Parenting - Prenatal to preschool/Parenting_PrenatalToPreschool.bin/dp/0045/00453.txt

Text File | 1993-06-14 | 43KB | 664 lines

$Unique_ID{PAR00453}
$Pretitle{}
$Title{Fertility:  The Social Facts
All Other Generations?}
$Subtitle{}
$Author{
Berger, Gary S
Goldstein, Marc
Fuerst, Mark}
$Subject{SOCIAL birth control pills sexual revolution fertility pesticide
pesticides chemicals acid LSD cigarettes careers working out menstruating
reproductive systems fertility infertility Thirties Twenties age fecundability
older delaying Postponement endometriosis abortions antisperm antibodies
promiscuous sterile Alcohol marijuana gonadotoxins varicocele Pergonal DINKs
Stress artificial insemination endometrial biopsy Depression sperm count
motility morphology in vitro fertilization IVF gonadotropin releasing hormone
GnRH gonadotropins FSH LH health diet vegetarian diets amenorrhea exercise
exercising hormonal balance menstrual cycle oligomenorrhea body fat
hypothalamus luteinizing hormone follicle stimulating hormones endorphins
estrogen progesterone testosterone diet Anorexia dieting protein zinc bran
Substance Abuse Drug cocaine Drugs luteal phases chromosome drinking
alcoholics barbiturates phencyclidine PCP angel dust Smoking tobacco Workplace
industrial chemicals radioactive radiation anesthetic anesthetics solvents
toxic lead DBCP vinyl chloride nitrous oxide VDTs heat temperature IVF
Specialist basal body temperature BBT}
$Log{
Drugs That Affect The Central Nervous System*0045301.TAB
Chart:  Body Fat Percentage*0045301.tif}

The Couple's Guide to Fertility


CHAPTER 3:  THE SOCIAL FACTS
Why Is This Generation Different from All Other Generations?


     With the first public sale of birth control pills in 1960, the sexual
revolution was off and running, followed closely by the free-spirited drug
culture and the rock 'n' roll music era.  Those days of free love and hedonism
may have taught us to live life to the fullest.  But many former swinging
singles now want a family and have learned--too late--that sexual freedom may
have lowered their fertility.
     The 1960s was also an era of environmental consciousness.  Rachel
Carson's Silent Spring caused an uproar over pesticides, but the publicity did
little to protect the fertility of pesticide workers and others exposed to
harmful chemicals at the worksite.
     Further problems arose, including reports of genetic damage to people who
"dropped acid" (LSD) repeatedly.  And although the Surgeon General warned us
about the health hazards of cigarettes, he failed to mention that smoking can
reduce fertility.
     Social trends of the 1970s added a further variable to the fertility
equation.  Former activists began building careers.  An increasing number of
women delayed childbearing to become lawyers and doctors, and the equal rights
movement encouraged women to take greater control of their own lives.  The
single, working woman became the image to be emulated.
     The "Me decade" also brought an increased emphasis on exercise and
healthy eating habits.  But some women who worked too hard at working out
stopped menstruating, while others found that strict diets and health foods
were detrimental to their reproductive systems.
     And in the 1980s, so-called yuppies, striving to one-minute manage their
lives, found that a lack of control over their reproductive systems can be
frustrating.  The factors that can affect fertility have finally caught up
with many of us.  Now that some are ready to reproduce, they find out that
they can't.  The first step is to cease potentially harmful behavior
immediately.  Then you may have to seek the help of a fertility specialist.

