Herbs and natural supplements in pregnancy

CHAPTER 11 HERBS AND NATURAL SUPPLEMENTS IN PREGNANCY



INTRODUCTION


Most women take over-the-counter medicines at some point during their pregnancy. This may occur intentionally or happen inadvertently during the early stages of pregnancy. The advice on many product labels and package inserts is to ‘consult your doctor’ or ‘consult your healthcare provider’ before using a particular medicine, yet many healthcare providers are poorly equipped to weigh up the benefits of taking, or not taking, a particular medicine during pregnancy. The risk/benefit assessment is possibly even more complex when considering the safety and efficacy of complementary medicines (CMs).


Medical and complementary medicine practitioners, pharmacists and other healthcare providers face similar challenges when advising the pregnant patient about CMs. Despite their popularity, there is very little published evidence regarding the efficacy and safety of natural medicines during pregnancy and lactation. Modern and traditional texts may warn against use, but little information is provided about the evidence upon which such a recommendation is based. Information about the potential efficacy of CMs in pregnancy is also scarce.


This chapter aims to provide readers with an introduction to the fundamental concepts and concerns surrounding the use of complementary medicines in pregnancy. Part 1 explores the use of herbs and natural supplements in pregnancy from contemporary and traditional approaches. Safety and evidence issues are discussed in Part 2. Central to this section is a discussion about the methods of establishing the safety of any medicine in pregnancy. Part 3 provides a guide to using the information in this chapter to shape clinical practice.



PART 1: USE OF HERBS AND NATURAL SUPPLEMENTS IN PREGNANCY


It is commonly known that complementary medicine (CM) is widely used throughout the world. In many countries traditional medicine continues to form the basis of primary healthcare (WHO 2002). There is a trend in developed countries, including Australia, towards an increase in the use of traditional medicine and CM (Thomas et al 2001, MacLennan et al 2002, Tindle et al 2005, Xue et al 2007). Recent literature indicates that women frequently use CM during pregnancy; however, usage estimates vary considerably owing to variations in the definition of CM used, geographical location, socioeconomic and cultural influences. For example, surveys conducted in Europe, USA and Canada indicate that the prevalence of CM usage in pregnancy ranges from 7.1% to 96% (Forster et al 2006). In Australia it is estimated that between 10% (Henry & Crowther 2000) and 91% (Forster et al 2006) of all pregnant women will use CM at some stage during their pregnancy. With regard to herbal medicines specifically, although the majority of women discontinue taking them once they know they are pregnant, some others may commence taking them on the advice of their maternity care providers (Ranzini et al 2001).


Surveys of Australian women have revealed that nutritional supplements are frequently taken before and throughout pregnancy. During the pre-conception period, the most common supplements taken are folate (29–33%), multivitamins (11–12%) and other supplements including vitamin C, and calcium and iron (12–15%). During pregnancy, use of folate increases to 70–79% of women (particularly in the first trimester), multivitamins to 27–35%, iron to 38–52%; use of other supplements also increases, including calcium (6–24%), vitamin B6 (1–13% predominantly in the first trimester) and zinc (1–7%). The herbal medicine most often used in pregnancy is raspberry leaf (particularly in the last trimester) (Maats & Crowther 2002, Forster et al 2006).


Despite the widespread use of CMs, pregnant women do not always disclose their use to healthcare providers. In one study only 1% of participants’ medical records listed their CM use (Maats & Crowther 2002), while another study reported that 75% of women had informed their primary care provider (Tsui et al 2001). Lack of disclosure is problematic because women miss the opportunity to receive informed advice about the effectiveness and safety of the medicines they have chosen to use and prevent unsafe outcomes, while unsupervised use potentially increases the risk of drug interactions with prescribed medicines and contributes to the under-reporting of side effects and adverse outcomes.


Some pregnant women are motivated to take CMs in lieu of conventional medicines because they believe CMs to be safer (Hollyer et al 2002). Sometimes self-prescribed use is justified, such as using nutritional supplements to meet increased nutritional requirements; to treat a pregnancy-related health issue (e.g. nausea or general pregnancy preparation); or to treat non-pregnancy-specific problems (e.g. the common cold) (Henry & Crowther 2000, Maats & Crowther 2002, Nordeng & Havnen 2004).


Pregnant women appear to use a variety of information sources to aid their selection of CMs, including healthcare practitioners (Tsui et al 2001, Forster et al 2006), friends, family members (Tsui et al 2001, Hollyer et al 2002, Maats & Crowther 2002, Nordeng & Havnen 2004) and media sources (e.g. magazines and the internet) (Tsui et al 2001).



NUTRITIONAL MEDICINE


Pregnant women may choose to use nutritional medicines as symptomatic treatment to improve their own general health and to optimise the healthy development of the growing child and its safe delivery.


