The Complete Guide to Ultrasound Schedule Timing During Pregnancy

Aug 11

11 min read

When Do You Get Ultrasounds During Pregnancy?

What weeks do you get ultrasounds during pregnancy? Many people have an early scan around 6 to 8 weeks when needed, a first-trimester dating scan around 10 to 14 weeks, and a detailed anatomy scan between 18 and 22 weeks. Some people also have a quick position check near 36 weeks, while others need extra scans based on their health or the baby's growth.

Pregnancy stage	Typical ultrasound timing	Main reason
Early pregnancy	6 to 8 weeks, if needed	Confirm location, dating, and heartbeat
First trimester	10 to 14 weeks	Confirm due date and early development
Second trimester	18 to 22 weeks	Check anatomy, growth, placenta, and fluid
Third trimester	Around 36 weeks, if needed	Check baby's position and monitor specific concerns

Ultrasounds use sound waves to create images of the pregnancy. They can answer important early questions, such as whether the pregnancy is developing in the uterus and how far along it may be. A scan is also only one part of prenatal care, so your provider will recommend timing that fits your individual situation.

I am Leo Kim, Executive Director of LivingWell Pregnancy Centers, and our team has supported women who are anxious about what weeks do you get ultrasounds during pregnancy and what an early scan can show. At LivingWell, we offer free, confidential pregnancy support at 2010 N Tustin St, Suite C, Orange, CA 92865, so you can get clear information and consider your next steps with care.

What Weeks Do You Get Ultrasounds During Pregnancy? The Typical Schedule

When you first discover you are pregnant, one of the very first questions on your mind is likely: When do I get to see my baby? The timeline for prenatal imaging can feel confusing, especially with so many terms like "dating scan," "nuchal translucency," and "anatomy survey" being tossed around.

In a routine, uncomplicated pregnancy, the American College of Obstetricians and Gynecologists (ACOG) recommends at least one standard ultrasound, typically performed during the second trimester. However, in modern clinical practice, most women undergo between one and two routine scans. According to official Ultrasound in Pregnancy schedule guidelines, expectant mothers usually receive a first-trimester scan to confirm gestational age and a second-trimester anatomy scan to review fetal development.

If your pregnancy is low-risk, your ultrasound schedule will generally follow a predictable path:

Early Confirmation / First Trimester Scan: Weeks 6 to 8 (if clinically indicated) or weeks 10 to 14.
Second Trimester Anatomy Scan: Weeks 18 to 22 (often called the 20-week scan).
Third Trimester Position Check: Around week 36 (a quick, optional office scan to confirm fetal presentation).

Understanding this timeline helps you know what to expect at each appointment, reducing anxiety and allowing you to prepare for every milestone.

Early Confirmation and First Trimester: What Weeks Do You Get Ultrasounds During Pregnancy for Initial Dating?

The first trimester is a period of rapid fetal development. Early imaging serves a specific set of clinical purposes: establishing that a pregnancy is viable, verifying that it is located safely inside the uterus (ruling out an ectopic pregnancy), establishing an accurate due date, and confirming whether you are carrying multiples.

Early ultrasound milestones occur on a remarkably precise timeline:

5 Weeks: The gestational sac becomes visible on an early transvaginal scan as a small fluid-filled structure within the uterus.
5.5 Weeks: The yolk sac appears inside the gestational sac, providing essential nutrients to the developing embryo.
6 Weeks: Fetal cardiac flickering can typically be detected once the embryo reaches a crown-rump length (CRL) of approximately 7 millimeters.
6 to 8 Weeks: An early viability scan may be performed if you are experiencing cramping, spotty bleeding, or if you are unsure of the date of your last menstrual period.

For women seeking immediate clarity without insurance barriers or out-of-pocket costs, our licensed medical team provides a free pregnancy verification scan to confirm early viability and determine accurate gestational age.

Between weeks 10 and 14, many women undergo a standard first-trimester dating scan. During this window, measuring the baby's crown-rump length gives healthcare providers the most accurate method for establishing an estimated due date. In fact, first-trimester ultrasound dating carries a small margin of error of only about 1.2 weeks, making it significantly more reliable than calculations based solely on a woman's last menstrual period (given that only roughly 4% of babies are actually born on their exact predicted due date).

