Fetal head is three weeks behind in third trimester.

I am having ultrasounds done every three weeks in a high-risk perinatal assesment facility due to an unknown cervical mass that may have been the cause for spotting early in my pregnacy. However, the mass now cannot be seen on ultrasound at 28 weeks yet another cause for concern has arisen. During my 25 week ultrasound it was noted that the female fetal head was lagging behind in growth (about the 8th percentile) while the rest of her body was growing normally. Now at 28 weeks her head is still behind in growth (one measurment three weeks behind and the other four) while her body is measuring normal for 28 weeks! There are no other markers of a problem during ultrasound and none found in genetic testing\counceling (quad screen). Her brain structure appears normal and I was told not to worry but at the same time it was suggested that I have a fetal MRI and\or amnio-centisis. I am very concerned about the outcome of this finding and would like to know what the odds are that this will eventually become a diagnosis of microsephaly? and the odds are of her head catching up in third trimester growth?

[Elaine Brown, MD]

Hi!
The biggest problem with doing tests is that very often something "incidental" is found which leads to lots more tests.

Microcephaly is defined as a head circumference which is more than three standard deviations below the normal range.  I don't know if your baby's head meets criteria for that, and I'm going to bet it doesn't.

Fetal position can have a lot to do with head measurements. If the baby's head is down really deep into the mom's pelvis, the head can be compressed and look smaller than it really is-- having the MRI wil help sort this out.

You don't mention any of the major causes of mircrocephaly which also makes it less likely.  Also, you don't mention any other abnormalities which might be part of a syndrome--and  an islolated finding is less likely to be serious.

Its your call on the amnio--but they are not too bad when done by  a high risk specialist,
It is probably worth the peace of mind to do it.

Finally, does anyone in the family have a small head?  Findings like these are often familial.

It sounds like your team intends to follow up on the finding, and not just leave you hanging.  Trust your docs and ask lots of questions.

Most likely, your baby will be perfect.  What is her name?

Good luck!
Dr B

[NeedSecondOpinion]

Thank you soooooooo much for your input Dr. B! Her name is Tempest Rae. : )  My doctors agree that she does'nt meet the criteria for microsephaly but also stated that they could'nt tell me 100% that she does'nt have a problem in there. One said that smaller head size can mean smaller brain. I'm not sure if a fetal MRI can diagnose something like that. Furthermore, she has not been in the head down position when these measurments were being considered. As for a small head being familial I would'nt necessarily consider the father of my babys head small but rather elongated and maybe somewhat pointed while he is 6' 2" and very thin(always has been). I must say it is of rather odd shape! lol. As for her older sibling, almost 3 years now, I must addmit that her head is noteably small & elongated as well but proportionate with her small but long body in my opinion. People often comment on how tall and thin she is. At her last pediatric appointment I recall she was in the 10th or 20th% for weight and 70% for height. Head was within normal range but I have not been informed of this measurment lately (now don't I wonder!). I don't know if this has any real relevance in the matter at hand but here are some picture links to make judgement of head size in my unborn childs family(hope it works):

http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=387082899&albumID=1412588&imageID=19678768

http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=387082899&albumID=1412588&imageID=19678767

http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=387082899&albumID=1412588&imageID=19678770

http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=387082899&albumID=46254&imageID=16228441

http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=387082899&albumID=46254&imageID=15669986

[NeedSecondOpinion]

oops. these links work:

http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=387082899&albumID=1412605&imageID=19679161

http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=387082899&albumID=1412605&imageID=19679163

http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=387082899&albumID=46254&imageID=16228441

[NeedSecondOpinion]

I am 34 weeks now & have had many ultrasounds and even a fetal MRI done since I last expressed my concerns on this site and am becoming less and less afflicted by worry. The results have been reassuring that her head is still growing (and not stoping or slowing in growth) yet is still on "the small side". It has actually had somewhat of a spurt in growth over the past 3 weeks and is now above the 10th percentile which I feel is a miracle due to my prayer. I have about 30 days left until she is born and will inform evereyone on this site of the outcome and if there has been any affect on her mental well being.