Most clinicians will be aware of the changes in nutritional requirements that occur in pregnancy and the need for women to increase their dietary intake of certain nutrients such as iron, calcium, folate and others. Nutritional supplements are sometimes used to help women achieve these higher intake levels and to correct preexisting deficiencies. The National Health and Medical Research Council’s nutritional guidelines for the adequate intake of vitamins and minerals (NHMRC 2006) are a guide for nutritional requirements during pregnancy. However, these guidelines are only estimates based on extrapolated data from other populations and models and do not take into account the individual’s specific needs. In practice, a detailed diet and lifestyle history and sometimes additional pathology testing are necessary so that clinicians can make more appropriate individual recommendations.


Besides enabling women to meet their basic nutritional needs, nutritional supplements are also used in larger doses to act as pharmacological agents to ameliorate symptoms and address specific health complaints. For example, calcium and magnesium supplements have been used to reduce the severity of leg cramps, pyridoxine to alleviate nausea, and folate to reduce the incidence of neural tube defects. Table 11.1 (pp 151–6) lists common nutritional supplements and their use in pregnancy.


TABLE 11.1 Nutrients During Pregnancy















































































Nutrient Therapeutic function/justification Dosage recommendations and issues
Vitamin A
• Required for gene expression and cellular differentiation in organogenesis and embryonic development of the spinal cord and vertebrae, limbs, eyes and ears, and heart (Morriss-Kay & Sokolova 1996).

• Poor maternal status will result in risk of infant deficiency (Ortega et al 1997) associated with poor immune function and increased risk of infection morbidity and mortality in infants and children (Grubesic 2004, Huiming et al 2005).

• Maternal deficiency increases the risk of mortality (West et al 1999), premature rupture of membranes (Westney et al 1994), preterm delivery (Radhika et al 2002), reduced haemoglobin levels and anaemia (Suharno et al 1993, Bondevik et al 2000), night blindness (Livingstone et al 2003) and immune suppression (Cox et al 2006).
• Excessive supplementation shown to be associated with adverse pregnancy outcomes, particularly in the first trimester.

• No association between moderate intake (< 10,000 IU) and fetal malformations (Martinez-Frias & Salvador 1990, Werler et al 1990, Botto et al 1996, Mills et al 1997, Shaw et al 1997, Mastroiacovo et al 1999, Johansen et al 2008).

• Supplement labels must carry the warning, ‘When taken in excess of 3000 μg retinol equivalents (10,000 IU), vitamin A may cause birth defects’.
Vitamin B6 (pyridoxine)
• Beneficial in the treatment of nausea in pregnancy (Jewell & Young 2003, Sripramote & Lekhyananda 2003, Jamigorn & Phupong 2007).

• Poor vitamin B6 status may decrease the possibility of conception (Ronnenberg et al 2007) and increase the risk of early pregnancy loss (Wouters et al 1993, Goddijn-Wessel et al 1996, Ronnenberg et al 2007).
• RDI during pregnancy is increased slightly to 1.9 mg, and upper recommended level is 50 mg with no evidence of teratogenicity.

• High-dose supplementation (mean 132 mg/day) for 9 weeks during the first trimester appears to be safe, with no associated increase in risk for major malformations (Shrim et al 2006). Doses used in studies for nausea are 30–75 mg/day.
Vitamin B9 (folic acid)
• Deficiency can lead to homocysteine accumulation, which may be associated with abnormalities of the placental vasculature and increased risk of miscarriage and preeclampsia (Dodds et al 2008, Napolitano et al 2008, Makedos et al 2007) and is associated with a two-fold increased risk of adult schizophrenia (Brown et al 2007).

• Intake of folic acid pre-conceptually and during the first 4–6 weeks of pregnancy reduces the risk of neural tube defects (NTDs) by more than 50% (Czeizel & Dudas 1992, Berry et al 1999) and may also decrease the risk of other congenital malformations, including urinary tract and cardiovascular defects, limb deficiencies and hypertrophic pyloric stenosis (Czeizel 1998). Individuals with polymorphisms in folate metabolism (methylenetetrahydrofolate reductase [MTHFR] gene) may be at greater risk of deficiency and subsequent adverse effects (Coppede et al 2007, Biselli et al 2008, Boyles et al 2008, Candito et al 2008, Steer et al 2008). In this instance, 5-methyl-tetrahydrofolate preparations are more advisable.
• Supplementation with folate has been linked to increased risk of multiple pregnancies (Czeizel 1998, Czeizel & Vargha 2004) but this has been disputed by others (Li et al 2003).