During weeks 10 to 13, some patients also opt for a specialized screening called a Nuchal Translucency (NT) scan. This non-invasive assessment measures the clear space at the back of the baby's neck. An NT measurement greater than 3.0 millimeters can indicate an increased risk for chromosomal conditions (such as Down syndrome) or physical heart defects, prompting further evaluation if desired.

Second Trimester Anatomy Scan: What Weeks Do You Get Ultrasounds During Pregnancy for Fetal Development?

The mid-trimester scan—commonly known as the 20-week anatomy scan or level II anomaly survey—is considered the cornerstone of prenatal imaging. This comprehensive evaluation is scheduled between weeks 18 and 22 of gestation (and up to week 24 per international protocol standards).

According to the ISUOG Practice Guidelines for mid-trimester scan, all pregnant women should be offered this scan to evaluate major structural organs and physical growth. Because the baby's organs have formed and are large enough to be visualized in detail, the sonographer spends 30 to 45 minutes carefully checking every part of the fetus.

During this detailed scan, the clinician systematically checks:

Brain and Skull: Measuring head circumference (HC) and biparietal diameter (BPD), checking the ventricles, cerebellum, and facial structures (such as upper lip integrity to rule out cleft lip).
Heart: Evaluating the classic four-chamber view, outflow tracts, and cardiac rhythm to confirm normal blood circulation.
Spine and Abdomen: Ensuring the neural tube is fully closed, verifying abdominal wall integrity, and observing internal organs like the stomach and kidneys. (The fetal bladder can reliably be visualized after 15 weeks of gestation).
Limbs: Measuring the femur length (FL) to track overall skeletal growth and counting fingers and toes.
Placenta and Amniotic Fluid: Checking placenta positioning relative to the cervix and measuring amniotic fluid depth to ensure the baby has a supportive environment.

Many parents wonder, "are ultrasounds that important at this mid-point if I feel fine?" The answer is yes; structural scans provide crucial diagnostic details that ensure both mother and baby receive appropriate specialized care before and during delivery.

Another exciting feature of the 20-week scan for many families is discovering the baby's biological sex. When fetal positioning allows a clear view, a skilled technician's assessment of biological sex at 20 weeks is accurate approximately 95% of the time. However, if the baby keeps their legs crossed or sits low in the pelvis, the sex may remain a mystery until a follow-up scan or birth!

Third Trimester Scans: Position Checks and Growth Monitoring

In a healthy, low-risk pregnancy, routine ultrasounds in the third trimester are often minimal. However, as you near your due date around week 36, many healthcare providers conduct a brief in-office scan or bedside check.

The main objective of a 36-week position check is confirming fetal presentation—specifically verifying that the baby is in a head-down (cephalic) position in preparation for labor, rather than breech (bottom or feet down) or transverse (sideways).

Third-trimester scans may also be scheduled to check:

Fetal Growth: Calculating an estimated fetal weight (EFW) using Hadlock formulas combining head circumference, abdominal circumference, and femur length if the mother's abdomen measures smaller or larger than expected.
Amniotic Fluid Levels: Measuring the deepest vertical pocket (DVP) of fluid. A DVP measurement of 2.0 cm or less indicates low fluid (oligohydramnios), whereas a pocket exceeding 8.0 cm suggests high fluid levels (polyhydramnios).
Placental Location Follow-up: If a low-lying placenta was noted during your 20-week anatomy scan, a follow-up third-trimester scan is ordered to verify that the placenta has migrated safely away from the cervical opening as the uterus expanded, ruling out persistent placenta previa.

Transvaginal vs. Abdominal Ultrasounds: What to Expect During Your Scan

Depending on what weeks do you get ultrasounds during pregnancy, the physical method used to capture images will differ. There are two primary types of diagnostic pregnancy ultrasounds: transvaginal and abdominal.

Transvaginal Ultrasounds (Early Pregnancy)

During early gestation—typically from 5 up to 12 weeks—the developing embryo is tucked deep inside the pelvic cavity behind the pubic bone. An abdominal scan may not yield sharp enough images at this stage.