Pregnancy in Their Thirties, Not Their Twenties

     One of the basic reasons why today's couples have trouble making babies
is that they have waited until their thirties before trying.  As the body
ages, conception becomes more of a gamble.  Just how much of a gamble depends
on your lifestyle, general health, and personal history.  And just as most of
us can run faster, stay up later, and eat more without gaining weight when
we're younger, a woman's body is more apt to cooperate in conceiving a baby at
age twenty than at thirty or forty.
     Since the mid-1960s, the proportion of married women under thirty who
have never had a baby has more than doubled, from 12 percent to 25 percent.
The primary reason is that couples are marrying later and delaying
childbearing.  More than half of women aged twenty to twenty-four and
one-quarter of those twenty-five to thirty had never married in 1985, more
than twice the percentages of never-marrieds among those age groups in 1960,
according to the Office of Population Research at Princeton University.
     Postponement of pregnancy represents a significant change by our
generation.  Women have their first child, on average, three years later than
women did twenty years ago.  In other words, when today's women try to
conceive, they are already three years older than their counterparts of past
generations.
     In addition to the natural decline in fecundability (the ability to
become pregnant) with increasing age, the longer a woman puts off becoming
pregnant, the more she risks having her fertility threatened for various other
reasons--including sexually transmitted diseases and complications due to
conditions like endometriosis.  Since a woman carries all her eggs from birth,
her eggs also have to survive all the drugs, chemicals, and X-rays that she
has been exposed to during her life.  The extra years of exposure to different
agents play a role in the increase in abnormal cell division seen in a woman's
eggs as she ages.  Older women, particularly those over age thirty-five, have
a greater chance of bearing a child with birth defects, even though mother
nature has a way of screening out most of these defective embryos in older
women:  she rejects them through miscarriages.
     Despite the body's changes, women in their thirties now account for an
increasing percentage of births.  Mothers older than thirty had one out of
four U.S. births in 1985, nearly twice as many as teenage mothers.  And
between 1980 and 1990, population experts anticipate a 46 percent rise in the
number of births to women over thirty-five.
     Some of these older women are self-supporting single who want a child
before their biological clocks run down.  The birth rates of unmarried women
in their thirties and forties has increased steadily over the past twenty
years, which may be a function of the increased number of unmarried women in
their thirties today.  In 1974, about one in seven women age thirty to
thirty-four was unmarried; in 1984, the figure had risen to one in four.
     Cohabitation without marriage has become an acceptable way for young
couples to live.  But the earlier days of free sex and swinging singles
parties may have caused unwitting damage to a significant number of
never-marrieds.  Reluctant to settle for less than their ideal mates, many
searched and searched, playing the field.  Some women used repeated abortions
as a means of birth control, which in some cases led to infection and scarring
of the uterus and fallopian tubes.  And after years of exposure to sperm, some
women have produced antisperm antibodies--one more obstacle to fertility.
     A man's fertility may also decline with age.  A promiscuous twenties can
lead to a sterile thirties, due to the ravages of venereal diseases affecting
the epididymis.  Alcohol and marijuana are proven gonadotoxins (toxic to the
testicles), and long-term substance abuse can reduce fertility.  Also, men
with varicocele, a collection of abnormally enlarged veins draining the
testicles, may be fertile when they are younger, but because a varicocele
slowly damages the testicle's ability to make healthy sperm, they become
infertile later in life.

     Economics

     "Whatever I do, I feel I have to do well," says Ginger, a
     forty-two-year-old sales representative.  "Everything I work hard at, I
     achieve.  I worked at having a baby, but didn't achieve it.  That's been
     hard to take."  Ginger has wanted to have a baby with her second husband,
     Steve, since they were married two and a half years ago.  After two
     miscarriages, she was referred to Dr. Berger, who diagnosed a hormonal
     problem.
       "I have read every book on fertility, and had a thorough history and
     practically every test conceivable," says Ginger, who has made notes
     about all of her fertility tests, treatments, and their outcomes "to see
     if I can shed some light.  I feel that I have done all that I could, that
     I have left no stone unturned."
       After three consecutive cycles of hormone stimulation with Pergonal
     without a pregnancy, Ginger has decided to take a break from treatment
     for a few months.  "I will probably try to get pregnant until I'm fifty.
     I'm not going to give up until I'm sure we have exhausted all of our
     resources.  I see it as a crapshoot--sometimes you win, sometimes you
     lose.  Eventually, your number is going to come up.  I'm going to rest
     up, and then go for it again."

