Pregnancy is an exciting, worrying, joyful ride filled with ups and downs. Among the many tools that help ensure a safe and healthy pregnancy, ultrasound scans play an important role. These non-invasive imaging techniques allow doctors and parents-to-be to monitor the baby’s development, assess maternal health, and detect any potential complications early.

An ultrasound is a safe procedure that uses sound waves to create images of your baby during pregnancy. It does not involve needles or radiation.

Depending on how many weeks pregnant you are and the type of ultrasound you are having, it can be used to check:

  • Your baby’s heartbeat and general progress
  • If you are pregnant with twins or triplets.
  • Your due date
  • Baby’s position in your uterus
  • Your cervix
  • Location of placenta
  • Baby’s growth and size
  • To rule out any anomalies

Several ultrasound scans are routinely done during pregnancy. Factors influencing the number of ultrasounds you’ll receive include your doctor’s standard protocol, medical history, and pregnancy complications.

Before you have an ultrasound scan, it’s a good idea to think about what you might learn.

You may be asked to:

  • Wear loose clothing
  • Drink water beforehand so that there is fluid in your bladder

Let us take a detailed, month-by-month look at pregnancy ultrasound scans, their importance, and insights for expectant mothers.

First Trimester Ultrasound (Months 1-3)

Purpose of Ultrasound Scans in the First Trimester :

The first trimester is a critical phase of pregnancy. Ultrasounds during this period primarily confirm the pregnancy and assess its viability. The scans help detect:

  • Gestational sac location (to rule out ectopic pregnancy).
  • Baby’s heartbeat, typically visible around 6-7 weeks.
  • Number of embryos (to identify single or multiple pregnancies).
  • Gestational age and estimated due date.

Key Ultrasound Scans :

Dating Scan (6-10 weeks) :

  • Importance: Confirms pregnancy, establishes accurate gestational age, and checks baby’s heartbeat.
  • Scientific Insight: Accurate dating minimizes errors in predicting delivery dates and helps schedule other tests effectively.

For Mum To Be : Abdominal and transvaginal ultrasound scan is quick and non-invasive.

Nuchal Translucency (NT) Scan (11-14 weeks) :

  • Importance: Assesses the risk of chromosomal abnormalities like Down syndrome when combined with blood tests. It can indicate other congenital abnormalities of the heart, abdomen, and skeleton
  • Scientific Insight: Measures fluid accumulation at the back of the baby’s neck, a potential marker for genetic issues.
  • This scan also checks baby’s growth, estimate due date and checks the physical development of the baby by measuring baby’s ‘crown rump length’ (measurement from head to bottom), the number of babies in the womb, and fetal cardiac activity.

For Mum-To-Be : Knowing the process and its relevance helps reduce anxiety.

  • Early scans provide reassurance and valuable information.
  • Drink water before abdominal scans for better clarity.

Second Trimester Ultrasound (Months 4-6)

Purpose of Ultrasound Scans in the Second Trimester :

This is often called the “golden period” of pregnancy. Ultrasounds during the second-trimester focus on detailed assessments of the baby’s anatomy and growth. They also monitor the placenta, amniotic fluid levels, and maternal health.

Key Ultrasound Scans :

Anomaly Scan  / Morphology scan (18-22 weeks) :

  • Importance: A comprehensive   thorough scan to evaluate the structure & growth of baby’s developing organs, limbs, spine, and brain development.
  • Scientific Insight: Detects congenital anomalies and structural abnormalities, allowing early intervention if needed.
  • Measurements made at the morphology scan help estimate your baby’s gestational age and size.
  • They’ll also count your baby’s fingers and toes, examine the placenta, and measure the amniotic fluid level.
  • The sonographer can make sure your placenta is in a good position and measure the length of your cervix.
  • Gender Determination: It is not medically necessary & illegal in our country.

Additional Scans in High-Risk Pregnancies :

  • Doppler Ultrasound: Measures blood flow in the placenta and umbilical cord to assess fetal well-being.
  • Cervical Length Scan: Determines the risk of preterm labor by measuring the cervix.

