Proximate Determinations of Fertility [Archives:1999/11/Health]

March 15 1999

Based on a survey of 10,414 women carried out by specialists of Macro International Inc. of the USA and the Central Statistical Organization of Yemen during 1997, this article presents conclusions pertaining to the planning and execution of family planning in Yemen. The survey addressed the factors which affect a woman’s fertility. These relate to the chances of a woman becoming pregnant and, thus, they determine fertility levels in Yemen. Specifically, they touch on marriage patterns, postpartum amenorrahea, postpartum abstinence, and menopause.
Marriage patterns have a major effect on fertility because they influence the onset of exposure to pregnancy. Populations in which women marry young are usually characterized by early childbearing and high lifetime fertility. Postpartum amenorrhea and postpartum abstinence, which determine the length of time a woman is insusceptible to pregnancy following childbirth, affect birth intervals and, thus fertility levels. Finally, the onset of menopause is important because the probability of becoming pregnant decreases as women near the end of their reproductive years and an increasing numbers of them become infecund.

The Statistics
Statistics show that 67% of Yemeni women are currently married, 2% are widowed, 2% are divorced, and less than 0.5% are technically married but are separated.
Some 28% of women have never married. Of these, about 75% are between the ages of 15-19 years, and 25% between 20-24 years. By age 50, almost all Yemeni women are married or have been married. Widowhood increases with age – 6% of women aged 40-44 years, and 8% of those aged 45-49 years are widows.
Among women aged 15-19 years, less than 1% are divorced, but the percentage increases to 2-3% among women aged 20 years and over.

Marriage between Relatives
In Yemen, as in other Arab countries, marriage between blood relatives (consanguineous marriages), usually cousins, occurs frequently. 25% of married women are married to a first cousin on their father’s side, another 10% are married to a first cousin on their mother’s side, and 6% are married to second/third cousins and other relatives. There are indications that consanguineous marriages are becoming more common in the country. For example, 30% of women aged 45-49 years are married to a blood relative compared with 44% of 20-24 year women – an increase of almost 50%. Women who were married at younger ages and those who were married for shorter periods were more likely to have married a relative.
Consanguineous marriages occur about equally among women in urban and rural areas and are slightly more likely to be found among women living on the coastal area than in other regions. No relationship was established between prevalence of marriage between blood relatives and women’s level of education. However, a slightly higher proportion of literate women or women who have completed primary schooling have married relatives than women in higher education categories.

Marriage is not as stable in Yemen as it might appear from the small proportion of women who are currently divorced or widowed; remarriage is relatively common. Yet, a large proportion of women (91%) have married only once.
Not surprisingly, the proportion of women who marry more than once gradually increases with age because of a higher likelihood of divorce and widowhood. The proportion of women who have married at least twice increases from around 5% among women aged 20-24 years, to 11% among 30-34 year women, and then rises to 16% among women in their forties. Dissolution of marriage is as likely to occur among women in rural areas as in urban areas. In the coastal region, the proportion of women marrying only once is slightly higher than in the other regions. Illiterate women are more likely to have married more than once than women who are literate or whose who have completed some level of education.

As a Muslim country, Yemen considers polygamy legal. Islam permits a man to have up to four wives at a time, provided the husband treats all of them equally. In order to collect information on the practice of polygamy, all currently married women in the survey were asked whether their husbands had other wives and if so, what her rank was.
7% of currently married women live in a polygamous marriage. Women living in urban areas and in the coastal region are less likely to have co-wives (4-5%) than women in rural areas and the mountainous region (8-10%).
There is a clear-cut relationship between education and polygamy. Polygamy is most common among illiterate women and least common among women with secondary or higher education.
The proportion of women living in a polygamous marriage increases with age – from 4% among women aged 15-19 years to 10% among women in the 45-49 year age group. In general, this same pattern is seen for most background characteristics.

Age at First marriage
Among women aged 20-49 years and presently married, 8% were married at age 13, 25% by age 15, 75% by age 20, and almost 90% had married by the time they were 25 years old. The average age for marriage for women 20-49 was slightly higher as compared to the statistics of the 1991-92 Yemen Demographic and Material and Child Health Survey. This points to a slight delaying of marriage age among Yemeni women. Data show that the average age at first marriage rose from 15.7 years among women aged today 45-64 to 16.6 years among those 25-29 years, and to 18.2 years among women age 20-24.
30% of women over age 30 had married by age 15 compared with 14% of women age 20-24 and to only 6% for women of the age of 15-19 years. Also, 64% of 20-24 year women 24 were married by age 20, compared with 81-88% among those over 30 years old.

The age group 15-19 is not included in the table because less than 50% of teenage women had married by age 15. As noted above, the average ages at marriage for women 20-49 and 25-49 in Yemen are 16.5 and 16.0 years, respectively. The average age at first marriage is slightly higher for urban women than for rural women. In the coastal region, women marry one year later than in the mountainous or the plateau and desert regions. Overall, the higher the level of education, the higher is the average age at first marriage.
Among 25-49 year women, the average age at first marriage for women who are illiterate is 16 years; for women who have completed primary schooling it was 18 years. The difference in average age at first marriage between those who have completed primary education and those who have completed at least secondary school is more than six years.

Age Difference Between Spouses
38% of women are married to men who are the same age as they are, or at most 4 years older. The majority of women are married to men much older than they are. For 33% of currently married women, the husbands are 5-9 years older, and for another 14%, they are 10-14 years older. One in 10 women is married to a man at least 15 years older than her, and 5% to men 20 or more years older.

