ABO Blood Groups and Fertility-with Special Reference to Intrauterine Selection due to Materno-fetal Incompatibility M SATYANARAYANA. M VIJAYALAKSHMI, C SAMBASIVA RAO
ANTI
SUSAN MATHEW Department of Human Genetics and Physical Anthropology, Andhra Uniuersity, Waltair, A P , India 530003
KEY WORDS ABO blood groups patibility
Compatibility . Incom . Prenatal death
. Abortion . Pregnancy wastage
ABSTRACT
The purpose of t h e present investigation was to study whether there is differential fertility between different mating types of ABO blood group system. Selective force which is operating through maternal-fetal incompatibility has been observed in t h e differential fertility between compatible and incompatible m a t i n g groups in t h e present sample of 183 families of Visakhapatnam town of Andhra Pradesh, India. The differences in t h e mean numbers of pregnancies as well as living children between t h e two major mating groups, compatible and incompatible a r e significant. The fertility rates of 0 fathers and 0 mothers were significantly higher t h a n those in matings in which neither parents belongs to 0. The selection is operating to reduce the gene ratio of A and to increase t h e gene ratios of 0 and B in this sample.
Since Hirszfeld's observation on t h e selective loss of infants who were incompatible with their mothers' ABO blood groups, investigations have been carried out and a number of papers have been published analyzing t h e relationship between parental ABO incompatibility and human reproductive failure. (Hirszfeld and Zborowski, '25). A selective effect of ABO incompatibility is of interest to geneticists because of its role in maintaining the ABO blood group polymorphism, and to t h e clinician because of its influence on fertility and early fetal survival (Tauritsen e t al., '75). Various characters such as prenatal deaths and infertility have been examined by several investigators. Matsunaga and Itoh ('58) were the first t o study fertility, blood groups and selection on a large scale. Analyzing data comprising more t h a n 1,500 families in Japan, they showed significantly higher frequencies of both infertile couples and spontaneous abortions among ABO-incompatible mating types t h a n among compatible mating types. Their results were confirmed later by Haga ('59). Hiraizumi ('64)collected a larger body of complete family data, also from Japan, specifically to study the effects of ABO incomAM. J. PHYS. ANTHROP. (1978) 49: 489-496.
patibility, but analysis failed to repeat the results obtained by Matsunaga and Itoh ('58); incompatibility had very little or no effect on fetal death. Several other studies have been reported in subsequent years (Cohen and Sayre, '68; Reed, '68) but results were inconsistent, so t h a t even after 50 years the question of whether ABO blood group incompatibility has etiological significance in spontaneous abortions and differential fertility remains unanswered. This study is designed t o consider to what extent family studies can help to examine or to investigate t h e effects of ABO incompatibility on differential fertility, and to present fresh data on this problem. MATERIAL9 AND METHODS
The data used in t h e present investigation was collected by field study of 183middle class families residing in Visakhaptanam (Andhra Pradesh). Though very few families with one child were included in the study, those with at least two children were selected at random. The information on t h e reproductive histories was obtained by interviewing t h e wives and this was checked with husbands t o eliminate t h e possibilities of recording a n induced abor-
489
490
M. SATYANARAYANA. M. VIJAYALAKSHMI, C. S. RAO, S. MATHEW
tion as spontaneous, a s family planning was in practice among these families and one of t h e methods used was induced abortions. The blood types were analyzed for 183 couples with 505 children.
