Post-term or post-date pregnancy is one that exceeds 42 weeks gestation. If a woman is healthy and well nourished then her placenta is likely to thrive and nourish the baby at any gestation. If there are signs that mother or baby will be healthier with baby Earth-side, then induction is warranted; otherwise it’s a much overused intervention that leads to a Cascade of Intervention.
Post-term is not the same as postmaturity, which refers to fetal condition. These babies are compromised as they receive insufficient nutrients through the placenta. Therefore continuing the pregnancy is not safe. Post-term or post-dates refers only to dates and has nothing to do with fetal condition.
Studies vary on outcomes of post-date pregnancies. Common belief is that post term leads to large, compromised babies, and that the placenta stops working. Macrosomia (large baby: >4000g / 8.8lb) occurs in 10% of post term births; 1% are > 4500g (9.9lb) (Fraser, Cooper, & Fletcher, 2003). SOGC reports current studies regarding pregnancy past 40 weeks don’t differentiate between healthy and complicated pregnancies and are too small to be accurate (Delaney & Roggensack, 2008). Canadian guidelines are to offer induction during the 41st week of pregnancy. By far the number one reason for induction is post-term pregnancy. Pharmaceutical induction turns birth into a medical process and doubles the risk of Caesarean birth. Women have the right to accept or refuse this intervention and are encouraged to ask enough questions to partake in shared decision making with their care-provider.
Reasons Your Pregnancy May Last Longer than 40 Weeks
- Inaccurate dates
- That’s just normal for you
- Malpositioned foetus e.g. facing the wrong way or head not flexed well
- Anything that interferes with optimal release of labour hormones e.g. fear, lack of privacy, conflict, lack of support
- Not being “ready” to receive the baby – birth-supplies, home, work responsibilities, too many friends or family around, calendar too full, waiting for someone
- Emotional issues – fear, needing to hold on
Ensuring Placenta Develops Normally and Remains Healthy – Avoiding Postmaturity Syndrome
All the things that contribute to a healthy pregnancy and baby, including:
- Good nutrition, including healthy salt and fat intake, minimizing or avoiding sugar and junk / processed foods
- Proper hydration
- Pregnancy tea
- Avoid smoking (including second-hand smoke), alcohol and drugs
- Avoid antacids, cheap or poor-quality vitamins and calcium supplements as these all contain calcium that humans don’t assimilate. This calcium builds up in placenta, decreasing function.
- Discuss any health issues with care-provider. Some conditions lead to inadequate hormone activity, circulation problems or malnutrition.
- Good prenatal care, including monitoring blood pressure and health of mother, foetus, placenta
- Time for relaxation and some light to moderate exercise daily
- Manage stress
- Surroundings – healthy environment including the people with whom you interact
Is Your “Due Date” Accurate for You and Your Baby?
- Review your estimated due date (EDD) with your practitioner and how it was determined
- Obstetrical history – some women tend to gestate longer than others
- Your mother’s obstetrical history – does it include “late” babies
- SOGC recommendations for determining accurate EDD (Delaney & Roggensack, 2008):
- Ultrasound (u/s) between 11-14 weeks
- If dates determined by 1st trimester u/s and LMP vary more than 5 days then u/s is used as EDD
- If dates determined by 2nd trimester u/s and LMP vary by more than 10 days then u/s should be used as EDD
- If u/s was done in 1st and 2nd trimester, then EDD is determined by earlier u/s
- Ultrasound accuracy for estimating EDD decreases as gestation increases. Accuracy is within 3-5 days in the first trimester, within 7-10 days in the second trimester, and decreases to within 2-3 weeks after 26 weeks (Varney, Kriebs, & Gegor, 2004)
Tips to Help Avoid Post-Term Pregnancy
There may be nothing to be done about post-term pregnancy as some babies just take longer than others. Like roses opening on a bush, they don’t all happen at the same time. However the following can help prepare you and the baby for labour. If they don’t bring your baby faster they will contribute to a healthier, more comfortable and efficient birth experience.
- Acupuncture helps prepare the body for labour and decreases need for pharmaceutical induction; can be used to induce labour (Winder, 2012). See an acupuncturist who specializes in pregnancy care for “birth prep” starting anytime in the last weeks. If you do require induction, it works better if you’ve already had some treatments.
- Hypnotherapy or other counselling techniques to help resolve fears or emotional issues that may be holding back progress.
- Homeopathic Actea racemosa Complex or a similar homeopathic labour-prep blend from 36 weeks on.
