QuestionHi Dorothy,
This question is late in coming, and I apologize for that. During my last lmp, before the conception of our baby, and a couple of months before that, my cycles have been about 32 days. My last lmp (before conceiving our baby) was on 10/5/07. My first ultrasound was done at 11/21/07, on which the baby measured at 6 weeks, 1 day, and around 4.5-5 mm. Here is where my first question arises. Since a 32 day cycle means late ovulation, shouldn't the fetus have measured 6 weeks, 5 days, and not 6 weeks, 1 day? My due date was determined using my lmp and a calendar, and the specialist came up with a due date of 7/11/08. Again, because of late ovulation, shouldn't the true due date have been around the 14th or 15th of July? I'm not sure if the ultrasound also presented a due date, but based on my understanding, if the ultrasound due date and due date based on lmp is a week or less, then the due date from lmp is kept. Is this correct? I'm concerned about this because I actually ended up giving birth on 6/26/08, and if my due date was on 7/11/08, then I gave birth 15 days early. If my real due date was on the 14th or 15th of July, then I gave birth almost 3 weeks early! Since I gave birth on 6/26, does this mean that I actually conceived in September, rather than in October? I got a period in October, but it might have been a bit lighter than the norm, so could this have been implantation bleeding? Does this mean that the first ultrasound at 6 weeks was off by several weeks? I also had an ultrasund taken at around 9 weeks, on 12/10/07, in which the baby measured about an inch (23 mm). Another ultrasound was taken on 12/24/07, in which the baby was around 2 inches at 11 weeks, (or 10 weeks 3 days, if late ovulation is taken into account). I took my nuchal translucency ultasound on 1/3/08, in which all was well, except the due date went from 7/11/08 to 7/14/08, and yet the due date of 7/11 was still kept. I am really confused over all of this. Could all of the ultrasounds, at 6, 9, and 11 (or 10 weeks 3 days), and then at nearly 13 weeks,(or 12 weeks 2 days, if ovulation is taken into account), have been off by several weeks? Please help me clarify matters and to ease my mind a bit. Thanks again!
AnswerSorry for the delay; with the holiday, I've been busy with family things.
It looks like they determined your due date by your lmp, basing it on a 28 day cycle. It depends on the dr whether or not they will change your due date if it's several days off - most of them won't if it's only a few days off. However, the ultrasound is going to give you a more accurate date than going by the lmp, especially if your cycles don't follow a 28 day pattern.
Looking at the fact that you had several first trimester ultrasounds, there is no way that you conceived in September. There is too much difference in development during the first trimester for the ultrasound to be 3 weeks off, especially since you had so many ultrasounds. If you were 9 weeks pregnant and thought you were 6 weeks pregnant, the ultrasound would have shown very clearly that you were 9 weeks.
Some babies just come early - it looks like that is the case with your baby. Your baby being born 2-3 weeks before his due date doesn't change what the ultrasounds showed during the first trimester.
Sincerely,
Dorothy H, LCCE
