Fertility treatments have evolved considerably over the years. A couple of generations ago, if a couple wasn't able to have children, little could be done for them. Today, we have numerous options available to aid in the process of conception. Natural progesterone is one of those options, and it is an often used supplement to improve the outcome fertility treatments.
Function
Progesterone is an important hormone during a woman's menstrual cycle. Once ovulation occurs, the corpus luteum releases progesterone to help thicken the lining of the uterus. The purpose is to prepare the uterus' endometrial lining for implantation of a fertilized egg. This is called the luteal phase. If the ovary does not become fertilized, the progesterone production is reduced and the uterine lining is shed.
Types
There are several types of natural progesterone available. Oral progesterone is used as support during the luteal phase. Suppositories and progesterone gels are also available and are inserted into the vagina for immediate contact with the uterus to support the endometrium during the luteal phase. Lastly, injectable progesterone is considered the best form and requires a large bore needle for intramuscular shots.
Effects On Fertility
Oral progesterone is considered the least effective, because it quickly breaks down in the stomach. However, a study published in the "Fertility And Sterility" journal compared intramuscular progesterone supplements and oral progesterone during in vitro fertilization and found the clinical pregnancy rate for oral progesterone was 45.8 percent. Intramuscular progesterone is often preferred by doctors for infertility treatment and the same study found the clinical pregnancy rate for intramuscular progesterone was 57.9 percent. Separate papers comparing progesterone in "Human Reproduction" journal found that vaginal progesterone produced a lower rate of miscarriage and a similar live birth rate as intramuscular progesterone.
Misconceptions
Though not previously mentioned, another source of progesterone is over-the-counter progesterone creams. A study in "Clinical Endocrinology" reported that pre-menopausal women using 64 mg of topical progesterone cream had only increased salivary levels of progesterone and no increase in blood serum levels. They concluded that higher doses may be required to affect the endometrium. For progesterone to affect fertility it must be present in the endometrial lining of the uterus. No studies have been conducted using topical progesterone cream to treat fertility.
Considerations
Progesterone supplements for fertility are not without side effects. Oral progesterone is metabolized in the liver causing more side effects, such as feeling tired or dizzy. Vaginal progesterone such as suppositories and gels can cause vaginal irritation, a buildup of gel in the vagina from the serum carrying the progesterone and some women are sensitive to the serums. Injectable progesterone is suspended in an oil base that some women are allergic to. It also requires a painful large bore--20 or 22-gauge--needle due to the viscosity of the oils.
References
- Conceiving Concepts: Progesterone
- "Fertility And Sterility"; Licciardi, F., et al; Oral versus intramuscular progesterone for in vitro fertilization: a prospective randomized study; April; 1999
- "Human Reproduction Update"; Tavaniotou, A. et al; Comparison between different routes of progesterone administration as luteal phase support in infertility treatments; March; 2000
- Conceiving Concepts: Types of Progesterone