- Massage therapy by a practitioner who understands pregnancy and the female pelvis.
- Osteopathy to address any structural issues.
- Webster, a chiropractic technique to help prepare pelvis for labour and achieve optimal fetal positioning (Pistolese, 2002).
- Ripen the cervix
- Sexual activity – female orgasm produces oxytocin, semen contains prostaglandins which act on the cervix.
- Evening Primrose Oil capsules orally and/or vaginally beginning at 36 weeks: 1500 mg daily orally, and/or insert 2 caps to the cervix before bed.
- In one practice guideline the SOGC recommends membrane sweeping beginning at 38-41 weeks (Delaney & Roggensack, 2008), while in another they state the procedure doesn’t change neonatal or maternal outcomes (Crane, 2001)
- Hill et al. (2008) found no benefit to membrane sweeping, and no decrease in induction rates. In fact they found this procedure can lead to risk of membranes releasing before onset of labour.
- This invasive procedure ranges from uncomfortable to very painful for the client.
- See this excellent article about Membrane Sweeping by Gloria Lemay
Induction – Holistic / Natural Methods
Natural induction is still induction, and should only be used in case it’s healthier for mother or baby to not remain pregnant. Please seek advice from qualified professionals who are experienced in pregnancy and induction care before embarking on this route, as some of these have side-effects.
- Acupuncture helps prepare the body for labour and decreases need for pharmaceutical induction; can be used to induce labour (Winder, 2012). It’s one of the safest and most effective of the natural methods.
- Reflexology is also safe and effective.
- Acupressure – see http://www.youtube.com/watch?v=wnEcLSHTI0s for excellent demonstration
- Massage 2 drops of Clary Sage essential oil with any carrier oil – can be used for acupressure treatments; stimulates hormones
- Herbs such as black and blue cohosh – seek a qualified herbalist.
- Homeopathic remedies such as Caulophyllum, Actea racemosa, Pulsatilla – your homeopath will have strong dilutions
- Castor oil drink is an actual preparation, not just chugging the oil! DO NOT SELF ADMINISTER! There are considerations so check with a qualified herbalist experienced in pregnancy care.
Induction – Medical Methods
- Pharmaceutical induction with cervical ripening agents and/or drugs to stimulate contractions
- Studies are mixed regarding outcomes with routine induction based on dates alone. SOGC (Delaney & Roggensack, 2008) recommends offering induction at 41+0 to 42+0 weeks, claiming a decrease in perinatal mortality and no change in caesarean rates. Many other studies such as (Grivell, Reilly, Oakey, Cahn, & Dodd, 2012) found increased rates of caesarean birth and complications with induction. Menticoglou & Hall (2002) present evidence that the original research was flawed, and that routine induction based on dates does more harm than good.
Crane, D. J. (2001). SOGC Clinical Practice Guideline No. 107: Induction of labour at term. J Obstet Gynaecol Can , 23 (8), 717-28.
Delaney, M., & Roggensack, A. (2008). SOGC Clinical Practice Guideline #214: Guidelines for the management of pregnancy at at 41+0 to 42+0 weeks. J Obstet Gynaecol Can , 30 (9), 800-10.
Dudley, N. J. (2005). A systematic review of the ultrasound estimation of fetal weight. Ultrasound Obstet Gynecol , 25 (1), 80-89.
Fraser, D., Cooper, M., & Fletcher, G. (Eds.). (2003). Myles textbook for midwives (14th ed.). Toronto: Chruchill Livingstone.
Frye, A. (1998). Holistic midwifery vol 1; Care during pregnancy. Portland, OR: Labrys.
Grivell, R., Reilly, A., Oakey, H., Cahn, A., & Dodd, J. (2012). Maternal and neonatal outcomes following induction of labor: a cohort study. Acta Obstetricia et Gynecologica Scandinavica , 91 (2), 198-203.
Pistolese, R. (2002). The Webster Technique: A chiropractic technique with obstetril implications. Journal of Manipulative and Physiological Therapeutics , 25 (6), E1-E9.
Tayler, R. (2000). Homeopathy for Pregnancy and Childbirth. Ottawa: Ottawa School of Homeopathy.
Varney, H., Kriebs, J. M., & Gegor, C. L. (2004). Varney’s Midwifery, 4th Ed. Toronto: Jones and Bartlett Publishers.
Winder, K. (2012). Naturally Inducing Labour – Natural Induction Methods. Retrieved from BellyBelly: http://www.bellybelly.com.au/birth/natural-induction-methods