Red Raspberry Leaf
Available as a tea, loose herb, or extract, red raspberry leaf is one of the safest and most widely used herbs for maintaining a healthy pregnancy. Because it contains the nutrient fragrine, red raspberry leaf strengthens and tones the uterus to prepare it for labor, and may help to enable a newly fertilized egg to properly embed itself in the uterus. Many American nurse-midwives recommend the use of red raspberry leaf, and the renowned herbalist Susan Weed recommends its use in Wise Women Herbal for the Childbearing Year.
Folic Acid
According to the March of Dimes and the FDA, supplementation with the B-vitamin folic acid can decrease the risk of miscarriage, neural tube defects, and preterm labor. It is most important immediately before pregnancy and during the first month following conception. There is no known toxic level for folic acid, and taking as much as 4000 mg may be ideal if you are trying to conceive.
Wild Yam
The renowned American midwife Anne Frye, author of Holistic Midwifery, recommends that women take a specific combination of supplements, containing wild yam, if they are at high risk for miscarriage or failed implantation. Wild yam's natural, progeterone-like qualities have been suggested to increase fertility and prevent early miscarriage. Wild yam has also been used to treat fibroids, a common cause of fertility issues.
Fish Oil
Fish oil's use before and during pregnancy is becoming an increasing topic of interest in obstetrics and pediatrics. Dozens of carefully controlled, published, and peer-reviewed studies have shown that the omega-3 fatty acids found in fish oil are effective in preventing miscarriage, controlling blood pressure, reducing the incidence of preterm labor, and preventing birth defects. Even more attention has been drawn to fish oil's ability to increase the IQ in babies whose mothers take it during pregnancy. This had led the governments of several EU nations to recommend that all women who are pregnant or trying to conceive take fish oil supplements.
Chaste Berry
Also known as vitex, chaste berry has been long believed to regulate cycles and encourage regular, healthy ovulation. Unlike other cycle-regulating herbs, chaste tree berry does not stimulate strong contractions and is not believed to cause miscarriage. Instead, it acts solely on the body's progesterone stores, which are often depleted in women who have PCOS or other fertility problems, which can assist in conceiving and maintaining a pregnancy. It is widely recommended by many herbalists and midwives.