• RDI in pregnancy is 600 mcg/day (200 mcg above RDI in non-pregnancy state). Upper limit recommended in pregnancy 1000 mcg — due to the possibility of masking a vitamin B12 deficiency.
Vitamin B12 (cyanocobalamin)
• Inadequate cobalamin status in pregnancy has been associated with several adverse outcomes such as preterm birth (Ronnenberg et al 2002), intrauterine growth-retardation (Muthayya et al 2006), increased risk of NTDs (Kirke et al 1993, Wright 1995, Steen et al 1998, Suarez et al 2003, Groenen et al 2004, Gaber et al 2007) and increased risk of miscarriage (Hubner et al 2008).

• Vitamin B12 is also required for homocysteine metabolism; increased levels have been associated with numerous conditions including preeclampsia (Napolitano et al 2008) and recurrent pregnancy loss (Hubner et al 2008). Inadequate maternal status may result in an infant with poor stores, and this may be further exacerbated by low stores in breast milk (Allen 1994).
• The RDI is slightly increased to 2.6 mcg/day in pregnancy. There is no upper level of intake as there is no evidence of adverse effects.

• Deficiency (indicated by macrocytic changes) may be masked by high-dose folic acid supplementation.
Vitamin C
• It has been suggested that vitamin C deficiency plays a role in several adverse pregnancy outcomes, such as preeclampsia, intrauterine growth restriction and pre-labour rupture of fetal membranes (PROM). A recent Cochrane Review, however, reported no difference for the risk of stillbirth, miscarriage, birth weight, placental abruption or intrauterine growth restriction between women supplemented with vitamin C (alone or combined with other supplements) and those given a placebo (Rumbold & Crowther 2005a, Rumbold et al 2005).

• Required for healthy immune function and significantly reduces the risk of urinary tract infections during pregnancy (Ochoa-Brust et al 2007).
• The recommended intake of vitamin is slightly increased in pregnancy to 60 mg/day.

• Early reports of high-dose maternal supplementation causing ‘conditioned or rebound scurvy’ in infants (Cochrane 1965, Rhead & Schrauzer 1971) have not been replicated in subsequent studies (Diplock et al 1998).
Vitamin D
• High prevalence of vitamin D deficiency in pregnancy and lactation has been reported (Hollis & Wagner 2004, Sachan et al 2005, Ainy et al 2006, Judkins & Eagleton 2006, van der Meer et al 2006).

• Maternal vitamin D status affects the infant’s vitamin D status (Hollis & Wagner 2004), intrauterine growth of long bones (Morley et al 2006), poor infant skeletal growth and mineralisation (Zeghoud et al 1997) and, in severe maternal deficiency, an increased risk of rickets in the infant (Specker 1994). Glucose intolerance (Maghbooli et al 2008), bone health and risk of osteoporotic fracture later in life may also be influenced (Javaid et al 2006).

• Vitamin D is important for normal brain development (Eyles et al 2003, Cui et al 2007) with fetal deficiency leading to alterations in brain structure and function (Feron et al 2005, Almeras et al 2007).

• Supplementation may protect against multiple sclerosis (Munger et al 2004, 2006) and reduce the risk of later preeclampsia in the infant (Hypponen et al 2007).

• Conversely, maternal concentrations of > 75 nmol/L of 25(OH)-vitamin D in pregnancy may increase the risk of eczema in infants and asthma in children, but has not negatively influenced the child’s intelligence, psychological health or cardiovascular system (Gale et al 2008).
• The amount of vitamin D required during pregnancy and lactation to avoid deficiency may be higher than the recommended amount (RDI 5.0 mcg) (Vieth et al 2001a, Hollis 2005, 2007). The recommended upper limit is 80 mcg (NHMRC 2006). Vieth et al (2001a), however, found no adverse effects even at doses of 100 mcg (4000 IU) per day. Toxicity is rare but may occur with excessive supplementation (Koutkia et al 2001).

• Breast milk is a poor source of vitamin D with infants requiring an exogenous source within a few months (Sills et al 1994, Daaboul et al 1997, Challa et al 2005, Hatun et al 2005).
Vitamin E
• Antioxidant activity is valuable in protecting the embryo (in vitro) and fetus from damage due to oxidative stress (Wang et al 2002, Jishage et al 2001, Cederberg et al 2001). Although oxidative stress plays an important role in the pathogenesis of preeclampsia (Gupta et al 2005), there is little evidence for the role of vitamin E in its prevention (Rumbold & Crowther 2005b, Polyzos et al 2007). Some evidence suggests that in women with poor antioxidant status it was beneficial (Rumiris et al 2006).

