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Labour induction


Labour induction is only desirable if one believes that pregnancy should be subjected to a set time limit, or if there is a genuine medical condition endangering the life of the mother-baby should the pregnancy continue any longer. 

I do not believe that pregnancy needs to conform to a specific time frame.  Nonetheless, women do choose to induce labour with herbs, and they need to be fully informed about the risks and benefits of doing so.

What follows is a review of the literature on two popular labour induction herbs, blue cohosh and castor oil.  Each has its own advantages and disadvantages, as you will see.

This article is featured on the BirthLove site.


Two ways not to induce labour: blue cohosh and castor oil

 From a review of the literature by Rachel Westfall, 2001

 If you use these materials, please cite this web page.

Blue Cohosh  (Caulophyllum thalictroides)  


Blue cohosh is a North American herb with a reputation for both causing and preventing miscarriage (abortion), but it is most widely known for its use in labour induction. 

There are some unpleasant side effects from blue cohosh, including elevated blood pressure and blood sugar levels, nausea, severe stomach pain, and toxicity.  There have been two case reports where blue cohosh was blamed for severe cardiac toxicity in infants whose mothers used the herb to induce labour.   In addition, the plant contains a toxic compound which is known to cause birth defects in cattle. 

The long story:

Blue cohosh Caulophyllum thalictroides (L.) Michx. grows in rich soil in the shady woodlands of Eastern North America (USDA, NRCS, 1999).  This perennial plant is a member of the family Berberidaceae. 

Blue cohosh roots and rhizomes have a long tradition of use as medicine by North American First Peoples (Belew, 1999; Duke, 1997; McFarlin et al., 1999; Stelling, 1994).   The fresh roots are gathered in the spring (Weed, 1986).  Blue cohosh tea is consumed near the end of pregnancy to prepare the uterus for childbirth and reduce uterine irritability and false labour pains (Stelling, 1994).  It is used to prevent miscarriage and to assist difficult labours (Belew, 1999). 

The Eclectic Physicians adopted blue cohosh into their materia medica in the 1800s.   They found it useful for speeding up labour when it is stalled due to the mother’s weakness, fatigue, or lack of uterine energy (Felter and Lloyd, 1992).  It was also used to ease pain in pregnancy and labour, as well as after pains (Felter and Lloyd, 1992).   It was used as an anti-abortive, as it relieved “the irritation in which the trouble depends” (Felter and Lloyd, 1992). 

Today, blue cohosh is valued as a uterine stimulant, anti-spasmodic and emmenagogue (Bartram, 1998; Beal, 1998; Burch and Sachs, 1997; Grieve, 1971).  It is believed to be one of the most powerful natural inducers of labour.  Its oxytocic effect is apparently produced by the glycosides caulosaponin and caulophyllosaponin (Duke, 1992b; Tyler, 1993).  It also contains the compound caulophylline, which raises blood pressure and blood sugar levels (McFarlin et al., 1999; Duke, 1992a).   

 Blue cohosh has a reputation as an abortifacient (Weed, 1986).  Paradoxically, the herb also has a reputation for preventing miscarriage in susceptible women, if it is used before conception to strengthen the uterus (Bartram, 1998; Belew, 1999; Lipo, 1996).  If  used after conception, it can prevent implantation of the fertilized egg (Lipo, 1996). 

The safety of blue cohosh has come into question in recent years.  Midwives have noticed a rise in fetal heart rates associated with its use (Weed, 1986).

 “A number of direct-entry midwives (DEMs) have stopped using blue cohosh, because they noticed an increased incidence of meconium-stained fluid, fetal tachycardia or fetal distress, and a high-pitched or inconsolable neonatal cry associated with the intrapartum use of blue cohosh (personal communication, May 1998, Shannon Anton, DEM, Susan Claypool, DEM, Lucero Dorado, DEM)” (Belew, 1999: 241-242). 

Midwives and herbalists are coming to the realization that blue cohosh should be used with discretion, and only in the most difficult labours.  According to herbalist Karyn Saunders, “Blue cohosh is thought to have a harsh effect on the spirit of the baby (Karyn Saunders, personal communication, May 1998)” (Belew, 1999). 

There have been two recent case reports of health problems in newborns associated with maternal use of blue cohosh.  In one case, reported by Gunn and Wright (1996), the mother used an unspecified amount of blue and black cohosh to induce labour.  The infant showed signs of ill health at birth, and was taken the hospital shortly afterwards with seizures, kidney damage, and the need for mechanical ventilation.  The authors pointed out that caulosaponin, a constituent of blue cohosh, causes coronary blood vessel constriction and myocardial toxicity.  They speculate that caulosaponin may have been responsible for the infant’s ill health.  Baillie and Rasmussen (1997) replied to this article, pointing out that our understanding of toxicity in these herbs comes from studies of the effects of isolated constituents on animals, often in unrealistic doses.  In the case of caulosaponin, laboratory animal experiments demonstrated a toxic effect from an amount that was equivalent to a human dose of 350g of the herb. 

