Understanding Discrepancies in Early Pregnancy Tests & Ultrasound Findings

Question
QUESTION: Hi.
I am really comfused. AT 7 weeks I was told by my OB/GYN that my blood test results didn't show a viable pregnancy. He sent me to do a higher resolution ultrasound before he could advise me further. At 7 weeks 3 days, I went for the ultrasound and saw a heartbeat of my baby at 102bpm. The fetus was measured at 0.28cm CRL at 5 weeks 6 days.

Can there be any discrepancies in the blood test results? And how accurate at ultrasound in picking baby's heart beat?

ANSWER: Dear Elaine,

In the 1st trimester of a healthy pregnancy, we expect hCG levels to double every 48-72 hours. It is a pretty reliable indicator of the health of the pregnancy. However, if you did note heart activity via ultrasound, there really is nothing to do at this point except to wait this out and see if the pregnancy will be able to maintain itself. The heart rate of 102 BPM was perfectly normal and it may be that everything will be fine. But the growth delay and the slow-rising hCG may indicate a problem. Again - all you can do is wait it out and let the doctor monitor progress in the next weeks.

I hope this has helped you and answered your question. I wish you well.

Brenda

---------- FOLLOW-UP ----------

QUESTION: Hi Brenda,

Thank you for your prompt response, I really appreciate it. I was at the MFM this afternoon to do another ultrasound. The latest findings of my baby are 3.8mm CRL at 6weeks 1 day, with a heart beat of 116 BPM, even though i should be 7 weeks 6 days (LMP). Is this a good sign that my baby is improving? I was also told that my progesterone level is low, what does that mean?

thanks again for your help.

Elaine

Answer
Dear Elaine,

Early ultrasound dating is almost always more reliable than LMP calculations. It may simply be that your original dates were off and that you conceived later than you thought. It is a positive sign that the baby continues to have a strong heart rate within normal rate expectations.

Progesterone plays a very important role in pregnancy. Progesterone is a hormone produced by the ovaries that helps prepare the uterus for pregnancy. It is first produced by the corpus luteum in the ovaries and later is maintained by the placenta. Some of its important functions are:
-Helps to regulate the menstrual cycle.
-Prepares the lining of the uterus for implantation.
-Keeps the lining of the uterus thick which is necessary for a successful pregnancy.
-Produces a rise in temperature after ovulation, which remains until menstruation occurs.
-Creates a nutrient rich environment for the baby by increasing glycogen and arterial blood to the lining of the uterus.
-Keeps the uterus from having contractions.
-Causes the cervix to thicken and create a mucous plug which prevents bacteria from entering the uterus.

Most doctors like to see an absolute minimum level of 10 ng/ml during the first few weeks of pregnancy (and often higher). If a woman has low progesterone levels this can be an indication that the pregnancy is at risk and some doctors will prescribe progesterone to boost those levels in an attempt to sustain the pregnancy.

I hope this has helped you and answered your question. Be well!

Brenda