• Low maternal levels contribute to increased risk of wheezing and asthma in childhood (Devereux et al 2006), and supplementation was useful in reducing pregnancy-related leg cramps (Shahraki 2006) and in increasing birth weight for gestation (Valsecchi et al 1999, Scholl et al 2006).
• The recommended intake for vitamin E (7 mg) is not increased for pregnancy. High-dose supplementation of vitamin E (400–1200 IU) appears to be safe and does not increase risk for major malformations, preterm deliveries, miscarriages and stillbirths (Boskovic et al 2005). The recommended upper limit in pregnancy is 300 mg/day (NHMRC 2006).
Vitamin K
• Poor maternal vitamin K levels can lead to relative deficiency in newborn infants (Shearer 1992). Low intake combined with the reduced gastrointestinal bacterial synthesis puts infants at risk of Vitamin K deficiency bleeding (VKDB) owing to the lack of activity of vitamin-K-dependent clotting factors (II, VII, IX and X) (von Kries et al 1993). This is compounded in breast-fed infants, as breast milk contains lower levels than formula, although this may be increased with maternal supplementation during lactation (Greer et al 1997).
• The recommended intake of vitamin K during pregnancy and lactation is the same as for a non-pregnant woman (60 mcg/day). To prevent infant health risks, prophylactic treatment of one intramuscular injection of 1 mg (0.1 mL) or three 2 mg (0.2 mL) oral doses at birth, 3–5 days of age and at 4 weeks are recommended (NHMRC 2000).
Calcium
• The newborn infant skeleton holds approximately 20–30 g calcium (Prentice 2003), 80% of which is acquired during the third trimester when the fetal skeleton is rapidly mineralising (Trotter & Hixon 1974). This increased demand for calcium during pregnancy is met by alterations to maternal calcium metabolism, particularly a two-fold increase in calcium absorption mediated by increases in 1,25-dihydroxyvitamin D and other mechanisms (Kovacs & Kronenberg 1997, Prentice 2003).

• A possible inverse relationship between calcium intake during pregnancy and risk of hypertension and preeclampsia has been suggested from epidemiological and clinical studies (Villar et al 1983, Villar et al 1987, Repke & Villar 1991). Supplementation (1.0–2.0 g/day) is recommended to reduce the risk of preeclampsia and gestational hypertension (Hofmeyr et al 2006, Hofmeyr et al 2007); it may also reduce the blood pressure of the offspring (Belizan et al 1997, Hatton et al 2003).

• Calcium supplementation during pregnancy has been shown to reduce maternal blood lead concentrations by an average of 11% by inhibiting the mobilisation of lead from bone and inhibiting intestinal absorption (Téllez-Rojo et al 2006). Supplementation (1200 mg) during lactation also reduces the risk of infant lead exposure by decreasing the concentration in breast milk by 5–10% (Ettinger et al 2006).
• Although pregnancy is a time of high calcium requirement, there is no increase in the RDI for pregnancy (1000 mg). If supplementation is required, it appears to be safe to use (Hofmeyr et al 2006).
Chromium
• Deficiency is believed to have an effect on glucose intolerance (Jovanovic-Peterson & Peterson 1996, Jovanovic & Peterson 1999). Chromium may protect against maternal insulin resistance and gestational diabetes (Morris et al 2000); however, studies are contradictory (Aharoni et al 1992, Gunton et al 2001, Woods et al 2008).
• Recommended daily intake during pregnancy is slightly increased to 30 mcg/day.

• Supplementation in gestational diabetes is likely to be safe (Jovanovic & Peterson 1999).
Iodine
• Iodine deficiency occurs in both developing and developed countries (Becker et al 2006). Deficiency during pregnancy (defined as urinary iodine concentrations < 150 mcg/L) has been found even in areas considered to have generally adequate intake. In a study conducted in Rome, where a salt iodination program has been introduced, only 4% of non-pregnant women were found to be iodine deficient (< 100–199 mcg/L) compared to 92% of pregnant women, suggesting that it may be necessary to monitor pregnant women even in regions where iodine deficiency is not common (Marchioni et al 2008). It enables the manufacture of maternal thyroid hormones, is protective against cretinism (Delange 2000), is vital for the development of the fetal brain, protects against neurological damage (Perez-Lopez 2007), and is also supplied to the breastfed infant via breast milk (Berbel et al 2007).

• Maternal hypothyroidism during early pregnancy is associated with other adverse outcomes including premature birth, preeclampsia, breech delivery and increased fetal mortality (Haddow et al 1999, Pop et al 2004, Casey et al 2005). High-risk women (personal or family history of thyroid disorders or a personal history of other autoimmune diseases) have more than a six-fold increased risk of hypothyroidism during early pregnancy (Vaidya et al 2007).
• Mild iodine deficiency (median UIE < 100 mcg/L) has been found in several areas in Australia, including New South Wales and Victoria (Li et al 2006).

• To prevent iodine deficiency disorders, the World Health Organization (WHO), United Nations Children’s Fund and International Council for the Control of Iodine Deficiency Disorders established that for a given population median urinary iodine concentrations (UIC) must be 150–249 mcg/L in clinically healthy pregnant women (Marchioni et al 2008).

