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Health Information

Pregnancy Support

Uses

Anemia
  • Anemia : Iron (If Deficient)
Prevention of Neural Tube Defects and Other Birth Defects
Assisting or Initiating Childbirth
Bladder Infections
Constipation
Diabetes in Pregnancy
Gingivitis
Jaundice of Pregnancy
Prevention of Low Birth Weight
Prevention of Miscarriage
Prevention of Prematurity
Support of Healthy Mental Function in Child

Pregnancy is a time of dramatic transitions. Body systems that once sustained a single human now support two. Organs, blood vessels, body chemistry, and even the solid supporting structures of a woman's body all go through changes; in the meantime, the fetus's body grows from a tiny bundle of cells to a full-sized baby.

It's no wonder that women feel the desire for remedies to help with these transitions. Since ancient times, women have tried herbs and other natural treatments to ease discomfort or assist with pregnancy, childbirth, and breastfeeding. However, pregnancy is also a circumstance when the potential risk of any treatment rises dramatically. Seemingly benign medications—even natural ones—have been found to cause birth defects or increase the risk of complications. Some traditional remedies, such as blue cohosh for labor stimulation, must be discarded for safety reasons.

Thorough study is needed before any treatment can be considered absolutely safe in pregnancy—and in many cases this research may never been done due to insurmountable ethical consideration regarding the safety of the fetus. It's important to talk with your doctor before deciding to use any treatment, whether it is natural or conventional.

Principal Proposed Natural Treatments

Many natural treatments have shown promise for conditions related to pregnancy. In this section, we discuss those with the most scientific support. However, treatments for nausea and vomiting of pregnancy and preeclampsia are not discussed here; instead, they are addressed in separate articles. Breastfeeding support also has an article of its own.

Note: The safety of the following treatments has not been confirmed, except for nutrients such as vitamins and minerals, for which appropriate dosages for pregnancy have been established. For more information on potentially harmful natural treatments, see Herbs and Supplements to Avoid During Pregnancy and Breastfeeding .

Varicose Veins

Increased pressure from the expanding abdomen and other factors can lead to pooling of fluid in the legs, a condition called venous insufficiency (closely related to varicose veins).

Venous insufficiency/varicose veins occur outside pregnancy as well, and a wide variety of natural treatments have shown promise in their treatment, including buckwheat, butcher’s broom , citrus bioflavonoids , gotu kola , horse chestnut , oligomeric proanthocyanidins (OPCs) , and red vine leaf. These are discussed in the Venous Insufficiency article.

Only one natural treatment, oxerutins, has been studied in a double-blind trial enrolling pregnant women with venous insufficiency. 1 In this study of 69 women, researchers found oxerutins more effective than placebo .

For more information, see the full Oxerutin article.

Hemorrhoids

Hemorrhoids are actually varicose veins in or around the anus. Oxerutins and citrus bioflavonoids have been studied for hemorrhoids during pregnancy. 12,13

A double-blind study enrolling 97 pregnant women found oxerutins (1,000 mg daily) significantly better than placebo at reducing the pain, bleeding, and inflammation of hemorrhoids. 13 Evidence for citrus bioflavonoids is limited to one open trial . 12 Other natural treatments for varicose veins are often recommended for hemorrhoids as well, although research on their use for this condition in pregnancy is lacking.

For more information, see the article on Hemorrhoids .

Anemia

Anemia is common during pregnancy, usually due to deficiency in iron. However, iron supplements can be hard on the stomach, thereby aggravating morning sickness. One study found evidence that a fairly low supplemental dose of iron—20 mg daily—is very nearly as effective for treating anemia of pregnancy as 40 mg or even 80 mg daily, and is less likely to cause gastrointestinal side effects. 112 (Interestingly, 20 mg daily is lower than the amount contained in standard prenatal vitamins.)

Pregnant women who are not anemic should not take more than the recommended daily allowance of iron in pregnancy, as excess iron intake may be harmful both for pregnant women and their unborn children. 14-16

Interestingly, one study suggests that iron plus folate is more effective for the treatment of iron-deficiency anemia in pregnancy than iron alone, even in women who do not appear to be folate-deficient. 17

Prevention of Neural Tube Defects and Other Birth Defects

Folate supplements can help prevent a serious and common type of birth defect known as neural tube defects (NTDs). 18-20 Folate, or folate plus multivitamin/multimineral supplements , may help prevent other birth defects as well, including cleft palate and anomalies of the heart and urinary tract. 108 A systematic review of five trials involving 6,105 women reinforced the evidence that folate supplementation can prevent NTDs in both women who have had a baby with an NTD and those who did not. 124 Participants took daily doses between 360 mcg to 4 mg with or without additional supplements. There was not enough information, though, to say whether folate can reduce the risk of developing other conditions, like cleft lip or cleft palate.

One preliminary study of 859 babies suggests that zinc may help prevent NTDs as well, but evidence so far is weak. 22

Other Proposed Natural Treatments

Other natural remedies have been recommended for treating discomforts and complications of pregnancy or decreasing risks to the baby.

Assisting Childbirth

Castor Oil

Castor bean oil was noted by the ancient Egyptians to stimulate labor, and it is still used by some conventional physicians and midwives to induce contractions—for example, if labor does not occur spontaneously after the water has broken. A recent controlled trial in 100 pregnant women compared oral castor oil to no treatment and found that 57.7% of those given castor oil began labor within 24 hours, compared to only 4.2% of those without treatment. 23 Other preliminary studies also suggest that castor oil may help. 24,25 Unfortunately, castor oil is a strong laxative, and diarrhea is a nearly universal effect—not a particularly pleasant experience during childbirth.

