Red raspberry (Rubus idaeus) leaf has been traditionally used as a partus preparator, that is, in preparation for childbirth. It is often recommended for use in the third trimester of pregnancy to tonify, strengthen, and prepare the uterus for labour and delivery. Red raspberry contains a compound called fragarine, which tonifies smooth muscle, especially the uterus. Red raspberry also contains tannins and flavonoids such as quercetin; as well as nutrients including zinc, magnesium, vitamin C, and tocopherols.^[1]

Traditional Use

According to King’s American Dispensatory, a traditional herbal text dating from the 1890s, red raspberry tea is a useful uterine tonic, with applications for uterine prolapse (may be combined with black cohosh and blackberry root), uterine fibroids, as well as in childbirth.^[2][3] “It is said that raspberry will, during labour, increase the activity of the uterine contractions when these are feeble, even in instances where ergot has failed, and that it has been found serviceable in after-pains.”^[4] Other applications described in traditional texts include dysmenorrhea (painful menstruation) and as a remedy for nausea and vomiting of pregnancy, as well as nausea and diarrhea in general.^[5]

Red raspberry may be used in the third trimester leading up to labour, as well as throughout labour. It may not only help ease and speed up delivery, but also assist uterine involution after delivery as the uterus returns to its normal size and tone, and it may help prevent postpartum hemorrhage. Red raspberry may also be useful in lactation, supporting breast-milk production.^[6]

Clinical Research

One double-blind, randomized, placebo-controlled trial evaluated the effect of red raspberry leaf tablets (2.4 g daily) on labour and birth outcomes.^[7] A total of 192 low-risk, nulliparous women consumed red raspberry leaf tablets from 32 weeks of gestation until labour. Raspberry leaf was found to cause no adverse effects for mother or baby, but it did not shorten the first stage of labour (cervical dilation). There was a modest, significant shortening of the second stage of labour (delivery of the baby) (mean difference = 9.59 min), and a lower rate of forceps deliveries between the treatment group and the control group (19.3% v. 30.4%). Authors suggested that higher doses may have yielded larger effects.

Similarly, a retrospective observational study by the same team suggested that red raspberry leaf consumption in late pregnancy was safe, and that there were some benefits on gestational outcomes. Among the 108 mothers, 57 of whom consumed red raspberry and 51 of whom did not, red raspberry was associated with a “decrease the likelihood of pre- and post-term gestation.”^[8] Another result was that “women who ingest raspberry leaf might be less likely to receive an artificial rupture of their membranes, or require a caesarean section, forceps or vacuum birth than the women in the control group.”^[9]

Meanwhile, a preclinical study found that exposing rat uterine muscle to commercially available preparations of red raspberry leaf had “variable effects on preexisting oxytocin-induced contractions” in pregnant rats.^[10]

Please note that red raspberry should not be taken in the first trimester, due to possible increased risk of miscarriage.

References

1. European Medicines Agency. Committee on Herbal Medicinal Products (HMPC). Assessment report on Rubus idaeus L., folium. 28 January 2014. https://www.ema.europa.eu/en/documents/herbal-report/final-assessment-report-rubus-idaeus-l-folium_en.pdf.
2. Felter, H.W., and J.U. Lloyd. “Rubus Idaeus (U.S.P.)—Raspberry.” King's American Dispensatory, 1898. https://www.henriettes-herb.com/eclectic/kings/rubus-idae.html.
3. Felter, H.W., and J.U. Lloyd. “Rubus (U.S.P.)—Rubus.” King's American Dispensatory, 1898. https://www.henriettes-herb.com/eclectic/kings/rubus.html.
4. Felter and Lloyd. “Rubus (U.S.P.)—Rubus.”
5. European Medicines Agency. Assessment report on Rubus idaeus L., folium.
6. Drugs and Lactation Database (LactMed). “Raspberry.” Bethesda: National Library of Medicine, 2006. http://www.ncbi.nlm.nih.gov/books/NBK501785/.
7. Simpson, M., M. Parsons, J. Greenwood, and K. Wade. “Raspberry leaf in pregnancy: Its safety and efficacy in labor.” Journal of Midwifery & Women’s Health, Vol. 46, No. 2 (2001): 51–59.
8. Parsons, M., M. Simpson, and T. Ponton. “Raspberry leaf and its effect on labour: Safety and efficacy.” Australian College of Midwives Incorporated Journal, Vol. 12, No. 3 (1999): 20–25.
9. Parsons, Simpson, and Ponton. “Raspberry leaf and its effect on labour.”
10. Zheng, J., M.J. Pistilli, A.C. Holloway, and D.J. Crankshaw. “The effects of commercial preparations of red raspberry leaf on the contractility of the rat’s uterus in vitro.” Reproductive Sciences, Vol. 17, No. 5 (2010): 494–501