Your 20 Week OB Appointment: What to Expect During Second Trimester Prenatal Care

Your 20-week OB appointment is one of the most anticipated prenatal visits during pregnancy. This milestone appointment typically includes an anatomy scan ultrasound and comprehensive health assessments that provide crucial information about your baby’s development and your well-being. Understanding what to expect can help you prepare questions and make the most of this important visit.

During the second trimester, which spans weeks 13 through 28, you’ll generally have prenatal appointments every four weeks. These regular check-ups are designed to monitor your health and your baby’s growth, address any concerns, and ensure your pregnancy progresses smoothly.

Standard Checks at Every Second Trimester Visit

At each prenatal appointment during your second trimester, your healthcare provider will perform several routine assessments to track both your health and your baby’s development.

Blood Pressure and Weight Monitoring

Your blood pressure will be checked at every visit to screen for potential complications like preeclampsia. Your weight gain is also tracked to ensure you’re gaining at a healthy rate for your pre-pregnancy body mass index. Proper weight gain supports your baby’s growth while maintaining your health.

Fundal Height Measurement

Starting around 20 weeks, your healthcare provider will measure your fundal height – the distance from your pubic bone to the top of your uterus. This measurement, taken in centimeters, typically correlates with the number of weeks you’ve been pregnant, give or take 2 to 3 centimeters. For example, at 24 weeks, your fundal height should measure approximately 22 to 26 centimeters.

This simple measurement helps assess whether your baby is growing appropriately and whether your amniotic fluid levels are normal.

Fetal Heart Rate Check

Your provider will use a handheld Doppler device to listen to your baby’s heartbeat. A normal fetal heart rate typically ranges from 110 to 160 beats per minute. Hearing your baby’s heartbeat provides reassurance that your baby is doing well and can be an emotional highlight of each visit.

Fetal Movement Discussion

Between 18 and 22 weeks, most pregnant women begin feeling fetal movement, often described as flutters, bubbles, or light kicks. Your provider will ask about when you first felt movement and how often you notice it. First-time mothers often feel movement slightly later than those who’ve been pregnant before.

The 20 Week Anatomy Scan: What Makes This Appointment Special

Your 20-week appointment is particularly significant because it typically includes the comprehensive anatomy ultrasound, also called the mid-pregnancy ultrasound or anomaly scan. This detailed examination usually takes 30 to 45 minutes and provides extensive information about your baby.

What the Anatomy Scan Examines

During the 20-week ultrasound, the sonographer will carefully examine:

• Brain and skull development: Checking for proper formation and identifying any potential neural tube defects
• Facial features: Examining the eyes, nose, lips, and profile to screen for cleft lip or palate
• Spine: Ensuring all vertebrae are aligned and the spine is properly closed
• Heart: Viewing the four chambers and major blood vessels to detect congenital heart defects
• Abdominal organs: Checking the stomach, kidneys, bladder, and intestines
• Limbs: Counting fingers and toes and measuring arm and leg bones
• Placenta position: Noting where the placenta is attached to determine if it’s near the cervix
• Amniotic fluid levels: Assessing whether fluid levels are normal
• Umbilical cord: Confirming it has the normal three blood vessels

Gender Reveal

If you wish to know your baby’s sex, the anatomy scan is when many parents find out. The sonographer can usually identify gender by examining the genital area, though accuracy depends on baby’s position. If you prefer to be surprised, make sure to tell the ultrasound technician before the scan begins.

Genetic Screening and Diagnostic Tests

Depending on your individual risk factors and previous test results, your healthcare provider may discuss additional testing options during your second trimester visits.

Quad Screen or AFP Test

Between 15 and 22 weeks, you may be offered the quad screen, a blood test that measures four substances to assess the risk of chromosomal abnormalities and neural tube defects, including:

• Down syndrome (Trisomy 21)
• Edwards syndrome (Trisomy 18)
• Spina bifida
• Anencephaly

This screening test doesn’t diagnose conditions but indicates whether further diagnostic testing might be recommended.