been recorded in compatible matings. The total number of pregnancy wastage is greater in incompatible matings when compared to compatible matings, t h e two figures being 34 (14.12%)and 44 (12.68%) respectively. Three childless couples were in the compatible m a t ing group (B x B), but are too small a number to be used in t h e present study. The observed and expected values of t h e total number of pregnancies, prenatal deaths and living children in the two mating groups are presented in table 2. The total number of pregnancies of t h e two major mating groups does not differ significantly when t h e difference between t h e two mating groups is considered CX: = 0.2857, P < 0.05). There is a slightly higher incidence of abortions in t h e incompatible t h a n in t h e compatible mating group and a higher incidence of living children in compatible than in incompatible matings
RESULTS
A summary of t h e reproductive performances of families in each mating type from compatible and incompatible matings is given in table 1.There were 106 compatible matings and 77 incompatible matings, with a total of 303 and 207 living children recorded under t h e compatible and incompatible mating groups respectively. Thirty-two prenatal deaths occurred in each of t h e two major mating groups, and a n interesting point in t h e present study is t h a t postnatal deaths are almost absent in incompatible matings whereas a considerable number of postnatal deaths have
TABLE I Summary of reproductive performances offumilies in each mating typr! f r o m compatible
land incompatible rnatings) Mating types i' x c'
Total no. of matings
Compatible matings AXA 9 B x B 18 A B X AB 1 A x 0 20 BXO 23 AB x 0 1 AB X A 4 AB X B 4 O X 0 26 Total 106 Incompatible matings OXA 11 OXB 21 OXAB 6 A X B 12 BXA 15 AXAB 5 BXAB 7 Total 71
Total no of Iiv.child
Prenalal deaths
Total pw.
Postnatal deaths
r a s tage
Total nn. of pregnancies
27 51 3 61 92 4 13 9 87 347
7 9
20 42 3 50
-
11 11
81
-
4 13 9 81 303
-.
6 44
36 72 21 32 46 14 19 241
5 8 3 6 5 2 3 32
30 64
'3
26 41 12 16 207
TABLE 2
Total number of pregnancies, prenatal deaths, and living children in compatible and incompatible matings with respect t o ABO blood groups Pregnancies
Prenatal deaths
Living children
s o of
ABO compatible ABO incompatible Total
mhbngs
Oba.
Exp.
Obs.
Exp.
Obs.
Exp.
106 77 183
347 241 588
340.6 247.4 588
32 32 64
37 27 64
303 207 510
295 215 510
49 1
ABO BLOOD GROUPS AND FERTILITY
but the differences are not statistically significant. CX: = 1.6015,P < 0.05 and X: = 0.5145, P < 0.05 respectively). The distribution of pregnancies for both mating groups is presented in table 3. The mean number of pregnancies in the compatible matings is 3.3 and that in incompatible
matings is 3.1, the difference being statistically significant (t = 2.3791, P > 0.02). The proportion of abortions in the compatible matings is 9.22% and that in the incompatible matings is 13.28%.The difference between these percentages is not statistically significant CX: = 2.4123, P < 0.05).
TABLE 3
DLstribution of pregnancies in ARO mating t w e s SE N u of' pregnancies i x
2.
0
1
3
2
6
6
4
5
8
11
of
Prob. of abort
Vanance ul nu. uf
mean nu. of
ppr preg.
of preg.
preg.
5 6
0.19 0.12
1.56 2.14
0.42 0.35
9 8
0.15 0.09
2.85 4.52 -
-
0.19 1.19 1.84 2.73
0.22 0.55 0.27 0.16
2.38 1.48
1.54 0.27
Mean Total no. of abort preg pcrprrg.