     Changes in the work world have given women more economic independence,
which in turn has led more couples to postpone marriage and childbirth.  Many
couples have waited until both the husband and wife have established careers
and they can afford to start a family.  But the stress and anxiety of making a
living in a competitive economic climate, even with two incomes, have taken
their toll on men's sperm counts and altered the delicate balance of women's
reproductive hormones.
     Many infertile couples want to control their reproductive lives just as
they do their business lives.  With two incomes, these couples usually have
the money and motivation to seek the top fertility experts.  Women executives
are more likely than other women to plan their pregnancies carefully.  More
than one in four women executives use home pregnancy and ovulation test kits,
according to a survey by Warner-Lambert's Early Pregnancy Information Center.
     For these high achievers and technology believers, it is especially
frustrating when a pregnancy doesn't happen on schedule.  Those who thought
they could overcome any obstacle in life keenly feel the disappointment of
infertility.
     An acronym that has been used to describe the millions of baby boom
couples who work for wages and, so far, don't have children is DINKs--Double
Income, No Kids.  Executives studying demographic changes for marketing
opportunities have now identified a large segment of the baby boom generation
as worthwhile targets.  An extreme example is "Video Baby," a videotape of a
newborn, which is being pitched to couples who don't have a child of their
own.
     Several factors have fed the DINKS trend.  First, there is the surging
presence of women in the workforce.  From 1965 to 1985, the number of women
with jobs almost doubled.  Among married couples aged twenty-five to
thirty-four, two-thirds of wives work, compared with fewer than half ten years
ago.  And about half of all women are working before their child's first
birthday.
     Back in the 1940s, 1950s, and even the 1960s, newlyweds normally took a
brief year to start a family.  It was unusual for the wife to work.  Today,
it's not unusual for wives to earn more than their husbands, or for couples to
wait ten years before having a child.  By postponing a family and having two
incomes, these DINKS have found that they can achieve their high material
aspirations.
     Today's middle-class wife is used to having control over her life.  So if
something goes wrong and she can't have a child, she faces a profound sense of
guilt and failure.  But most biological problems that cause infertility are
not within her control.  And the treatment of infertility adds stresses of its
own.

Stress and Its Effects

     "I tried all my life to prevent pregnancies, starting on the Pill when I
     was a teenager," says Jan, aged twenty-eight.  "I was in college a long
     time, then worked hard to save some money.  I thought everything was in
     place.  I had a good job as a nurse, a house, a good husband.  After so
     many years of marriage, we were going to have a baby.  It was all
     calculated."
       What Jan and her husband Larry, aged thirty, hadn't counted on was a
     combination of fertility problems.  Her obstetrician-gynecologist ordered
     tests and found that her mucus was "hostile" to Larry's sperm, which had
     a high percentage of abnormal forms.  An artificial insemination attempt
     was unsuccessful, and so they went to see Dr. Berger.  An endometrial
     biopsy and hormone studies revealed that Jan had a luteal phase defect.
     After hormone treatments, another artificial insemination failed.  Jan
     decided to stop fertility treatments, and she and Larry have applied to
     an adoption agency.
       I had to stop.  It was getting too stressful," says Jan.  "I quit my
     job, even though I loved it, because I found myself slipping away from
     work, not giving 100 percent, thinking about having a baby.  I'm trying
     to slow down, not put any pressure on myself.  I've always been a
     go-getter.  But when I got to the point of feeling like I was losing
     control, it scared me."

     The infertile couple grapples with a problem that is stressful for them
physically, emotionally, and financially.  Both husband and wife are
distressed by a loss of choice and control over the direction of their lives,
feelings of being damaged or defective, and over their personal and sexual
identities.
     Some sociologists attribute the high amount of emotional turmoil
experienced by the current generation of prospective parents to their large
numbers.  Because of supply and demand, a large age group--baby boomers, who
total nearly one third of all Americans--faces lower wages, higher
unemployment, and less upward job mobility than smaller-sized age groups. Most
of today's young couples have high material expectations because they grew up
in prosperous times.  To achieve their expectations in a highly competitive
job market, many have stayed single, or formed families with working spouses
and few, if any, children.
     Our generation may feel more stressed and clinically depressed earlier in
life than previous generations.  Female baby boomers have a 65 percent greater
chance than earlier generations of being clinically depressed at some time in
their lives.  The suicide rate among women aged fifteen to twenty-four in 1980
was nearly three times that of a comparable age group in 1950.  Depression has
changed from a disease of people in their forties, fifties, and older to one
of people in their twenties and thirties.
     Chronic stress can have detrimental effects on the reproductive system,
just as it can on any other organ system.  It has been associated with
lowering a man's sperm count, motility (how well sperm swim) and morphology
(the percentage of normally shaped sperm).  Depressed testosterone levels have
been linked not only with the stress of combat or combat training but also
with the stressful business climate today's men face everyday.
     Stress has been known to lower semen volume and raise the percentage of
abnormal sperm forms.  The additional stress of an infertility evaluation and
treatment particularly for an in vitro fertilization (IVF) program, can
further lower a man's semen quality.
     Stress also affects a woman's reproductive function and her ability to
become pregnant.  Chronic stress can reduce the output of gonadotropin
releasing hormone (GnRH) from the hypothalamus, which in turn causes the
pituitary to reduce its output of the gonadotropins (FSH, LH).  Because of the
reduced signals to the ovaries from the pituitary gland, ovulation may not
occur.
     Women under stress may suddenly stop having their periods.  For example,
when a woman moves to a new city to change jobs or go to school, it's
relatively common for her next period to be delayed.
     Even extremely healthy people are susceptible to the reproductive ravages
of stress.  Both male and female athletes who put themselves through intense,
ofttimes stressful training periods may have disrupted reproduction.