How It Works: A slender, lubricated wand (transducer) is gently inserted a few inches into the vagina.
Preparation: Unlike abdominal scans, a transvaginal ultrasound is easiest and most comfortable with an empty bladder.
What It Feels Like: You may feel slight pressure, similar to a routine pap smear, but the procedure is non-invasive and painless.
Clinical Purpose: Transvaginal imaging provides high-resolution views necessary to detect a early free ultrasound baby heartbeat, calculate exact crown-rump length, and rule out ectopic pregnancies.

Abdominal Ultrasounds (12 Weeks and Beyond)

After the 12th week of pregnancy, the growing uterus rises out of the pelvis and into the abdomen, making abdominal imaging the standard technique for the remainder of your pregnancy.

How It Works: The technician applies a clear, water-based gel to your lower abdomen. The gel eliminates air pockets so sound waves can transmit smoothly into the body. A handheld transducer is then moved across your belly to bounce high-frequency sound waves off internal tissue and produce real-time moving images on screen.
Preparation: For scans performed between 12 and 20 weeks, you may be asked to arrive with a full bladder. A full bladder acts as an acoustic window, pushing the intestines away and tilting the uterus upward for clearer imaging.
What It Feels Like: You will feel mild pressure as the transducer glides over your stomach.

As detailed in clinical literature like the StatPearls sonography protocols, standard routine scans typically take about 20 minutes, while an in-depth second-trimester anatomy survey takes between 30 and 45 minutes.

Importantly, diagnostic ultrasound technology uses non-ionizing acoustic sound waves rather than radiation (like X-rays). Sound waves bounce back from fetal bones and soft tissues to construct live digital images without emitting heat or radiation, rendering ultrasound imaging completely safe for both mother and child when performed by credentialed medical personnel.

Reasons You Might Need Additional Pregnancy Ultrasounds

While having two scans is standard for an uncomplicated pregnancy, many women require additional imaging. Having more scans does not automatically mean something is wrong; rather, extra scans allow your medical team to keep a close eye on your health and your baby's development.

The table below outlines common clinical reasons why a pregnancy schedule might shift from routine monitoring to additional specialized scans:

Indication / Scenario	Routine Schedule	Additional Scanning Protocol
Low-Risk Pregnancy	1–2 scans total (Dating + Anatomy)	Standard 10–14 wk and 18–22 wk scans; optional 36 wk position check
Maternal Age (35+)	Standard baseline	Growth scans every 4 weeks in the third trimester
Twin or Multiple Gestation	Standard baseline	Scans every 2 to 4 weeks starting at week 16 to check growth equality
Gestational Diabetes / Preeclampsia	Standard baseline	Serial growth ultrasounds in third trimester (weeks 28, 32, 36)
First-Trimester Vaginal Bleeding	Standard baseline	Immediate early transvaginal scan to confirm fetal viability
Placenta Previa (Low Placenta)	Identified at 20 wks	Follow-up scan at 32–36 weeks to confirm placental migration

According to the comprehensive Healthline ultrasound frequency guide, health factors that frequently call for extra ultrasound monitoring include:

Maternal Health Conditions: Pre-existing conditions such as chronic high blood pressure, pregestational or gestational diabetes, kidney disease, or autoimmune disorders require serial growth monitoring to ensure optimal placental blood flow.
High-Risk Pregnancy Indicators: Being 35 years or older during your first pregnancy places you in a higher-risk category where third-trimester growth tracking is routinely recommended.
Multiple Gestations: Expecting twins, triplets, or more means your provider must carefully monitor fluid volumes, individual growth rates, and screen for conditions like Twin-to-Twin Transfusion Syndrome (TTTS) every 2 to 4 weeks.
Complications in Prior Pregnancies: A history of fetal growth restriction (FGR), preeclampsia, or preterm birth often prompts preventative surveillance scans.
Unusual Physical Symptoms: Unexpected symptoms like vaginal bleeding, severe abdominal pain, sudden decreases in fetal movement, or fluid leaks will prompt immediate diagnostic scans.

