The Shidduch Crisis--Playing the Numbers Game--Part #3

Much has been said elsewhere about a crisis in shidduch making due to a disparity in the number of males and females available. There are more females born then males. This means that there will be more females looking for shidduchim then there will be males to marry. Short of genetic manipulation there also doesn't seem to be any solution to this "problem." Not exactly. If you don't like looking at facts and figures, then by all means skip the rest of this posting. But if you want to actually see just what the numbers are and how they are getting here, please read on.

Let's look at some data. An article published in the Journal of the American Medical Association ("Reduced Ratio of Male to Female Births in Several Industrial Countries. A Sentinel Health Indicator?" Journal of the American Medical Association v. 279, n. 13, 1apr98 Devra Lee Davis, PhD, MPH; Michelle B. Gottlieb, MES; Julie R. Stampnitzky) had the following to say. " The sex ratio of 1.06:1, the ratio of male to female births, has declined over the past decades. Recent reports from a number of industrialized countries indicate that the proportion of males born has significantly decreased, while some male reproductive tract disorders have increased." The study covered the years from 1970 to 1990.

"In all of the analyses of changes in male proportion throughout time in industrial countries, reported variation occurs in fractions of percentage points. Such small changes, however, can have profound implications for large populations, where hundreds of thousands or millions of births occur each year. For example, the reported statistically significant decrease of 2.2 males per 1000 births in a country the size of Canada with an annual average of 333 159 births represents a cumulative decline of about 8600 male births since 1970. During the same period, the US decline of 1 male birth per 1000 corresponds to approximately 38 000 male births."

Thus, over the twenty year period 38,000 fewer males were born then females were born in the US. For the year 2006 the total population for the US was 296,410,404 and the Jewish population was 6,452,030 or 2.2 percent of the total population. If the Jewish population follows the trends in the general population then the Jewish population represents 2.2% of the 38,000 fewer males that are born each year. This would then be approximately 800 fewer Jewish boys being born then Jewish girls each year.

There have been some systematic attempts at establishing the Jewish birth rate. One such study gave the following figures: "The present estimate for Orthodox Jews in Eretz Yisrael is between 900 thousand and one million; in North America, between 550-650 thousand; and in the rest of the world between 120-150 thousand, making for a total of between 1.67-1.8 million[4]. Thus, the religious Jewish population of the US is only about 10% of the total Jewish population. Therefore, the birth decline for males would be approximately 80 fewer boys per year born then girls. However,
there is this: "Established (approximate) assimilation figures for the year 2000: 50-52 % among Jews of America and France." Jews, as a percentage of the total population, are shrinking due to assimilation. This will result in a smaller percentage, which will affect the actual number of fewer boys born per year for the Jewish population. However, as posting #2 in this series shows, the birth rate for the Orthodox population is much higher then the birthrate for both the Jewish population at large and the non-Jewish population. Therefore, the decline for males born to the Orthodox population would be higher then the 80 fewer boys per year as noted above.

What are some of the reasons for this decline in male births?

"General medical factors and conditions documented to reduce the male proportion of offspring include older age of fathers, in vitro fertilization, nonHodgkin lymphoma, hepatitis, and use of fertility drugs, such as clomiphene....Other factors that have been hypothesized to affect the sex of offspring include stress, which increases pituitary secretion of corticotropin (adrenocorticotropic hormone). In men and women, elevated levels of corticotropin produce paradoxical effects on gonadotropin, which is consistent with this hypothesis. In men, increased corticotropin levels lower the endogenous levels of testosterone and increase the relative proportion of estrogen, which, in turn, leads to the production of more female offspring. In women, increased corticotropin levels activate the adrenal cortex, yielding relatively elevated levels of testosterone, and create a hormonal milieu that yields more male offspring.20 High maternal gonadotropin levels are associated with the production of females. Dosing with testosterone prior to conception. has been shown to increase the male offspring in humans as well as in experimental animals.' In one study, men who were given methyltestosterone therapy sired 45 boys and 17 girls.21....Parental age has also been hypothesized to affect sex at birth, although findings appear inconsistent. Male proportion has been observed to decline with increases in paternal22 and maternal age. 18 One recent study of births in 301 families found that the difference in age between parents was a significant predictor of the sex of the first children. 23 The age of either one of the parents had only a weak effect on the sex of the offspring, while parents with a greater difference between their ages gave birth to an excess of boys. In contrast, a small age difference between husbands and wives was associated with more female births."