Health Kicks

     The national obsession with fitness and health has had its reproductive
repercussions.  The search for the "runner's high" has led some female
athletes to become prone to scanty or missed periods, and some male athletes
to have lowered testosterone levels and impaired sperm production.  Women who
diet to become fashionably slim may run a risk of compromising their
reproductive function since too little body fat can impair a woman's ability
to ovulate.
     Strict vegetarian diets may also have hurt today's fertility rates.
Low-protein diets, particularly those lacking in meat, may affect a woman's
fertility.  Seemingly healthful vegetarian diets often lack essential
nutritional requirements, such as zinc, which a man needs in sufficient
amounts to produce sperm.
     Once prevalent mainly among ballet dancers who felt the pressure to be
thin, amenorrhea (no menstruation) has been spread by the exercise boom to
runners, swimmers, and gymnasts.  A decade of research has shown how exercise
can disrupt a woman's hormonal balance and her menstrual cycle, particularly
among competitive athletes:  Regular exercise can delay a girl's first period,
cause her to have irregular periods (oligomenorrhea) or no periods at all
(amenorrhea).  Older women athletes who become excessively thin can also
experience menstrual irregularities or have no periods at all.  Many women who
began running in their mid-teens and have run long distances through their
twenties have found that they are having trouble getting pregnant in their
thirties.
     Lack of body fat is one of the causes of this type of infertility.  The
body's fat tissues store and convert hormones, including reproductive
hormones.  To allow the natural rise and fall of hormones during the menstrual
cycle, a woman must maintain a body fat content of about 22 percent.  Too much
exercise, along with an excessively rigorous diet, may reduce a woman's body
fat and cause her to have ovulation problems.  Runners with a body fat content
of 17 percent or less don't menstruate.
     Aside from body weight or fat content, exercise itself can disrupt the
pattern of hormone pulses that initiate the menstrual cycle.  Normally, the
"master" regulatory gland in the brain, the hypothalamus, emits pulses of
gonadotropin releasing hormone (GnRH) every 90 to 120 minutes in women as a
message to the pituitary to release luteinizing hormone (LH) and follicle
stimulating hormone (FSH).  But during strenuous exercise, the brain signals
to the hypothalamus are altered, so the pulse pattern of GnRH becomes
irregular.  As a result, the pituitary puts out less than normal amounts of
FSH and, in turn, the ovaries produce less estrogen (required for endometrial
proliferation and for good cervical mucus production) and less progesterone
(needed to make the uterine lining receptive for implantation).  Also, a woman
may not have a surge of LH during the middle of her menstrual cycle.  Without
these hormonal fluctuations, a woman may not ovulate or menstruate.
     Another change in hormones found among competitive women athletes is an
increased output of the stress-related adrenal hormone cortisol.  The
emotional stress of a strenuous training lifestyle, along with boosts in
cortisol production, has led some women athletes to lose weight and stop
having their periods.
     The normal production of gonadotropins may also be hindered by increased
production of endorphins in the brain.  The release of these natural
painkillers is thought to cause the so-called "runner's high."
     Most of these athletes can reverse their infertility by simply gaining
some weight.  In fact, some women athletes who monitor their weight carefully
know that if they gain some weight, their periods will return.  The
accompanying height and weight chart, devised by Harvard's Dr. Rose Frisch,
shows you how much women of different heights need to weigh to maintain
menstruation.
     For example, if you are 5'8" tall and weigh ninety-eight pounds, your
body fat level is less than 17 percent.  Looking at the chart, you can see
that you fall beneath the 17 percent body fat cutoff line.  Lack of body fat
may be the reason why you aren't menstruating.  But if you gained ten pounds
and weighed 108 pounds, you would be above the 17 percent body fat line.  You
would have the body fat necessary to store hormones and begin menstruating
again.

