Basic Reproduction

From www.preconception.com.au

Adapted from Sydney IVF www.sydneyivf.com.au

Female reproductive anatomy and physiology

Hormones

Hormones control the highly complex sequence of events leading to ovulation and those that prepare the endometrium for a potential pregnancy.

The main ones are – follicle stimulating hormone (FSH), luteinizing hormone (LH), oestrogen and progesterone. Other hormones that affect the reproductive system include testosterone and prolactin.

The pituitary gland in the brain produces FSH and LH that convey messages to the ovary. The actions of these hormones result in three phases in the monthly menstrual cycle.

Menstrual cycle

Adapted from Sydney IVF www.sydneyivf.com.au

Understanding your cycle is key to conceiving. Through detecting cervical mucus changes

and measuring your basal temperature, also known as Natural Family Planning, you can identify any symptoms that may indicate irregularity or problems with ovulation. It helps you 'target' ovulation and thus make conception easier. The Path to Pregnancy – Know your cycle will provide you with all you need to understand your cycle.

Your ovulation can be affected by: stress - medications - alcohol, cigarettes and other social drugs - travel - illness and ill health - dieting, weight changes and being overweight - excessive exercise - perimenopause - PCOS or other reproductive conditions

Coming off the Pill

If you have been on the oral contraceptive pill (The Pill) for years, your 'true' cycle will only reveal itself once you are off it. Sometimes, establishing a regular cycle can take many months and fertility may be affected for up to a year. In most cases it is only a matter of time, however in others a delay in establishing a regular cycle may indicate an underlying hormonal problem or nutritional concern.

The Pill can cause decreased levels of vitamins B2, B6, B12, C and folic acid and zinc. Levels of these essential nutrients can take months to recover (as has been shown in the case of folate) so it is recommended to avoid conceiving immediately after coming off the Pill. You need some time to build up healthy levels of essential nutrients for conception. For example, it can take up to 5 months to build up your iodine levels.

Intercourse TimingSperm can last for up to 5 days in the female reproductive tract, but the egg only lasts for 12-24 hours. In a study of healthy women planning to become pregnant nearly all pregnancies were attributed to intercourse during a six day period ending on the day of ovulation.

Probability of conception after a single act of intercourse in relation to ovulation

Time to conception

The chance of conceiving in one cycle is 20-25% in normal couples.

After 6 cycles with intercourse in the fertile window, 80% of couples are expected to have conceived. After that, every second couple (10%) is probably seriously subfertile.

However, of these couples who keep on trying after a year, nearly 55% will have a baby in the following 36 months.

After 4 years 5% of the couples are definitely infertile with a nearly zero chance of becoming spontaneously pregnant in the future.

It will take longer to conceive if you are Over 35 years of age. See Figure 2. Overweight or obese (even if you have a normal

menstrual cycle). Drink alcohol, even moderately (5 or less drinks per

week). Smoke cigarettes. Consume caffeine (3 or more cups of coffee per day). Are stressed. Have irregular cycles or other reproductive problems

Figure 2: Natural Conception Rates and Maternal Age

Age Related Facts

The median age of all mothers giving birth has increased from 26.9 years in 1983 to 30.5 years in 2003. As a result, there are more first time mothers in the age group 30-39 years. As you can see from the graph below, a normal woman's chance of conceiving each month decreases with age.

Figure 1: Probability of pregnancy following intercourse on a given day relative to ovulation for women of average fertility aged 19–26, 27–29, 30–34 and 35–39 years.

                                                                                                                               

The reason for this decline appears to be a combination of a decline in egg quantity and quality, decreased uterine health, hormonal changes and less frequent intercourse with age.

Male Reproductive Health

The saying "it takes two to tango" definitely applies to preconception care and fertility. Sperm health is a reflection of a man’s general health and as such, preconception care is essential for the prospective father.

All the issues affecting female fertility also affect male fertility. For example, with age, sperm production and quality is reduced. The hormonal imbalance and excess heat associated with being overweight significantly reduces fertility in men. Couples have a high risk of reduced fertility if they are both either overweight or obese.

Probability of pregnancy following intercourse for women of average fertility with partners of the same age or 5 years older

Men’s sperm quality also starts to decrease from age 35, which affects both a couple’s chance of conceiving and the health of the pregnancy.

Preconception Care (PCC)

is about taking care of your health in preparation for a pregnancy. It is a commonsense approach to ensuring both of you have done everything you can to have not only a baby, but a healthy one.

It is now widely accepted that lifestyle factors impact significantly on fertility. These include the effects of age, illness, medications, toxins, social drugs, poor nutrition, and weight problems. Many women do not find out they are pregnant until several weeks after conception. Those early weeks are key for the baby. Some medicines, illnesses, toxins or bad habits (such as smoking and drinking alcohol) can affect your baby before you know you are pregnant. To be safe, experts say you should act like you are pregnant if you are trying to get pregnant.

Timeframe

Women are born with all their eggs, which are stored in an immature state in the ovaries. A group of eggs begin developing and maturing 3 months prior to an ovulation. As a result, this group is affected by nutritional deficiencies, illness and toxin exposure for approximately 100 days leading up to ovulation.

Men’s health

Sperm take on average 72 days to develop, mature, be stored and finally ejaculated. Sperm development occurs in 16 day cycles, needing approximately 5 cycles to produce one sperm. Because of this 3-month development period, illness or poor health, toxic exposure and nutritional deficits that were present 2 months ago may affect today’s ejaculation, regardless of a man's health today.