Amniocentesis

If screening tests show elevated risk or if structural abnormalities are detected on ultrasound, your provider may recommend amniocentesis. This diagnostic test, typically performed between 15 and 20 weeks, involves taking a small sample of amniotic fluid to analyze your baby’s chromosomes and genes.

While amniocentesis carries a small risk of complications, it provides definitive diagnostic information about genetic conditions. Your healthcare provider will discuss the risks and benefits to help you make an informed decision.

Glucose Screening for Gestational Diabetes

Between 24 and 28 weeks of pregnancy, you’ll undergo screening for gestational diabetes – a form of diabetes that develops during pregnancy. The glucose challenge test involves drinking a sweet glucose solution and having your blood sugar tested one hour later.

If results are elevated, you’ll need a follow-up glucose tolerance test that provides more detailed information. Gestational diabetes requires management to protect both you and your baby, but with proper care, most women with this condition have healthy pregnancies and babies.

Blood Type and Rh Factor Testing

If you haven’t already been tested, or if you’re Rh negative, you’ll have blood work to check for Rh antibodies. Rh factor is a protein found on red blood cells. If you’re Rh negative and your baby is Rh positive, your body might produce antibodies that could affect future pregnancies.

If you’re Rh negative, you’ll typically receive a RhoGAM injection around 28 weeks to prevent antibody formation. This is a standard preventive measure that protects your baby and any future pregnancies.

Iron Levels and Anemia Screening

Your blood count will be checked during the second trimester to screen for anemia. Pregnancy increases your blood volume significantly, and many women develop iron-deficiency anemia during this time. Your healthcare provider may recommend iron supplementation if your levels are low, as adequate iron is essential for your baby’s development and your energy levels.

Common Second Trimester Symptoms to Discuss

The second trimester is often called the honeymoon period of pregnancy because many early pregnancy symptoms ease. However, new symptoms may emerge that you should discuss with your provider:

Round Ligament Pain

As your uterus expands, the ligaments supporting it stretch, causing sharp pains in your lower abdomen or groin area. This is typically normal but can be uncomfortable.

Back Pain

As your belly grows and your center of gravity shifts, back pain often develops. Your provider can suggest safe stretches, proper posture techniques, and support options.

Leg Cramps

Many pregnant women experience leg cramps, especially at night. Staying hydrated and stretching before bed may help.

Skin Changes

Darkening of the skin on your face, abdomen, or other areas is common due to hormonal changes. The linea nigra, a dark line down the center of your belly, often appears during the second trimester.

Nasal Congestion and Nosebleeds

Increased blood flow can cause nasal passages to swell and become congested. Nosebleeds may also occur more frequently.

Important Questions to Ask at Your 20 Week Appointment

Come prepared with questions to maximize your appointment time. Consider asking about:

• Results from your anatomy scan and what they mean
• Any concerns about measurements or findings
• Exercise recommendations and limitations
• Safe sex during pregnancy
• Travel plans and any restrictions
• Prenatal classes available in your area
• Signs of preterm labor to watch for
• When you should start thinking about your birth plan
• Vaccination recommendations, including flu and Tdap vaccines
• Any symptoms you’re experiencing that concern you

Preparing for Your 20 Week OB Appointment

To make the most of your appointment, consider these preparation tips:

Before the Appointment

• Drink plenty of water before your ultrasound – a moderately full bladder can help with imaging
• Wear comfortable, loose-fitting clothing that’s easy to lift or remove for the examination
• Write down questions or symptoms you want to discuss
• Bring your partner or support person if you’d like company during the ultrasound
• Consider whether you want to learn your baby’s sex and communicate this clearly

What to Bring

• Your insurance card and identification
• A list of any medications or supplements you’re taking
• Your pregnancy journal or symptom log if you keep one
• A small snack for after any blood work

What Happens If Abnormalities Are Detected

While most anatomy scans show that babies are developing normally, sometimes concerns are identified. If your healthcare provider finds something unusual, try not to panic. Many findings require follow-up testing to determine their significance.

