Dating the pregnancy

"Dating" a pregnancy is the process of calculating the estimated date of delivery (EDD). Typically, the EDD is set at 40 weeks after the mother's last menstrual period (LMP). This assumes that all women have a standard 28-day cycle with ovulation on day 14.

In many cases, this assumption isn't valid, and then, the EDD should be determined by other means. Doctors like to use early ultrasounds to date pregnancies, since embryos grow at a very well-defined rate during the first few weeks of pregnancy.

In addition, women can "chart" their cycles and identify their personal ovulation date with a great degree of accuracy. I'm not going to get into a whole explanation of charting here, but if you're interested in learning more, I highly recommend the Fertility Friend site or the book Taking Charge of Your Fertility.

With Littles -- October 2007
My own cycles have always been on the long side, suggesting that I likely ovulate later than day 14. I explained this to the nurse at my first appointment after getting pregnant with Littles. I was not charting, but based on this and some other signs, I suspected that my actual EDD was about six days later than my EDD per LMP.

The nurse got me set up with an ultrasound, at what was 8 weeks 4 days per LMP, but 7 weeks 5 days per my suspicion. Littles measured 8 weeks 0 days -- so, closer to what I suspected based on my cycle history.

But Dr. K said that since Littles measured within a week of my EDD per LMP, she would not adjust my EDD. At the time, I thought this was great! Six fewer days of the miserable first trimester to put up with!

I came to regret it at the end of my pregnancy. My OBs would not let me go past 42 weeks gestation, because the risks to the baby increase past that point. Since my EDD had been set based on my LMP, this meant 42 weeks from my LMP.

I ended up having to be induced. Of course, if my suspected EDD was actually correct, I was really closer to 41 weeks at my induction date. We could have allowed Littles to keep baking for another six days before she got into the increased-risk territory.

As I've explained previously, I ended up having a very positive induction experience anyway. But I still felt a little deprived of the experience of spontaneous labor. I still believe that Littles would have come on her own had she had those extra days that she rightfully deserved.

With Noob -- June 2009
I started charting after my pregnancy with Littles, so when I got pregnant with Noob, I knew that I had ovulated nearly two full weeks later than "expected." This was another reason why I insisted on an early ultrasound (in addition to wanting some peace of mind after my previous miscarriage).

The ultrasound was at 8 weeks 2 days per LMP, but only 6 weeks 5 days per my chart. It came as no surprise to me that Noob measured 6 weeks 3 days. I didn't quibble over those two days, since I knew it gave him two more days to bake at the end!

As it turns out, he arrived two days "early" -- that is, precisely on his EDD per my chart. Of course, had we not accurately dated the pregnancy, he would have been considered 11 days "late." Many doctors would have induced him by that point... wrongly, because he was not at all overdue.

With Baby Q -- December 2011
I charted again, and so I know that I ovulated late again. But my midwife, C, does not routinely induce for being overdue. If I reach 42 weeks, as long as everything is fine with Q and me, we'll keep waiting. This is another reason why I didn't insist on an early ultrasound with this pregnancy: I'm less worried about accurately dating it, because I know there's no induction looming at the end.

(By the way, you might be curious as to why my OBs with Littles felt that it was too risky to continue past 42 weeks, but C is fine with it. I'll address that in another post, at some point.)

Also, unlike many doctors, C trusts my chart. When we went through the initial paperwork yesterday, she asked me not only what my LMP was (as all my previous providers have done), but also if I knew my ovulation date and my actual EDD -- both of which I do know, thanks to my chart. That's what we're using for dating purposes. Neither of my previous providers ever asked me about these two key pieces of data.

Houston, we have a heartbeat

I don't think any parent ever forgets the moment when they first hear their baby's heartbeat. It's truly magical.

With Littles -- October 2007
Our initial appointment was with a nurse, to do paperwork, go over do's/don'ts, etc. I wasn't entirely sure of my conception date, so the nurse got me set up with an early ultrasound at 8 weeks to date the pregnancy.

That was when we first met "Dr. K." And that's when we first saw and heard the heartbeat, beating away steadily in a small object that closely resembled a gummy bear. She took her time, explaining how she did the measurements, pointing out when Littles "moved" (it looked like a quick shudder), listening to the heartbeat and mapping it on the screen. My husband and I were just awestruck by the entire experience.

I happened to be wearing my Ironman finisher's shirt that day, and Dr. K noticed it and commented on it. We chatted a bit about it, and she thought it was very cool that I had done that.

I might get into my Ironman experience more in a future post, but for now, suffice it to say that it's the only experience in my life that even comes close to mimicking labor and childbirth.  To know that I've gone through that, and to comprehend what it means, is to understand a whole lot about me: When I put my mind to doing something, I do it. I'm not afraid of a little hard work -- or a lot of it. And my body is capable of some pretty amazing things.

All qualities that have served me very well at both my births.

Anyway, I really think that Dr. K "got" that, right from the start. I always felt really comfortable with her. Not so much with her partner, "Dr. S," who came highly recommended but whom I increasingly butted heads with over the course of my pregnancy.

We couldn't know it at the time, but nearly eight months later, Dr. K would be the one to catch Littles. I credit her for playing a huge part in making Littles' birth such a positive experience. And I really think it all started in that little room with that little beating heart.

With Noob -- June 2009
After a previous miscarriage, my midwife was happy to get me set up with an early ultrasound. We went in at 6 weeks.

I loved my midwives, but unfortunately, they could not do ultrasounds themselves (only the OBs in the practice could do so). And as it turns out, their ultrasound tech's bedside manner left something to be desired. At this ultrasound, she inserted the probe and a little blob appeared on the screen. Silently, she messed around with the image a bit.

Where's the heartbeat? My stomach sank.

Then she made a few comments and mumbled something about a heartbeat. Wait, what? "So there's a heartbeat?"

"Yes. 120 bpm." Which is great for 6 weeks.

It was a very different experience from our first ultrasound with Dr. K. But regardless -- Noob had a heartbeat. That was enough to put a big smile on my face.

We had to wait over five more weeks to actually hear the heartbeat for the first time, at a regular appointment with one of the midwives.

With Baby Q -- today! December 6, 2011
This was my first pregnancy where I didn't have an early ultrasound. I probably could have asked Dr. C to refer me at any one of my appointments with her, but I didn't feel like hassling with the referral process. Plus, it goes against my overall philosophy of minimizing interventions as much as possible. There have been concerns raised about the effects of ultrasounds on developing fetuses, and while I don't find any of the arguments to be particularly convincing, it does seem prudent to minimize ultrasound use to only what's medically necessary. And really, I had no medical reason to need an early ultrasound this time around.

Anyway. Waiting also meant that we'd get to hear the heartbeat for the first time with our friendly homebirth midwife "C," rather than some random ultrasound tech.

Unlike my previous providers, C gave me the option to come in for my first appointment whenever I wanted. I opted to wait until 10 weeks, because I figured there wasn't much point in coming any earlier. C has no ultrasound equipment, and the heartbeat isn't usually audible on the doppler until around 10 weeks. Paperwork can be filled out anytime. I knew I could contact C via phone or email if I had any questions in the meantime.

Finally, 10 weeks rolled around, and I headed over to C's office. When it was time to listen for the heartbeat, C showed us a model of a 12-week old fetus and warned us that it can take some time to find the heartbeat of such a little being. Indeed, she had to poke around some, but finally she moved the wand a bit to my right side and there it was. Clip-clop. Clip-clop. Clip-clop. The unmistakable sound of a tiny heart beating away.

We all got big smiles on our faces. That sound was well worth the wait.