Nu. of niatmgs
Tata! nu. uf' prea
9 18 1 20 23 1 4 4 26 106
27 51 3 61 92 4 13 9 87 347
3.00 2.83 3.00 3.05 4.00 4.00 3.25 2.25 3.35 3.27
-
-
4 32
0.05 0.09
11 21 6 12 15 5 7 77
36 72 21 32 47 14 19 241
3.27 3.43 3.50 2.67 3.13 2.80 2.17 3.13
5 8 3 6 5 2 3 32
0.14 0.11 0.14 0.19 0.11 0.14
Compatible matings
AXA BXB ABXAB A x 0 B x O AB X 0 AB x A AR X B O x 0
- 1
-
2
-
4 3 1 - 1 - - 4 7 1 2 1 - - -
1 - -
-
-
5 4
Total
-
-
- _ - -
7 3
-
2 410 6 2 Total 110233420 7 Incompatible matings
O x A OXB OxAB AXB BXA AxAB BxAR
-
2 1 1 - 1 -7 2 4 - - I I - - - - - - - 3 1 - _ - - _ 1 2 I - - - - 3 2
_ -
1 1 - 8 I 1 1
2 2 1 - 1 7 3 6 - - - 3 3 - - - - - 2 4 3 2 I - - - - 1 4 6 1 2 1 - - - - 2 2 I - - - - - - 4 2 1 0 423251211 1 1 -
1
5 4
-
- - -
_ _ - -
-
-
~-
-
-~
-
1.39 1.72
0.34 0.34
1.54
0.14
-
0.16 0.13
-
0.38 0.44
-
TABLE 1
Distribution of Ziuing chddrrrz i n ABO mating tvpes Nu. of children j
x ::
n
I
2
1 1
5 7
3
4
'Total no ul children
no. of children
- - - 1 1 3
20 23 1 4 4 26 106
20 42 3 50 81 4 13 9 81 303
2.22 2.33 3.00 2.50 3.52 4.00 3.25 2.25 3.12 2.86
1 1 3 - - - - - 1 - - - - - 5 1 -
11 21 6 12 15 5 7 77
30 64 18 26 41 12 16 207
2.73 3.05 3.00 2.17 2.73 2.40 2.29 2.69
5
6
10
No o f mntings
MP'iIl
Variance of children
Y.E.
us
llleali ,I
ANTI
SUSAN MATHEW Department of Human Genetics and Physical Anthropology, Andhra Uniuersity, Waltair, A P , India 530003
KEY WORDS ABO blood groups patibility
Compatibility . Incom . Prenatal death
. Abortion . Pregnancy wastage
ABSTRACT
The purpose of t h e present investigation was to study whether there is differential fertility between different mating types of ABO blood group system. Selective force which is operating through maternal-fetal incompatibility has been observed in t h e differential fertility between compatible and incompatible m a t i n g groups in t h e present sample of 183 families of Visakhapatnam town of Andhra Pradesh, India. The differences in t h e mean numbers of pregnancies as well as living children between t h e two major mating groups, compatible and incompatible a r e significant. The fertility rates of 0 fathers and 0 mothers were significantly higher t h a n those in matings in which neither parents belongs to 0. The selection is operating to reduce the gene ratio of A and to increase t h e gene ratios of 0 and B in this sample.
Since Hirszfeld's observation on t h e selective loss of infants who were incompatible with their mothers' ABO blood groups, investigations have been carried out and a number of papers have been published analyzing t h e relationship between parental ABO incompatibility and human reproductive failure. (Hirszfeld and Zborowski, '25). A selective effect of ABO incompatibility is of interest to geneticists because of its role in maintaining the ABO blood group polymorphism, and to t h e clinician because of its influence on fertility and early fetal survival (Tauritsen e t al., '75). Various characters such as prenatal deaths and infertility have been examined by several investigators. Matsunaga and Itoh ('58) were the first t o study fertility, blood groups and selection on a large scale. Analyzing data comprising more t h a n 1,500 families in Japan, they showed significantly higher frequencies of both infertile couples and spontaneous abortions among ABO-incompatible mating types t h a n among compatible mating types. Their results were confirmed later by Haga ('59). Hiraizumi ('64)collected a larger body of complete family data, also from Japan, specifically to study the effects of ABO incomAM. J. PHYS. ANTHROP. (1978) 49: 489-496.
