Your Prenatal Care Schedule — Every Test and Appointment Explained

Prenatal care follows a time-tested schedule designed to catch complications early while supporting a healthy pregnancy. For a low-risk pregnancy, the typical visit frequency is every 4 weeks from your first appointment (around weeks 8-10) through week 28, every 2 weeks from week 28 through week 36, and every week from week 36 until delivery.

Your first prenatal visit is the longest and most comprehensive. Expect a complete health history (medical, surgical, family, and obstetric), a physical exam including a pelvic exam and Pap smear if due, blood work (blood type, Rh factor, complete blood count, hepatitis B, HIV, syphilis, rubella immunity, and possibly thyroid function), a urine test for protein and bacteria, blood pressure and weight measurements, and discussion of genetic screening options. You may also have your first ultrasound to confirm the pregnancy, check for multiples, and estimate your due date.

Subsequent routine visits are shorter (15-20 minutes) and typically include weight and blood pressure checks, urine testing for protein and glucose, measuring fundal height (the distance from your pubic bone to the top of your uterus), listening to the baby's heartbeat with a Doppler, and a chance to ask questions and discuss any concerns. From week 28 onward, fetal position may also be assessed.

High-risk pregnancies — including those with multiples, gestational diabetes, preeclampsia risk, or pre-existing conditions — require more frequent monitoring and additional testing. Your provider will customize your schedule based on your individual risk factors.

Most women with uncomplicated pregnancies have at least two ultrasounds — though the number varies by provider and risk factors. The first-trimester ultrasound (typically weeks 8-12) confirms the pregnancy, checks for a heartbeat, determines the number of babies, estimates the due date based on crown-rump length (the most accurate dating method), and may be combined with the nuchal translucency measurement for first-trimester screening.

The anatomy scan (also called the mid-pregnancy ultrasound or level-2 ultrasound) is performed between weeks 18-22 and is the most detailed routine ultrasound. The sonographer systematically examines the baby's brain, face, spine, heart (all four chambers and valves), stomach, kidneys, bladder, limbs, and umbilical cord. They also evaluate the placenta's location, the amount of amniotic fluid, and the cervical length. This is typically when the sex can be determined, if you choose to find out.

Additional ultrasounds may be recommended if the anatomy scan reveals anything that needs follow-up, if your baby is measuring significantly larger or smaller than expected, if you have conditions like gestational diabetes or hypertension, if you're carrying multiples, if the placenta was low-lying at the anatomy scan (a follow-up at 32 weeks is standard), or in the third trimester to assess fetal growth or position.

A growth ultrasound may be offered in the third trimester (around weeks 32-36) for higher-risk pregnancies to estimate fetal weight, check amniotic fluid levels, and evaluate the baby's position. Ultrasound is considered safe throughout pregnancy — there's no evidence of harm from diagnostic ultrasound at standard frequencies.

The glucose challenge test, performed between weeks 24-28, screens for gestational diabetes mellitus (GDM) — a condition where pregnancy hormones interfere with insulin's ability to regulate blood sugar. GDM affects 6-9% of pregnancies and can cause complications including larger-than-average babies (macrosomia), increased cesarean risk, neonatal hypoglycemia, and increased risk of developing type 2 diabetes later in life for both mother and child.

The one-step approach involves a 75-gram oral glucose tolerance test (OGTT) done fasting, with blood drawn at fasting, one hour, and two hours. The two-step approach (more common in the U.S.) starts with a non-fasting 50-gram glucose challenge — you drink a very sweet glucola drink and have your blood drawn one hour later. If your result exceeds the threshold (typically 130 or 140 mg/dL, depending on your provider), you'll proceed to the three-hour, 100-gram OGTT done fasting, with blood drawn at fasting, one, two, and three hours.

If diagnosed with gestational diabetes, the first line of treatment is dietary management — working with a dietitian to balance carbohydrates, eating smaller and more frequent meals, and monitoring blood sugar at home. Regular physical activity like walking after meals helps significantly. About 70-85% of women with GDM can manage it with diet and exercise alone. If blood sugar remains elevated despite lifestyle changes, medication (insulin or metformin) may be needed.

Women with risk factors — BMI over 30, family history of diabetes, prior GDM, PCOS, or certain ethnic backgrounds — may be screened earlier in pregnancy. With proper management, most women with gestational diabetes have healthy pregnancies and deliveries.

Group B streptococcus (GBS) is a type of bacteria that normally lives in the intestines and can colonize the vaginal and rectal areas. About 25% of healthy women carry GBS — it's not a sexually transmitted infection and doesn't cause symptoms in adults. However, it can be passed to the baby during vaginal delivery and cause serious neonatal infections including sepsis, pneumonia, and meningitis.