Tips for Expectant Mothers:

  • Bring a partner or family member to share this special moment.
  • Ask for an image or video as a memory to cherish & keep.

Third Trimester Ultrasound (Months 7-9)

Purpose of Ultrasound Scans in the Third Trimester :

The final trimester focuses on monitoring fetal growth, positioning, and overall well-being, ensuring the mother’s readiness for delivery.

Key Ultrasound Scans :

Growth Scan (28-32 weeks) :

  • Importance: Evaluate the baby’s size, weight, and position.
  • Scientific Insight: Ensures the baby’s growth as expected and checks amniotic fluid levels.
  • If you have high blood pressure, bleeding, low levels of amniotic fluid, preterm contractions, or over age 35, ultrasound will be repeated
  • If the placenta was near or covering the cervix in an earlier ultrasound, then it will be repeated to monitor its location
  • Patient-Friendly Approach: Highlighting normal progress provides peace of mind.

Biophysical Profile (BPP) (32-36 weeks) :

  • Importance: Assesses fetal health through five parameters: breathing, movement, muscle tone, heart rate, and amniotic fluid volume.
  • Scientific Insight: A score from the BPP helps identify any need for early delivery.

Positioning Scan (36-38 weeks):

  • Importance: Determines the baby’s position (head-down or breech) for delivery planning.
  • Scientific Insight: Breech babies may require additional monitoring or delivery adjustments.

• Ultrasounds in the third trimester can help identify potential complications such as fetal distress or placental insufficiency.
• Stay hydrated and maintain a healthy diet for optimal results.

Specialized Ultrasounds during Pregnancy : 

3D and 4D Scans :

  • Purpose: Provides detailed images of the baby’s facial features and movements.
  • Scientific Insight: While not medically necessary, these scans can identify cleft lip and other external anomalies.

Fetal Echocardiography :

  • Purpose: Examines the baby’s heart in detail, especially in high-risk pregnancies.
  • Scientific Insight: Identifies congenital heart defects.

Doppler Ultrasound:

  • Purpose: Monitors blood flow between the mother and baby.
  • Scientific Insight: Detects conditions like preeclampsia or growth restriction.

Importance of Ultrasound Scans in Pregnancy : 

Monitoring Baby’s Development :
Ultrasounds track the baby’s growth and detect any anomalies early, enabling timely interventions.

Ensuring Maternal Health :
Identifies complications such as placenta previa, placental abruption, or excessive amniotic fluid.

Planning for Delivery :
Knowing the baby’s position and health helps plan for safe delivery, whether vaginal or cesarean.

Emotional Connection :
Seeing their baby during ultrasounds strengthens the bond between parents and the unborn child.

FAQs About Pregnancy Ultrasounds :

1. Are ultrasounds safe ?
Yes, they are non-invasive and use sound waves, posing no harm to the mother or baby when performed by trained professionals.

2. How many ultrasounds are necessary ?
Typically, 3-4 scans are standard in a low-risk pregnancy, but more may be required in high-risk cases.

3. Do ultrasounds have limitations ?
While highly accurate, ultrasounds may occasionally miss subtle abnormalities or produce unclear images due to maternal weight or baby’s position.

Conclusion

Ultrasounds play a crucial role in prenatal care, providing essential information about the health and well-being of the mother and the baby. From confirming pregnancy in the first trimester to preparing for delivery in the third, these scans provide vital information at every stage. By understanding the purpose and importance of ultrasound, expectant mothers can approach their pregnancy with confidence and peace of mind. Always consult with your healthcare provider to ensure you receive the right scans at the right time for a healthy pregnancy journey.

Disclaimer:

This blog is for informational purposes only and is not intended as medical advice. The content is based on general pregnancy ultrasound guidelines and may not apply to every individual. Always consult your doctor, obstetrician, or a qualified healthcare professional for personalized medical guidance.

Author Name:

Dr. Meena Shah
Child Specialist, Ante Natal–Post Natal Coach & Master
Trainer