Throughout the Western World birth rates have been falling, most dramatically in Western Europe. By 1998 total fertility rates (TFR) in Europe declined to levels as low as 1.1 children per woman in Bulgaria, 1.2 in Spain and Italy, 1.3 in Germany and Greece, and 1.6 in Britain and France. A negative birth rate is defined as when women bear less than two children on average, as this is the number necessary to numerically replace their parents and maintain a country’s population without the need for immigration.
In Europe only Albania, Ireland, Iceland, Macedonia and the Faroe Islands have managed to stave off a negative birth rate. In 1998 the total fertility rate (children per woman) for the European Union was 1.45, which is low in comparison to non-European nations such as Turkey (2.38), the USA (2.07) or India (3.24). Europe is not alone however, as Japan has seen a similar decline in fertility (TFR of 1.46) in recent years.
Life and technology have become every more complex, demanding ever higher levels of training and longer periods of education. Given that raising a child to educated independence takes longer and costs hundreds of thousands of Euros, then it should perhaps come as no surprise that the university-educated classes are deciding to have fewer children and to do so later in life. Indeed they may have to wait until their mid or late thirties to pay off their debts and achieve comparative affluence. However male fertility and testosterone levels start to fall at around 27 years of age, and female fertility may begin to decline even earlier, possibly as early as 25. Women between the ages of 19 and 26 have around a 50% chance of becoming pregnant in any one menstrual cycle, falling to around 40% for women aged between 27 to 34, and to less than 30% for women between 35 and 39 with a partner of the same age, decreasing still further to around 20% if the partner is five years older.
The American Society for Reproductive Medicine argues that while the age-related decline in female fertility has been well demonstrated, almost 90% of women overestimated by five to ten years the age at which their fertility begins to decline. This may be due to a social educational system that prioritises birth control and contraception, yet does not publicise age-dependent changes in human fertility.
Other social and economic reasons for delaying or avoiding having children include an absence of child-care, oppressive labour laws, an absence of part-time work options, and the lack of subsidised housing for young parents. Educated women find that their career patterns do not encourage them to have an early break to raise children. However the decline in European fertility cannot be firmly correlated with such variables as urbanization, education or income. Whether the decline in fertility may also be attributed to other social and economic trends such as increases in the number of women entering employment after the Second World War, a decrease in employment levels and disposable income amongst men, increased stress, or an increase in the real cost of raising children is unclear.
Male fertility is defined in terms of the number and viability of sperm produced in an ejaculate of semen, typically some 2-5 milliliters. More than 20 million sperm per milliliter is considered normal provided over 50% of the sperm show motility, and 30% have a normal form or morphology. However millions of men may not maintain healthy fertility levels due to a myriad of factors including stress, smoking, drinking, a compromised immune system, exposure to environmental chemicals, aging, or raising sperm temperature above 35C. In about fifteen percent of couples fertility will be solely a male problem.
For instance infections of the urethra can cause male infertility by irritating the genital tract, obstructing the release of sperm, or by hindering sperm production. Many recreational drugs can reduce fertility including alcohol (which reduces sperm count and quality), tobacco (which may reduce sperm motility), and marijuana, anabolic steroids and opiates such as heroin and morphine (which may affect hormone production). Researchers also suggest that men who drink too much coffee may have an increased incidence of abnormal sperm, often with reduced motility.
Many prescribed drugs also reduce fertility, including anti-cancer drugs and antibiotics.
Many studies have revealed falling sperm counts and declining male fertility, possibly due to environmental pollution. The number and concentration of environmental toxins and radiation has increased dramatically over the past fifty years. Some of these have been clearly demonstrated to have effects upon fertility. Alkylphenols, used as industrial and domestic detergents, dioxins, used in the paper industry, and the organochlorine pesticides such as DDT are so-called hormonal disrupters, as are the phthalates used in the plastics industry, and also the naturally occurring plant phyto-oestrogens, and vinclozolin, a fungicide used on foods. Hormones levels dictate sexual behaviour and fertility in both men and women, and male fertility can decline where insufficient testosterone is produced or there is an excessive production of prolactin or stress hormones. As hormones determine our reproductive cycles, sexuality and fertility, the dramatic increase in environmental estrogens and other hormone disrupters may have a lot to answer for in explaining recent declines in fertility throughout the grain belt of Europe. Indeed the widespread explosion in the use of the pesticide DDT correlates particularly uncomfortably with the decline in the European birth rate.
