16 answers

Due Date Discrepancy

Hi Moms,

Have any of you ever had a due date discrepancy? I'm expecting my third baby and have always kept accurate records on my cycles and have always been accurate with the doctor in determining my due dates. Well, this is not the case now. My doctor has told me that my due date is late August. Well, my hubby and I planned on having a July baby, so my last cycle was in October. When I went for my first doctor appointment and they did a transvaginal ultrasound, it was determined that I was 7 weeks pregnant due to the size of the baby. Well, I thought for sure I was 10 weeks based on my calculations and plus I already have had two children and have always been on cue with the due date and baby size. Now, my baby is measuring 3 weeks ahead of where he should be according to the doctor--leading me to believe MY calculations are correct. However, I've been told that the first and second ultrasounds are more accurate than my own calculations--meaning I'm three weeks behind. The reason this is a problem for me is because my hubby is out of town and may end up missing the baby's birth unless we have a more accurate due date. I went to the doctor this week and was told my due date may be a span of one whole month! I don't know how to plan it so that I'm not delivering alone. Have any of you moms ever had this happen to you? Are ultrasounds more accurate than your own calculations?

Please advise, thank you.


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Due dates are not an exact science as thousands of women would agree. My daughter was born 3.5 weeks ahead of her due date and we had an early ultrasound that confirmed the due date.

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Ultrasounds are not 100% accurate with due dates. All babes are different and too many times docs will follow the 'generalities' and make them sound like absolutes.

My first ultrasound put me behind where I KNEW I was. Come to find out, I delivered one day early of MY calculations. My second ultrasound actually put me back where my calculations had me.

Now, even with that, you have to realize that the 'due date' .... really is an arbitrary number. At some point in history a doctor decided that human gestation was 40 weeks. When in fact, human gestation is anywhere from 38-42 weeks. (so, yes... your due date can span a month and a good knowledgeable doctor will tell you so).

I understand your position. TRULY understand. When I was pregnant with my daughter we were living in Germany at the time. I DID NOT speak German and had already experienced difficulties finding doctors who spoke English very well. I did not want communication issues with my first labor and delivery. So, we opted for me to come home and spend my third trimester State side. Obviously, we had some planning to do so my husband could be home for the birth. Between trying to get his company to cooperate, and working with when baby was going to decide to be born ... it was difficult. For awhile, I really thought he was going to miss it. Then, my sister reminded me .... even if he did miss it... he would still be there for the really important thing... the rest of her life. That put things back into perspective for me and I was able to move forward and not stress about whether or not my husband would be there.

I would encourage you to have a back up labor coach. Obviously if your hubby can be there, that is optimal. BUT, I would encourage you not to rush nature. There is a reason why baby should determine when it is time to be born. Baby will come when baby is ready. There are very few times when something goes wrong and baby stays in too long. Most times doctors (or parents) will decide when baby should be born. More and more research is showing that when baby is fully developed, and all their bits and pieces are ready to enter the world then baby sends out a hormone that starts labor. Rushing this isn't the best option for baby.

I will tell you, that for us... everything worked out. Hubby arrived and 5 days later baby made her entrance.

I would tend to believe your calculations are more accurate. You know your body and your cycles. Just because doctors have fancy machines, doesn't mean they know your body better then you do. But in the end, try not to stress about it. It isn't good for you or baby.

1 mom found this helpful

They pushed my due date with my daughter back 19 days. I was charting and knew when I ovulated. In some sense we were both right on the due date. She was so big that she never dropped and I had to have a scheduled c-section. Your due date is an estimate and can vary by quite a bit. I hope the baby stays put until Daddy can be home.

I have three children, but in the case of the second pregnancy, my dates didn't coincide with the ultrasound calculations. I followed the doctors orders. I don't go into labor for some reason, so I had three C sections. He scheduled the surgery based on the ultrasounds. My son was 9 lbs, 8 oz and 3 weeks premature. He turned blue when off oxygen, had under developed lungs, etc. Not a fun time! With my third son which was 10 lbs, he scheeduled me 2 weeks earlier than my dates. I refused to go and with our previous experience he agreed. You know. Stick with your insticts. I happen to have large babies, but still all the tests run on averages. I'm not normal or average I guess and my son paid the price for those first few days.

yes M.
that was the case with all four of my girls you know when you got preg and you know your body i would bet the doc is wrong and you are right sometime they start out slow growing .because now you are right on track for size and weight that matches up with cycle ? wright

Due dates are not an exact science as thousands of women would agree. My daughter was born 3.5 weeks ahead of her due date and we had an early ultrasound that confirmed the due date.

i would defintly talk to the doctor. I would relay more on the first ultrasound. I know when i was pregnant with my daughter, i knew when i conceived her. they thought i was about 10 weeks along, and sent me for an ultrasound, since i had just had a miscarriaged 3 months prior. I told them i was only about 6 weeks. And sure enough the ultrasound showed i was 6 weeks and 4 days. So just big enough to have a heartbeat. Throughout the entire rest of my pregnancy, my uterus was measuring 5 weeks further ahead than i was. I had my daughter one week before my due date, and that is only because i had to be induced.

Though you know your body, but just because you are measuring at one point, doesn't mean that the measurement is accurate at all. The early ultrasounds are really where they determine the approximate date, your baby will come. But it is true it can be within 2 weeks on either side of that date. But the baby will come when they are ready.

you said your husband is working, is there any way that his work can keep him in the area come the end of july. If he explains the situation, they may be willing to work with him, and keep him around here more, so he can still work, but can be there quickly for you as well.