That the difference in ages between spouses is decreasing is indicated by the lower mean age differences for younger women. The mean difference in husband’s and wife’s ages has decreased from 8 years for women in their forties to around 6 years for women under 30. Regional differences are small.
Women getting married a second (or more times) are more likely to be married to older men than women marrying for the first time. Although 7% of women married for the second time, are married to younger men, 14.3% of the re-married women have husbands who are at least 20 years older than them. The mean age difference between spouses is 9.5 years for women who have married more than once or three years higher than the average difference for women who have married only once.
In a polygamous marriage, the gap between a husband’s and a wife’s ages increases dramatically according to rank of the woman. The first wife is, on average, 7 years younger than her husband; the second wife is almost 16 years younger. The pattern continues, although the results are based on a small number of cases.

Ideal Age at Marriage for Women
Adolescent marriages are still considered desirable by a majority of women in Yemen. 6% of all married women consider marriage at the age of 15 as the most suitable age for marriage, and 5% mentioned ideal age for marriage as when a girl reaches “adolescence.” 1% would like their daughter to marry when she finishes school. Almost 25% consider 15 years to be an ideal for girls to marry and another one-quarter think 16 to 19 years is the most suitable age. Only one third of all married women consider age 20 or older as the ideal marriage age for girls.
The proportion of women who mentioned 20 years or older as the ideal marriage age increases with the rising age of women. Those women under age 20 least favor marriage at age 20 or later. Surprisingly, more urban women compared with rural women consider age 20 or above as the lowest suitable age for daughters to marry. The proportion of women in the plateau and desert regions who favor marriage at 20 years or later is higher than that in the other regions.
Education is strongly associated with favoring a late marriage for daughters. Only one-quarter of illiterate women compared with three-quarters of women with secondary or higher education would like their daughters to marry after their twentieth birthday.

How does the respondent’s attitude toward age at marriage for her daughter compare with the age at which she herself was married? The majority of women want their daughters to marry at an age that is higher than the age at which they themselves were married; while 14% want them to marry at the same age at which they were married. Overall, less than one-quarter (23%) of women reported an ideal age at marriage for their daughter that was lower than their own age at marriage. It is interesting to note that one-third of women who have at least completed secondary level education consider early-age marriage as ideal. Some groups have a higher proportion of women whose ideal age of marriage for their daughters is later than their own. For urban women it was 63%, for women who have completed the primary level, it was 65%, and for women who have completed preparatory level, it was 71%.

Postpartum Amenorrhea and Insuceptibility
The risk of pregnancy following a birth is influenced by two factors: breast-feeding and sexual abstinence. Breast feeding prolongs postpartum protection from conception through its effect on the length of the period of amenorrhea (the period prior to return of menses) following a birth. More frequent breast-feeding for longer duration as wel as delays in the age at which supplementary foods are introduced are associated with longer periods of postpartum amenorrhea. Delaying the resumption of sexual relations following a birth also prolongs the period of postpartum protection. Women are defined as insusceptible to pregnancy if they are not at risk of conception because they are amenorrheic or abstaining following a birth.
These distributions are based on current status information, i.e., on the proportions of births occurring x months before the survey for which mothers were amenorrheic, abstaining, and insusceptible at the time of the survey.

The data are grouped in two-month intervals to minimize the fluctuations in the distributions. The prevalence/incidence mean is obtained by dividing the number of mothers who are amenorrheic, abstaining, and insusceptible by the average number of births per month over the 36-month period.

The percentage of births for which mothers are amenorrheic declines from 93% in the two-months immediately following a birth to 68% in the 2-3 months after a birth. By the period 6-7 months following a birth, fewer than half of the mothers (48%) are still amenorrheic, and by 12-13 months, only one-fifth of mothers have not resumed menstruation.

As in other Islamic countries, many couples in Yemen observe the traditional practice of abstaining from sexual relations for a period of 40 days (Nifas) following a birth. Reflecting this tradition, the proportion of births for which mothers are still abstaining decreases dramatically from 76% in the two-months period immediately following a birth to 19% at 2-3 months after a birth.

The combined effects of postpartum amenorrhea and postpartum abstinence are reflected in the period of postpartum insusceptibility following a birth. The duration of postpartum amenorrhea is the major determinant of the length of time a Yemeni woman is insusceptible to the risk of pregnancy. The average duration of amenorrhea is 6 months, as is the average duration of insusceptibility, while the duration of abstinence is less than 2 months. Overall, the proportion insusceptible at any duration postpartum is 1 to 2 percentage points higher that the proportion amenorrheic. The median and mean duration of insusceptibility are 6.4 and 9.4 months, respectively. The prevalence/incidence mean is 9.2 months.

Although the period of postpartum abstinence is about the same for both younger and older women, the period of amenorhea and the period of insusceptibility are longer for older than younger women. The media duration of amenorrhea and insusceptibility is higher among women in rural than urban areas, illiterate than literate women, and women who have completed some level of schooling. The shortest period of insusceptibility is for woman who have completed secondary or higher education.

After age 30, the risk of pregnancy declines with age as increasing proportions of women become infecund. Although the onset of infecundability is difficult to determine for an individual woman, there are ways of estimating it for the population. Eleven percent of women age 42-43 are currently menopausal; among younger women the percentages are much smaller (1 to 6 percent). Menopause sets in faster after age 42-43 and rises to 26 percent among women 48-49.

Adopted and abridged from:
YEMEN: Demographic and Maternal and Child Health Survey: 1997, November 1998.