Raspberry may not now be amongst the herbs most commonly used as an astringent, but it is very widely used as a ‘partus praeparator’, to prepare for birth. Although it is considered to have been used ‘since ancient times’, references to use by women are few in the older authors. The Old English Herbarium gives ripe blackberries for ‘a woman’s menstrual flow,’ ‘three times seven’, simmered down in water by two thirds, made daily and taken on an empty stomach for 3 days. Dodoens recommends the juice of brambles for heavy menstrual flow. Gerard refers to the use of the decoction in all bleeding, and Parkinson, followed by Culpeper, recommends the decoction of the leaves and dried blackberry stems for heavy menstrual flow. Miller says it is considered good in miscarriage. However, there is an association between astringency and strengthening of the tissues and this provides a linkage to the recommendation of raspberry as a ‘partus praeparator’. Quincy includes astringents under strengtheners; substances which maintain the solids in a condition ready to exert themselves into action when needed. Strengtheners include substances ‘which crisp and corrugate the fibres into a more compacted tone’ and substances which absorb and dry up superfluous humidity, which are the astringents, but they strengthen too as too much moisture may contribute to relaxation. Hoffmann describes raspberry as strengthening and toning the tissue of the uterus and suggests an infusion of 1 cup of boiling water poured over 2 teaspoons of dried herb and infused for 10-15 minutes. Trickey describes raspberry as improving uterine muscle tone and makes the practical point that raspberry is light and fluffy when dried, so may need a larger volume than other dried herbs. Coffin gives an account of the treatment of two women, aged 20, in Troy, Ohio. One had not had a period for 7 months and one suffered from flooding. He gave each woman the same treatment: composition powder in a strong raspberry leaf tea for 2 days, then a vapour bath and lobelia Lobelia inflata emetic every other day for 3 weeks, stomach bitters in raspberry leaf tea daily, and an injection of oak bark Quercus robur, valerian Valeriana officinalis and cayenne Capsicum omnium. Treatment was successful, in both cases and he uses this example to support the principle of heating and equalizing the circulation. While this robust course of treatment would be considered too intense today, it serves to illustrate the point that herbs cannot be categorized merely by indication.
Thomson (1832) is our first advocate of the use of raspberry in pregnancy or labour. He states that a tea made of the leaves, with milk and sweetened, is very pleasant and may be used freely. ‘It is the best thing for women in travail of any article I know of. Give a strong tea of it, with a little of No. 2 capsicum, sweetened, and it will regulate everything as Nature requires. If the pains are untimely, it will make all quiet; if timely and lingering, give more No. 2.’
Raspberry is further endorsed by Coffin, who recommends it in ‘obstruction of menses’, premature labour pains and to promote progress of labour. He includes raspberry in a tea for sickness in early pregnancy but does not appear to advocate its use in preparation for birth. Coffin is at pains to emphasize that childbirth is a natural process and gives an account of the anatomy and physiology of the process. The first edition was written in 1849 and this account reflects his desire to promote knowledge. He advocates temperance, regular meals, loose clothing and no tight corsets, free pure air and ‘everything needed to keep the mind composed and happy”. In the management of labour, he was speaking from experience as he describes difficult births at which he was in attendance. In normal births, Coffin recommends an enema to ensure that the bowels are active, and to have a very strong decoction of raspberry leaves ready. At the onset of pains, the woman should take a wineglassful (60 mL) sweetened, as hot as can be borne, at intervals, occasionally adding as much cayenne Capsicum annuum as will lie on the end of a common teaspoon. Both Thomson and Coffin discuss the use of raspberry during labour rather than in preparation for labour.
Cook quotes Thomson and states that raspberry has a fine influence on the uterus, when flagging in labour, anticipates flooding and relieves after-pains. Fox suggests it is an excellent remedy in profuse and painful menstruation and to regulate labour pains in childbirth. Fox advises a teacupful of strong tea, in which the juice of an orange has been pressed, three times a day in the last month of pregnancy to prevent pain and render labour easy when the hour of parturition has arrived. This is repeated in Wren as ‘rendering parturition speedy and easy, take freely before and during confinement, with composition essence, always take warm’. Trickey (1998) gives the same recommendation as Fox ‘in the last months of pregnancy’. Grieve states that it is ‘unequalled as a warm infusion drunk before and during childbirth’ and recommends it for men-orrhagia, flooding and miscarriage. Hool recommends use of a warm infusion with a pinch of composition essence as valuable for women in labour, for quieting untimely pains and rendering them more efficient if labour has commenced. He advises 1 teacupful of infusion every hour until labour is completed but also that ‘it may be taken, with grateful results, for several months before the expected event. If this herb were generally used instead of ordinary tea, haemorrhage would rarely occur after confinement and instruments would rarely be required’. Priest & Priest also note its use in heavy periods and to prepare for childbirth. All 16 collaborators in a review of the use of raspberry mention its role in preparation for childbirth. The dosage given is 3-4 pints per week in the last 3 months and a full pint of hot tea with 2 teaspoons of composition essence when labour begins.
Raspberry leaf is one of the few herbs which continue to be self-prescribed and surveys have found that self-prescribing is common in pregnancy. A survey of all women who visited an antenatal clinic at around 37 weeks in Melbourne, Australia found that 36% of the 588 women were taking a herbal supplement and 14% of the 588 were taking raspberry leaf. In interviews with 201 women in Adelaide, Australia, 9% took raspberry leaf in the last trimester in preparation for labour, usually on the recommendation of friends or relatives. A survey of 500 nurse-midwives in the USA found that, of the 90 who replied, 63% used red raspberry leaf to ‘stimulate labour’ in particular in home births or birth centres. 69% of the midwives had learned about the use of raspberry from colleagues and only 22% included use of herbs in their written protocols. In an observational study of 55 women in Australia, 32 drank the tea with 75% taking up to 3 cups a day, and 23 took tablets at a dose of 1-8 tablets of which 43% took 6 tablets a day.
