My Ultrasound Showed No Fetal Pole. Am I Miscarrying?

Fetal Pole
The fetal pole should become visible in the gestational sac via ultrasound somewhere between 5 and 6 weeks of pregnancy. Image © A.D.A.M.

Fetal pole is a term for the developing baby when it first becomes visible inside the gestational sac on an early pregnancy ultrasound. The fetal pole appears curvy, with a head at one end and a tail-like structure at the other end—it is the first sign of a developing embryo.

It can be unnerving to go in for an early pregnancy ultrasound and be told there is no fetal pole or an "empty gestational sac." Obviously, it would be far more reassuring to see a baby developing right on schedule for what was expected, and ideally with a strong fetal heartbeat.

But having no fetal pole does not automatically mean miscarriage.

How Incorrect Dates Can Explain Lack of a Fetal Pole

Although an early pregnancy loss is one possibility, the other possibility is that your pregnancy is simply not far enough along to see a fetal pole on an ultrasound. The fetal pole becomes visible in a transvaginal ultrasound somewhere between five and a half to 6 and a half weeks of gestational age. So any small error in dating the pregnancy can throw an ultrasound interpretation off because the early pregnancy development varies so much from one day to the next.

For example, if you incorrectly remembered your last menstrual period date, that can change the expected findings on an ultrasound. Or if you have an irregular cycle and do not ovulate two weeks after the start of your last menstrual period, your pregnancy may not technically be five or six weeks along—even if it has been five or six weeks since your last menstrual period.

If you tell your doctor you do not know your last menstrual period date, he or she may provide a rough estimated due date based on measuring the gestational sac. 

When No Fetal Pole Means Miscarriage

This all being said sometimes an ultrasound finding of no fetal pole can be a sign of a miscarriage. This situation is sometimes called a blighted ovum—meaning a gestational sac forms but the baby never develops enough to become visible on an ultrasound.

A blighted ovum can sometimes persist a number of weeks before any miscarriage symptoms appear, and the gestational sac may continue growing despite the lack of a baby.

Followup When There is No Fetal Pole

If there is any possibility that the ultrasound shows no fetal pole because of an error in dating the pregnancy, the doctor will usually ask the woman to come in for another ultrasound in one to two weeks time.

This wait can be understandably difficult but is necessary to avoid misdiagnosis of a miscarriage. If the problem was dating, the follow-up ultrasound should show continued development with a larger gestational sac and most likely the appearance of a fetal pole. If the follow-up ultrasound shows no development from the previous ultrasound, the doctor can diagnose a miscarriage.

In these instances, a miscarriage can be definitively diagnosed by ultrasound:

  • A gestational sac larger than 25mm with no fetal pole
  • No embryo with a heartbeat 2 weeks or more after an ultrasound that shows no fetal pole
  • No embryo 11 or more days after an ultrasound showed a gestational sac with a developing yolk sac 

A Word from Verywell

It is normal to feel anxious if your ultrasound is not depicting a fetal pole.

Talk with your doctor about your worries and your plan of care, like when to follow-up, and what you can expect from your next visit.


American College of Obstetrics and Gynecology. (May 2015). Practice Bulletin: Early Pregnancy Loss.

American Pregnancy Association, (August 2015). Concerns Regarding Early Fetal Development.

Doubilet, P.M. et al. (2013). Diagnostic criteria for nonviable pregnancy early in the first trimester. N Engl J Med, Oct, 369, 15, 1443-51.

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