The GBS screening is a simple test performed between weeks 36-37. Your provider uses a swab to collect a sample from the vagina and rectum (you can do the swab yourself if you prefer). Results come back within 24-48 hours. GBS colonization can be transient — you may test positive in one pregnancy and negative in another, or even fluctuate during the same pregnancy. This is why testing is done close to the due date.

If you test positive, you'll receive intravenous antibiotics (typically penicillin or ampicillin) during labor — ideally at least 4 hours before delivery for maximum protection. This intrapartum antibiotic prophylaxis (IAP) reduces the risk of early-onset neonatal GBS disease by approximately 80%. You don't need antibiotics before labor starts — they need to be present in your system at the time of delivery.

Special situations: if you've had a previous baby with GBS disease, or if GBS is found in your urine during this pregnancy (indicating heavy colonization), you'll automatically receive antibiotics during labor regardless of the swab result. If you have a planned cesarean before labor begins and your membranes haven't ruptured, GBS prophylaxis may not be necessary — discuss with your provider.

If you test negative, no antibiotics are needed during labor for GBS (though they may be given for other reasons, like prolonged rupture of membranes).

Two vaccines are specifically recommended during every pregnancy, regardless of prior vaccination status, because the antibodies you produce cross the placenta and protect your baby during their vulnerable first months of life.

The Tdap vaccine (tetanus, diphtheria, and pertussis/whooping cough) is recommended between weeks 27-36, with the optimal window being weeks 27-32. Whooping cough is particularly dangerous for newborns — babies under 2 months are too young to be vaccinated themselves, and pertussis can cause severe respiratory illness, hospitalization, and even death in infants. Getting vaccinated during pregnancy provides your baby with passive immunity through your antibodies. Studies show that maternal Tdap vaccination is 78-91% effective at preventing pertussis in infants under 2 months.

The flu vaccine (inactivated influenza vaccine — the shot, not the nasal spray) is recommended for all pregnant women during flu season, regardless of trimester. Pregnancy increases the risk of severe flu complications due to changes in the immune system, heart, and lungs. The flu vaccine protects both you and your baby, as antibodies transfer across the placenta. Getting vaccinated during pregnancy reduces the risk of flu-related hospitalization by approximately 40%.

The RSV vaccine (Abrysvo) may be offered between weeks 32-36 during RSV season (September through January) to protect the newborn from respiratory syncytial virus, which is a leading cause of infant hospitalization. Discuss timing with your provider.

The COVID-19 vaccine is recommended during pregnancy if you are eligible for an updated dose. mRNA vaccines (Pfizer and Moderna) have extensive safety data in pregnancy and provide antibodies that protect the newborn.

All of these vaccines have strong safety profiles in pregnancy. Live vaccines (like MMR and varicella) should be avoided during pregnancy — if you're not immune to these, they can be given after delivery.

Blood work is a cornerstone of prenatal care, with different tests performed at different stages to monitor your health and screen for complications. At your first prenatal visit, a comprehensive panel typically includes blood type and Rh factor — if you're Rh-negative and the baby is Rh-positive, you'll need RhoGAM injections at week 28 and after delivery to prevent antibody formation. A complete blood count (CBC) checks for anemia, which is common in pregnancy due to expanded blood volume.

Infectious disease screening includes hepatitis B surface antigen, HIV, syphilis (RPR or VDRL), and rubella immunity. Depending on risk factors, hepatitis C and gonorrhea/chlamydia may also be tested. These infections can be transmitted to the baby during pregnancy or delivery, and early detection allows for treatment or preventive measures.

The first-trimester screening blood work (weeks 11-14) measures PAPP-A and free beta-hCG to assess chromosomal risk. If you opt for NIPT (cell-free DNA screening), blood is drawn as early as week 10.

At weeks 24-28, the glucose challenge test screens for gestational diabetes, and a repeat CBC checks for anemia. If you're Rh-negative, an antibody screen is repeated and RhoGAM is administered.

In the third trimester, your provider may repeat certain tests including the CBC, and STI screening (syphilis, HIV, hepatitis B, and chlamydia/gonorrhea) is recommended again for women with risk factors or as required by state law. Some providers also check thyroid function if symptoms suggest thyroid issues.

Additional blood tests may be ordered based on individual circumstances — bile acids if you report severe itching (to screen for cholestasis), liver and kidney function for suspected preeclampsia, or coagulation studies before planned procedures.