Due Dates

One thing I have begun to notice with this pregnancy is how important ‘due dates’ tend to be for many pregnant women. It is the number one question we are asked. I don’t think there has been a time when I let someone know I was pregnant that their first question wasn’t “When are you due?” We also look forward to that time in our life when we are finally able to hold this little baby we are growing. I think for most women waiting for their baby is the hardest emotional part of pregnancy. Not only are we tired, cranky, and sore - but we also have to deal with the unknown onset of when the baby will actually make their arrival. I know for me, and a lot of my friends, we looked towards our due date and kept telling ourselves "just this many more days." For all but a few of us, our due dates came and went - and so did our sanity.

Recently I have had more than a few rather unhappy friends who have gone past their due dates. It sounded like their lives were miserable. So what is the reasoning behind it? Because even though we are told in our doctors office that our baby is supposed to arrive anywhere from 38 weeks to 42 weeks, we all hope we are going to be one of those elect few who go before their 40 week mark. The last little bit of pregnancy is a hard and emotional journey for many women, so it’s no wonder that they would find major disappointment in the fact that they have to wait even LONGER for their little bundle to arrive.

So that got me thinking about due dates and how they came to be. After some research this is what I found, and I hope it helps me this pregnancy not succumb to the disappointment that comes when your pregnancy continues past your due date.

History of your estimated due date:

1850 a man by the name of Dr. Naegele decided that the average length of human gestation, or pregnancy, lasted around 266 days from conception. He assumed that the average woman had cycles that lasted 28 days, and she ovulated midway through on day 14 of her cycle. From his data he came up with a mathematical calculation for due dates that we still use today.

That formula is your Last Menstural Period (LMP) +7 days, and then you - 3 months.

For example my last menstural cycle was September 17, 2008 + 7 days = September 24th, 2009. You minus 3 months from that and you get June 24th, 2009. Our EDD.

Why it is only an estimated due date:

The Naegele formula is flawed because of certain factors that don't work into his calculation. For example, with this pregnancy I had very irregular cycles that were no where near 28 days. One of my cycles was 45 days, another was 2 days. So it's obvious that not every woman ovulates on magical day 14 like the formula states.

Other situations such as ethnicity, how many successful pregnancies the mother has had (also known as parity), prenatal care, better nutrition, and other screening factors. Because women are receiving better prenatal care and are becoming more educated about different risk factors, nutrition, and prenatal screening the length of gestation for many women has lengthened.

One study indicates that we need to add 15 days to the Naegele due date calculations for Caucasian, first time moms, and 10 days for Caucasian moms having subsequent children. African American and Asian women tend to have shorter gestations.

If there is a question of menstrual history ultrasounds, like I mentioned before, an ultrasound can be an effective way of dating a pregnancy. However, this accuracy is lost if it is not performed in the first half of pregnancy.

What this means for me:

When I interviewed with my new doctor (Dr. J) I told him I was a little nervous about when my estimated due date was. When we found out we were going to add another little one to the brood I looked through when my cycles were. First cycle? 45 days. 2nd cycle. 2 days. 3rd cycle: 35 days… As you can see, they were very irregular, which I knew would make my estimated due date a lot less accurate. With this pregnancy I am hoping I won't have to get induced, for a variety of reasons, so I was a little nervous because they just did the normal 28 day cycle to give me my due date when I know that is most likely not the case for us.

Dr. J. said that there are many other ways to date a pregnancy, although most authorities agree that not just one of these factors should be used on their own to determine the final due date. Some of the things he mentioned was quickening, or when the mom feels the baby move for the first time. (Ours was right after Christmas). He also said they can check when the baby's heart tones can be heard through a stethoscope. (We had an ultrasound so we heard and saw the baby's heart beat then. We were measuring 9 weeks 1 day, just 2 days ahead of our EDD). They also measure your uterus through out pregnancy, which is done to measure the fundal height. Generally speaking if you are measuring 17 cm then you should be around 17 weeks.

Our doctor went through with us what the baby was measuring at our first drs. appointment. Baby was measuring 9 weeks 1 day, which would only move the normal due date up a few days based off my cycle. However, it was not a vaginal ultrasound, which I guess makes the accuracy go down a little. Our 16 week ultrasound the baby was measuring four days ahead of schedule, so that doctors office switched it to what the ultrasound said because I had told them that I had been very irregular before then. So what it comes down to? I'm not really basing my life or 'countdown' to my due dates because I really have no idea... My doctor said he'll keep watching me, and although he does have to note when our due date is because of Idaho regulations, he'll keep our feelings about being induced in mind, especially since I had longer cycles and the baby could be younger than our due date determines. He said worse case scenario they can actually do something where they stick a needle in the stomach and take a sample of the amniotic fluid and would be able to see the actual age of the baby - but that comes with risks too, so we're hoping we won't even have to deal with that - but it is an option.

Ways to avoid being disappointed when you go over your due date:

*Countdown to a week after your due date: I think this is a good idea. This time around I think once my due date gets closer I’m going to set my baby countdown tickers back until I would be 41 weeks and would be going post-term. Sneaky huh? That way I won’t have a counter saying I’ve gone OVER my due date and making me crazy, and I’d see that I still had time before I had to worry about the baby.

*Continue telling yourself positive affirmations about your pregnancy: Instead of thinking that you have past your due date, realize that your baby is born on their birthday and not on a day that a doctor decides. Continue to remind yourself that the baby will come when it is best for them, even if that doesn’t necessarily follow your time table. It does work! Try it!

*Remind yourself that your due date is more a guess date: It’s there to give you an estimate of when your baby would be arriving, not a deadline of success or failure.

If any of you have any other ideas that helped you I’d love to hear!

Good articles (where a lot of the information came from):
When Will my Baby Be Born
Pregnancy Due Date
When is that baby due?