The following information has been produced to help you to be aware of some of the issues that may arise when pregnancy continues beyond the estimated due date, and to empower you for wise decision making to help you decide what to do when you’re overdue.
Your EDD (estimated due date) has probably been in your mind since your first antenatal checkup. It can be very disappointing and frustrating to find that you are still pregnant a week or more beyond this date. Added to the normal discomforts of the final weeks of pregnancy, you may well feel very fed up and desperate for labour to start, especially when people around you keep phoning to find out if you have had the baby yet, and the hospital is talking about booking a date to induce labour. This can be a very vulnerable time. However you may not be genuinely ‘overdue’ at all, and unless there is a medical problem, you can take your time to assess the situation and consider the options.
Induction of labour is a contentious subject, yet many hospitals have a policy of routinely inducing after a certain date. Sometimes induction of labour is strongly recommended between 41-42 weeks as this has been shown by research to reduce the overall (very small) number of babies who die in childbirth in the UK (approximately 4-5 babies out of 1000 are likely to die just before or soon after birth and an even smaller number in labour).[1]
It has been estimated that when induction is done routinely, approximately 500 women are induced before 42 weeks to potentially save one baby. However this does not mean that induction is appropriate or safe for everyone, nor does it address the other potential hazards, risks and consequences of routine induction policies.
Marjory Tew, the renowned statistician, says in her book ‘Safer Childbirth?’ :
‘Confirmation is hard to find that induction reduces the danger of perinatal death even in the medical complications for which it is advocated’. [2]
It has also been shown that convenience is another non medical factor underlying induction policies. Since the advent of induction, studies have shown birth to be more common on weekdays.[3]
There are many doctors and midwives who are critical of routine induction policies and who prefer to follow a different approach. This involves assessing each woman who is ‘overdue’ individually and then deciding what would be best for her and her baby. The aim is to determine whether the pregnancy is normal (albeit longer than the estimated average length), or whether there are any signs of post maturity such as slowing of the baby’s heart rate or a very low amniotic fluid level and therefore cause for concern or possible intervention.
Genuine post maturity can endanger the baby, so a thorough assessment will provide the information needed when deciding whether to induce or not. [4] An induction would only be performed if the risk of the baby remaining in the uterus was considered greater than those associated with inducing. Sometimes, if the baby is thought to be at great risk, a caesarean section may be the preferable option.
The decision making process should involve the parents and take their views into account. Legally they are not obliged to agree to an induction, whether or not it is hosital policy. However if there are convincing signs of post maturity, if there is an existing medical or health problem or if you are having twins, where the risks of prolonged pregnancy are greater, it is best to follow the advice of your midwife or obstetrician.
Other reasons to induce may include progressive high blood pressure or pre-eclampsia, convincing indications of placental insufficiency and slow growth of the baby, significantly reduced amniotic fluid which is outside of the normal range, premature rupture of membranes with an extended period of no contractions (beyond 48 hours), or failure to progress in labour (this is called augmentation or acceleration of a labour which has already started).
Before deciding whether or not to induce labour, the following can be considered
Estimated due date
The length of a normal pregnancy may be anywhere between 37-43 weeks and, very rarely, can even extend beyond this. If conception occurred later than the average estimate of day 14 of the menstrual cycle (i.e. with an irregular or longer menstrual cycle) this may be the reason that the baby is not yet ready for birth and labour hasn’t started. Ultrasound scan estimates of the due date are approximate and are not always accurate.
The usual method of estimating the average length of normal labour (nine months and one week since the first day of the last menstrual period) is known as Naegele’s r
ule and was first established in the mid 19th century. There has been no satisfactory evaluation of this method and it has been shown that the results from obstetric ‘wheels’ made by different manufacturers used to calculate the length of pregnancy are not consistent [5].
Research has shown that the average length of pregnancy may be 41 weeks and one day for many women with a 28 day cycle. Japanese and black women tend to have shorter pregnancies than white Americans. There is a wide range of variation in the length of a normal pregnancy. [6]
Definition of post-term pregnancy
There is also a lot of controversy about the normal length of human gestation and therefore over the definition of post-term pregnancy. The normal length of gestation for babies is variable. Babies initiate labour themselves when their lungs are ready for breathing, by releasing hormones into the amniotic fluid. These are absorbed into the mothers bloodstream and act as messengers to her brain.
This kicks off the release of the hormone oxytocin which gets contractions going and starts labour. Being born too early may mean that maturation of the baby’s lungs is not yet complete. That is why premature babies often need help to start breathing.
If labour is induced when the dates are wrong, the baby may be born prematurely and have problems breathing, possibly needing special care.
