fluids; the trend over weeks matters more. If any change feels off, call the clinic and ask for a quick check.
The phrase “4 months pregnant—what to expect” will still guide your next steps: steady meals, regular movement, smart sleep, and a short list of red flags. If your path looks different, that’s normal. Stay in touch with your care team and use each visit to tailor the plan to your body.
If you searched for “4 months pregnant—what to expect,” you’re in the right spot. Use the steps above, watch the call list, and set a pace that fits your month.