My boss's daughter was born at 34 weeks according to doctor's calculations but was clearly the healthy full term infant my boss was expecting.

You sound just like what happened to me. The doctor have me a late November due date and I thought she was crazy given MY calculations. And I was told the same thing. First ultrasounds are the most accurate. Needless to say, my second was born late OCTOBER, a full month ahead of schedule to them, right on target for my calculations. You know your own body, you know the changes and where you should be. Trust your instincts. You will probably be right.

Hopefully I can try to help a little. It really doesn't matter to your baby who says which date because he/she will come when ready which is why it's an estimated due date. Typically ultrasounds that at done early like 6-10 weeks are much more accurate for dating then anything else. However there are things that can make the calculations be off. Do you know if you have a tilted uterus? That can cause the tech trouble seeing and can cause measurements to be off. If the equipment isn't up to par they can be off. If the tech was newer they can be off. It is also very possible for your calculations to be off. Ovulation doesn't always happen the exact same time every month and it's possible you ovulated late. Even once you ovulate it take anywhere between 6-12 days for the egg to implant. So it is possible to be 2-3 weeks off in calculations due to either/both of these things happening. Babies do grow at different rates and it's possible your had a huge growth spurt before your last ultrasound and some babies just are bigger babies which is why some people have 10+lb babies. I know it can be frustrating to not have a date but I think you should just kind of think of the middle 2 weeks as your Estimated Due Dates and plan it will most likely happen sometime in there. However it is always possible for anyone to deliver early (especially being a 3rd) or late. Best of luck to you.

1st trimester ultrasounds ARE the most accurate. It is Very possible that you Ovulated later in your cycle than usual.

And all women technically have a "DUE MONTH" babies can come anytime between 37 and 42wks. Due dates are really just a best guess.

Keep this in mind, if your dates are correct (and not your docs) that means that you likely won't be subject to an induction which reduces your risks of complications during birth.

When I was expecting I was told not to get too hung up on my "due date" because my doctor said taht they consider 2 weeks oneither side of the due date "normal". Good luck!

At least the doctor said a later due date. And guess what, the baby will come when it is due, and I am sure it will be closer to your calculation. After all, you are the mom. I was having my fourth child 23 years ago. I knew I was due the very end of May or beginning of June. My ultrasound said I was due the end of February. At that time, the techs measured head size and my babies have large heads. Also, they said the baby would be over 10 pounds. She was 7.5 lbs. and born June 1. My ob decided to listen to me the mom. Thank goodness for some doctors that do listen to their patients. There were some talking of inducing in March if she did not come naturally after the ultrasound's determined due date. She would have been a premie. Stick with your calculations.

My cousin had the same issue. She went into labor about a month early per the dr. calculations. Her husband was snowboarding in a remote location in Canada. They originally rushed the baby to NICU...then returned 30 mintues later with the welcome diagnosis that it was a healthy full term baby...and her due date had been off.

Tell your husband to stay home!

You know your body better than any doctor or ultrasound ever good! I would go with your instincts!

This did happen to me with my first and second baby. Like you, my cycles were like a clock....one day late = pregnant. Baby #1, this was 31 years ago so a home preg test was not an option. When I was a week late I went for a test. It was positive. My calculations told me I was due on November 23. Through the pregnancy doc was concerned because I didn't gain ANY weight for 6 months. I got a cute little bump, felt great and doc encouraged me to eat more. I did and finally gained 8 pounds. In October doc said there was something wrong with my calculations and that I wouldn't be having this baby THIS YEAR, I told him if that was the case, I wasn't even pregnant when he took the test. As it turned out baby was transverse, laying on her back so he couldn't tell how big she was. She arrived 9 days early, November 14. Only 5# 5oz, but healthy and considered term. # 2 doc did the same thing. Ironically, I had the same due date, November 23. At 18 1/2 weeks he said I was MAYBE 12 weeks pregnant. I told him he was full of it but he did an ultrasound (finally invented) and the results said exactly the same as MY calculation. She arrived on November 30...a week late. # 3 came right on her due date. So, with or without an ultrasound my calculations were correct. I had the same thing...neither of the first 2 daughters were conceived by accident. They were both very intentional so I knew what I was talking about. #3 is the "bonus" baby, whoops. Go with your gut. Since this is #3 for you, you know your body better than anyone. Baby will arrive when it is ready anyway Congrats and I am rooting for July!


I know it can be very stressful with due dates. Especially since both of my children were born on the actual days that I was due to check into the hospital for my labor to be induced! My son was off by an actual month and though I was so over being pregnant and just wanted it all over with, he just simply wasn't ready to come out and didn't want to be forced out apparently. We all know that you can be told a due date that's at least 2 weeks off (either pass or ahead) so the fact that you've always been on point is amazing to me. I believe that I know exactly when my children were conceived as well, but the calculating I've never actually done.

So my suggestion is to continue with your gut feeling and pray that the baby agrees with your time table. Because unless you're scheduling a c-section, they come when they're ready. I understand your frustration because you need/want your husband there. So pray that your bundle will come when daddy can definitely be there. I'll be rooting for you! I believe that amnio's are more accurate than ultrasounds, but they're not as comfortable or easy as the ultrasounds. You didn't state if you had a new doctor or not, or if you'd stated your frustrations with them or not but keep informing them of your issue without causing more stress on yourself. Hard at times, but in the long run everything will work out for the better. You never know, your husbands trip may be cancelled right at the nick of time.

Best of luck,


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