Prenatal care schedule: what happens at each visit in U.S. clinics

The first time I looked at a prenatal appointment card, the dates felt like stepping stones across a stream—close at first, then farther apart, then suddenly packed as the due date approached. I wanted a plain-English map of what actually happens at each visit, so I pulled together notes from my own clinic experiences and what major U.S. guidelines suggest. My goal here is simple: if you’re walking into a prenatal visit, you know what to expect, what paperwork or lab slip might be waiting, and how to keep track without getting overwhelmed.

The rhythm most clinics follow through pregnancy

Most U.S. clinics use a pretty standard cadence, with flexibility for individual needs. It looks like this for many low-risk pregnancies:

• First trimester (weeks 6–13) One longer “new OB” visit after pregnancy is confirmed (often around 8–12 weeks), plus any early check-ins if needed. A provider may discuss options for genetic screening; see ACOG’s overview for what’s typically offered.
• Second trimester (weeks 14–27) Visits about every 4 weeks. The big event is the detailed anatomy ultrasound around 18–22 weeks; more on that below.
• Third trimester (weeks 28–36) Visits about every 2 weeks. You’ll usually get the Tdap vaccine between 27–36 weeks to protect your newborn from pertussis; the CDC has a clear explainer here.
• Late third trimester (weeks 36–birth) Weekly visits, including Group B strep (GBS) screening around 36–37 weeks; CDC’s GBS page is helpful here.

That’s the backbone. High-value takeaway: the schedule is a template, not a contract. Complications, multiples, preexisting conditions, or just “I have a worry today” can shift the plan. Good clinics flex.

What typically happens at every visit

Even when there isn’t a “special” test, quite a lot is happening under the hood. Here’s the short list providers usually check at each appointment:

• Vitals Blood pressure (preeclampsia screening), pulse, weight, and sometimes temperature. BP checks are a key safety measure; the USPSTF recommends screening for hypertensive disorders throughout pregnancy, which practically means at every visit (policy summary available from USPSTF; a general overview of prenatal care components is at MedlinePlus).
• Urine dip Many clinics do periodic urine checks for protein, glucose, and sometimes signs of infection, especially if symptoms or risks are present.
• Fetal heartbeat and growth After about 10–12 weeks, they’ll use Doppler to listen for the fetal heart tones. From ~20 weeks, they measure fundal height (belly measurement) to track growth.
• Symptoms and counseling Nausea, sleep, mood, pain, bleeding, movement, contractions—this is your time to bring up anything. You may see periodic screening for depression or anxiety; perinatal mental health matters and clinics increasingly use brief tools to check in (see ACOG’s resources).

The first long visit sets your baseline

That initial appointment is the “setup” for the rest of care. Expect:

• History and physical Medical conditions, prior pregnancies, medications/supplements, allergies, surgeries, family history, and social supports. Many clinics also ask about safety and intimate partner violence in a private, respectful way (resources via CDC).
• Dating confirmation Early ultrasound may be done to confirm viability and refine due date if periods are irregular or dates are uncertain.
• Baseline labs Blood type and Rh factor, antibody screen, complete blood count (anemia), rubella and varicella immunity, hepatitis B and C, HIV, syphilis, sometimes thyroid function based on risks, and a urine culture for asymptomatic bacteriuria (USPSTF recommends this early in pregnancy; see their summaries here).
• Genetic screening options These can include carrier screening (e.g., cystic fibrosis, SMA), first-trimester combined screening (nuchal translucency + labs), or cell-free DNA screening from ~10 weeks. A clear patient snapshot is on ACOG’s FAQ.
• Vaccination review Seasonal influenza vaccine can be given in any trimester; Tdap is later; COVID-19 vaccination is recommended during pregnancy per CDC guidance (CDC COVID-19 and pregnancy).

One more thing: if you are Rh-negative, make a mental note that a Rho(D) immune globulin shot is usually planned at ~28 weeks and again after birth if the baby is Rh-positive; ACOG explains this in patient materials (overview).