Alarm bells started to ring when a study of the decline of alligator and black panther populations in Florida revealed that many male alligators had smaller penises than normal, and that female alligators had excessive and abnormal ovulation. An investigation revealed that a massive spillage of DDT (dichloro-diphenyl-trichloroethane) into Lake Apopka in 1980 had disrupted the animals' reproductive systems.
Florida was not the only disaster area as various fish species in the Great Lakes showed feminization and hermaphroditism (physical characteristics of both sexes) in males. The concentrations of both DDT and PCBs (polychlorinated biphenyls) in the Great Lakes are known to be high. Although DDT was eventually banned from use in the 1970s, its manufacture and use continues unabated. More worrying is the observation that the principal metabolite derived from DDT is called DDE, a xenoestrogen that lingers in fat deposits in the human body for decades.
As early as 1993 decreasing sperm counts in men were correlated with the growing abundance of environmental estrogens. Corroborating evidence came from Michigan where the accidental contamination of cattle feed with PCBs in 1973 resulted in high concentrations in the breast milk of women who consumed the beef. It was noted by the medical community that the sons of these mothers exhibited defective genitalia. As though this were not evidence enough, the growing number of environmental estrogens within the environment has been linked to the earlier onset of puberty in girls. Whilst the normal age of the onset of puberty is between 12 and 13, recent studies in the United States, UK, Canada, Puerto Rico and New Zealand have indicated that 7% of white and 27% of coloured girls may exhibit physical signs of puberty by the age of seven, and by the age of 10, these figures increase to 68% and 95%, respectively. Whether this phenomenon of early onset of puberty is due to environmental estrogens in plastics or synthetic steroid hormones in meat and milk products is unclear. As female fertility is set into overdrive, male fertility is reduced by these compounds, causing an imbalance in human fertility. As child obesity is on the increase, and environmental estrogens are known to accumulate in fat tissue, this may provide yet another factor. Plant ‘Phytoestrogens’ are present in flax seeds, soybeans, legumes, some herbs, sunflower seeds and alfalfa sprouts. However these are generally weaker than natural estrogens and are generally not stored within the body, but are readily metabolized and excreted, pointing the finger at the synthetic estrogens. However it is not just what we eat that gives cause for concern. Estrogen-like activity has also been found in various lotions such as sunscreens and cosmetics, including the parabens family which may cross the skin. Sceptics who doubt the cumulative impact of environmental estrogens upon human fertility have clearly not done their homework.
Many causes of male and female infertility can be successfully overcome using a range of treatment options. Once infertility testing has been completed, your doctor will review the results and recommend a treatment plan. This plan may include one or more treatment alternatives including ovulation induction to enhance the production of healthy eggs, intrauterine inseminations (IUI) to enhance the sperms ability to fertilize the egg, or more advanced care using ‘Assisted Reproductive Technologies’ such as IVF.
The past decade has seen an explosion in the number of couples seeking IVF treatment. From 1997-1999 the number of treatment cycles increased by 24% across Europe from 203,225 per year to 249,624, almost half of these cycles being performed in Germany (60,723), France (51,868) and the UK (30,868). In the United States almost 100,000 cycles are performed each year, whereas only 15,215 are performed in Italy which has one of the lowest fertility rates in Europe. Success rates vary tremendously from Iceland with a 42.3% success rate, to Hungary which manages only 22.7%, the United Kingdom falling somewhere inbetween at 29.4%. Denmark has the greatest number of assisted reproduction techniques per head of population with 1,659 treatment cycles per million inhabitants in 1999. This contrasts with Finland (1,407), Iceland (1,383), Sweden (915), France (882) and the UK (585). Proportionately the United States lags far behind Europe with only 250 cycles per million head of population.
If these statistics are born out in an increased birth rate, this equates to some 80,000 births a year through assisted fertility treatment in Europe. Certainly IVF is becoming an increasingly impactive factor in countering the decline in birth and fertility rates, as even defective sperm may be used to fertilise an ovum and produce a viable embryo.
One consequence of IVF is that the proportion of women having multiple births has reached record levels, increasing by 20% over the past 10 years in the UK. This may be because two or more embryos are transferred to the mother's womb during IVF treatment to increase the chances of success of IVF treatment. Another consequence is the cost burden to individuals and the state. In the UK the NHS is limiting couples to only one cycle of IVF treatment per couple, and this will drive wealthier couples towards private IVF treatment. Indeed there is still very little NHS funding for fertility treatments - and an average IVF treatment cycle costs the NHS more than £3,000. However this seems a comparatively small price to pay for the perpetuation of the human race.
