Scientists have discovered much to their surprise (and that of the regular folk) that the length of pregnancy between different women can vary up to five weeks! So don’t expect the due date to be set in stone; it’s only the doctor’s best guess ;-)
“So when was the last date of your menstruation?” I was asked by my gynecologist. Oh dear! This is the question I dread the most. I’m not one of those women who mark the date religiously on the calendar. So, I honestly can never remember the exact date my period began or ended. Was it the 29th or the 30th of August? I still don’t understand the concept of LMP and gestational age calculation in its entirety.
This is how it is commonly explained. It is a known fact that the average time between menstrual cycles is nearly 28 days. Also, ovulation happens only before 14 days of commencement of next cycle. Hence, when a doctor claims a healthy woman’s predicted gestational age is 6 weeks’ LMP, they actually mean she became pregnant nearly 4 weeks ago. This is the same time around ovulation.
So knowing the LMP is crucial as it helps the doctor calculate the estimated due date. The predicted pregnancy duration is around 40 weeks from the intial day of LMP. Guess what! That’s 4 weeks extra than the regular 9 months by which we usually count. The recently published study about the length of pregnancy, however, does turn things around a bit!
Until I decide to go for another baby in a few years, I don’t have to rack my brains around LMP. But if you are planning a pregnancy then you probably would like to know how to increase your chances of nailing it (rumble between the sheets is simply not enough) or rather when to expect the stork to deliver!
In reality, mere 4% of women deliver on their expected delivery date and for the rest of us, it can be either two weeks before or two weeks later (I delivered in my 39th week which was four days before my EDD). The scientists at the National Institute of Environmental Health Sciences (NIEHS) found that the length of a pregnancy was affected by a number of factors. Older women tended to deliver later (not because they are older), while women who had been heavier at birth also had longer pregnancies.
The results of the study are based on the urine samples of 125 women who were trying to conceive naturally. Studying the hormone level in the urine helped the researchers pinpoint the actual exact date of conception. So while your doctor may guess the EDD based on LMP, in the study, it was the urine that gave accurate dates 125 times! This is most helpful for women who may be urged to undergo induced labour when they appear relatively inactive around the time of the EDD.
My EDD was 8th June; however 5 days earlier I was told by my doctor that I was showing no signs of going into labour and that I should consider a caesarean. Since I didn’t see any reason to wait, I agreed. Is it possible that the reason I wasn’t going into labour was because my due date was further away than what was predicted? So, unless we have this kind of a test which can help us detect the accurate date, we do have to rely on the doctor’s guess. The U.S based researchers believe that patients should not be given a precise due date as the length of pregnancy can vary up to five weeks.
Some doctors believe that the study doesn’t make any new revelations. They already tell their patients that they are likely to give birth sometime between 37 and 42 weeks from the date of their last menstrual period (a five-week range). While due dates are still useful, the tool of predicting accurate due date will help prevent early intervention in the pregnancy. The midwives welcome the study results as they have long believed that medical intervention is more of a hindrance than help. I, for one, am glad I have conceived, carried and successfully delivered a healthy baby.