• Iodine requirement increases during pregnancy and recommended intakes are 250–300 mcg/day (Delange 2007).

• To monitor iodine status, WHO suggest that a median urinary iodine concentration > 250 mcg/L and < 500 mcg/L indicates adequate iodine intake in pregnancy (Zimmermann 2007).
Iron
• Iron requirements increase significantly in pregnancy to support expansion of maternal red blood cell mass and fetal growth (Bothwell 2000).

• Accurate assessment of iron status during pregnancy is more challenging owing to the physiological changes occurring at this time (Milman et al 1991). Haemodilution affects iron parameters such as haemoglobin concentration, haematocrit, serum iron, ferritin and total-iron binding capacity. Serum ferritin is regarded as the most reliable indicator of iron stores (Byg et al 2000), while haemoglobin levels are used as an inexpensive marker to diagnose anaemia (Reveiz et al 2007). The evaluation of iron status and of the risk of anaemia developing during pregnancy may be more accurate when done early in pregnancy before the maternal plasma volume expands (Scholl 2005). Demands are partly met by a progressive increase in iron absorption as the pregnancy advances (Bothwell 2000); however, depending on initial iron reserves, this may not be sufficient to prevent deficiency (Casanueva et al 2003). The risk of iron deficiency increases with parity (Looker et al 1997). Maternal iron stores at conception appear to be a strong predictor of the risk of anaemia in later pregnancy (Bothwell 2000, Casanueva et al 2003). WHO estimates indicate that iron deficiency anaemia affects 22% of women during pregnancy in industrialised countries and 52% in non-industrialised countries (WHO 1992).

• Supplementation raised haemoglobin levels by 7.5 g/dL and reduced the risk of iron deficiency and iron-deficiency anaemia at term (Pena-Rosas & Viteri 2006).
• The RDI of iron during pregnancy is increased to 27 mg/day. Upper limit is 45 mg based on the risk of side effects and potential systemic toxicity.

A daily supplement of 40 mg ferrous iron from 18 weeks’ gestation appears adequate to prevent iron deficiency in 90% of women (Milman et al 2005). However, individual assessment of iron status in early pregnancy may be useful to tailor the appropriate prophylaxis to prevent iron deficiency and iron deficiency anaemia: ferritin ≤ 30 mcg/L — 80–100 mg ferrous iron/day; ferritin 31–70 mcg/L — 40 mg ferrous iron/day; those with ferritin > 70 mcg/L do not require supplementation (Milman et al 2006).

• High-dose supplementation may reduce the absorption of zinc (Hambidge et al 1987, O’Brien et al 2000) and other divalent cations (copper, chromium, molybdenum, manganese, magnesium) (Rossander-Hulten et al 1991).

• Side effects of high-dose supplementation typically include gastrointestinal disturbances, most commonly constipation and nausea (Melamed et al 2007).
 
• Numerous studies have showed an association between adverse outcomes and iron deficiency anaemia, including increased risk of maternal mortality, infection, low birth weight and premature delivery. Fetal and infant iron deficiency may adversely impact on brain development, function and neurocognition (Grantham-McGregor & Ani 2001). Poor maternal iron status may contribute to reduced fetal stores (Preziosi et al 1997, de Pee et al 2002, Emamghorashi & Heidari 2004). However, in a recent cross-sectional study pregnant women with iron deficiency or mild anaemia were not found to produce offspring with significantly altered iron levels (Paiva Ade et al 2007). Similarly, iron supplementation during the second half of pregnancy was not found to influence the iron status of the children at 6 months or 4 years of age (Zhou et al 2007). On a cautionary note, excessive iron supplementation resulting in high haemoglobin and increased iron stores may be associated with increased adverse pregnancy outcomes (Scholl 2005), including low birth weight and premature delivery (Casanueva & Viteri 2003).
  
Magnesium
• Magnesium is involved as a co-factor in more than 300 enzyme pathways (Wacker & Parisi 1968) and acts as a neuromuscular relaxant. The infant has stored approximately 750 mg at birth (Prentice 2003).

• Positive trials highlight the benefits of magnesium supplementation for leg cramps (Dahle et al 1995) and possibly for preeclampsia, although evidence is inconsistent for this last indication (Dawson et al 2000, Kisters et al 2000, Adam et al 2001, Duley et al 2003, Ahmed 2004, Shamsuddin et al 2005, Omu et al 2008, Seydoux et al 1992, Handwerker et al 1995, Sanders et al 1999, Makrides & Crowther 2001).
 •The RDI for magnesium during pregnancy is increased slightly to 350 mg (age 19–30 years) and 360 mg (31–50 years). The upper level of intake from non-food sources is 350 mg/day.
Zinc
• Zinc deficiency has been associated with adverse outcomes in pregnancy. Numerous animal models demonstrate an association between zinc deficiency and increased developmental abnormalities and fetal losses. Deficiency has also been associated with reduced interuterine growth, preterm delivery, labour and delivery complications, poor immunological development (Caulfield et al 1998) and congenital malformations (Hambidge et al 1977). In humans, acrodermatitis enteropathica, a genetic disease that produces severe zinc deficiency, has been found to increase fetal losses and malformations, most probably owing to the key role it plays in protein synthesis and cellular growth (King 2000).