Second trimester feels steadier and adds key screens

Here’s what usually lands between weeks 14–27:

• Anatomy ultrasound ~18–22 weeks A detailed look at the baby’s organs, placenta location, and measurements. If views are limited, expect a repeat to complete the survey.
• Maternal serum screening If not done in the first trimester, some clinics offer second-trimester screening for neural tube defects and other conditions. Exact panels vary; your clinic should walk you through pros/cons (ACOG has a plain-language refresher here).
• Glucose screening 24–28 weeks The 1-hour glucose challenge (and possibly a follow-up 3-hour test if needed) screens for gestational diabetes. The CDC’s page on gestational diabetes gives a solid overview.
• Rhogam planning If you’re Rh-negative, the 28-week shot gets scheduled now.
• Birth prep conversations begin Travel, work accommodations, classes, hospital preregistration, doulas, and breastfeeding questions often surface here. Many clinics share handouts or point to MedlinePlus pregnancy pages.

Third trimester shifts into preparation and closer monitoring

From weeks 28 onward, visits pick up and the focus expands from wellness to readiness:

• Vaccines Tdap at 27–36 weeks, ideally earlier in that window to pass antibodies to the baby (CDC guidance here). Flu and COVID boosters as seasonally indicated.
• Anemia recheck A repeat blood count may be done around 28 weeks to catch treatable iron deficiency.
• GBS screening ~36–37 weeks A vaginal/rectal swab checks for Group B strep; if positive, antibiotics in labor reduce newborn risk (CDC primer here).
• Position and planning Providers palpate for baby’s position; ultrasounds may confirm breech or transverse, with counseling about options.
• Extra testing if needed For certain conditions (e.g., high blood pressure, diabetes, growth concerns, IVF conception, age-related risks), clinics may add nonstress tests (NSTs) and/or biophysical profiles (BPPs) once or twice weekly in the final weeks.

Also in this stretch: labor signs review, kick counts, hospital bag checklists, and discussion of pain management preferences. ACOG’s patient pages on labor are a handy primer (induction, labor and delivery basics).

Visit-by-visit snapshot you can skim

• 8–12 weeks Comprehensive intake, dating confirmation, baseline labs, genetic screening options, early ultrasound as indicated.
• 12–16 weeks Review first-trimester results, check vitals and heartbeat, discuss second-trimester screening choices.
• 16–20 weeks Fundal height begins; schedule anatomy scan; address sleep, back pain, nutrition, and exercise goals.
• 20–24 weeks Anatomy scan results, plan for glucose testing, travel/work adjustments, childbirth class sign-ups.
• 24–28 weeks 1-hour glucose screen; CBC recheck; give Rhogam if Rh-negative; Tdap planning; kick-count tips.
• 28–32 weeks Biweekly visits; discuss birth preferences; breastfeeding resources; review warning signs.
• 32–36 weeks Position check; hospital preregistration; pack bag; car seat plan; discuss induction timing if needed.
• 36–37 weeks GBS culture; weekly visits begin; cervix checks if relevant; finalize pediatrician choice.
• 37–40+ weeks Weekly assessment; NSTs if indicated; membrane sweep discussion; postpartum planning (support at home, mood check, lactation plan).

When the schedule changes and why that’s okay

Pregnancy is not a performance test; it’s a dynamic process. Your plan may expand because of twins or higher-order multiples, high blood pressure, gestational diabetes, autoimmune disease, IVF pregnancies, or growth concerns. If your clinic adds ultrasounds or NSTs, it’s typically to get more data for timely decisions. Good questions to ask: “What is this test looking for?”, “How might the result change my care?”, and “Is the result urgent or just informative?” ACOG offers patient-friendly explanations of common conditions and monitoring choices (ACOG patient hub).

Lab tests and vaccines most people encounter

• Infectious disease screening HIV, hepatitis B, syphilis are standard early screens; hepatitis C screening during each pregnancy is recommended by CDC (details).
• Urine culture Early pregnancy screen for asymptomatic bacteriuria reduces kidney infection risk later (see USPSTF recommendations summarized on their site here).
• Gestational diabetes 24–28 weeks screening; management ranges from diet changes to medication depending on results (CDC overview here).
• Vaccines Influenza (any trimester), Tdap (27–36 weeks), COVID-19 per CDC; some clinics consider RSV vaccination timing if available in your area and season (check the latest guidance on CDC’s pregnancy vaccine page).
• GBS culture 36–37 weeks to guide in-labor antibiotics (CDC GBS info here).