Environment can also factor into the decline of male births. "...unusual environmental exposures can be the primary cause of reduced sex ratio in some circumstances....Several researchers have assessed whether general environmental exposures to materials linked to alterations in sex at birth in highly exposed workers might also produce alterations in children conceived in neighborhoods with similar exposures. 32 The evidence on this matter remains incomplete, but provocative. Five different retrospective studies of heavily polluted Scottish residential areas revealed significantly impaired sex ratio. 33 The pollutants included some highly visible emissions from acrid smelters, steel foundries, and incinerators in Scotland between 1975 and 1983....Under some unusual workplace conditions, male proportion has been found to be radically altered. One analysis from the state of Washington found that fathers who worked in the aluminum industry from 1980 to 1990 as carbon setters, anode setters, or carbon changers had 53 male and 86 female births, for a proportion of male births of 0.381 (P=.003). 26 Other factors that have been reported to reduce male proportion significantly include workplace exposures to organochlorine pesticides27 and waste anesthetic gases. 28 One study in the Netherlands of offspring born from 1978 to 1990 revealed a remarkable shift toward more daughters, and a male proportion of 0.248, in children conceived by men who had received workplace exposure to pesticides. This report also found that time to conception was significantly longer for fathers who were estimated to have incurred greater exposures, as measured in terms of the number of days of pesticide spraying. Other workplace exposures have also been linked to lowered male proportion, including other types of pesticides, inorganic borates, 29 alcohol, lead, and solvents."

What did the researchers attribute the change in birth patterns to? "The ratio of human males to human females at birth is not static. Between 1900 and 1950, the proportion of males rose significantly in several industrial countries, beyond the range of historical variation. This was chiefly due to general improvements in obstetrical care, which produced a decline in stillbirths, 7,44,45 that disproportionately affect males. In general, male fetuses appear to be more susceptible to reproductive hazards, as they also experience higher rates of many birth defects than do females. Since 1970, a significant downward trend has occurred in the proportion of males in the Netherlands, Denmark, Canada, and the United States, and recent reports indicate that parallel declines also have occurred in Sweden, Germany, Norway, and Finland. 10 It is distinctly possible that the causes of these trends, however, are not benign. Rather, the reduction of the proportion of males born may be a sentinel health event that some, as yet, unrecognized environmental health hazards are affecting the sex ratio of births as well as other unexplained defects in male reproduction."

What are the conclusions? "The study of sex determination remains a field full of speculation and with limited empirical evidence. As a consequence, factors that affect the sex ratio remain poorly understood. Many of the causes of reduced male births that have been identified, such as stress of fathers, in vitro fertilization, less frequent intercourse, and multiple sclerosis, are unlikely to account for the time trends that have recently been observed in several industrial countries. Several specific workplace and environmental exposures have altered the sex ratio in those who were highly exposed to some pesticides and other general environmental contaminants. Whether these agents could account for some of the recently observed patterns is a matter of considerable concern....Geographic monitoring of changes in sex ratio could prove a useful tool for assessing whether specific, avoidable medical or environmental exposures are occurring in specific regions.

Relatively small reductions in male proportion over the past 2 decades in the United States and Canada theoretically account for decreases in about 38 000 and 8600 male births, respectively. 8 The potential repercussions of conditions that may alter the ratio of the sexes at birth should be considered a matter of utmost .concern. The extent to which other adverse health consequences are linked to this phenomenon is a matter of grave importance for public health."

In short, there are a number of factors which can affect the ratio in the population of males born and females born. I was particularly intrigued with the finding above that stated " The age of either one of the parents had only a weak effect on the sex of the offspring, while parents with a greater difference between their ages gave birth to an excess of boys. In contrast, a small age difference between husbands and wives was associated with more female births." More and more people are trying to push for shidduchim with an age difference of no more than two years. I posted an article before in which shadchanim were being offered a "bonus" for redding this kind of shidduch. And yet, if a close difference in age results in more female births then male births, what some people see as a solution to the problem today will result in an even bigger problem for the next generation. Nor does mandating a huge age gap solve the problem, as more boys will be born then girls. Perhaps one answer might be to stop emphasizing age, in any direction, as a requirement for making a shidduch. Presumably if no "ideal" age gap were talked about the population as a whole would find themselves somewhere in the middle, with some at either end, and the ratio of males to females might even out.

Just a thought: entire areas of New York City and Long Island were aerially sprayed very heavily with pesticides as a preventative measure against West Nile Disease over the last two years. I wonder what the male/female ratio for babies born was in those areas during those times.