• The usefulness of zinc supplementation during pregnancy is unclear. Supplementation has been shown to reduce preterm birth (Mahomed et al 2007), assist the accumulation of lean tissue in the infant during the first year of growth (Iannotti et al 2008) and reduce the risk of delivering via caesarean section (Mahomed et al 2007).

• While women with preeclampsia have significantly lower zinc and superoxide dismutase (SOD) levels compared to healthy pregnant women (Ilhan et al 2002), zinc supplementation had no significant effect in pregnancy hypertension or preeclampsia (Mahomed et al 2007); and no significant differences were seen for several other maternal or infant outcomes, including pre-labour rupture of membranes, antepartum haemorrhage, post-term birth, prolonged labour, retention of placenta, meconium in liquor, smell or taste dysfunction, maternal infections, gestational age at birth or birth weight (Mahomed et al 2007).
• During pregnancy, RDI is increased to 11 mg/day, and the recommended upper level of intake is the same as for adults, at 40 mg/day. Vegans/vegetarians may need an additional 50%.

• The teratogenic effects of alcohol may be exacerbated by a concurrent zinc deficiency (Keppen et al 1985).
Omega-3 DHA/EPA)
• High fetal demands for omega-3 fatty acids result in the progressive decrease of maternal stores throughout pregnancy (Al et al 1995, Bonham et al 2008).

• Omega 3 is important for optimal fetal and infant neurodevelopment and may be associated with benefits for other pregnancy and infant health outcomes, including growth and development of the fetal and infant brain (Horrocks & Yeo 1999), improvements to children’s eye–hand coordination (Dunstan et al 2008) and higher infant cognitive function (Oken et al 2005, Hibbeln et al 2007).

• Lower maternal intake was associated with: increased risk of infants with poorer outcomes for prosocial behaviour, fine motor ability, communication, and social development scores (Hibbeln et al 2007); increased risk of infant asthma (Olsen et al 2008), increased risk of postnatal depression (Levant et al 2006, 2008) and increased depressive symptoms in postpartum women (Hibbeln 2002). However, more recent studies have found no associations (Browne et al 2006, Sontrop et al 2008, Rees et al 2008, Freeman et al 2008) or mixed outcomes (Su et al 2008).

• Lower dietary intake of fish (Oken et al 2007), and biochemical markers of omega-3 fatty acid intake (Velzing-Aarts et al 1999, Qiu et al 2006, Mehendale et al 2008) have been reported in women who develop preeclampsia. Intervention studies with fish oil supplementation, however, generally have not found a protective effect. In a recent Cochrane Review there was no significant difference in risk of gestational hypertension (five trials) or preeclampsia (four trials) between those taking the fish oil (133 mg/day to 3 g/day) and control groups (Makrides et al 2006).
• Fish oil supplementation during pregnancy appears to be safe. Mild side effects such as belching and unpleasant taste are reported (Makrides et al 2006, Freeman & Sinha 2007).

• Recommendations for dietary intake of EPA/DHA (adequate intake) for pregnancy is 115 mg/day. An upper level of intake of 3 g is recommended for adults (no pregnancy specifications).

• Maternal dietary DHA intake of at least 200 mg/day is associated with positive infant neurodevelopmental outcomes (Cetin & Koletzko 2008).
Probiotics
• Prenatal and postnatal supplementation with probiotics may play a role in immune regulation and the prevention of allergies developing in the infant. Numerous positive studies in the prevention of allergies, including eczema, in the child have involved the following strains:

Lactobacillus reuteri (ATCC 55730) (Abrahamsson et al 2007)

L. rhamnosus GG (ATCC 53103) (Kalliomaki et al 2001, Rautava et al 2002, Kalliomaki et al 2003)

L. rhamnosus GG (ATCC 53103); L. rhamnosus LC705 (DSM 7061); Bifidobacterium breve Bb99 (DSM 13692); and Propionibacterium freudenreichii ssp. shermanii JS (DSM 7076) (Kukkonen et al 2007)

L. rhamnosus GG and B. lactis Bb12 (Huurre et al 2008)

• Prophylactic enteral supplementation reduces the occurrence of necrotising enterocolitis and death in premature infants born weighing less than 1500 g (Alfaleh & Bassler 2008); this may be owing to normalisation of gut flora and stimulation of natural host defences (Hammerman & Kaplan 2006).