     Men, Exercise and Fertility

     Strenuous exercise can cause a man's testosterone levels and sperm
production to drop, also by interfering with the brain's signals that control
hormones.  It takes greater alterations in hormone levels to affect a man's
fertility, however, and it usually takes a man longer than a woman to notice
the symptoms of hormonal changes.  If a man's testosterone level falls far
enough over a long period, he will eventually lose his libido, and his sperm
count will drop drastically.
     Regular long-distance running may produce changes similar to those
experienced by women long-distance runners.  Prolonged periods of intense
exercise can interfere with a man's rhythmic release of GnRH from the
hypothalamus and, subsequently, the release of pituitary hormones LH and FSH,
just as in women.  For a man, the result can be reduced testosterone levels
and a lower sperm count.
     This may explain why men who run 200 or more miles each week often
complain of a low sex drive.  (They also may be tired from running nearly
thirty miles a day!)  New research shows that men who run twenty-five to
thirty-five miles a week have a 20 to 30 percent drop in testosterone levels
and a slightly impaired sperm count.
     A study of competitive wrestlers shows that their testosterone levels
were higher after the season, when they gained weight, than during the season,
when they were fighting to make their weight class.  This correlation between
change in body fat combined with intense, stressful competition and falling
hormone levels parallels that of women athletes striving to stay slim.

Food and Fertility

     Coupling exercise with a severely restricted diet can add to a man's or
woman's chance of reduced fertility.  Anorexia, a nervous disorder in which a
person loses his or her appetite and eats very little food, is rarely a
problem for men.  But a man may go on a low-calorie diet as he starts a
strenuous exercise program in order to reduce his weight, which may reduce his
testosterone level.
     More often, it's fashion-conscious women pursuing to-the-bone thinness
who compromise their fertility through dieting.  Some of these extremely thin
young women with unexplained infertility or menstrual problems have sex
hormone levels that match those of anorexic women.
     A woman's weight normally increases with age.  Healthy women in their
twenties and thirties who emulate teenage fashion models are trying to achieve
an image that's not normal for their stage of life.  As a result they are
often underweight and may not ovulate or menstruate.
     Young women in their twenties starving down to high-fashion figures may
even hormonally repeat the experience of puberty.  Researchers have found a
general tendency for the LH level in the blood and the ratio of LH to FSH to
increase as these underweight women begin to approach their ideal body weight.
Just before a pubescent girl starts menstruating, the LH jumps way up and is
maintained at this elevated level for several months, then drops down into the
normal adult range.  Women below their ideal body weight may become suspended
in a hormonal state similar to puberty.  Once they gain a few pounds, however,
their pituitary gland function generally returns to normal.
     Another factor may be what's in the diet.  Nonmenstruating women athletes
tend to consume less protein and take in fewer calories each day than
menstruating women athletes.  A Tufts University study shows nonmenstruating
athletes consume an average of thirteen grams less protein per day than
menstruating women athletes of the same height and weight.  (One turkey
sandwich and an eight-ounce glass of skim milk usually provide an adequate
daily protein intake for an adult, say the Tufts nutritionists.)
     A lack of meat in the diet can also affect ovulation.  A German study of
nine healthy young women on a balanced, meat-filled diet and nine women on a
vegetarian diet found that seven of the vegetarian dieters stopped ovulating
during a six-week weight loss program compared to only two of the meat-eating
weight watchers.  In addition, the menstrual cycles of all the vegetarians
became significantly shorter than those of the nonvegetarians.  The
researchers at the Max Planck Institute in Munich suggest that inadequate
amounts of protein in the vegetarian diet may have contributed to the
athletes' hormone problems.
     A strict vegetarian diet has also been linked to male infertility due to
a zinc deficiency.  In fact, a low sperm count may be a tip-off to a mild zinc
deficiency.  Some men with low sperm counts have been successfully treated
with high doses of zinc.
     Men who are strict vegetarians and who want to father children may need
zinc supplements to give their fertility some zest.  Although certain foods
included in a typical vegetarian diet, such as whole grains, nuts, and
legumes, contain zinc, animal protein is considered the best source of this
element.  The widespread use of bran in non-meat diets may counterbalance zinc
intake:  Bran attaches itself to zinc in the intestine and stops it from being
absorbed.