In addition, considering how common this treatment is, research on its safety and effectiveness is surprisingly scant. One case of a potentially fatal complication linked to use of castor oil has been reported, though some have questioned whether the castor oil was responsible. 25,26 In addition, an observational study of South African women found that those self-treating with castor oil and/or other traditional herbs had a higher incidence of meconium (fetal feces) in the amniotic fluid, a sign of fetal distress. 27

Acupuncture and Acupressure

A number of studies, including a 2011 review of 13 trials, found evidence that acupuncture is helpful in reducing labor pain. 28,29,94,109,221,224 In a study involving 212 women in active labor, researchers found that, in countries where epidural anesthesia is not available, acupuncture can help to reduce pain compared to standard care early in labor. 217

Not all of the evidence to support the use of acupuncture to treat labor pain has been high-quality, though. 28,29,94 And there have been some studies that have contradicted this conclusion. For example, in one study, sterile water injections were found to be more effective than acupuncture for lower back pain and relaxation during labor. It is unclear whether or not the patients in the study knew which treatment they were receiving at the time. 115 And, in a placebo-controlled trial, real acupuncture was no better than sham acupuncture in relieving pelvic pain prior to labor. 119 A carefully conducted review of 10 randomized controlled trials involving 2,038 woman was unable to uncover consistent evidence of acupuncture's effectiveness for labor pain either alone or in combination with other treatments. 122 In one study involving 60 women, postoperative acupuncture or electro-acupuncture reduced pain within the first 2 hours (but no longer) and demand for pain medication within the first 24 hours after cesarean section. 121 And in a study involving 105 women giving birth to their first baby, there was no difference in the need for pain relief between the women receiving real or sham acupuncture. 218

A study of 45 pregnant women found that women who received acupuncture on the mathematically calculated birth “due date” gave birth sooner than those who did not. 30 However, this trial used a no-treatment control group instead of sham acupuncture, making its results unreliable. Another study suggested that the use of acupuncture may help stimulate normal term labor. 107 On the other hand, a third study of 106 women with premature rupture of membranes (“water breaking” too early) found that acupuncture did not effectively speed up delivery. 113 It should be noted that none of these 3 studies used sham (fake) acupuncture as a control, making their results unreliable. However, in a subsequent trial that attempted to address this problem, real acupuncture administered for 2 days prior to a planned induction of labor (artificial stimulation of labor) was no better than sham acupuncture at preventing the need for induction or shortening the time of labor. 120

Two studies suggest that acupuncture and associated therapies can help "turn" a breech presentation. 96,97 In 2008, researchers published a review of 6 randomized controlled trials that investigated acupuncture-like therapies (moxibustion, acupuncture, or electro-acupuncture) applied to a specific point (BL 67). They concluded that these therapies were effective at decreasing the incidence of breech presentations at the time of delivery. 118 Again, however, not all of these studies employed a sham acupuncture group for comparison.

According to a small, randomized trial, acupuncture may also help to reduce pain after labor in women undergoing an episiotomy. 225

Other Natural Treatments

One double-blind, placebo-controlled trial evaluated the effects of red raspberry in 192 pregnant women. 32 Treatment (placebo or 2.4 g of raspberry leaf daily) began at 32 weeks of pregnancy and was continued until the onset of labor. The results failed to show any statistically meaningful differences between the groups. Red raspberry did not significantly shorten labor, reduce pain, or prevent complications.

Blue cohosh is a toxic herb and should not be used. One published case report documents profound heart failure in a baby born to a mother who used blue cohosh to induce labor. 33 Severe medical consequences were also seen in a child whose mother took both black and blue cohosh. 34

Proteolytic enzymes may reduce inflammation and discomfort following episiotomy. 79-81

Hypnotherapy has shown some promise for assisting labor. 82-85

Researchers have also focused on the potential benefits of massage therapy . 86-88,226 An analysis of 5 randomized trials, including 326 pregnant women, compared massage therapy with usual care during childbirth. 226 (One study compared massage to music therapy in addition to usual care.) Those in the massage therapy groups reported feeling less labor pain and/or anxiety. These favorable results are limited by the absence of an adequate control group in any of the studies.

Evidence has been mixed regarding whether aromatherapy is helpful during childbirth. In a large controlled trial involving more than 600 participants, lavender oil failed to improve pain after childbirth. 89 But, a randomized controlled trial involving 251 pregnant women did find evidence that aromatherapy may help reduce the perception of pain during labor and possibly reduce the risk of a newborn needing intensive care. 219 In contrast, a review of 2 randomized trials failed to find a positive effect. In the larger of the two studies, 513 women were randomized to receive aromatherapy ( Roman chamomile , clary sage , frankincense , lavender, or mandarin essentials oils) or standard care. Different methods were used to expose the women to the oils, like applying a compress, giving a massage, or using a footbath. There were no differences between the two groups in level of pain, rate of cesarean section, or use of pain medication. 220

For a discussion of homeopathic approaches to pregnancy support, see the childbirth support article in the in the Homeopathy Database .

Constipation

Constipation frequently occurs during pregnancy, for reasons that are not entirely clear.

Fiber supplements, such as psyllium seed, are commonly recommended for the treatment of constipation in pregnancy because of their apparent safety. Flaxseed is another high-fiber seed, and alternative practitioners often recommend it. However, flaxseed contains estrogen-like substances that might pose hazards to the fetus; one study found an effect on reproductive organs and function in baby rats whose mothers ate large amounts of flaxseed during pregnancy. 35

Other natural remedies for constipation during pregnancy include dandelion root36 and a combination of glucomannan and lactulose. 37 However, there is no meaningful evidence to indicate that they are effective.