It would be useful to have more guidance on dosage, effectiveness and safety but this raises some of the problems in investigating herbal medicines. ‘Preparation for labour’ is not a disease entity and planning the methodology and gaining ethical approval for a clinical trial would raise complex issues. For an estimate of the safety of any herb or drug, very large surveys are required to make statistical inferences and this would be difficult to organize. Equally, it is not possible to merely assume that raspberry leaf is safe because it is widely used as surveys show that there is low reporting of use of herbs to healthcare professionals. Adverse events in pregnancy and labour are unpredictable and multifactorial, and a history of use of herbal medicines may not be investigated. There is little evidence on the effectiveness or safety of raspberry and so Ernst (2002) and Barnes (2003) advise that it should not be taken during pregnancy. However, this recommendation could not be enforced, even if one supported it, and it is useful to review the evidence such as it is. Women are mainly taking raspberry on personal recommendation in an ‘underground’ way and would like more guidance from healthcare professionals. Lowdog (2005) reviews the evidence and suggests that raspberry is safe but takes a similar view to Coffin that the preparation of the psyche is most important.
What evidence is there for efficacy, effectiveness and safety? Regarding efficacy or mechanism of action, there have been in vitro studies on rat and human uterine tissues. Studies on animals or animal tissues are widely used to support the traditional usage of herbal medicines with the implicit assumption that that the action will be found in human studies. For example, Trickey (1998) uses the statements made by Bamford et al (1970), who propose that raspberry leaf would prevent or reduce the risk of incoordinate uterine action by regulating the action of uterine muscle. This publication was a poster only. Contractions in strips of uterine tissue from pregnant rats were inhibited, and contractions were stimulated in strips of human uterine tissue (1-16 weeks of pregnancy). In both tissues, normal contractions were resumed and became less frequent but more regular over 20 minutes. Criticisms of this study are the sparse experimental detail given and that contractions during labour are influenced by oxytocin release and thus this study may have no relevance to labour.
There has been one study of the safety of raspberry leaf. A study on 40 Wistar rats who were given an oral dose of raspberry leaf (10 mg/kg per day), quercetin, kaempferol or control, found no differences in the birthweight or survival of the offspring but found a significant lengthening in gestation and a reduction in the number of live births in the raspberry group. It also found that the females in the next generation of offspring had a significantly earlier puberty. The relevance of these findings is limited as there were only 10 rats in each group and because normal practice is to take raspberry only in the last weeks of pregnancy rather than from conception.
There have been two studies of the effectiveness of raspberry leaf. An observational study in Australia compared 57 women who had consumed raspberry leaf products with 51 women from the same hospital who had not, and found no significant differences in outcome for the baby and a possible association between raspberry leaf consumption and normal delivery without interventions. On the basis of this study, a double-blind, randomized, placebo-controlled trial was carried out in a hospital in Sydney, Australia. Two hundred and forty low-risk women who were expecting their first baby were entered into the trial. There were 48 withdrawals for medical and non-medical reasons which are not given in complete detail. The results were analysed for the 192 women who continued with the trial until labour. They took raspberry leaf tablets (1.2 g per day) or placebo from 32 weeks until birth. The women were carefully monitored. An important finding is that there were no major differences in outcome between the two groups. There was no shortening of the first stage but there was a shortened second stage of labour (mean difference 9.6 minutes) and a lower rate of forceps deliveries in the treatment group (19% treatment/30% placebo). There was no difference in mean length of gestation or in the rate of spontaneous labour (48% treatment/51% placebo), medical augmentation of labour (31% treatment/28% placebo), induction (20% treatment/21% placebo) or emergency caesareans (18% treatment/19% placebo). The study did not show a significant benefit of raspberry and the authors discuss whether they were too cautious with the dosage. A weakness of the study is that the results are not presented as an intention-to-treat analysis, which tends to make the treatment seem comparatively more effective than it was. A second weakness of the study is that the reasons for withdrawal are not given in complete detail. Finally, of the 240 women initially recruited, 4% from the raspberry group and 2% from the placebo group developed pregnancy-induced hypertension and pre-eclampsia. Six of these 15 women remained in the study. This has raised concerns about a possible association with hypertension but others have not taken this view. The trial shows that, apart from this possibility, taking raspberry was not associated with any increase of adverse events in labour in this group of 192 women. Randomized controlled trials can flag up concerns but the numbers are too small to draw firm inferences on questions of safety.
Thomson did not admit that his practice was influenced by Native American usage, but Coffin (1866) claims that Native American women gave birth with ease. De Bairacli-Levi (1966) claims that raspberry is useful as a tonic throughout pregnancy and in labour, and advises 2 tea-spoonfuls of leaves as a tea every 2-3 hours in labour. She states that ‘it would be rare for a gypsy woman to go through pregnancy without having taken raspberry leaf teas from the first weeks of knowledge of conception. And the true nomad gypsy gives birth to her children with the ease of a wild vixen’. This potent image is attractive but deeply flawed as it arises from the myth of the ‘noble savage’ but yet, excessively cautious safety concerns are disempowering to women. We may conclude that in contrast to some other herbs recommended for use in pregnancy, raspberry has been shown to be safe. Menzies-Trull adds a caution that it should not be used in ‘athletic typology pregnancies,’ or where there is a history of precipitate labour and should be discontinued if there are early labour pains.