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Focusing in on the Due Date

It’s Called An “Estimated” Due Date For A Reason…

Today, I wanted to dive into more information on estimated due dates (or “guess dates” if you are a Hypnobabies student). There are a few different ways to calculate the time frame in which your baby will be born, but the most important thing to remember is that this date is just an estimation. Only about 5% of babies are born on their “due dates,” and this estimate includes inductions.

My own boys completely ignored their due dates. Our first arrived 5 days over. Our second arrived two days over. And our third arrived 10 days over my due date. I remember really being excited and ready for that birth to start!

It was not until our third pregnancy that I lost all interest in my “due date.” It was July 28th, and I told most of my family and friends when asked that our baby was coming some time in August. It was so freeing to just be patient, knowing he would arrive when he needed to. And I had a care provider I trusted watching over our care, ready to make suggestions if anything medically necessary needed to happen.

The History:

Currently, when being first assessed by a care provider, you will be asked for you LMP (Last Menstrual Period). Then, by adding 280 days to the first day of bleeding (you can also add 7 days to your LMP then subtract 3 months) you achieve the estimated due date. This is called Naegele’s Rule, and Naegele came up with this method in 1812.

Their are draw-backs to this method. It assumes all women have a perfect 28 day cycle, and that ovulation occurred exactly on day 14. (Knowing and tracking your ovulation can be a big plus in calculating a more accurate date!)

Thus, large studies have shown that this method consistently underestimates due dates by 2-4 days. Some believe that the gestation period of 40 weeks should be revisited, to more accurately reflect when babies are born.

Achieving Accuracy:

In the 1970s, ultrasounds became more popular. And now, studies have shown that early ultrasounds can more accurately predict the end of a pregnancy.

The most accurate predictions occur from ultrasound dating between 11-14 weeks of gestation. It is important to note however, that even this form of obtaining a due date is not perfect either.

To be even more precise, knowing the day of ovulation and the day (or days) of intercourse or insemination can be much more helpful in calculating a date. But this still can depend on the length of time it took the embryo to implant.

What’s The Big Deal?

It’s only a couple of days off, right? Is that really a possible issue? Yes, it could be.

The organs that finish developing before the onset of birth are the brain and the lungs. If a due date is off by a couple of days, and a non-medically indicated induction is pushed right at the due date, the baby may not be as ready to be born as believed. Many babies that are born at term (37 - 42 weeks) may still need to enter the NICU if their lungs are not quite ready to breathe out of the womb.

Someone experiencing a high risk scenario, and needing to schedule a medically-indicated induction at 37 weeks, could benefit from an extra 2 - 4 days.

What’s The Take Away?

Always ask questions and have a good open line of communication between you and your care provider. Some good tips:

  • Ask how the due date in your chart has been calculated. If it’s based on your LMP, offer an early ultrasound dating, or let them know if your cycle length is longer or shorter than 28 days

  • Let them know if you chart your cycle, and if you know the exact day of ovulation and intercourse

  • Ask your care provider how they feel about pregnancies in late term (40 - 42 weeks)

  • Release your expectations: know that your baby will most likely arrive between 37 - 42 weeks of gestation

Everything should be offered up as a choice you get to make during your pregnancy. Sometimes the choices are easy and sometimes they are hard. But it is your body and your baby, and you should always be respected and heard.

Current Services:

  • New Hypnobabies Group Class Starting November 6th

  • Open Spaces for Fertility Doula Support

  • Open Spaces for Prenatal Doula Support

  • Private Childbirth Classes available any time

  • Menarche and Cycle Awareness Classes available at any time

Check out all of my services listed here: Gentle Voice Services

I am archiving my past newsletters for you to share with family and friends. You can find them all here: Gentle Word Blog

I hope your week is starting off great. Let me know if there any questions I can address and attempt to answer for you!


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