Your provider may refer you to a maternal-fetal medicine specialist (perinatologist) for a more detailed ultrasound and consultation. Some findings seen on ultrasound may resolve on their own, while others may require monitoring or treatment after birth.

Your healthcare team will provide support, information, and guidance about any findings and what they mean for your pregnancy and your baby’s future health.

Lifestyle and Nutrition Guidance

Your second trimester appointments are good opportunities to discuss nutrition, exercise, and lifestyle modifications that support a healthy pregnancy.

Nutrition Focus

During the second trimester, your baby’s rapid growth increases your nutritional needs. Discuss with your provider:

• Appropriate calorie intake for your activity level
• Protein requirements for fetal development
• Foods rich in iron, calcium, and folate
• Safe seafood choices that provide omega-3 fatty acids
• Foods to continue avoiding during pregnancy

Physical Activity

Most women can continue exercising safely throughout the second trimester. Your provider can advise you about:

• Safe exercise intensity and duration
• Activities to avoid as your pregnancy progresses
• Warning signs to stop exercising
• Benefits of prenatal yoga or swimming

Planning Ahead: Third Trimester Preparations

Your 20-week appointment is an excellent time to start thinking about the remainder of your pregnancy. Your provider may discuss:

• When your appointments will increase in frequency
• Additional tests scheduled for the third trimester
• Signs of preterm labor
• When to start preparing your hospital bag
• Childbirth education class options
• Pediatrician selection

Warning Signs to Report Before Your Next Appointment

Between scheduled visits, contact your healthcare provider immediately if you experience:

• Vaginal bleeding or fluid leaking
• Severe abdominal pain or cramping
• Sudden decrease in fetal movement after you’ve established a pattern
• Signs of infection like fever, chills, or burning during urination
• Severe headaches that don’t respond to rest
• Vision changes like seeing spots or blurriness
• Significant swelling of face, hands, or feet
• Persistent vomiting

The Emotional Aspects of Your 20 Week Appointment

The 20-week anatomy scan can be emotionally intense. Seeing your baby in such detail often makes the pregnancy feel more real. Some parents feel excited and relieved, while others may feel anxious about possible findings.

It’s completely normal to have mixed emotions. If you’re feeling anxious or overwhelmed, talk to your healthcare provider. They can provide reassurance and connect you with resources if you need additional support.

After Your Appointment

Following your 20-week visit, you’ll typically schedule your next appointments through the remainder of your second trimester. Most providers will want to see you around 24 weeks and again at 28 weeks before increasing appointment frequency in the third trimester.

Keep all documentation from your appointment, including ultrasound images and any test results. These records help track your pregnancy’s progression and can be valuable if you need to see a different provider or if complications arise.

Making the Most of Second Trimester Prenatal Care

Your 20-week OB appointment and other second trimester visits are crucial components of prenatal care. These appointments help identify potential issues early when intervention can make the most difference. They also provide reassurance that your pregnancy is progressing normally and give you opportunities to ask questions and address concerns.

Remember that no question is too small or silly when it comes to your health and your baby’s wellbeing. Your healthcare team is there to support you throughout your pregnancy journey. Being proactive, attending all scheduled appointments, and maintaining open communication with your provider are some of the best things you can do to support a healthy pregnancy.

The second trimester often brings renewed energy and the exciting milestone of feeling your baby move. Enjoy this special time while staying attentive to your body and your baby’s development through regular prenatal care.

Sources:

• American College of Obstetricians and Gynecologists – Prenatal Care
• Centers for Disease Control and Prevention – Pregnancy
• March of Dimes – Prenatal Care and Tests
• MedlinePlus – Prenatal Care
• National Institute of Child Health and Human Development – Prenatal Care