Note : Avoid use of powerful laxatives, including natural remedies such as buckthorn, cascara, rhubarb, castor bean oil, and senna, as these can induce uterine contractions. 36 (See the Assisting Childbirth section above.) The traditional remedy yellow dock , though milder, might warrant similar caution. 36,38

Leg Cramps

Pregnant women sometimes experience painful leg cramps. A double-blind study of 73 women with this symptom found that magnesium was significantly more effective than placebo in decreasing their distress. 39

Calcium has also been studied for this problem, but research so far gives little indication that it helps. 40-42 A combination of vitamins B 1 and B 6 has also been suggested for leg cramps, but evidence that it helps remains minimal. 43

Prevention of Prematurity and Miscarriage

Interesting though not entirely consistent evidence suggests that use of fish oil or its constituents by pregnant women might help prevent premature births. 50,51,90,99,110 Double-blind studies have evaluated the minerals calcium , 52-54zinc , 55-58 and magnesium59-61 for this purpose as well, but the results have been mixed. A number of trials suggest that anemia is linked to prematurity; however, evidence as to whether iron supplements can help remains inconclusive. 54,62

Numerous studies have investigated the effects of vitamin supplementation on prematurity and/or miscarriage. In a review of several studies, folate was not found to be effective for preventing premature birth. 63 One study failed to find vitamin C helpful for preventing premature birth. 95 However, another study found that vitamin C (100 mg/day after 20 weeks of pregnancy) helped prevent early rupture of the membranes ("water breaking"). 100 Another study suggested that the use of vitamin E (400 IU daily) and vitamin C (500 mg/day) after premature rupture of membranes helped to hold off delivery by several days. 101

Low levels of vitamin B 12 may increase risk of miscarriage, and B 12 supplements may help. 93 However, despite this limited evidence of benefit, a more recent review of 28 trials involving over 98,000 pregnancies failed to show that vitamin supplements of any kind (starting at 20 weeks gestation) prevent miscarriage or stillbirth. 216

Prevention of Low Birth Weight

Babies born below a specific weight (5-½ pounds)—called low birth weight—are at greater risk for complications.

A recent meta-analysis of 7 controlled studies looked at the effects of calcium supplementation on birth weight. 64 These studies predominantly focused on preventing hypertension and/or preeclampsia in the mother, both of which can result in low-birth-weight babies. Overall, calcium appeared to decrease the percentage of babies weighing less than 5 pounds 8 ounces. 64 However, other analysts looking at a somewhat different group of studies came to the opposite conclusion. 65,66

Quite a few double-blind studies have examined zinc58,67-72 as well as magnesium59,60,73 for preventing low birth weight, with mixed results. Results have been similarly mixed in other controlled trials of folate61,74 and fish oil or one of its fatty acids. 50,65,75Vitamin D and B vitamins have also been proposed, but so far evidence of their usefulness is weak. 54,76

Several decades ago, iron was believed to be helpful in preventing low birth weight. However, a recent large-scale unblinded study of well-nourished women found that routine iron supplements in pregnancy had no effect on birth weight. 77 In addition, as previously noted, iron supplementation in pregnant women who are not anemic may not be good for either mother or baby.

In a double-blind, placebo-controlled study of 1,877 women, use of combined vitamin E and vitamin C failed to prove helpful. 102

Other Uses of Natural Treatments

Gingivitis

A common problem in pregnancy is an increased tendency toward swollen or bleeding gums—a condition known as gingivitis. Two, small, double-blind studies suggest that folatemouthwash may help. However, folate supplements do not appear to be especially effective against gingivitis. 44,45

Healthy Mental Function in Children

Folate has also been studied for its possible role in the intellectual development of children. In one trial, researchers compared children whose mothers took daily folate and iron supplements while pregnant with those who did not. 215 At age 7-9, the children whose mothers did take the combination supplement scored higher on intellectual tests. It is unknown whether or not the folate, iron, or both contributed to this benefit, although the study took place in an area where iron deficiency is common (rural Nepal).

Another study involving 38,954 children found that the use of folate supplementation during early pregnancy reduced the children’s chance of having a severe language delay at 3 years of age. 223

Intrahepatic Cholestasis

A condition called intrahepatic cholestasis may occur during pregnancy, causing jaundice and other complications. Preliminary evidence suggests that the supplement s-adenosylmethionine (SAMe) might be helpful for preventing this. 48,49,103-105

Bladder Infections

A single-blind trial found suggestive evidence that vitamin C, taken at a dose of 100 mg daily, might help prevent bladder infections in pregnancy. 111

Gestational Diabetes

One placebo-controlled study of 30 women suggests that the mineral chromium may be useful for gestational diabetes, the term for diabetes that occurs during pregnancy. 46 Vitamin B 6 has also been proposed for this condition, but evidence in support of its effectiveness is minimal. 47

Prevention of Miscarriage

Low levels of vitamin B 12 may increase risk of miscarriage, and B 12 supplements may help. 93

Depression

A small preliminary study found that fish oil was significantly more effective than placebo at alleviating postpartum depression. 117 However, other studies have failed to find either fish oil or one of its chief components, docosahexaenoic acid (DHA), helpful for preventing perinatal (including postpartum) depression. 98,116 For example, a large study involving 2,399 women found that fish oil capsules—a combination of DHA 800 mg/day and eicosapentaenoic acid (EPA) 100 mg/day—did not prevent postpartum depression. 123

Cognitive and Visual Function in Children

Studies have found evidence that the use of fish oil or DHA and EPA by pregnant women might help support healthy cognitive and visual function in their children. 91,92,106

Anxiety

A review of 8 randomized controlled trials found some evidence that mind-body interventions (eg, hypnotherapy, imagery) may help reduce the anxiety many women feel before and during labor. 222

Herbs and Supplements to Avoid During Pregnancy

For information on this important topic, see Herbs and Supplements to Avoid During Pregnancy and Breastfeeding .

