Much research has been done, however, in the last 30 years, to answer these questions. Here is what happens during the menstrual cycle and pregnancy as it relates to hCG.

There are three phases of the menstrual cycle:

1. Follicular phase: the pituitary gland increases release of follicle stimulating hormone (FSH) and luteinizing hormone (LH). FSH stimulates growth of follicles in the ovary and prompts the release of estrogen from the ovary. Estrogen, in turn, causes the thickening of the endometrium. One follicle will mature and release an ovum (egg). LH is secreted mid-cycle, and stimulates the release of that ovum from the follicle in the ovary.

2. Ovulatory phase: The ovum is released from the follicle and makes its way down the fallopian tubes toward the uterus, perhaps to be fertilized along the way. There are increased levels of LH during this phase. An ovulation prediction kit will detect a surge in LH about 1-2 days before ovulation.

3. Luteal phase: this covers the time from ovulation through the next menstrual period. Following ovulation the follicle that released the ovum closes and becomes the corpus luteum. LH sustains the corpus luteum until, in the event of pregnancy, it is supported by hCG. Increased production of estrogen and progesterone follow. Both hormones prepare the endometrium for the implantation of a fertilized egg.

If pregnancy does not occur: the corpus luteum regresses, the hormone levels of progesterone and estrogen go back down, and the breakdown of the endometrium causes menstrual bleeding. The corpus luteum will last 10 to14 days and then die. If pregnancy does occur, the corpus luteum begins to produce hCG. This hormone stimulates the corpus luteum, preventing it from dying in early pregnancy. The corpus luteum produces estrogen and progesterone in the early part of the pregnancy, and is therefore vital for maintaining that pregnancy. Later, these hormones will be produced by the placenta. Therefore, if the corpus luteum does not function early on, the uterine lining will not support a pregnancy. Menstruation will occur and the pregnancy will miscarry. hCG is produced by the placenta in pregnancy, specifically by what is called the trophoblast of the chorionic villi. Levels are higher in the first trimester and then decrease as other hormones take over the job of protecting the embryo and, later, the fetus.If, for any reason, the embryo does not develop normally, the trophoblast will lose its capacity to sustain the rapid rise in hCG necessary to maintain the corpus luteum. To force support of the corpus luteum and sustain a pregnancy, hCG can be used clinically as part of IVF (in-vitro fertilization) and other infertility programs.

Information

Here are some birth control methods for you to consider

CONDOMS

• A condom is a thin latex or polyurethane sheath. The male condom is placed around the erect penis. The female condom is placed inside the vagina before intercourse. Semen collects inside the condom, which must be carefully removed after intercourse.
• Condoms are available in most drug and grocery stores. Some family planning clinics offer free condoms.
• Latex condoms help prevent HIV and other STDs. Polyurethane condoms may give some protection against STDs, but they are not as effective as latex ones.
• About 14 pregnancies occur over 1 year out of 100 couples using male condoms, and about 21 pregnancies occur over 1 year out of 100 couples using female condoms. They are more effective when spermicide is also used.
• Risks include irritation and allergic reactions, particularly to latex.
• Condoms are used only once.

DIAPHRAGM AND CERVICAL CAP

• A diaphragm is a flexible rubber cup that is filled with spermicidal cream or jelly.
• It is placed into the vagina over the cervix, before intercourse, to prevent sperm from reaching the uterus.
• It should be left in place for 6 to 8 hours after intercourse.
• Diaphragms must be prescribed by a woman’s health care provider, who determines the correct type and size of diaphragm for the woman.
• About 5-20 pregnancies occur over 1 year in 100 women using this method, depending on proper use.
• A similar, smaller device is called a cervical cap.
• Risks include irritation and allergic reactions to the diaphragm or spermicide, and urinary tract infection. In rare cases, toxic shock syndrome may develop in women who leave the diaphragm in too long. A cervical cap may cause an abnormal Pap test.

COMBINATION BIRTH CONTROL PILLS

• Also called oral contraceptives or just the “pill”, this method combines the hormones estrogen and progestin to prevent ovulation.
• A health care provider must prescribe birth control pills.
• The method is highly effective if the woman remembers to take her pill consistently each day.
• Women who experience unpleasant side effects on one type of pill are usually able to adjust to a different type.
• About 2 to 3 pregnancies occur over 1 year out of 100 women who never miss a pill.
• Birth control pills may cause a number of side effects including: Dizziness, irregular menstrual cycles, nausea, mood changes, and weight gain. In rare cases, they can lead to high blood pressure, blood clots, heart attack, and stroke.

• Risks include irregular bleeding, weight gain, and breast tenderness.

THREE-MONTH PILL (SEASONALE)

• In 2003, the FDA-approved an estrogen and progestin pill called Seasonale. It is taken for three straight months, followed by one week of inactive pills.
• A women gets her period about four times a year, during the 13th week of her cycle.
• Seasonale is available by prescription.
• Fewer than 2 out of 100 women per year get pregnant using this method.
• The risks are similar to other birth control pills. Some women may have more spotting between periods.
• The pills must be taken daily, preferably at the same time of day.

SKIN PATCH

• The skin patch (Ortho Evra) is placed on your shoulder, buttocks, or other convenient location. It continually releases progestin and estrogen. Like other hormone methods, a prescription is required.
• The patch provides weekly protection. A new patch is applied each week for three weeks, followed by one week without a patch.
• About 1 pregnancy occurs over 1 year out of 100 women using this method.
• Risks are similar to combined birth control pills.

EMERGENCY (”MORNING AFTER”) BIRTH CONTROL

• The “morning after” pill consists of two doses of hormone pills taken as soon as possible within 72 hours after unprotected intercourse.
• A prescription is required.
• The pill may prevent pregnancy by temporarily blocking eggs from being produced, by stopping fertilization, or keeping a fertilized egg from becoming implanted in the uterus.
• The morning after pill may be appropriate in cases of rape; having a condom break or slip off during sex; missing two or more birth control pills during a monthly cycle; and having unplanned sex.
• Risks include nausea, vomiting, abdominal pain, fatigue, and headache.

CALL YOUR HEALTH CARE PROVIDER IF:

• You would like to further information about birth control options.
• You want to start using a specific method of birth control that requires a prescription or needs to be inserted by a health care provider.
• You have had unprotected intercourse or method failure (for example, a broken condom) within the past 72 hours, and you do not want to become pregnant.