Drinking red raspberry leaf tea is considered safe for most adults when consumed in moderation. However, pregnant women should run it by their doctor before making it a regular part of their diet.
Laboratory, animal, in vivo and in vitro studies demonstrate that raspberry leaf extracts have stimulant and relaxation effects on smooth muscle (including the uterus) depending on herbal preparation, tissue or cell type and baseline tone.
Pregnant women
A lot of pregnant women are eager to meet their baby, especially when the due date comes and goes. But some babies aren’t in a hurry to leave their comfy home inside mum’s womb. This can lead to speculation and suggestions on how to ‘nudge’ them along. Talking to other pregnant friends, or reading Baby Club forums, you’ll often find that a cup of raspberry green tea is suggested to help ease labour pains.
Despite the popularity of this herbal remedy, there is little scientific evidence to support its effectiveness. In fact, a recent study found no difference in gestation, augmentation of labour, artificial rupture of membranes, narcotic or epidural analgesia, duration of any stage of labour or mode of birth between groups of women who drank raspberry leaf tea and those who didn’t.
The active ingredients in raspberry leaf may have stimulating or relaxing effects on the smooth muscle of the uterus, depending on the preparation used, method of administration, baseline muscle tone and pregnancy status. However, the results of previous studies have been conflicting and it’s important that you speak to your midwife or GP before drinking any herbal teas or supplements.
If you want to try raspberry leaf tea during your pregnancy, it’s best to start at around 32 weeks and gradually increase your intake as the weeks progress. Some anecdotal reports also suggest that it may have laxative properties, so you’ll need to be careful about how much you drink and whether you’re already taking any other medications, particularly those for diabetes.
Women who are breastfeeding
Women who are breastfeeding should not drink raspberry leaf tea as it contains chemicals that may be harmful to the baby. They also might interfere with the absorption of certain vitamins and minerals. Raspberry leaf tea is a good source of iron, vitamin A, calcium, magnesium, and manganese. It is also believed to help prevent excessive postpartum bleeding.
It has been used for millennia to help prepare women for labour and is still drunk to try to induce labour today. It is thought that the tea works because it stimulates blood flow to the uterus and strengthens the muscle fibers in the uterus, which in turn trigger contractions. This makes the labour process shorter and less painful. It is also thought that the tea helps to stave off postpartum bleeding by regulating the menstrual cycle and helping the uterus return to its normal size.
There is not much research on raspberry leaf, but the few studies that have been done suggest it may have some benefits for pregnancy and birth. One study* at a tertiary-level hospital found that women who took raspberry leaf from 32 weeks through to labour had a second stage of labour that was 16.6% shorter than those who did not take the tea. The tea was also associated with a lower incidence of forceps delivery (19.3% vs 30.4%).
However, the results from this and other studies are not consistent and further research is needed. It is also important to be aware that the use of herbal remedies such as raspberry leaf tea can interfere with the effectiveness of some medicines including insulin and antidepressants.
Women who have high blood pressure
Although a number of herbalists recommend raspberry leaf tea to help prepare the uterus for labor, research on its efficacy is limited. It is generally recommended to start drinking raspberry leaf tea in the third trimester, between 28-37 weeks, so it can potentially support the body’s natural readiness for labor.
The uterine tonic contains an alkaloid called fragrine, which has been shown to affect smooth muscle in laboratory experiments. This may explain why some people believe the herb can stimulate contractions. However, the research is based on small samples and is therefore inconclusive.
Despite the lack of solid scientific evidence, some women swear by its ability to reduce menstrual cramps and ease the symptoms of perimenopause. Historically, anecdotal reports suggest that raspberry leaf tea can reduce mild period cramps and improve a woman’s mobility. In addition, it is known to have a diuretic effect and may help alleviate water retention during pregnancy and menopause.
It is important to speak with a health professional before drinking any new herbal remedy, including raspberry leaf tea. In some cases, the herb can interact with certain medications or cause an adverse reaction. It is particularly important to avoid this herb if you have high blood pressure or have diabetes or gestational diabetes.
A recent study found that women who drank raspberry organic green tea during their first pregnancy had shorter second stages of labor than those who did not. They also had a lower rate of forceps birth. The study was not a randomised controlled trial (RCT), which is the gold standard in medical research, and it has a small sample size and selection bias.
Women who have diabetes
Women through the centuries have used various herbs to help with pregnancy, labour and birth. The research base in this area is under-developed, but there is a growing interest from midwives and other maternity care providers to understand the biophysical effects and safety of these herbs for women during pregnancy and childbirth.
Although there is some anecdotal evidence to suggest that raspberry leaf may help to tone the uterus and support labour and childbirth, it is important to talk to your midwife about whether this is right for you. It is also worth noting that it can affect your bowels and cause diarrhoea, so is best avoided if you are suffering from these symptoms.
There is only one human randomised controlled trial (RCT) of this herb and this is the best evidence available. This trial involved low risk nulliparous women who were randomly assigned to two daily doses of raspberry leaf tablets (2 x 2.4 g per day) or placebo from 32 weeks gestation. The results of this study showed no differences in any measured outcome including the length of any stage of labour, augmentation of labour, artificial rupture of membranes and narcotic or epidural analgesia.
However, this case study was not powered to measure any difference in forceps delivery and a significant proportion of participants were given this procedure. A further RCT of this herb was published in 2013 and this included a larger sample size and compared the results of women who took raspberry leaf with those who did not. It found that women who drank this herbal tea experienced a significantly shorter second stage of labour, the equivalent of about 10 minutes less pushing.