Jones and Lawson (1998) also published a case report of some adverse effects of blue cohosh.  In this case, the mother was advised to take one blue cohosh tablet daily for the last month of her pregnancy.  She chose to take three tablets daily, and she gave birth after three weeks.  The amniotic fluid was slightly meconium stained, and by 20 minutes of age, the infant required mechanical ventilation.  The infant was diagnosed with profound congestive heart failure, and although the child eventually recovered, left ventricular function was still slightly impaired at two years of age.  The authors implicated the glycosides caulosaponin and caulophyllosaponin as they are known to have a toxic effect on cardiac muscle. 

Blue cohosh has been known to cause nausea (Romm, 1997; Gardner, 1987), severe stomach pain, and toxicity (Ferguson et al., 1954).  The roots contain the alkaloid anagyrine, which is held responsible for the congenital deformity ‘crooked calf disease’ (Keeler, 1984; McFarlin, 1999).  The disease does not appear to occur in other species, but there is a case report of a similar human congenital deformity which could have been due to maternal consumption of anagyrine contaminated goat’s milk in early pregnancy (Ortega et al., 1987; McFarlin, 1999).  With the evidence stacking up against it, blue cohosh appears to be a herb best left alone.

Castorbean     Ricinus communis (L.)


Castorbean seeds, from which castor oil is pressed, contain the toxic compound ricinic acid.  The compound is used medicinally in small, controlled doses to cause abortion and female sterility; it is a teratogen (causes birth defects). 

Castor oil has been widely used to induce labour for the past century, not just by women in their homes (as we tend to think of it now) but by the medical system.  It appears to work only if the cervix is ripe, meaning the woman must be physiologically ready to have her baby already. 

The safety of castor oil is being questioned as reports come in of increased meconium staining of amniotic fluid, something which is usually interpreted as an indicator of fetal distress (and will therefore precipitate further interventions).  In women, there have been reports of thrombosed hemorrhoids, precipitous labour, nausea, vomiting, diarrhea, and flatulence as a result of castor oil.   

The long story:

 Castorbean is a large perennial plant in the family Euphorbiaceae.   It which grows as a tree in tropical climates, a slender shrub in warm temperate climates, and is cultivated as a shrubby annual in cooler regions (Grieve, 1971).  It is believed to have originated in India (Phillips and Foy, 1990), but it has been so widely cultivated for thousands of years that its origins are disputed (Scarpa, 1982). 

Castorbean has been known since ancient times as a medicine.  Castorbean seeds were found in Egyptian tombs, and Pliny the Elder and Dioscorides both wrote of the oil’s use as a purgative (Phillips and Foy, 1990).   It appeared in the European materia medica in 1764 when the English doctor Peter Cavane published a dissertation on the oil (Nabors, 1958).  It has been widely used in European medicine as a purgative since then. 

The green leaves of castorbean have a wide range of medicinal applications. The green leaves were used in the folk medicine of ancient Greece to treat tumours, including mammary tumours after childbirth (which were probably blocked or infected milk ducts) (Scarpa, 1982).  Women of the Canary Islands bind the green leaves to their breasts to increase their production of milk (Bartram, 1998; Grieve, 1971), as do women in South Africa, Cape Verde Islands, Madagascar, and Italy (Scarpa, 1982).  In India and Pakistan, a decoction of the leaves is used the same way (Scarpa, 1982).  The leaves are used to relieve engorged breasts in New Caledonia (Scarpa, 1982). A decoction of the leaves is used as an emmenagogue in Algeria, where it is known to have caused permanent sterility (Scarpa, 1982).  The Thonga people of South Africa wrap premature infants in the leaves of the castorbean plant; the infant is then placed in a large pot in the sun (Goldsmith, 1990). 

Scarpa (1954) conducted clinical trials of the application of the leaves or their juice in compresses to lactating women’s breasts.  The treatment increased milk production considerably, as estimated by the weight of the babies before and after suckling.   

Castorbean seeds are extremely toxic, due to the presence of the glycoprotein ricin (Scarpa, 1982), but they have been used in small doses medicinally.  They are considered to be a contraceptive capable of bringing on a late period.   Women in India eat the seeds the day after childbirth to prevent conception for the next nine months (Scarpa, 1982).  In Mexico, the seeds are used to bring about permanent sterility (Scarpa, 1982).   