Revision Information

  • 1

    Bergstein NA. Clinical study on the efficacy of O-(beta-hydroxyethyl)rutoside (HR) in varicosis of pregnancy. J Int Med Res. 1975;3:189-193.

  • 2

    Pulvertaft TB. General practice treatment of symptoms of venous insufficiency with oxerutins. Results of a 660 patient multicentre study in the UK. Vasa. 1983;12:373-376.

  • 3

    Unkauf M, Rehn D, Klinger J, et al. Investigation of the efficacy of oxerutins compared to placebo in patients with chronic venous insufficiency treated with compression stockings. Arzneimittelforschung. 1996;46:478-482.

  • 4

    Lohr E, Garanin G, Jesau P, et al. Anti-edemic therapy in chronic venous insufficiency with tendency to formation of edema [translated from German]. MMW Munch Med Wochenschr. 1986;128:579-581.

  • 5

    Steiner M, Hillemanns HG. Investigation of the anti-edemic efficacy of Venostasin® retard [translated from German]. MMW Munch Med Wochenschr. 1986;128:551-552.

  • 6

    Alter H. Drug therapy of varicosis [translated from German]. Z Allgemeinmed. 1973;49:1301-1304.

  • 7

    Friederich HC, Vogelsberg H, Neiss A. Evaluation of internally effective venous drugs [translated from German]. Z Hautkr. 1978;53:369-374.

  • 8

    Cesarone MR, Laurora G, De Sanctis MT, et al. The microcirculatory activity of Centella asiatica in venous insufficiency. A double-blind study [translated from Italian]. Minerva Cardioangiol. 1994;42:299-304.

  • 9

    Pointel JP, Boccalon H, Cloarec M, et al. Titrated extract of Centella asiatica (TECA) in the treatment of venous insufficiency of the lower limbs. Angiology. 1987;38:46-50.

  • 10

    Guilhou JJ, Fevrier F, Debure C, et al. Benefit of a 2-month treatment with a micronized, purified flavonoidic fraction on venous ulcer healing. A randomized, double-blind, controlled versus placebo trial. Int J Microcirc Clin Exp. 1997;17(suppl 1):21-26.

  • 11

    Sohn C, Jahnichen C, Bastert G. Effectiveness of beta-hydroxyethylrutoside in patients with varicose veins in pregnancy [in German; English abstract]. Zentralbl Gynakol. 1995;117:190-197.

  • 12

    Buckshee K, Takkar D, Aggarwal N. Micronized flavonoid therapy in internal hemorrhoids of pregnancy. Int J Gynaecol Obstet. 1997;57:145-151.

  • 13

    Wijayanegara H, Mose JC, Achmad L, et al. A clinical trial of hydroxyethylrutosides in the treatment of haemorrhoids of pregnancy. J Int Med Res. 1992;20:54-60.

  • 14

    Lao TT, Tam K, Chan LY. Third trimester iron status and pregnancy outcome in non-anaemic women; pregnancy unfavourably affected by maternal iron excess. Hum Reprod. 2000;15:1843-1848.

  • 15

    Hemminki E, Rimpela U. A randomized comparison of routine versus selective iron supplementation during pregnancy. J Am Coll Nutr. 1991;10:3-10.

  • 16

    Hemminki E, Merilainen J. Long-term follow-up of mothers and their infants in a randomized trial on iron prophylaxis during pregnancy. Am J Obstet Gynecol. 1995;173:205-209.

  • 17

    Juarez-Vazquez J, Bonizzoni E, Scotti A. Iron plus folate is more effective than iron alone in the treatment of iron deficiency anaemia in pregnancy: a randomized, double blind clinical trial. BJOG. 2002;109:1009-1014.

  • 18

    Laurence KM, James N, Miller MH, et al. Double-blind randomised controlled trial of folate treatment before conception to prevent recurrence of neural-tube defects. Br Med J (Clin Res Ed). 1981;282:1509-1511.

  • 19

    MRC Vitamin Study Research Group. Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. Lancet. 1991;338:131-137.

  • 20

    Rose NC, Mennuti MT. Periconceptional folate supplementation and neural tube defects. Clin Obstet Gynecol. 1994;37:605-620.

  • 21

    Kurtzweil P. How folate can help prevent birth defects. Food and Drug Administration website. Available at: http://www.fda.gov/fdac/features/796%5Ffol.html . Accessed August 22, 2000.

  • 22

    Velie EM, Block G, Shaw GM, et al. Maternal supplemental and dietary zinc intake and the occurrence of neural tube defects in California. Am J Epidemiol. 1999;150:605-616.

  • 23

    Garry D, Figueroa R, Guillaume J, et al. Use of castor oil in pregnancies at term. Altern Ther Health Med. 2000;6:77-79.

  • 24

    Davis L. The use of castor oil to stimulate labor in patients with premature rupture of membranes. J Nurse Midwifery. 1984;29:366-370.

  • 25

    Summers L. Methods of cervical ripening and labor induction. J Nurse Midwifery. 1997;42:71-85.

  • 26

    Steingrub JS, Lopez T, Teres D, et al. Amniotic fluid embolism associated with castor oil ingestion. Crit Care Med. 1988;16:642-643.

  • 27

    Mitri F, Hofmeyr GJ, van Gelderen CJ. Meconium during labour—self-medication and other associations. S Afr Med J. 1987;71:431-433.

  • 28

    Ramnero A, Hanson U, Kihlgren M. et al. Acupuncture treatment during labour—a randomised controlled trial. BJOG. 2002;109:637-644.

