Should the Yolk Sac Grow?
QUESTION
At my first (transvaginal) ultrasound, the technician measured the black dot and said I was approximately 3 weeks and 6 days. Prior to my ultrasound, my doctor had looked at my BBT chart and estimated that I was about 5 weeks along, so there was a difference of about a week.
I didn't worry too much, but I had experienced a little bleeding so the doctor had me come in for blood tests just to make sure my hormone level was rising properly, which it is.
I started to bleed again almost 2 weeks later. My doctor was out of town, so I had to see to the on-call doctor. At this point I was supposed to be 5 weeks 5 days.
The ultrasound technician (a different one from the first time) said before we got started that we should be able to see a lot more than the last ultrasound, but when she got started I didn't see very much and she kind of got quiet. She measured everything again and sent me to the doctor.
She came in with my ultrasound results and said the yolk sac had not changed size. She checked me to see if I was dilated (I wasn't), but didn't check to see where the bleeding was coming from. She didn't tell me much except that she didn't think I was having a normal pregnancy and said I could wait to see what happened or schedule a D&C.
I decided to wait for my primary doctor to come back to see what he thought. I had more blood taken to see if my levels had risen again (they did, they came back at 3,584 and had been 1,780 previously). My next appointment with my doctor is scheduled in eight days.
What does it mean when the yolk sac hasn't gotten larger? Can it get larger or is it a sign of an abnormal pregnancy? Is there any hope?
Thank you for your advice.
ANSWER
Hello,
The first ultrasound you describe with the "black dot" was measuring the gestational sac. The sac would be black because it contains a small amount of fluid. This is normal.
The sonographer dated you at 3w 6d. It is impossible to see a gestational sac this early. I am going to guess she told you the date from conception and not from your last period. There are always two extra weeks added on to any pregnancy because the counting starts from the first day of your last period not conception. So lets just say you were 5w 6 days at the first ultrasound which makes sense.
At this point you may or may not see what is called the fetal pole. This is the embryo. What you will see before the fetal pole has developed is the yolk sac, inside of the gestational sac. This is a normal part of a first trimester pregnancy. The yolk sac does not grow. The gestational sac is what will grow and I think this is what the sonographer was telling you. The gestational sac did not grow.
The good news is that your HCG level doubled! You did not say the time frame, but the levels should double every 24-48 hours.
In these early days of a pregnancy, there are so many "what ifs?" The "what ifs" cause anxiety. I like our mommies to let go of the so called scientific side and let the pregnancy progress as it will. There is not a lot that modern day medicine can do for an early pregnancy that is not going to progress normally. This is why time and decreasing anxiety are your two friends. After a 10 day interval in between ultrasounds, a heartbeat should be seen in the fetal pole if the pregnancy is developing well.
In the meantime, relax and just enjoy the fact that you have created a life with its own little spirit just waiting to connect with Mom. The next ultrasound will tell the story.
With regards,
Jane RDMS
Jane Foley
Jane Foley has worked as a Sonographer (Ultrasound Technologist) since 1979. Jane has lived and worked in many parts of the world including Saudi Arabia. She is a Registered Diagnostic Medical Sonographer or RDMS. She pulls a wealth of information from her experience in the field of Radiology and her interactions with such a broad cross-section of cultures she has visited. She now makes her home on the island of Maui with her English husband, Michael.
