Astract
Objectives : To find out the proportion of consanguineous marriages and study its association with socio-demographic profile and history of other consanguineous marriages in the family. To find out awareness regarding the ill-effects of consanguinity.

Methods : In this cross-sectional analytical study, 237 women having at least one child in the age group of 5 to 10 years were interviewed using non-probability sampling and pre-tested semi-structured interview-schedule.

Results : 28.7% women were consanguineously married. Consanguineous marriages were not associated with religion, education or economic status of the couple but were associated with social traditions and age at marriage. They were seen to run in clusters in families. 2.1% of respondents were aware of the ill-effects of consanguinity before their marriage.

Conclusions : There is a need to create public-awareness regarding ill-effects of consanguinity due to its high proportion and little awareness observed.

Introduction

Consanguineous marriages are marriages contracted between blood relatives. According to World Health Organization, a consanguineous marriage is defined as a marriage between people who are second cousins or more closely related.1The tradition of consanguineous marriages is rather old and in some cultures, such marriages were encouraged. The ancient Egyptians and the Incas favoured marriages between brothers and sisters of the reigning dynasty -“royal blood” being considered worthy to mix with other royal blood only.2 Even eminent personalities like Albert Einstein, Charles Darwin chose to marry their cousins.

Observations of ill-effects of consanguineous marriages in progeny might have lead to the customs or laws of some societies to discourage marriages between close relatives.2 In few castes and communities such marriages are not accepted at all. In India, the Hindu Marriage Act of 1955 bans uncle-niece marriage with a corollary saying “Unless where custom allows it”.³

It is estimated that globally about 20% population live in communities having a preference for consanguineous marriage, and at least 8.5% of children have parents who are consanguineously married.4 Prevalence of consanguineous marriages varies from 2-4% in France, UK, USA and Japan to 50-60% in Jordan, Saudi Arabia and Kuwait. The incidence in India shows a wide range from 5 to 60% depending upon different religions and geographic areas.5 It is a well-known fact that the consanguineous marriages have more chances of bringing rare recessive alleles together leading to various ill-effects such as infertility, repeated abortions, stillbirths, congenital malformations, mental retardation in children, etc. For the offspring of first cousins the incidence of congenital malformations is increased to approximately 2½ times that which is seen in the offspring of unrelated parents. Though there is some recognition of the potential disadvantageous genetic effects of consanguinity, the communities also strongly believe that these effects are greatly overweighed by social advantages such as greater marital and family stability.5 In communities where there are large demands for dowries and the proportion of dowry deaths is high, consanguineous marriages are believed to be preferable.

Thus it was thought that it would be of importance to find out the proportion and awareness of consanguineous marriages in the women.

Methods

The present study is a hospital-based study carried out in the outpatient department (O.P.D.) of Preventive and Social Medicine in Lokamanya Tilak Municipal Medical College, Mumbai. Any woman attending the O.P.D. and having at least one child in the age group of 5 to 10 years and willing to give consent was interviewed. The minimum required sample size was estimated to be 224. By non-probability sampling, a total of 237 women were interviewed using a pre-tested semi-structured interview-schedule. These interviews were conducted over a period of 3 months.

The data was collected, compiled and analyzed using SPSS 10.0. Frequencies and percentages were calculated. Analyses of associations between relevant factors were performed by applying the chi square test.

Definition

Awareness of ill-effects of consanguineous marriages was defined as any answer by the respondent relating the ill-effects in relation to conception (infertility, repeated abortions, stillbirths) or any ill-effects in progeny (malformations, mental retardation) of the consanguineously married couple.

Results

A total of 237 women were interviewed. The mean age of the respondents was 28.9 years (standard deviation = 5.0 years). 40.1% of the respondents were illiterate. 48.5% were Hindu, 41.4% were Muslim, 3.0% were Christian and 7.2% were Buddhist.

28.7% women were consanguineously married. Of these, 73.5% were married with third degree relatives (first cousins), 20.6% were married with second cousins or other relatives and 5.9% were married with second degree relatives (uncle-niece, aunt-nephew).

27.0% of Hindu, 28.6% of Muslim, 57.1% of Christian and 29.4% of Buddhist were consanguineously married. The number of respondents belonging to Christian (7) and Buddhist (17) groups was small. So chi-square test was applied to Hindu and Muslim categories only. The difference was not found to be statistically significant.

The proportion of consanguineous marriage was also found to be not associated with the education of the wife or the husband.

