The leaves of the red raspberry plant are commonly recommended for strengthening and toning the uterus. Naturopathic midwives, herbalists, gynecologists and obstetricians recommend raspberry leaf as an herbal remedy for menstrual cramps, and it is frequently included in tonics and teas for pregnancy support. Peer-reviewed medical literature regarding red raspberry leaf is scant, but most studies have found few or no side effects associated with red raspberry leaf consumption. In general, red raspberry leaf is viewed as a safe, nutrient-based remedy for supporting the female reproductive organs.
Safety in Pregnancy
Traditionally, red raspberry leaf is considered to be safe for women during all stages of conception and pregnancy. The plant contains multiple nutrients, including magnesium and folic acid, that are essential for the development of a healthy pregnancy. Additionally, red raspberry leaves contain fragrine, a volatile oil that appears to beneficially affect the muscles of the womb. According to a report published by the Australian College of Midwives, red raspberry leaf can decrease the incidence of preterm labour, post-term labour, forceps delivery and caesarean section without any increased risk of complications.
Many mainstream obstetricians object to the use of red raspberry leaf and other herbal compounds, since they have not been studied thoroughly by the medical community. There is some concern that red raspberry leaf can cause or contribute to miscarriage or preterm labour, but this theory is not backed by peer-reviewed scientific literature. While fragrine is known to encourage Braxton-Hicks (practice) contractions, it has never been demonstrated to induce preterm birth. In fact, most studies have demonstrated that red raspberry leaf actually reduces the likelihood of experiencing a miscarriage or preterm labour. As a precaution, some practitioners recommend that pregnant women use red raspberry leaf only in the third trimester.
Because of red raspberry leaf's high magnesium content, it may cause a mild and temporary decrease in blood pressure. This is generally viewed as beneficial, especially for women with pre-existing hypertension or pre-eclampsia. However, women with clinically low blood pressure may experience lightheadedness or dizziness after consuming red raspberry leaf. This side effect is temporary and will usually pass within a few moments. Women who experience frequent fluctuations in blood pressure should contact a professional to rule out underlying medical conditions.
Because red raspberry leaf contains vitamin B-6 and several other nutrients that can combat morning sickness, many practitioners recommend the use of red raspberry leaf in the prevention and treatment of pregnancy-related nausea and vomiting. Nevertheless, a few women seem to experience worsened nausea after consuming red raspberry leaf. The most likely reason for this correlation is that some pregnant women develop an aversion to the "earthy" taste of the leaf. For women who swallow red raspberry leaf in the form of a capsule or tablet, a gag reflex may trigger the onset of nausea--or, rarely, vomiting. It is unlikely that any compounds in raspberry leaf contribute to this effect.
Safety During Lactation
Experts disagree about the safety of raspberry leaf for women who are nursing. Since no controlled studies have documented the plant's effect on lactation, all theories about its safety and efficacy are based in tradition and speculation. Many women use red raspberry leaf to enhance the quantity or nutritive quality of their breastmilk, but it is possible that the herb may actually have a negative influence on the levels of prolactin in a mother's body. Lactation experts like Dr. Jack Newman indicate that the odds of a medicinal herb adversely affecting a baby are slim to none; nevertheless, nursing mothers should speak to a lactation consultant before using raspberry leaf or any other herb.