Ultrasound During Pregnancy
What does an ultrasound show, when should you have one, and how is it done?
18/08/2026
What Is an Ultrasound and Is It Safe?
An ultrasound scan uses high-frequency sound waves — not radiation — to create images of your baby inside the uterus. The sound waves are completely safe for you and your baby at the frequencies used in pregnancy ultrasound. There is no evidence of harm from standard obstetric ultrasound, which has been used safely in pregnancy for over 50 years.
A gel is applied to your abdomen and a small probe is moved over your skin. The sound waves bounce off your baby and are converted into an image on a screen. You can see your baby's outline, movement, and — depending on your baby's position — facial features. An internal (transvaginal) probe may be used in early pregnancy for a clearer image.
When Are Ultrasounds Typically Done?
Rwanda MoH recommends that all pregnant women have at least one ultrasound scan before 24 weeks of pregnancy. The WHO 2016 guidelines recommend one ultrasound at 24 weeks or earlier to confirm gestational age, identify multiple pregnancies, detect major fetal anomalies, and plan appropriate care.
In practice, ultrasound availability varies across Rwanda's health facilities — referral hospitals and most district hospitals have ultrasound, while health centres may not. If your local health centre cannot perform an ultrasound, you may be referred to a district hospital for the scan.
The First Trimester Ultrasound (Weeks 7–13)
An early ultrasound in the first trimester confirms that the pregnancy is inside the uterus (ruling out ectopic pregnancy), that the heartbeat is present, and provides the most accurate dating of your pregnancy — essential for calculating your due date and scheduling ANC contacts correctly.
Early ultrasound also detects multiple pregnancies (twins, triplets). Twin pregnancies have specific additional risks and monitoring requirements, and early detection allows your care team to plan accordingly.
The Anatomy Scan (Weeks 18–22)
The detailed anatomy scan at weeks 18–22 is the most comprehensive ultrasound of pregnancy. A trained sonographer systematically examines all of your baby's organ systems — brain, spine, heart, kidneys, stomach, limbs, abdominal wall, and placenta. The purpose is to identify any structural abnormalities (anomalies) that may require specialist management.
In Rwanda, where access to tertiary paediatric surgery is limited, detecting certain fetal anomalies during pregnancy allows the delivery team to plan for any special needs at birth — including ensuring delivery occurs at a referral hospital with the right specialist capacity. Your provider will explain any findings from the anatomy scan and what, if any, further assessment is needed.
The Third Trimester Ultrasound (Weeks 28–36)
Ultrasound in the third trimester assesses your baby's growth, position, and amniotic fluid volume. A baby measuring significantly smaller than expected for gestational age may have intrauterine growth restriction (IUGR) — a condition requiring more frequent monitoring and often planned early delivery. Placenta position is also assessed — a low-lying placenta (placenta praevia) covering the cervix is a cause of severe bleeding and requires caesarean delivery.
If your baby is in a breech (bottom-down) or transverse (sideways) position at 36 weeks, ultrasound confirms the finding and your provider will discuss management options. In Rwanda, caesarean delivery for breech presentation is available at all district hospitals and referral centres.
Related Articles
ANC: More Than Just a Clinic Visit
Antenatal care is a comprehensive programme of health checks, tests, treatments, and education — not just a routine appointment. Here is what ANC actually delivers for you and your baby.
Read articles
When Should I Start ANC?
Rwanda MoH and WHO both recommend starting ANC before 12 weeks. Here is why early registration is critical and what to do if your pregnancy was discovered late.
Read articlesHow Many ANC Contacts Should I Have?
Rwanda MoH recommends a minimum of four ANC contacts, while WHO recommends eight or more. Here's the schedule, what each contact delivers, and why none should be missed.
Read articles