The 5th-week ultrasound can help detect any irregularities in the pregnancy. It gives the parents the first glimpse of their developing baby. An ultrasound may be prescribed around this stage to identify any possible complications. It is better to wait for at least 12 weeks of pregnancy for an otherwise healthy mother.
Read this post to understand the importance of undergoing an ultrasound during week 5 of pregnancy care.
When To Go For The First Ultrasound Scan?
According to the American College of Obstetricians and Gynecologists, a pregnant woman can go for an ultrasound scan between 18 and 22 weeks of pregnancy (1). However, each pregnancy is different, and the doctor will decide the first and subsequent ultrasound visit.
Why Is 5-Week Ultrasound Important?
The week five ultrasound scan is a part of regular pregnancy care. In the case of a healthy pregnancy, parents can do their first visit to a midwife or a doctor at around six to eight weeks of pregnancy (2).
- Growth of the embryo
- Gestational age
- Due date
- Genetic disorders
- Multiple pregnancies
- Embryo’s heart rate
- Ectopic pregnancies
Generally, a 5-week ultrasound should show developmental milestones. According to peer-reviewed studies, if nothing is seen in the ultrasound, it could mean the following (4).
- Pregnancy might be too early to show up in the ultrasound scan
- Ectopic pregnancy, in which the embryo implants outside the uterus. In this case, the embryo will not survive and can lead to severe complications.
- Pregnancy might have gone through a miscarriage.
The ultrasound is a non-invasive procedure, and it does not affect pregnancy. However, the overuse of ultrasound on the developing embryo can have unknown harmful effects.
What Are The Precautions For A 5-Week Ultrasound?
- There is no scientific evidence regarding the harmful impact of ultrasound on pregnancy. However, some studies suggest avoiding excessive and unnecessary ultrasound exposure as it may risk the developing embryo.
- 3D and 4D sonograms are unnecessary unless in special medically required cases.
- Sometimes, more ultrasounds may be done if there are problems or in high-risk pregnancies.
What Can You See On A 5-Week Ultrasound?
- Location of the embryo that looks curled and is around 2 mm in size.
- Gestational sac, a fluid-filled structure around an embryo, will be visible beyond 4.5 weeks. It gives a 97.6% confirmation for an intrauterine pregnancy (IUP).
- Yolk sac, a circular structure seen within a gestational sac, becomes visible in 5.5 weeks. Visibility of the yolk sac is a 100% confirmation for an IUP.
- In normal pregnancies, a beating heart might be visible. However, parents should not get worried if they cannot see a beating heart at this stage. It is entirely normal as every pregnancy is unique.
If the ultrasound detects any abnormalities in the fetal pole, yolk sac, and gestational sac, the healthcare provider will address the condition based on the severity.
How To Prepare For A 5-Week Ultrasound Scan?
Some of the vital preparations required for a 5-week ultrasound exam are (10):
- You should have a full bladder. Drink water and do not go to the toilet until after the scan.
- You can have regular food before the fetal ultrasound.
- Wear comfortable clothing that you can easily remove to facilitate vaginal examination using an ultrasound probe.
How Is A 5-Week Ultrasound Performed?
The World Health Organization (WHO) mandates at least one ultrasound scan throughout pregnancy (11). The ultrasound scan gives an accurate estimation of the size of the embryo and the delivery date. In the 5th week of gestation, ultrasound is carried out in the transvaginal route instead of the abdominal.
- A small transducer covered with a sterile lubricated condom is inserted into the vagina.
- The transducer transmits sound waves and records the reflections.
- The ultrasound machine interprets the echoes in the form of an image or video, which are displayed on a screen
Though not painful, this procedure could cause some discomfort.
How Long Does A 5-Week Ultrasound Take?
In general, the whole ultrasound procedure takes around 30 minutes to one hour (12). If another patient is in line, it might add the waiting time to the procedure.
Can A 5-Week Scan Detect Twins?
Ultrasound can detect twins between six and eight weeks. However, a 5-week ultrasound is too early to detect if twins are present in the same sac. A doctor might determine the heartbeat pattern to detect twins; however, there is a chance to miss this.
Ultrasounds conducted during pregnancy help doctors regularly monitor the growth and development of the fetus. The fifth-week ultrasound is conducted to ensure the developing baby has no genetic anomalies. Hence, you should visit your doctor regularly for checkups and ultrasounds to ensure there are no probable complications. Further, if any anomalies are detected during these visits, they may be effectively treated with early intervention. Take proper care of yourself from the beginning of the pregnancy, and consult your gynecologist if you have any questions or concerns.
Frequently Asked Questions
1. Can I see a miscarriage at five weeks on ultrasound?
A five weeks ultrasound may not accurately show a miscarriage. It may be difficult to identify a heartbeat early in pregnancy, and whether a fetus has died, failed to develop, or is smaller than expected, may not be fully understood (13).
2. What is the size of the gestational sac as seen on the fifth-week ultrasound scan?
At around five weeks of pregnancy, the gestational sac appears centrally in the uterus and measures two to three millimeters in diameter (14).
- Five-week ultrasound scan is a part of regular antenatal care for women who have a history of miscarriage or have conceived via IVF.
- Vaginal bleeding after pregnancy confirmation might also need this scan.
- This endovaginal scan helps determine embryo growth, gestational age, and embryo’s heart rate.
- If the doctor observes any issues in the yolk sac, gestational sac, or fetal pole, they will decide the course ahead accordingly.
- Ultrasound Exams.
- Your first antenatal visit
- Early pregnancy ultrasound measurements and prediction of first trimester pregnancy loss: A logistic model.
- The Use of Ultrasonography in the Diagnosis of Ectopic Pregnancy: A Case Report and Review of the Literature.
- The accuracy of ultrasound estimation of fetal weight in comparison to birth weight: A systematic review.
- Safety of ultrasonography in pregnancy: WHO systematic review of the literature and meta-analysis.
- Gestational Sac Evaluation.
- What will I see at a 5 week early pregnancy scan, why should I wait until 7 weeks?
- Pregnancy at week 5.
- How To Prepare for an Ultrasound During Pregnancy.
- WHO recommendations on antenatal care for a positive pregnancy experience.
- Transvaginal Ultrasound.
- Ultrasound scans.
- Olga Dewald and Jennifer T. Hoffman; (2022);Gestational Sac Evaluation.