Substance Abuse

     Drug abuse has so permeated our society that the use of marijuana,
alcohol, cocaine, and other mood-altering substances has become commonplace
among young adults.  An estimated 5 to 10 percent of women of childbearing age
use illicit drugs on a regular basis, and another 5 percent have more than two
drinks a day.
     Drugs that affect the central nervous system (see accompanying list) will
affect the control of gonadotropin secretion.  Because of their actions on the
central nervous system, these drugs can modify the brain's output of hormones
that control the production of reproductive hormones.  Changes in
concentrations of the pituitary hormones LH, FSH, and prolactin can result in
reduced libido, sexual dysfunction, and infertility.
     Marijuana's effects on reproduction have been well established.  Studies
show that women who smoke marijuana have shorter menstrual cycles and shorter
luteal phases, particularly when they smoke during the late phase of the
cycle.  Men who are long-term marijuana smokers produce less sperm, and tend
to have lower testosterone levels, lower sperm motility, and more abnormally
shaped sperm than nonsmokers.  Chronic marijuana smokers may also have
chromosome damage, which may lead to problems in conception or to birth
defects.
     Likewise, chronic use of cocaine inhibits gonadotropin production, and
elevates prolactin concentrations, resulting in impairment of a man's
fertility by suppressing testosterone and sperm production, as well as his
libido.
     Alcohol, another commonly abused substance, may also adversely affect the
reproductive system.  As with other chemicals, alcohol's effects on fertility
depend on the amount consumed.  Chronic alcohol abuse in men can lead to
reduced secretion of testosterone.  In addition, chronic drinkers who have
liver damage commonly have small sex organs, enlarged breasts, and
irreversible impotence.
     Both short- and long-term drinking can lead to abnormal sperm production.
A man's sperm may have heads with deformities, curled tails, and swollen
midpieces after a binge.  Sperm from chronic alcoholics show high numbers of
abnormal shapes.
     Women alcoholics also may suffer from infertility and menstrual
disorders.  And sexologists at Rutgers University have found that the
intensity and frequency of orgasms among women drop rapidly as their alcohol
level rises.
     Other drugs that affect the central nervous system--such as barbiturates
and phencyclidine (PCP or "angel dust")--also show signs of impairing
fertility.  Barbiturates inhibit both LH and FSH production, and therefore
depress reproductive hormone secretion.
     "Angel dust" affects many areas of the brain.  PCP has been shown to
depress both testosterone and LH levels in the blood of animals.  Although
there aren't any studies of PCP's effects on reproductive function in humans,
its effects are probably comparable.

Smoking

     Smoking tobacco can also affect the physiologic functions necessary for
reproduction.
     Smoking alters a woman's estrogen metabolism and depletes her egg
production.  It can lead to cervical problems since cervical mucus production
depends on estrogen production.  What's more, high levels of nicotine, found
in female smokers' cervical mucus, can be toxic to sperm.
     Inhaling tobacco smoke may also impair the ability of the lining of the
fallopian tubes to fight off infections.  Nicotine and other components in
cigarette smoke affect the cilia lining the tubes, and may alter the way the
tubes' lining responds to inflammation.  This may allow more infections of the
tubes and pelvic inflammatory disease, which can lead to tubal damage and
ectopic pregnancy.
     Women who start smoking before age sixteen and smoke an average of more
than half a pack a day show an increased risk of tubal infertility.  If these
women have used IUDs or had more than five lifetime sex partners, their
infertility risk rises significantly.  Women smokers have twice the risk of
tubal pregnancy compared to women who have never smoked.  They also have more
frequent miscarriages and premature deliveries than nonsmokers.
     Men who smoke are not immune to the harmful effects of tobacco on
reproduction.  They have significantly lower sperm counts and sperm motility
and a significantly greater percentage of abnormally shaped sperm than
nonsmokers.

