Ultrasound during pregnancy

An ultrasound is a procedure that uses high-frequency sound waves to scan a woman's abdomen and pelvis, creating an image (ultrasound) of the baby and placenta. Although the terms "ultrasound" and "ultrasound" are technically different, they are used interchangeably and refer to the same examination.

There are basically seven different ultrasounds, but the basic process is the same:

Transvaginal scanning. Specially designed transducers are used inside the vagina to obtain ultrasound images. Most often used in early pregnancy.
Standard ultrasound examination. A traditional ultrasound that uses a transducer in the abdomen to create 2D images of a developing fetus.
Advanced ultrasound. This examination is similar to a standard ultrasound, but it targets the suspected problem and uses more sophisticated equipment.
Doppler ultrasound. This imaging procedure measures small changes in the frequency of ultrasonic waves as they bounce off moving objects such as blood cells.
3D ultrasound. Uses specially designed sensors and software to create 3D images of a developing fetus.
4-D or dynamic 3-D ultrasound. Uses specially designed scanners to study the face and movements of the baby before delivery.
Fetal echocardiography. Uses ultrasound waves to assess the anatomy and function of the baby's heart. This is used to evaluate suspected congenital heart defects.

How is an ultrasound performed?

The traditional procedure involves applying a gel to the abdomen that acts as a conductor of sound waves. Your doctor uses a transducer to create sound waves in the uterus. The sound waves bounce off the bones and tissues and return to the transducer, creating black and white images of the fetus.

When is an ultrasound done?

Ultrasound can be performed at any time during pregnancy, and the results are immediately visible on the monitor during the procedure. A transvaginal scan can be used early in pregnancy to diagnose a possible ectopic or molar pregnancy.

There is no recommended number of ultrasounds that should be performed during routine antenatal care. Because ultrasound should only be used when medically indicated, many healthy pregnant women do not need an ultrasound. The average number of ultrasounds varies from doctor to doctor.

Additional ultrasounds may be ordered separately if the doctor suspects complications or problems with the pregnancy.

What does an ultrasound look for?

Ultrasounds are diagnostic procedures that detect or help detect abnormalities and conditions associated with pregnancy. Ultrasound is usually combined with other tests, such as triple tests, amniocentesis, or chorionic villus biopsy, to confirm the diagnosis.

An ultrasound may be done during pregnancy for the following medical reasons:

First trimester:

Confirm viable pregnancy
Confirm heartbeat
Measure the crown-rump length or gestational age
Confirm molar or ectopic pregnancies
Assess abnormal gestation

Second Trimester:

Diagnose fetal malformation
Weeks 13-14 for characteristics of potential Down syndrome
Weeks 18-20 for congenital malformations
Structural abnormalities
Confirm multiples pregnancy
Verify dates and growth
Confirm intrauterine death
Identify hydramnios or oligohydramnios – excessive or reduced levels of amniotic fluid
Evaluation of fetal well-being

Third Trimester:

Identify placental location
Confirm intrauterine death
Observe fetal presentation
Observe fetal movements
Identify uterine and pelvic abnormalities of the mother

What are the risks and side effects for the mother or baby?

Ultrasound is a non-invasive procedure that, when used correctly, does not harm the fetus. The long-term effects of repeated ultrasound exposure on the fetus are not fully known. Ultrasound is recommended for medical use only.

If an ultrasound is done at 6-7 weeks, and the heartbeat is not detected, does this mean that there is a problem?

No, that doesn't mean there is a problem. The heartbeat may not be detected for reasons such as: a tilted uterus, a large belly, or inaccurate dating of the last menstrual period. Palpitations are best detected with a transvaginal ultrasound in early pregnancy.

Anxiety usually occurs in the absence of fetal cardiac activity in an embryo with a crown-sacral length of more than 5 mm. If you do an ultrasound after the 6th week, your doctor will start to worry if there is a gestational sac.

How accurately does an ultrasound determine the gestational age?

Your doctor will use your hormone levels, last menstrual period, and in some cases, ultrasound results to estimate your gestational age. However, variations in each woman's cycle and each pregnancy can affect the accuracy of the gestational age calculation.

If your doctor uses an ultrasound to get an estimated due date to help determine the timing of your prenatal care, your original estimated due date will not change.

Why do some doctors prescribe ultrasound differently?

If there are questions about the duration of the pregnancy, the location of the placenta, or possible complications, additional ultrasounds may be ordered. Because ultrasound should only be used when medically indicated, many healthy pregnant women do not need an ultrasound. The average number of ultrasounds varies from doctor to doctor.

How accurate are ultrasounds in determining the date of conception to determine paternity?

Your doctor will use your hormone levels, last menstrual period, and in some cases, ultrasound results to calculate your expected conception date. However, the many differences in each woman's cycle can interfere with the accuracy of calculating the date of conception.

Sperm viability also varies, meaning intercourse three to five days before ovulation can lead to conception. Ultrasound dating of conception is unreliable for determining paternity because ultrasound can be off by at least 5-7 days in early pregnancy.

When can an ultrasound determine the sex of a baby?

You may have an ultrasound between 18 and 20 weeks to evaluate dates, multiple pregnancies, placenta location, or complications. This ultrasound can also determine the gender of your baby. Several factors, such as the stage of pregnancy and the position of the fetus, will affect the accuracy of the sex prediction.

To be 100% sure, you will have to anxiously wait until delivery!

Is ultrasound a necessary part of antenatal care?

An ultrasound is only needed if there are medical problems. As mentioned above, ultrasound allows the doctor to assess the well-being of the child and diagnose possible problems. For women with uncomplicated pregnancies, ultrasound is not a necessary part of antenatal care.