Mother and baby’s well being
If routine checks reveal no sign of anything abnormal in either mother or baby, then there is no pressing reason to intervene by inducing labour. Another option is to reassess the situation on a daily basis and to continue waiting for nature to take its course, provided there are no problems. After 42 weeks, daily monitoring of the baby’s heartbeat is recommended. This may necessitate a daily visit to the hospital and is the most reliable way to check the baby’s well being. A consistently satisfactory heartbeat indicates that the baby is getting enough oxygen and the placenta is functioning normally.
An ultrasound scan
This may help to assess the size of the baby, the volume of amniotic fluid, the placental function and to provide more information about the baby’s well being. If clinical monitoring and an ultrasound scan confirm normal development of the baby then the pregnancy can continue.
A second opinion
Since there are known risks attached to medical induction, seeking a second obstetric opinion is justified unless the need to induce is urgent. Try to find an obstetrician who does not have a strictly interventionist approach. This can include an ultrasound scan.
Signs that labour is imminent
Take note of any encouraging signs that labour is imminent. These may include more frequent or mild contractions which may stop and start, a mucous discharge or ‘show’, unusual back pain, or feeling a bit ‘spaced out’. Your midwife may tell you that the cervix has softened, moved forward or has dilated to 1 or 2 cms.
You may experience diarrhoea as the bowel starts to empty or there may be some leaking of the amniotic fluid or the membranes may break. Also, don’t worry if none of these are happening – not everyone experiences these changes prior to the onset of labour. Try to be patient, relax and take it easy without being unduly stressed or anxious.
If there are no problems, then everything is on course and you will go into labour when your baby is ready. This is a great time to indulge in a pampering treat like a wonderful aromatherapy massage.
If you do decide to opt for an induction, you can consider the natural methods first unless the need to induce is urgent. All methods of induction, natural or medical, are likely to work best when carried out as close as possible to the day when your baby is ready to be born and labour is imminent.
Natural methods of inducing labour
The following suggestions may help to initiate labour:
- Get some gentle exercise such as walking, swimming or doing yoga. Meditate and relax every day to stay in tune with your baby and your inner guidance.
- Acupuncture and/or reflexology combined with homoeopathy can be very effective in helping to get labour started. It’s best to consult a specialised practitioner with experience in this area. Alternatively, most complementary therapies can help to initiate labour, especially if you have already been having treatment during your pregnancy.
- Wait as long as possible and then try a glass or two (no more!) of good organic wine one evening.
- Provided your membranes haven’t broken, you could try making love. There are natural prostaglandins in semen which soften the cervix, and nipple stimulation may also help to release more oxytocin, the hormone that makes the uterus contract.
- Your midwife could do a ‘cervical sweep’ – a massage around the cervical opening. This may stimulate the secretion of natural prostaglandins which soften and ‘ripen’ the cervix and help to start labour. This may be uncomfortable but has been shown by research to be effective. You should always be consulted and agree to this procedure beforehand. [7]
- Drink three cups of organic raspberry leaf tea per day. This is a mild uterine tonic and stimulant.
- Evening primrose oil is said to be helpful in ripening the cervix. You can take three capsules of 500mg everyday from 36 weeks until birth.
References
1. Anderson T. Post-term Pregnancy. The Practising Midwife, Dec 1999. Vol 2, no 11, pp 10–12.
2. Tew, M. Safer childbirth? Chapman and Hall, 1995, pp 263.
3. Macfarlane,A. Variations In Numbers Of Births And Perinatal Mortality By Day Of The Week In England And Wales. British Medical Journal,Vol. 2, 1978, pp1670–73.
4. Chamberlain, C and Zander, L. Induction. British Medical Journal,Vol. 318,April 1999, pp 995–998.
5. McParland, P and Johnson, H. Time to Reinvent the Wheel. British Journal of Obstetrics and Gynaecology, 1993,Vol 100, pp 1061–1062
6. Hutchon, DJR. Expert Analysis Of Menstrual And Ultrasound Data In Pregnancy – Gestational Dating. Journal of Obstetrics and Gynaecology,Vol 18, no 5, Sept 1998, pp 435–438.
7. Boulvain, M and others. Does Sweeping Of The Membranes Reduce The Need For Formal Induction Of Labour? Journal of Obstetrics and Gynaecology,Vol 105, no 1, Jan 1998, pp 34–40.
This article is taken from “Preparing for Active Birth Handbook” by Janet Balaskas and includes lots more information about being overdue, Active Birth benefits, complementary therapies and every aspect of labour and birth. Copies are available to order from the Active Birth Centre for £9.95 per single copy or £50 for a pack of 10, plus postage and packaging. Books come as singles or 10. To order copies please contact info@postalandcourieretc.co.uk
Very clear, informative and relaxing article, Janet!