Environmental and Workplace Hazards

     Some of the industrial chemicals introduced in the 1960s have been
implicated in fertility problems, especially in lowering a man's sperm count.
In some instances, doctors and hospital personnel in contact with radioactive
materials, radiation, and anesthetic gas have also suffered low fertility
rates.
     The testicles are the most sensitive organs in a man's body when it comes
to exposure to environmental agents.  Radiation, pesticides, and industrial
solvents may all harm his sperm production.  Many of these agents interfere
with male hormone production and sperm formation, causing a loss of libido and
impotency, or infertility.
     Many toxic substances, including radiation and cancer drugs, have their
greatest effect on cells with the highest metabolic rates, that is, cells in
the process of growing and dividing.  That's why the testicles, which make new
sperm every day, are so prone to damage.
     Of the 60,000 chemicals in widespread commercial use today, only three
are regulated based on their documented effects on human reproduction:
metallic lead, the pesticide dibromochloropropane (DBCP), and the
pharmaceutical solvent ethylene oxide.  Most of the remaining 59,997 chemicals
haven't been as thoroughly studied, so no one knows what their effects on
sperm production might be.
     Infertility due to occupational hazards has been less well studied among
women, although women who work in the manufacture of oral contraceptives may
have altered menstrual function.  And pesticides may produce ovarian problems,
possibly leading to early menopause.
     If a woman becomes pregnant, exposure to various chemicals may damage her
developing embryo.  Substances having the potential to cause early miscarriage
include:  ethylene oxide, used in the chemical sterilization of surgical
instruments; vinyl chloride, used in the plastics industry; chemical solvents
used in manufacturing industries; nitrous oxide exposure among anesthetists,
operating room nurses, veterinarians, dentists, and dental assistants; and
metallic compounds of manganese, arsenic, and nickel.
     What's more, the sex partners of men chronically exposed to lead, DBCP,
vinyl chloride, and anesthetic gases, particularly nitrous oxide, may be at
increased risk of a miscarriage.  Several insecticides, including DDT,
chlordecone, and methoxychlor, and metals, including organic lead, copper,
cadmium, and zinc, can prevent implantation of the fertilized egg.
     Pregnant women who work with video display terminals (VDTs) may also have
an increased risk of miscarriage.  About a dozen unexplained "clusters" of
miscarriages among VDT users have been reported since 1980, but so far the
cause of the miscarriages hasn't been authoritatively linked to VDTs.  One
study by researchers at the Kaiser-Permanente Medical Care Program in Oakland,
California, reported that clerical workers who used VDTs for more than twenty
hours a week had almost twice as many miscarriages as women who did other
kinds of office work.  However, women executives who spent as much time in
front of VDTs as the clerical workers didn't have an increased miscarriage
rate.  So it's not clear yet whether exposure to VDTs is truly associated with
more miscarriages.

     Heat and Infertility

     Intense exposure to heat in the workplace may cause significant fertility
loss among men.  Workers at risk of heat-provoked infertility include men
involved in the smelting of metals and the manufacture of glass, those
laboring in the engine rooms of ships, and possibly bakers, farm laborers, and
long-distance truck drivers exposed to engine heat.
     Normally, the temperature of the testicles is between 93 and 95 degrees
Fahrenheit, or 34 and 35 degrees Centigrade.  Temperatures above normal body
temperature (98.6 degrees F or 37 degrees C) can impair a man's sperm count
and motility and cause him to produce abnormal sperm forms.  Although the
impact on sperm production is generally reversible, a worker exposed on a
daily basis, year after year, could experience long-term or even permanent
impairment, according to Dr. Richard J. Levine, chief of epidemiology at the
Chemical Industry Institute of Toxicology in Research Triangle Park, North
Carolina.
     A man's testicular temperature tends to be higher when he is sitting than
when he is standing.  The poor semen quality of paraplegics has been
attributed, in part, to elevated testicular temperatures because they are
forced to sit in a wheelchair, Dr. Levine notes.  Others who sit for long
periods, such as long-distance bus drivers and workaholic executives, may also
be at increased risk of infertility.
     The connection between exposure to heat and male infertility has also
been noted outside the workplace.  A high fever has long been associated with
impaired sperm production.  In tropical and subtropical climates, fewer women
tend to become pregnant during the hot seasons, and men seem to have higher
sperm counts during the winter.