• Vaginal application reduces the risk of vaginal infections in pregnancy (Othman et al 2007).
• Based on review of literature, prescription appears to be safe for internal and vaginal application.
Choline
• Choline status in pregnancy influences the development of the memory centre (hippocampus) in the fetal brain, and may have a life-long impact on memory (Zeisel 2004).
• The RDI is slightly increased at 440 mg/day, with an upper level of 3000 mg/day.


Long-term impact of maternal nutrition


The ‘developmental origins of disease’ hypothesis suggests that the benefits of a nutritional intervention may extend much further than the more immediate outcomes. Environmental factors during development, such as maternal nutrition, have been shown to influence the expression of our phenotype. The most sensitive time for this influence has been shown to be in utero. Fetal nutrition can alter the body’s structure, function and metabolism, subsequently affecting the risk of developing diseases later in life (Barker 2004). Longitudinal studies from around the world have found that low birth weight (in relation to gestational age) is associated with an increased risk of coronary heart disease, stroke, hypertension and type 2 diabetes in adulthood (Barker 2007). Furthermore, maternal vitamin D status during pregnancy appears to influence the bone-mineral density of offspring even in late childhood (Javaid et al 2006). Similarly, there is some evidence to suggest that calcium supplementation during pregnancy can reduce the offspring’s blood pressure during childhood (Hatton et al 2003).



HERBAL MEDICINE


Herbal medicines are used in pregnancy as pharmacological agents. They are used as foods, such as ginger, in extract form (liquid and solid dose forms) and also as teas. In many developing countries, herbal medicines have been used as the dominant form of medicine and continue to play a major role in healthcare, reproductive health and midwifery (WHO 2002).



A traditional approach


Although conception is a problem for some women, a more common problem throughout the ages was contraception. Ethnobotanical studies conducted in many parts of the world reveal that herbal medicines have been used widely for generations to prevent conception and induce miscarriage, and in some parts of the world their use continues despite the availability of pharmaceutical contraceptive pills and devices. Besides this, herbal medicines have been used to enhance fertility, regulate menstruation, facilitate childbirth, help with the expulsion of the placenta and promote lactation.


In many cultures, herbal healers have special reverence for herbs that are thought to have abortifacient or emmenagogue properties. These concepts are foreign in Western medicine and deserve some discussion.



Abortifacients


Since ancient Egyptian times, plants have been used as a source of both contraceptives and early-term abortifacients (Riddle 1991) and in some parts of the world this practice still exists. The abortifacient effects of herbs are attributed to their inherent toxicity or ability to induce uterine contractions (Noumi & Tchakonang 2001). It is also suspected that abortifacient activity may be immune-mediated, hormonal or due to non-specific actions, such as the ability to reduce uterine blood flow. Examples of Western herbs with abortifacient potential due to suspected toxicity include wormwood (Artemsia absinthium), pennyroyal (Mentha pulgeum), poke root (Phytolacca decandra), pau d’arco (Tabebuia avellanedae), rue (Ruta graveolens) and tansy (Tanacetum vulgare) (Mills & Bone 2005).



Emmenagogues


The term ‘emmenagogue’ is used to describe a herb that will stimulate menstrual flow. Traditionally, such herbs have been indicated for delayed menstruation and have developed a reputation of being contraindicated in pregnancy for fear they may induce miscarriage. Herbalists consider emmenagogues to exert oxytocic-like effects that cause uterine contractions; however, this mechanism is unlikely to explain how they promote menses in a non-pregnant woman. Changes to lymph or blood flow and hormonal effects are more likely mechanisms. Examples of herbs thought to act as emmenagogues found on many traditional lists include aloe (Aloe vera), juniper (Juniperus communis), pennyroyal (Mentha pulgeum), goldenseal (Hydrastis canadensis), black cohosh (Cimicifuga racemosa), blue cohosh (Caulophyllum thalictroides), dong quai (Angelica polymorpha), rue (Ruta graveolens), tansy (Tancetum vulgare) and thuja (Thuja occidentalis). Some herbs considered to be emmenagogues are also regarded as potential abortifacients if used in sufficient quantities (e.g. oxytocin agonists); however, not all abortifacients may act as emmenagogues (e.g. potentially toxic herbs with no hormonal or uterine effects).



Historical perspectives


Medicinal plants have been used in Mexico since pre-Hispanic times. Nearly 10 million indigenous people speaking nearly 85 different languages inhabit the region, and many still depend for primary therapy upon plants from the diverse flora (almost 5,000 medicinal plants) (Andrade-Cetto 2009). An ethnobotanical study of the medicinal plants from Tlanchinol, Hidalgo, Mexico, identified several plants that are used as abortifacients (Andrade-Cetto 2009): Galium mexicanum var mexicanum, Ruta chalepensis, Zaluzania triloba and Tanacetum parthenium. The herb Cinnamomum veru is generally considered useful to induce childbirth and Pedilanthus tithymaloides to reduce ovarian pain.