El Mauhoub et al. (1983) reported a case of an infant with a series of birth defects that the authors attributed to the mother’s consumption of castor oil seeds for eight weeks after conception.  They imply that castorbean seeds are not a safe contraceptive or abortifacient. 

The oil pressed from the seeds of the castorbean is widely used as a laxative, purgative, and uterine stimulant for induction of labour.  It is used as a gentle laxative for pregnant women (Phillips and Foy, 1990), although most herbalists would not recommend it (or any laxative) as it might cause premature births (Campion, 1996).  It is used as an emmenagogue and a galactagogue in Somalia and as a galactagogue in Haiti (Scarpa, 1982).   Women in India and Pakistan smear the oil on their breasts to relieve mastitis (Dastur, 1962).  It contains a mixture of triglycerides, of which 75-90% is ricinoleic acid, which stimulates the motor activity of the bowel (United States Dispensatory, 1955).   Its usefulness for labour induction is thought to be due to its profound effect on the intestinal tract, which stimulates reflux of the uterus (McFarlin et al., 1999).  It is also absorbed systemically, and it is not known whether it crosses the placental barrier (McFarlin et al., 1999). 

It was not until the 1920’s that castor oil gained popularity among physicians for inducing labour (Nabors, 1958).  It remained popular until the mid 1950’s, when it likely fell out of favour as oxytocin was introduced and became widely available (Davis, 1984).  It still remains popular as a folk remedy, and many nurses and midwives still recommend it to their overdue clients (McFarlin et al., 1999; Osborn, 1994).  A questionnaire sent to American Certified Nurse-Midwives revealed that of those respondents who used herbal preparations to stimulate labour in their practices, 93% used castor oil.  They generally felt most comfortable using it over other herbal preparations, and they considered it to be the most effective (McFarlin et al., 1999). 

Castor oil is believed to successfully induce labour only when the cervix is ripe and the baby is ready to be born (Campion, 1996; Summers, 1997). Its ineffectiveness in inducing labour before the cervix is ripe was reflected in the clinical trial reported by Nabors (1958).  Most of the women in that study required induction because of complications such as pre-eclampsia; under those circumstances, castor oil was found to be less effective than oxytocin.  The author concluded that castor oil is of no value in inducing labour, and is irritating and dehydrating besides.  In contrast, Mathie and Dawson (1959) concluded that castor oil might be useful for stimulating labour after demonstrating that it caused an increase in uterine activity in a laboratory setting. 

Labour induction with castor oil has been the subject of a number of scholarly papers in recent years.  Davis (1984) conducted a retrospective study of the use of castor oil to stimulate labour following premature rupture of the membranes.   Soon after the membranes have ruptured, the medical system insists that labour must commence because of the risk of infection.  If labour does not commence spontaneously within a specified timeframe (currently 24 hours), medical intervention is warranted.  This study demonstrated the effectiveness of castor oil in inducing labour.  Out of 107 women who used castor oil, 75% went into labour shortly afterwards.  Of the 89 women who did not use castor oil, 58% went into labour spontaneously.  There were nearly three times as many cesarean sections in the control group.   

Garry et al. (2000) conducted a clinical trial of castor oil in a group of women whose babies were overdue.  Of the 52 women who used castor oil, 30 (57.7%) went into labour within 24 hours, as compared to 2 (4.2%) of the 48 women who received no treatment. 

With regards to the use of castor oil for the induction of labour, some safety concerns have arisen in recent years.  Mitri et al. (1987) found in a survey of 498 South African women whose babies were overdue that meconium passage was found more commonly in those who had recently taken castor oil or a herbal preparation called ‘sihlambezo’.  Steingrub et al. (1988) published a case report of amniotic fluid embolism, associated temporally with the mother’s ingestion of castor oil; it is conceivable that the woman’s contractions were strong enough to result in an embolism.  In a survey sent by McFarlin et al. (1999) to Certified American Nurse-Midwives, some respondents reported adverse effects of castor oil including thrombosed hemorrhoids, precipitous labour, nausea, vomiting, diarrhea, and flatulence were reported.  Two midwives reported an increase in meconium stained amniotic fluid- a classic indicator of fetal distress.

 The inconsistencies in the level of success of labour induction with castor oil may come in part from the huge variations in dosage.  McFarlin et al. (1999) reported dosages from 5 mL to 120 mL in the practices of American Certified Nurse-Midwives.  Susun Weed (1986) suggests using two ounces (four tablespoons) of castor oil, two ounces of vodka, and two or more ounces of orange juice, followed by a hot shower.  The dose is repeated after an hour, and an enema is given.   The dose is repeated again an hour later, and another hot shower is taken.  Labour should begin three to five hours after the last dose.  I would personally not wish to give birth under the effects of 6 ounces of vodka!


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