How to Prevent Further Damage

     Although you or your mate might fit into one of the above categories,
that doesn't mean that you won't ever have a baby.  Even if your lifestyle or
habits have led to damage, you may still be able to prevent further damage to
your fertility.
     Obstetrics textbooks specify that a thirty-five-year-old woman who gets
pregnant for the first time is considered to be an "elderly primigravida,"
which reflects the medical profession's concern with the medical and obstetric
complications accompanying delayed childbearing.  The ideal time, from a
physical standpoint, for a woman to become pregnant is in her early or
mid-twenties when her body is physically mature, her reproductive system is
most responsive, and her chances of producing a genetically abnormal child are
minimal.
     From a socioeconomic view, however, delayed childbearing may be more
advantageous.  Studies supported by the National Institute of Child Health and
Human Development have found that older mothers tend to have more education,
higher status jobs, and better incomes than do mothers five or ten years
younger.  They also are likely to have higher aspirations for their children
and more money to provide material goods and a quality education.
     There have been many babies born to women in their late thirties and
early forties, both naturally and through advanced reproductive technologies
such as IVF.  Perhaps the most unusual example is Pat Anthony, a
forty-eight-year-old woman who gave birth to her own grandchildren--triplets
conceived in vitro by her daughter and son-in-law--which she carried for them,
proving the reproductive power of at least one over-forty woman to do what her
daughter, who had had a hysterectomy, couldn't do.
     When it comes to stress, a woman whose job or life circumstance places
her under excessive pressure would be wise to delay pregnancy until she can
reduce that stress, if at all possible.
     The degree to which stress and exercise affect a man's testosterone level
or sperm count depends on the individual man.  Usually, hormonal changes in
men who exercise regularly aren't severe enough to cause a loss in libido.
For a man who exercises strenuously, is having difficulty fathering a child,
and has a low sperm count, cutting back on exercise may help.  Male athletes,
particularly those involved in ever-popular "ultrasports," such as triathlons,
may need to moderate their activity levels.  Keeping body weight within normal
limits, including a body fat content above 5 percent, will likely maintain a
man's fertility.
     People with an already damaged reproductive system will compound their
fertility problems if they use illicit drugs.  The type and amount of drug
taken, how often it's taken, and the amount of active ingredient (which varies
widely in street drugs), all affect the degree of reproductive, as well as
general health, risks.  Other factors include the user's age and the duration
of use.
     Fortunately, most drugs have a temporary effect on the central nervous
system pathways necessary for normal production of gonadotropins.  So when you
stop using drugs, the harmful effects on your reproductive function are likely
to be reversed.
     Infertile couples who smoke cigarettes should quit if they want to
improve their fertility potential, not to mention their general health and the
health of their baby.
     The problems of workplace reproductive hazards underscore the need to
know the occupational history of each partner as part of the fertility workup.
The history may also help in planning treatment.  For example, it may take
several months for a man to recover sperm production after an environmental
insult, so periodic semen analyses are often useful in monitoring his
response.
     Assessing the significance of workplace exposures is often difficult.
Occupational exposures are usually not isolated to one chemical, and the
dosage may vary according to the particular job, tasks on the job, and
accidents and spills.  Exposure to potentially harmful agents is not routinely
monitored in most workplaces.
     One potential problem--excessive heat--can usually be overcome.  If a man
has sperm problems, he should minimize his exposure to heat.
     The possible association of video display terminal use and miscarriage is
potentially serious, since about half of the estimated 10 million people who
use VDTs on the job are women of childbearing age.  These women can use
protective screens over their VDTs to absorb radiation.  Pregnant women who
work with computers for more than half the working day should take frequent
breaks from the machine, interspersing non-VDT work with VDT work.  Some
pregnant women who operate VDTs have arranged with their employers to let them
do other kinds of work or to cut down their hours at the computer during their
term of pregnancy.

When to Seek Help from a Specialist

     You and your spouse may have been trying to have a baby for a few months
and are wondering, "Do we have a fertility problem?"  There are simple tests
that your family doctor, ob-gyn, or urologist can perform to give you a clue
about your fertility before going through a full workup by a fertility
specialist.  With the ovulation predictor kits now available in drugstores,
you can determine when you are ovulating, and can have sex around this most
fertile time.  Keeping a basal body temperature (BBT) chart may also help
identify your normal ovulation days and hormonal cycles.
     Remember that the odds of a woman getting pregnant are only about one in
four each month, even under optimal conditions.  That's why most couples
should wait at least six months before seeking medical help.
     The American Fertility Society recommends waiting two years for women
under thirty and one year for women over thirty before seeking a specialist.
But the view shared by many doctors is that a full year's wait isn't justified
for couples in their thirties since fertility naturally declines with age.
Because women in their thirties may be fighting their biological clocks, a
wait of one year may waste precious time.  Most fertility specialists
recommend an evaluation if the wife is over thirty and the couple hasn't
conceived after six months of frequent intercourse without birth control.
Couples under thirty should seek medical counseling if they haven't conceived
after one year of unprotected intercourse.
     When the woman is over thirty, or if either partner has reason to believe
there is a risk factor in their background--a history of genital infections, a
DES mother, irregular periods, unusual sexual development--this certainly
justifies an early evaluation.  Women who have a history of two or more
miscarriages and no live births may want to seek out a fertility specialist.
     If you are over thirty or have clues from the past that you might have a
fertility problem, and you still don't get pregnant after optimizing your
chances by timing sex around ovulation, then you need not wait as long as six
months before seeking medical help.