Little habits that made my visits smoother

• Keep a running note I use my phone to jot symptoms, questions, medication doses, and kick-count patterns. It turns five scattered thoughts into one clear conversation.
• Bring snacks and water Glucose days can be long. Even routine visits can run behind; a granola bar can rescue your mood.
• Use reminders for time-sensitive steps Calendar alerts for the anatomy scan window, glucose screen week, Rhogam at 28 weeks, and Tdap timing saved me mental load.
• Ask for printouts or portal messages Many clinics will upload handouts or summaries to your patient portal. I bookmark mine next to links like MedlinePlus Pregnancy for quick refreshers.

What providers listen for between the lines

Across visits, clinicians are quietly assessing how you’re coping. Are you sleeping? Is pain manageable? Are there social stressors? Is your mood okay? It’s normal to need extra support. If you want a mental health check, say so—there are short screeners and referrals that can help (ACOG’s perinatal mental health program offers tools).

Signals that tell me to slow down and call

Not every twinge is urgent, but these are the classic “do not wait” signs most clinics highlight (your exact instructions may vary):

• Vaginal bleeding heavier than spotting or with cramps, any time.
• Severe headache, vision changes, right-upper-quadrant pain, or sudden swelling (possible high blood pressure concerns).
• Decreased fetal movement after you’ve noticed a regular pattern.
• Leaking fluid that could be amniotic fluid.
• Regular, painful contractions before 37 weeks or any labor pattern that worries you.
• Fever or symptoms of infection.

Most clinics have a 24/7 nurse line; save the number in your phone. When in doubt, calling is appropriate. For general symptom pages, I like MedlinePlus on prenatal care.

Preparing for after the birth while you’re still pregnant

Postpartum isn’t a single six-week visit anymore. Many clinics aim for contact within 1–3 weeks and a comprehensive visit by 12 weeks, with earlier checks if you had a complication. In the late third trimester, I found it helpful to line up:

• A postpartum plan Who’s on your support team? How will you get sleep? What signs of mood changes will you watch for?
• Feeding support If you plan to breastfeed, ask about lactation resources before delivery; if you plan to formula feed, ask about safe prep and storage.
• Chronic condition follow-up If you had gestational diabetes or hypertensive disorders, ask what labs or BP checks happen after delivery (CDC has a concise GDM follow-up note within their pages here).

What I’m keeping and what I’m letting go

I’m keeping three simple principles: one page for my questions, one calendar for the big milestones, and one trusted source per topic (for me, that’s ACOG for pregnancy-specific choices, CDC for immunizations, and MedlinePlus when I want a calm overview). I’m letting go of the idea that every visit needs a “big result.” Sometimes the most important thing a visit does is quietly confirm you and the baby are okay.

FAQ

1) Do I have to follow the exact visit schedule?
Answer: The standard cadence is a safe default, but clinics individualize it. If you have risk factors or just feel unsure, it’s reasonable to ask for an extra check. ACOG’s patient hub explains why schedules can flex here.

2) Which vaccines are routinely recommended in pregnancy?
Answer: Influenza (any trimester), Tdap at 27–36 weeks, and COVID-19 per current CDC guidance. Your clinic may discuss RSV depending on season and availability. See CDC’s pregnancy vaccine page here.

3) What is Group B strep and why is the swab so late?
Answer: GBS is a common bacteria; screening at 36–37 weeks best predicts your status at delivery, guiding antibiotics during labor if positive. CDC’s GBS overview is here.

4) How do I prepare for the glucose test?
Answer: Your clinic will give specific instructions (many do not require fasting for the 1-hour screen). Bring a snack for afterward and plan extra time at the lab. CDC’s GDM page gives context here.

5) What if I’m Rh-negative?
Answer: You’ll likely get Rho(D) immune globulin at ~28 weeks and again after birth if your baby is Rh-positive. ACOG’s patient explainer is here.

Sources & References

• ACOG Patient Resources
• CDC Vaccines and Pregnancy
• CDC Group B Strep
• USPSTF Pregnancy Screening Summaries
• MedlinePlus Pregnancy

This blog is a personal journal and for general information only. It is not a substitute for professional medical advice, diagnosis, or treatment, and it does not create a doctor–patient relationship. Always seek the advice of a licensed clinician for questions about your health. If you may be experiencing an emergency, call your local emergency number immediately (e.g., 911 [US], 119).