Dear Doctor,

I am writing with a question of concern in early pregnancy. My wife and I recently underwent a successful FET in which two blastocysts were transferred on August 31. Of the two blastocysts, one was a grade AA 5 day blastocyst, and one was a grade AB 6 day blastocyst. I asked the embryologist at time of transfer about their differences, but he said they were so morphologically similar that it was impossible to tell.

In typical fertility language, I am the egg donor and my wife is the gestational carrier. We utilized a sperm donor with at least one confirmed prior pregnancy. I was 39 at the time of egg retrieval and my wife is 27 years old. This is our first attempt at pregnancy.

After transfer, we were fairly certain when implantation occurred, as my wife had mild cramping and spotting. We took home pregnancy tests six days after transfer and were getting positive results. Our first HCG yielded a number of 75, which was within average range, the second HCG surged forward rapidly, multiplying by seven times instead of doubling, and the third doubled, though at a rate of 2.5-3 days. Progesterone and estradiol have been monitored during the process, and both have been good.

Our first ultrasound was at 7.2 weeks. At that time, the technician quickly found a heartbeat that was visible and audible, of 143 BPM. We could see little arm and leg buds in the ultrasound picture. The heart rate was regular.

We then met with our physician, who informed us that the embryo measured 6.5 days instead of 7.2 days. As a result of the fact that this baby is the result of in-vitro technology, the dating is accurate. The doctor told us that this was evidence of a slow-growing pregnancy, and that it was a definite red flag. He told us that although the first HCG and second looked good, the third didn't multiply as rapidly. He said that alone would not have raised a flag, but that, in addition to the embryo measuring small was suggestive of a problem. He told us that it could be fine, or could result badly.

Afterwards, I met with a nurse and asked how concerned we should be. She seemed extremely dire and told us that it isn't good, and we should be prepared for a possible negative outcome. We went home frightened and crestfallen, and have been struggling this past week to maintain a positive outlook. Our next ultrasound is scheduled for a little over a week from now, at which point we will be 9.2 weeks.

My wife continues to have pregnancy symptoms, and has not had any spotting or cramping, so certainly no signs of imminent miscarriage. I don't know if this information is relevant at this point, but I am an extremely small adult (five feet tall, 112lbs) and the women in my family are extremely small. In addition, my wife is very small at 5'2, and doesn't weigh much more than me. Our donor was tall, at 6'. My questions are as follows:

1) Could the size of the embryo be related to my extremely small genetic stature?

2) Can you give us reason to hope that this pregnancy outcome may be okay, based on the information I provided? Obviously, with a small embryo, I am concerned about chromosomal abnormality (given my age), but I had hoped that the selection process for five day blastocysts would have significantly reduced the risks.

Any input you can provide will be greatly appreciated. Thank you for taking the time to read this very long post.