The difference between the proportions of consanguineous marriages with respect to the economic status of the family was not found to be statistically significant. 33.3% women with lower economic class were consanguineously married while the proportion was 27.4% for those with upper lower economic class and 25% for those with lower middle, upper middle or upper economic class according to modified B.G. Prasad’s classification.6

Statistical analysis showed the association between traditional acceptance of consanguinity and consanguineous marriage to be significant (Table 1).

The association between family history of consanguinity and consanguineous marriage was also statistically significant (Table 2).

It was found that the consanguineous marriages run in clusters in many families (Table 3). Out of 237 women interviewed, 125 women had families with a history of consanguineous marriage (1 to 9 consanguineous marriages in such families). 40 out of 68 (58.8%) consanguineously married women had at least one of her siblings or parents consanguineously married.

The proportion of consanguineous marriages was found to be significantly high amongst women who got married at an early age (Table 4).

Overall awareness regarding the ill-effects of consanguineous marriages amongst the women was found to be low. 17 out of 237 (7.2%) women were aware of some of the deleterious effects of consanguineous marriage. 7 of these were consanguineously married. Before marriage, only 5 out of 237 (2.1%) had some awareness.

Discussion

Consanguineous marriages are prevalent worldwide and across all the cultures and studies have been conducted to know about the socio-demographic profile, causes and effects of the same.

In a similar study conducted in Pondichery amongst pregnant women, consanguinity was observed in 30.8%, with a higher frequency amongst women from rural areas and amongst Hindus. In the consanguineous group, first cousin marriages were present in 47.4%, and uncle-niece marriages in 23.4% of women.7 In another study done in rural women of Belgaum, the prevalence of consanguineous marriages was found to be 36%; first cousin marriages were present in 54.4% and uncle-niece marriages in 33.8% of women.8 In the present study, the proportion of consanguinity was observed to be 28.7%. Out of these, the uncle-niece marriages were 5.9% and first cousin marriages were 73.5%. Traditional acceptance and previous consanguineous marriage in the family are the important factors that determined consanguinity. Tradition plays an important role in India even today. Also one successful consanguineous marriage boosts the faith in the system of consanguineous marriages. Similar findings were also obtained by Khoury and Massad.9 In present study, consanguinity was also seen to be associated with early age at marriage. Usually the parents of the bride are worried about her security. Especially when the bride is younger, they feel that she will be safe and it will be easier for her to adjust in a new home if she gets married consanguineously. The finding in present study is in conformity with those made by Afzal et al10 and Bittles et al.^11,12

27.0% of Hindu, 28.6% of Muslim, 57.1% of Christian and 29.4% of Buddhist were consanguineously married. It was found that consanguinity is independent of religion in the study-population.

In a similar study in Jordan, it was found that the education, especially of the father was negatively correlated with consanguinity. Female university graduates showed greater freedom in selection of husbands.9 In a study in Beirut, it was concluded that the low educational level, low occupational status, and the Muslim religion of the husband was associated with higher proportion of consanguineous marriages.13 The highest rates of such marriages have been reported in rural areas, among individuals with low educational level and among the poorest.14 Education empowers a person to make right decisions. It is usually observed that women, who get opportunity to pursue education, can usually implement their choices. Thus the effect of education is probably one of the most important factors. But, in the present study consanguinity was found to be independent of education. Overall low education and economic level of the respondents may provide a probable explanation.

Conclusions and Recommendations

In present study, overall awareness regarding the problems associated with consanguinity was found to be very low. Tradition and history of similar marriages in the family in the past were the most important influencing factors.

Consanguineous marriages were seen to run in clusters in some families. So occurrence of one such marriage may be considered as a factor leading to more consanguineous marriages in the family. If a health worker comes across any such marriage, he/she should educate the family about this issue in order to help them choose the right option for a subsequent marriage in the family. Consanguineously married person should be questioned regarding any defects in the ancestors and/or progeny and should be advised about genetic counselling. Health workers should make it a routine practice to ask about the history of consanguinity to any person who would be a future parent and advise accordingly.

Appropriate and convenient time to instill the importance of preventing consanguineous marriages seems to be the adolescent age. Therefore it will be useful for every school and college to create awareness amongst adolescents and their parents regarding consanguineous marriages and the probable effects.

At the individual level, the risk of having problems associated with consanguinity is very small. However, in a broader perspective, the society has to shoulder the burden of taking care of congenital malformations and other problems arising out of such marriages. Considering the high proportion of population opting for consanguineous marriages, this may thus put a great burden on the society. Increasing public awareness in general and giving the right advice to people will play a crucial role in the reduction of the proportion of such marriages.

Acknowledgements

Authors would like to acknowledge Mr. Kailas Gandewar, Lecturer, P.S.M. Department, L.T.M.M.C, for his guidance during statistical analysis.

References

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