If you are experiencing unexpected pregnancy symptoms and searching online for trustworthy ultrasounds for pregnancy near me, seeking an immediate medical-grade scan is the best way to gain peace of mind and protect your health.

Frequently Asked Questions About Pregnancy Ultrasound Timing

Navigating ultrasound schedules raises many practical questions. Below are clear answers to the questions expectant mothers ask most frequently regarding pregnancy imaging timing and safety.

Is it safe to get multiple ultrasounds during pregnancy?

Yes, getting multiple medically necessary ultrasounds during pregnancy is safe. Ultrasound technology relies entirely on non-ionizing, high-frequency sound waves rather than ionizing radiation. Decades of clinical research have shown no link between diagnostic ultrasound use and adverse effects on fetal growth, birth weight, or childhood development.

To ensure absolute safety, trained sonographers adhere strictly to the ALARA principle (As Low As Reasonably Achievable). This means ultrasound equipment is set to the minimum acoustic power output and exposure duration necessary to capture accurate diagnostic images.

However, medical organizations like ACOG and the FDA strongly advise against commercial 3D/4D "keepsake" ultrasound businesses found in shopping malls. Unregulated keepsake scans can expose a fetus to prolonged ultrasound energy for up to an hour purely for non-medical entertainment photos, often operated by individuals without clinical certifications. Always ensure your pregnancy ultrasounds are performed by licensed medical professionals inside an accredited healthcare setting.

How accurate is the 20-week ultrasound for determining baby's sex?

The 20-week anatomy scan is approximately 95% accurate for determining a baby's biological sex. By 18 to 22 weeks of gestation, external genitalia are sufficiently developed to be clearly identified on high-resolution imaging.

However, diagnostic accuracy depends heavily on three key variables:

Fetal Positioning: If the baby is curled up tightly, positioned breech low in the pelvis, or sitting with their legs crossed over the groin, the technician may be unable to get a clear view.
Amniotic Fluid Volume: An adequate pocket of fluid surrounding the baby provides clear acoustic window contrast.
Maternal Body Habitus: Higher abdominal tissue density can sometimes soften sound wave resolution.

If the sonographer cannot see the genitalia clearly, they will prioritize completing critical organ measurements rather than guessing.

What happens if an ultrasound scan is incomplete?

It is surprisingly common for a standard 20-week anatomy scan to remain incomplete after your first appointment! In fact, clinical studies indicate that between 0.5% and 5% of routine anatomy scans cannot visualize every required organ view in a single sitting due to fetal positioning, an uncooperative posture, or maternal body density.

If your baby refuses to move into a position that permits views of the heart chambers, face profile, or lower spine, there is no need to panic. Your sonographer may ask you to stand up, walk around the office, drink a glass of ice water, or eat a light snack to encourage the baby to shift position.

If the baby still stays tucked away, your provider will simply reschedule a follow-up ultrasound scan in two to three weeks. Rescheduling ensures every structure is evaluated thoroughly to confirm normal development.

Accessing Free Pregnancy Ultrasounds and Support Services

Facing an unplanned pregnancy or wondering about your timeline can feel overwhelming—especially if you lack health insurance, are worried about out-of-pocket costs, or are unsure of your options.

At LivingWell, we believe every woman deserves compassionate, professional care without financial stress. Located conveniently at 2010 N Tustin St, Suite C, Orange, CA 92865, our reproductive health clinic has provided medical-grade support to women in our community since 1985. In 2025 alone, our licensed medical team served 1,420 local women with completely free services.

When you walk through our doors, you will receive:

Free Medical-Grade Pregnancy Testing: Lab-quality urine testing to confirm pregnancy hormones with high accuracy.
Free Pregnancy Verification Ultrasounds: Performed by licensed doctors, registered nurses, and certified ultrasound technicians to confirm a live intra-uterine pregnancy, establish accurate gestational age, and detect an early heartbeat.
Confidential Option Consultations: A safe, non-judgmental space to ask questions, discuss your timeline, and understand all of your options in a warm, supportive environment.

You do not have to figure out your pregnancy timeline alone. If you are wondering how far along you are or need early confirmation imaging, reach out to our caring medical team today to schedule your free ultrasound or call us to learn more about how we can support you.