  • 29

    Skilnand E, Fossen D, Heiberg E. et al. Acupuncture in the management of pain in labor. Acta Obstet Gynecol Scand. 2002;81:943-948.

  • 30

    Rabl M, Ahner R, Bitschnau M, et al. Acupuncture for cervical ripening and induction of labor at term—a randomized controlled trial. Wien Klin Wochenschr. 2001;113:942-946.

  • 31

    McFarlin BL, Gibson MH, O'Rear J, et al. A national survey of herbal preparation use by nurse-midwives for labor stimulation. Review of the literature and recommendations for practice. J Nurse Midwifery. 1999;44:205-216.

  • 32

    Simpson M, Parsons M, Greenwood J, et al. Raspberry leaf in pregnancy: its safety and efficacy in labor. J Midwifery Womens Health. 2001;46:51-59.

  • 33

    Jones TK, Lawson BM. Profound neonatal congestive heart failure caused by maternal consumption of blue cohosh herbal medication. J Pediatr. 1998;132:550-552.

  • 34

    Gunn TR, Wright IM. The use of black and blue cohosh in labour. N Z Med J. 1996;109:410-411.

  • 35

    Tou JCL, Chen J, Thompson LU. Flaxseed and its lignan precursor, secoisolariciresinol diglycoside, affect pregnancy outcome and reproductive development in rats. J Nutr. 1998;128:1861-1868.

  • 36

    Belew C. Herbs and the childbearing woman: guidelines for midwives. J Nurse Midwifery. 1999;44:231-252.

  • 37

    Signorelli P, Croce P, Dede A. Clinical study on the use of a glucomannan and lactulose association in pregnancy constipation [in Italian; English abstract]. Minerva Ginecol. 1996;48:577-582.

  • 38

    Newall C, Anderson LA, Phillipson JD. Herbal Medicines: A Guide for Health-Care Professionals. London, England: Pharmaceutical Press; 1996.

  • 39

    Dahle LO, Berg G, Hammar M, et al. The effect of oral magnesium substitution on pregnancy-induced leg cramps. Am J Obstet Gynecol. 1995;173:175-180.

  • 40

    Hammar M, Berg G, Solheim F, et al. Calcium and magnesium status in pregnant women. A comparison between treatment with calcium and vitamin C in pregnant women with leg cramps. Int J Vitam Nutr Res. 1987;57:179-183.

  • 41

    Odendaal HJ. Calcium for the treatment of leg cramps during pregnancy [in Afrikaans]. S Afr Med J. 1974;48:780-781.

  • 42

    Hammar M, Larsson L, Tegler L. Calcium treatment of leg cramps in pregnancy. Effect on clinical symptoms and total serum and ionized serum calcium concentrations. Acta Obstet Gynecol Scand. 1981;60:345-347.

  • 43

    Avsar AF, Ozmen S, Soylemez F. Vitamin B1 and B6 substitution in pregnancy for leg cramps [letter]. Am J Obstet Gynecol. 1996;175:233-234.

  • 44

    Pack AR, Thomson ME. Effects of topical and systemic folic acid supplementation on gingivitis in pregnancy. J Clin Periodontol. 1980;7:402-413.

  • 45

    Thomson ME, Pack AR. Effects of extended systemic and topical folate supplementation on gingivitis of pregnancy. J Clin Periodontol. 1982;9:275-280.

  • 46

    Jovanovic L, Gutierrez M, Peterson CM. Chromium supplementation for women with gestational diabetes mellitus. J Trace Elem Exp Med. 1999;12:91-97.

  • 47

    Bennink HJ, Schreurs WH. Improvement of oral glucose tolerance in gestational diabetes by pyridoxine. Br Med J. 1975;3:13-15.

  • 48

    Frezza M, Pozzato G, Chiesa L, et al. Reversal of intrahepatic cholestasis of pregnancy in women after high dose S-adenosyl-L-methionine administration. Hepatology. 1984;4:274-278.

  • 49

    Nicastri PL, Diaferia A, Tartagni M, et al. A randomised placebo-controlled trial of ursodeoxycholic acid and S-adenosylmethionine in the treatment of intrahepatic cholestasis of pregnancy. Br J Obstet Gynaecol. 1998;105:1205-1207.

  • 50

    Olsen SF, Sorensen JD, Secher NJ, et al. Randomised controlled trial of effect of fish-oil supplementation on pregnancy duration. Lancet. 1992;339:1003-1007.

  • 51

    Olsen SF, Secher NJ. A possible preventive effect of low-dose fish oil on early delivery and pre-eclampsia: indications from a 50-year-old controlled trial. Br J Nutr. 1990;64:599-609.

  • 52

    Villar J, Repke JT. Calcium supplementation during pregnancy may reduce preterm delivery in high-risk populations. Am J Obstet Gynecol. 1990;163:1124-1131.

  • 53

    Crowther CA, Hiller JE, Pridmore B, et al. Calcium supplementation in nulliparous women for the prevention of pregnancy-induced hypertension, preeclampsia and preterm birth: an Australian randomized trial. FRACOG and the ACT Study Group. Aust N Z J Obstet Gynaecol. 1999;39:12-18.

  • 54

    Ramakrishnan U, Manjrekar R, Rivera J, et al. Micronutrients and pregnancy outcome: a review of the literature. Nutr Res. 1999;19:103-159.

  • 55

    Cherry FF, Sandstead HH, Rojas P, et al. Adolescent pregnancy: associations among body weight, zinc nutriture, and pregnancy outcome. Am J Clin Nutr. 1989;50:945-954.