The Criollo people of Argentina use a vast plant pharmacopoeia. To date, 189 species with 754 different medicinal applications have been recorded (Martinez 2008). The absence of a normal menstrual cycle and amenorrhoea are matters of concern among the Criollo and are treated with emmenagogue plants, the most common being Anemia tomentosa, Tripodanthus flagellaris, Lippia turbinata and Trixis divaricata. Contraceptive herbs used in the region include Zea mays, Anemia tomentose, and abortifacient herbs include Artemisia absinthium, Cheilantes buchtienii, Chenopodium aff. hircinum, Cuphea glutinosa, Ligaria cuneifolia, Lippia turbinate and Pinus spp (Martinez 2008).


Rama midwives in eastern Nicaragua currently use a diverse group of plants in the practice of midwifery: 162 species from 125 genera and 62 families (Senes et al 2008). This extensive ethnopharmacopoeia is employed to treat the many health issues of pregnancy, parturition, postpartum care, neonatal care and primary healthcare of women and children. The 22 most popular midwifery species are medicinals that are widely used by practitioners other than midwives, not only in eastern Nicaragua but elsewhere. Very few herbal species are used as contraceptives in this region, whereas abortifacients are well known and mostly made with bitter-tasting plants (the bitter taste is probably due to alkaloids and other bitter-tasting compounds). The most widely used abortifacients are decoctions made from the leaves and seeds of soursap and the roots of guinea hen. Others are decoctions made with the leaves and/or flowers of barsley, broom weed, trompet, sorosi and wild rice, and from the root of ginja.


Interestingly, midwives in other parts of the world use many Rama midwifery species for the same purpose: for example, sorosi and lime are both widely regarded as important in midwifery. Sorosi is one of the most widely used medicinals in eastern Nicaragua, where it is used as an abortifacient, with similar use in Africa, Australia, Brazil, India, Malaysia, the Philippines and the West Indies (Senes et al 2008). Lime is a domesticated crop used by the Rama and other indigenous groups of eastern Nicaragua as an abortifacient and to accelerate labour. It is also used to induce abortion by tribal people in India, Honduran midwives and the Tikunas of northwestern Amazonia.


In Europe, herbal medicine has a rich history and continues to be popular today. As in other parts of the world, plants were used for reproductive health, to prevent conception and induce abortion, with women and midwives as the main keepers of herbal knowledge. Savin (Juniperus sabina) was one abortifacient herb of choice and pennyroyal, sage, thyme and rosemary were considered powerful emmenagogues (Belew 1999). Unlike some other parts of the world, information exchange down the generations was interrupted during the 18th and 19th centuries because there was a major shift in the management of the birthing process (Schiebinger 2008). During this period, female practitioners with knowledge of herbal lore lost ground to obstetricians (men trained primarily as surgeons), and plant-based treatments were gradually replaced with surgical procedures (Schiebinger 2008). As a result, much knowledge about the use of herbal medicines in fertility and reproduction in Europe was lost.


The North American Indians used herbal medicines extensively throughout the reproductive life cycle and had many remedies for improving fertility, preventing miscarriage, treating symptoms during pregnancy and facilitating the birthing process. A large number of these treatments became known to European settlers in North America through careful study, observation and subsequent clinical use. If repeated use indicated the treatments were effective, the herbs were recorded and prescribed by the Eclectic physicians, who flourished from the mid-1800s to around 1920 in the United States (Belew 1999). Many of the herbal medicines used by the North American Indians and described by the Eclectic physicians are still in use today as part of the Western herbalists’ and traditional midwives’ cache of treatments.


The Eclectics considered black cohosh a ‘remedy par excellence to stimulate normal functional activity of the uterus and ovaries’ throughout the reproductive life cycle (Belew 1999). They reported that when used regularly at the end of pregnancy ‘it will render labor easier and quicker, and give a better getting up’. Black haw was highly regarded by the Eclectic physicians, who used it both before and during pregnancy to prevent miscarriage, prepare for labour and relieve false labour pains and after-pains. The Eclectic physicians preferred to use cottonroot (Gossypium) as an oxytocin agonist rather than the newly available sublingual oxytocin preparation, because the herb was considered to have a gentler action and produce more predictable results. Squaw vine (Mitchella repens) was well considered when enhanced fertility was called for. It was extensively used to promote menstruation and alleviate physical discomfort in the latter months of pregnancy, and was thought to be a good preparative to labour, rendering the birth easier.

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Jul 18, 2016 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Herbs and natural supplements in pregnancy

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