Due Dates

Many moons ago, when you saw that blue line on the pregnancy test, you were given a date, a magical date, carefully conjured by an internet site calculator, or lo-tech by your doctor with their little plastic wheel. In went the date of your last menstrual period, perhaps half guessed, and out came your due date. At every check up since then the first thing you are asked is this due date. It must be exact, precise, not a day here or there, this is your date, your EDD. It is further honed by your scans, which, based on the length of you child’s leg bones and spine on a given day, lead to further bartering on the due date, up a day or down two.

So, how many babies arrive on their due date? Only 4%! With 50% coming within a week of the due date, and over 90% within two weeks. Therefore it is far more accurate to think of a “prepared period”, two weeks either side of your due date.

The EDD was established by Dr Naegele, a German obstetrician in the early 1800s. He declared that a pregnancy “should last ten moon months, that is, ten months of four weeks each.” Calculated at forty weeks from the date of your last period, the due date is based on the assumption that you have a regular 28 day cycle, and conceived 14 days after the first day of your period.

According to Dr Sarah Buckley in her book, Gentle Birth, Gentle Mothering,

“Menstrual dates will be most accurate for women who know the actual date of conception [usually a little more memorable!] and count 38 weeks ahead.”

Some studies have shown that calculations based on menstrual dates are likely to underestimate the due date, compared to dating scans at between 12 and 22 weeks. This then leads to inductions of babies that are not actually overdue.

As well as the length of your cycle and the size and development of your baby, environmental factors also have an effect on when your baby arrives. Chances are if you’re ill, going through stress, not getting enough sleep, labour might not start until your body is strong enough to go through it. Midwives also report that there is a noticeable increase in the number of women going into labour around the time of the full moon!

A study of US. mothers showed the average pregnancy length for first-time white mothers was 274 days (41 weeks and one day) from ovulation. Black women, women younger than 19 and older than 34, women with previous births and women pregnant with boy babies all tend to have shorter pregnancies.

Of course every pregnant woman is sure she is going to go early, she wills it to happen, despite her possible earlier misgivings about the act of giving birth, she is usually big and uncomfortable and wants “that thing out of her, like, yesterday!”

But its not only the woman wanting her baby to come. Overdue friends, myself included are bombarded with text messages and Facebook posts telling you to get a move on – as if pressure on you is going to help matters!

Pressure from the medical establishment is particularly strong, with some caregivers wanting to give overdue scans only a couple of days after the due date is passed. According to renowned US midwife, Ina May Gaskin, in Ina May’s Guide to Childbirth, induction of labour in the US was shown to have doubled during the 1990s from about 10% to about 20%, in large part because of the introduction of a new range of induction drugs.

Of course pre-eclampsia is of concern, as is fetal distress and a reduction of amniotic fluid, but all of these are quite unusual, and more often than not, baby will come when its good and ready. But once you’re past a week over due, you start coming under real pressure with threats, sorry, offers of membrane sweeps and induction. Most hospitals have 42 weeks as their upper limit before induction or caesarian are compulsory. Currently up to a third of pregnancies are induced, despite World Health Organisation recommendations that “no geographic region should have rates of induced labour over 10%.”

So your due date is looming. Is there anything you can do to help things along?

  • Castor oil has been safely used by indigenous peoples around the world to induce labour. No one knows exactly how or why it is so effective, but it is thought that its laxative properties, which may well send you rushing for the toilet, also stimulate labour. A tablespoon can be taken in juice or scrambled eggs at breakfast time after the due date has passed, with another later in the day if no effects have been felt.
  • Sexual activity is also a great starter. The contractions of the uterus during orgasm can start labour contractions and semen contains prostaglandins which can help to ripen the cervix. Nipple stimulation produces oxytocin which is needed for labour. Sex is perfectly safe at full-term, provided your waters haven’t broken – in which case, I’m guessing, you wouldn’t be up for it any way!
  • Walking is another effect way to help get the uterus contracting, blood flowing and baby’s head engaged in the pelvis. Getting out of the house also acts as a distraction.
  • Deep sleep is very important, as the primal part of the brain which activates labour is interfered with by our logical, rational brains which are used for speaking, thinking and modern daily life. It is no coincidence that a majority of labours start at night.
  • Acupuncture and homeopathy can both be extremely helpful – always use an experienced practitioner.

Lucy Pearce

A version of this article first appeared in Modern Mum magazine.