  • 56

    Goldenberg RL, Tamura T, Neggers Y, et al. The effect of zinc supplementation on pregnancy outcome. JAMA. 1995;274:463-468.

  • 57

    Jonsson B, Hauge B, Larsen MF, et al. Zinc supplementation during pregnancy: a double blind randomised controlled trial. Acta Obstet Gynecol Scand. 1996;75:725-729.

  • 58

    Caulfield LE, Zavaleta N, Figueroa A, et al. Maternal zinc supplementation does not affect size at birth or pregnancy duration in Peru. J Nutr. 1999;129:1563-1568.

  • 59

    Kovacs L, Molnar BG, Huhn E, et al. Magnesium substitution in pregnancy. A prospective, randomized double-blind study [translated from German]. Geburtsh Frauenheilk. 1988;48:595-600.

  • 60

    Spatling L, Spatling G. Magnesium supplementation in pregnancy. A double-blind study. Br J Obstet Gynaecol. 1988;95:120-125.

  • 61

    Sibai BM, Villar MA, Bray E. Magnesium supplementation during pregnancy: a double-blind randomized controlled clinical trial. Am J Obstet Gynecol. 1989;161:115-119.

  • 62

    Hemminki E, Rimpela U. Iron supplementation, maternal packed cell volume, and fetal growth. Arch Dis Child. 1991;66:422-425.

  • 63

    Villar J, Gulmezoglu AM, de Onis M. Nutritional and antimicrobial interventions to prevent preterm birth: an overview of randomized controlled trials. Obstet Gynecol Surv. 1998;53:575-585.

  • 64

    Atallah AN, Hofmeyr GJ, Duley L. Calcium supplementation during pregnancy for preventing hypertensive disorders and related problems. Cochrane Database Syst Rev. 2002;CD001059.

  • 65

    de Onis M, Villar J, Gulmezoglu M. Nutritional interventions to prevent intrauterine growth retardation: evidence from randomized controlled trials. Eur J Clin Nutr. 1998;52(suppl 1):S83-S93.

  • 66

    Bucher HC, Guyatt GH, Cook RJ, et al. Effect of calcium supplementation on pregnancy-induced hypertension and preeclampsia: a meta-analysis of randomized controlled trials. JAMA. 1996;275:1113-1117.

  • 67

    Goldenberg RL, Tamura T, Neggers Y, et al. The effect of zinc supplementation on pregnancy outcome. JAMA. 1995;274:463-468.

  • 68

    Jonsson B, Hauge B, Larsen MF, et al. Zinc supplementation during pregnancy: a double blind randomised controlled trial. Acta Obstet Gynecol Scand. 1996;75:725-729.

  • 69

    Cherry FF, Sandstead HH, Rojas P, et al. Adolescent pregnancy: associations among body weight, zinc nutriture, and pregnancy outcome. Am J Clin Nutr. 1989;50:945-954.

  • 70

    Simmer K, Lort-Phillips L, James C, et al. A double-blind trial of zinc supplementation in pregnancy. Eur J Clin Nutr. 1991;45:139-144.

  • 71

    Hunt IF, Murphy NJ, Cleaver AE, et al. Zinc supplementation during pregnancy: effects on selected blood constituents and on progress and outcome of pregnancy in low-income women of Mexican descent. Am J Clin Nutr. 1984;40:508-521.

  • 72

    Mahomed K, James DK, Golding J, et al. Zinc supplementation during pregnancy: a double blind randomised controlled trial. BMJ. 1989;299:826-830.

  • 73

    Onwude JL, Lilford RJ, Hjartardottir H, et al. A randomised double blind, placebo controlled trial of fish oil in high risk pregnancy. Br J Obstet Gynaecol. 1995;102:95-100.

  • 74

    Bulstra-Ramakers MT, Huisjes HJ, Visser GH. The effects of 3g eicosapentaenoic acid daily on recurrence of intrauterine growth retardation and pregnancy induced hypertension. Br J Obstet Gynaecol. 1995;102:123-126.

  • 75

    Brooke OG, Brown IRF, Bone CDM, et al. Vitamin D supplements in pregnant Asian women: effects on calcium status and fetal growth. Br Med J. 1980;280:751-754.

  • 76

    Doyle W, Crawford MA, Wynn AH, et al. The association between maternal diet and birth dimensions. J Nutr Med. 1990;1:9-17.

  • 77

    Hemminki E, Rimpela U. Iron supplementation, maternal packed cell volume, and fetal growth. Arch Dis Child. 1991;66:422-425.

  • 78

    Ernst E. Herbal medicinal products during pregnancy: are they safe? BJOG. 2002;109:227-235.

  • 79

    Zatuchni GI, Colombi DJ. Bromelains therapy for the prevention of episiotomy pain. Obstet Gynecol. 1967;29:275-278.

  • 80

    Howat RC, Lewis GD. The effect of bromelain therapy on episiotomy wounds—a double-blind controlled clinical trial. J Obstet Gynaecol Br Commonw. 1972;79:951-953.

  • 81

    Soule SD, Wasserman HC, Burstein R. Oral proteolytic enzyme therapy (Chymoral) in episiotomy patients. Am J Obstet Gynecol. 1966;95:820-823.

  • 82

    Martin AA, Schauble PG, Rai SH, et al. The effects of hypnosis on the labor processes and birth outcomes of pregnant adolescents. J Fam Pract. 2001;50:441-443.

  • 83

    Freeman RM, Macaulay AJ, Eve L, et al. Randomised trial of self hypnosis for analgesia in labour. Br Med J (Clin Res Ed). 1986;292:657-658.

  • 84

    Jenkins MW, Pritchard MH. Hypnosis: practical applications and theoretical considerations in normal labour. Br J Obstet Gynaecol. 1993;100:221-226.

