What Is That Circular Structure In My Ultrasound?


  • That circle is known as the Yolk Sac (YS).
  • It is a membrane that is connected by a tube to the embryo, and acts as the start of the circulatory system.
  • The Yolk Sac also is what provides nourishment to the growing fetus until the placenta is fully formed.
  • Once the placenta is fully formed in your second trimester, the placenta takes over this role.
  • The placenta is attached to the uterine wall and is connected to the fetus by the umbilical cord.
  • It transports oxygen and nutrients to the growing fetus, as well as, filters out any waste.
  • The placenta continues to grow and change in order to accommodate the fetus’s needs as the fetus becomes bigger.
  • The placenta can also help to protect the fetus from certain infections and maternal diseases.

First Choice Women's Resource Centers offers free pregnancy tests and ultrasounds to medically confirm pregnancy. Call 973-840-8924 or text 973-840-8924 for an appointment in our Jersey City, Montclair, Morristown, Newark or Plainfield locations.






Schedule An Appointment

If you think you could be pregnant, please come in for a pregnancy test and to receive information about your options. All of our services are free of charge.

Pregnancy tests are the only service that can be scheduled online. STD screens and ultrasounds must be scheduled via phone or text.