  • 85

    Brann LR, Guzvica SA. Comparison of hypnosis with conventional relaxation for antenatal and intrapartum use: a feasibility study in general practice. J R Coll Gen Pract. 1987;37:437-440.

  • 86

    Chang MY, Wang SY, Chen CH. Effects of massage on pain and anxiety during labour: a randomized controlled trial in Taiwan. J Adv Nurs. 2002;38:68-73.

  • 87

    Field T, Hernandez-Reif M, Taylor S, et al. Labor pain is reduced by massage therapy. J Psychosom Obstet Gynaecol. 1997;18:286-291.

  • 88

    Field T, Hernandez-Reif M, Hart S, et al. Pregnant women benefit from massage therapy. J Psychosom Obstet Gynaecol. 1999;20:31-38.

  • 89

    Dale A, Cornwell S. The role of lavender oil in relieving perineal discomfort following childbirth: a blind randomized clinical trial. J Adv Nurs. 1994;19:89-96.

  • 90

    Smuts CM, Huang M, Mundy D, et al. Plasse T, Major S, Carlson SE. A randomized trial of docosahexaenoic acid supplementation during the third trimester of pregnancy. Obstet Gynecol. 2003;101:469-479.

  • 91

    Helland IB, Smith L, Saarem K, et al. Maternal supplementation with very-long-chain n-3 fatty acids during pregnancy and lactation augments children's IQ at 4 years of age. Pediatrics. 2003;111:E39-E44.

  • 92

    Lauritzen L, Hansen HS, Jorgensen MH, et al. The essentiality of long chain n-3 fatty acids in relation to development and function of the brain and retina. Prog Lipid Res. 2001;40:1-94.

  • 93

    Reznikoff-Etievant MF, Zittoun J, Vaylet C, et al. Low vitamin B 12 level as a risk factor for very early recurrent abortion. Eur J Obstet Gynecol Reprod Biol. 2002;104:156-159.

  • 94

    Nesheim BI, Kinge R, Berg B, et al. Acupuncture during labor can reduce the use of meperidine: a controlled clinical study. Clin J Pain. 2003;19:187-191.

  • 95

    Steyn PS, Odendaal HJ, Schoeman J, et al. A randomised, double-blind placebo-controlled trial of ascorbic acid supplementation for the prevention of preterm labour. J Obstet Gynaecol. 2003;23:150-155.

  • 96

    Habek D, Cerkez Habek J, Jagust M. Acupuncture conversion of fetal breech presentation. Fetal Diagn Ther. 2003;18:418-421.

  • 97

    Neri I, Airola G, Contu G, et al. Acupuncture plus moxibustion to resolve breech presentation: a randomized controlled study. J Matern Fetal Neonatal Med. 2004;15:247-252.

  • 98

    Llorente AM, Jensen CL, Voigt RG, et al. Effect of maternal docosahexaenoic acid supplementation on postpartum depression and information processing. Am J Obstet Gynecol. 2003;188:1348-1353.

  • 99

    Knudsen VK, Hansen HS, Osterdal ML, et al. Fish oil in various doses or flax oil in pregnancy and timing of spontaneous delivery: a randomised controlled trial. BJOG. 2006 Mar 27. [Epub ahead of print]

  • 100

    Casanueva E, Ripoll C, Tolentino M, et al. Vitamin C supplementation to prevent premature rupture of the chorioamniotic membranes: a randomized trial. Am J Clin Nutr. 2005;81:859-863.

  • 101

    Borna S, Borna H, Daneshbodie B, et al. Vitamins C and vitamin E in the latency period in women with preterm premature rupture of membranes. Int J Gynaecol Obstet. 2005 May 19. [Epub ahead of print]

  • 102

    Rumbold AR, Crowther CA, Haslam RR, et al. Vitamins C and E and the risks of preeclampsia and perinatal complications. N Engl J Med. 2006;354:1796-806.

  • 103

    Binder T, Salaj P, Zima T, et al. Ursodeoxycholic acid, S-adenosyl-L-methionine and their combinations in the treatment of gestational intrahepatic cholestasis (ICP)]. Ceska Gynekol. 2006;71:92-98.

  • 104

    Burrows RF, Clavisi O, Burrows E. Interventions for treating cholestasis in pregnancy. Cochrane Database Syst Rev. 2001;CD000493.

  • 105

    Roncaglia N, Locatelli A, Arreghini A, et al. A randomised controlled trial of ursodeoxycholic acid and S-adenosyl-l-methionine in the treatment of gestational cholestasis. BJOG. 2003;111:17-21.

  • 106

    Decsi T, Koletzko B. N-3 fatty acids and pregnancy outcomes. Curr Opin Clin Nutr Metab Care. 2005;8:161-166.

  • 107

    Harper TC, Coeytaux RR, Chen W et al. A randomized controlled trial of acupuncture for initiation of labor in nulliparous women. J Matern Fetal Neonatal Med. 2006;19:465-470.

  • 108

    Goh YI, Bollano E, Einarson TR, et al. Prenatal multivitamin supplementation and rates of congenital anomalies: a meta-analysis. J Obstet Gynaecol Can. 2006;28:680-689.

  • 109

    Hantoushzadeh S, Alhusseini N, Lebaschi AH. The effects of acupuncture during labour on nulliparous women: a randomised controlled trial. Aust N Z J Obstet Gynaecol. 2007;47:26-30.

  • 110

    Olsen SF, Osterdal ML, Salvig JD, et al. Duration of pregnancy in relation to fish oil supplementation and habitual fish intake: a randomised clinical trial with fish oil. Eur J Clin Nutr. 2007 Feb 7. [Epub ahead of print]

  • 111

    Ochoa-Brust GJ, Fernandez AR, Villanueva-Ruiz GJ, et al. Daily intake of 100 mg ascorbic acid as urinary tract infection prophylactic agent during pregnancy. Acta Obstet Gynecol Scand. 2007;86:783-787.

  • 112

    Zhou SJ, Gibson RA, Crowther CA, et al. Should we lower the dose of iron when treating anaemia in pregnancy? A randomized dose-response trial. Eur J Clin Nutr. 2007 Oct 10. [Epub ahead of print]

  • 113

    Selmer-Olsen T, Lydersen S, Morkved S. Does acupuncture used in nulliparous women reduce time from prelabour rupture of membranes at term to active phase of labour? A randomised controlled trial. Acta Obstet Gynecol Scand. 2007 Oct 25. [Epub ahead of print]

  • 114

    Bech BH, Obel C, Henriksen TB, et al. Caffeine and birth weight—randomised double blind trial. Ugeskr Laeger. 2007;169:3300-3302.

  • 115

    Martensson L, Stener-Victorin E, Wallin G. Acupuncture versus subcutaneous injections of sterile water as treatment for labour pain. Acta Obstet Gynecol Scand. 2008;87:171-177.

  • 116

    Rees AM, Austin MP, Parker GB. Omega-3 fatty acids as a treatment for perinatal depression: randomized double-blind placebo-controlled trial. Aust N Z J Psychiatry. 2008;42:199-205.

  • 117

    Su KP, Huang SY, Chiu TH, et al. Omega-3 fatty acids for major depressive disorder during pregnancy: results from a randomized, double-blind, placebo-controlled trial. J Clin Psychiatry. 2008 Mar 18.

  • 118

    van den Berg I, Bosch JL, Jacobs B, et al. Effectiveness of acupuncture-type interventions versus expectant management to correct breech presentation: A systematic review. Complement Ther Med. 2008;16:92-100.

  • 119

    Elden H, Fagevik-Olsen M, Ostgaard HC, et al. Acupuncture as an adjunct to standard treatment for pelvic girdle pain in pregnant women: randomised double-blinded controlled trial comparing acupuncture with non-penetrating sham acupuncture. BJOG. 2008;115:1655-1668.

  • 120

    Smith CA, Crowther CA, Collins CT, et al. Acupuncture to induce labor: a randomized controlled trial. Obstet Gynecol. 2008;112:1067-1074.

  • 121

    Wu HC, Liu YC, Ou KL, et al. Effects of acupuncture on post-cesarean section pain. Chin Med J (Engl). 2009;122:1743.

  • 122

    Cho SH, Lee H, Ernst E. Acupuncture for pain relief in labour: a systematic review and meta-analysis. BJOG. 2010;117(8):907.

  • 123

    Makrides M, Gibson RA, McPhee AJ, et al. Effect of DHA supplementation during pregnancy on maternal depression and neurodevelopment of young children: a randomized controlled trial. JAMA. 2010;304(15):1675-1683.

  • 214

    De-Regil L, Fernandez-Gaxiola A, Dowswell T, Pena-Rosas J. Effects and safety of periconceptional folate supplementation for preventing birth defects. Cochrane Database Syst Rev. 2010;(10):CD007950.

  • 215

    Christian P, Murray-Kolb LE, Khatry SK, et al. Prenatal micronutrient supplementation and intellectual and motor function in early school-aged children in Nepal. JAMA. 2010;304(24):2716-2723.

  • 216

    Rumbold A, Middleton P, Pan N, Crowther C. Vitamin supplementation for preventing miscarriage. Cochrane Database Syst Rev. 2011;(1):CD004073.

  • 217

    Hjelmstedt A, Shenoy ST, Stener-Victorin E, et al. Acupressure to reduce labor pain: a randomized controlled trial. Acta Obstet Gynecol Scand. 2010;89(11):1453-1459.

  • 218

    Mackenzie IZ, Xu J, Cusick C, et al. Acupuncture for pain relief during induced labour in nulliparae: a randomised controlled study. BJOG. 2011;118(4):440-447.

  • 219

    Burns E, Zobbi V, Panzeri D, Oskrochi R, Regalia A. Aromatherapy in childbirth: a pilot randomised controlled trial. BJOG. 2007;114(7):838-844.

  • 220

    Smith C, Collins C, Crowther C. Aromatherapy for pain management in labour. Cochrane Database Syst Rev. 2011;(7):CD009215.

  • 221

    Smith C, Collins C, Crowther C, Levett K. Acupuncture or acupressure for pain management in labour. Cochrane Database Syst Rev. 2011;(7):CD009232.

  • 222

    Marc I, Toureche N, Ernst E, et al. Mind-body interventions during pregnancy for preventing or treating women's anxiety. Cochrane Database Syst Rev. 2011;(7):CD007559.

  • 223

    Roth C, Magnus P, Schjølberg S, et al. Folic acid supplements in pregnancy and severe language delay in children. JAMA. 2011;306(14):1566-1573.

  • 224

    Ma W, Bai W, Lin C, et al. Effects of Sanyinjiao (SP6) with electroacupuncture on labour pain in women during labour. Complement Ther Med. 2011;19 Suppl 1:S13-8.

  • 225

    Marra C, Pozzi I, Ceppi L, Sicuri M, Veneziano F, Regalia AL. Wrist-ankle acupuncture as perineal pain relief after mediolateral episiotomy: a pilot study. J Altern Complement Med. 2011;17(3):239-241.

  • 226

    Smith CA, Levett KM, Collins CT, Jones L. Massage, reflexology and other manual methods for pain management in labour. Cochrane Database Syst Rev. 2012;2:CD009290.