patibility, but analysis failed to repeat the results obtained by Matsunaga and Itoh ('58); incompatibility had very little or no effect on fetal death. Several other studies have been reported in subsequent years (Cohen and Sayre, '68; Reed, '68) but results were inconsistent, so t h a t even after 50 years the question of whether ABO blood group incompatibility has etiological significance in spontaneous abortions and differential fertility remains unanswered. This study is designed t o consider to what extent family studies can help to examine or to investigate t h e effects of ABO incompatibility on differential fertility, and to present fresh data on this problem. MATERIAL9 AND METHODS
The data used in t h e present investigation was collected by field study of 183middle class families residing in Visakhaptanam (Andhra Pradesh). Though very few families with one child were included in the study, those with at least two children were selected at random. The information on t h e reproductive histories was obtained by interviewing t h e wives and this was checked with husbands t o eliminate t h e possibilities of recording a n induced abor-
489
490
M. SATYANARAYANA. M. VIJAYALAKSHMI, C. S. RAO, S. MATHEW
tion as spontaneous, a s family planning was in practice among these families and one of t h e methods used was induced abortions. The blood types were analyzed for 183 couples with 505 children.
been recorded in compatible matings. The total number of pregnancy wastage is greater in incompatible matings when compared to compatible matings, t h e two figures being 34 (14.12%)and 44 (12.68%) respectively. Three childless couples were in the compatible m a t ing group (B x B), but are too small a number to be used in t h e present study. The observed and expected values of t h e total number of pregnancies, prenatal deaths and living children in the two mating groups are presented in table 2. The total number of pregnancies of t h e two major mating groups does not differ significantly when t h e difference between t h e two mating groups is considered CX: = 0.2857, P < 0.05). There is a slightly higher incidence of abortions in t h e incompatible t h a n in t h e compatible mating group and a higher incidence of living children in compatible than in incompatible matings
RESULTS
A summary of t h e reproductive performances of families in each mating type from compatible and incompatible matings is given in table 1.There were 106 compatible matings and 77 incompatible matings, with a total of 303 and 207 living children recorded under t h e compatible and incompatible mating groups respectively. Thirty-two prenatal deaths occurred in each of t h e two major mating groups, and a n interesting point in t h e present study is t h a t postnatal deaths are almost absent in incompatible matings whereas a considerable number of postnatal deaths have
TABLE I Summary of reproductive performances offumilies in each mating typr! f r o m compatible
land incompatible rnatings) Mating types i' x c'
Total no. of matings
Compatible matings AXA 9 B x B 18 A B X AB 1 A x 0 20 BXO 23 AB x 0 1 AB X A 4 AB X B 4 O X 0 26 Total 106 Incompatible matings OXA 11 OXB 21 OXAB 6 A X B 12 BXA 15 AXAB 5 BXAB 7 Total 71
Total no of Iiv.child
Prenalal deaths
Total pw.
Postnatal deaths
r a s tage
Total nn. of pregnancies
27 51 3 61 92 4 13 9 87 347
7 9
20 42 3 50
-
11 11
81
-
4 13 9 81 303
-.
6 44
36 72 21 32 46 14 19 241
5 8 3 6 5 2 3 32
30 64
'3
26 41 12 16 207
TABLE 2
Total number of pregnancies, prenatal deaths, and living children in compatible and incompatible matings with respect t o ABO blood groups Pregnancies
Prenatal deaths
Living children
s o of
ABO compatible ABO incompatible Total
mhbngs
Oba.
Exp.
Obs.
Exp.
Obs.
Exp.
106 77 183
347 241 588
340.6 247.4 588
32 32 64
37 27 64
303 207 510
295 215 510
49 1
ABO BLOOD GROUPS AND FERTILITY
but the differences are not statistically significant. CX: = 1.6015,P < 0.05 and X: = 0.5145, P < 0.05 respectively). The distribution of pregnancies for both mating groups is presented in table 3. The mean number of pregnancies in the compatible matings is 3.3 and that in incompatible
matings is 3.1, the difference being statistically significant (t = 2.3791, P > 0.02). The proportion of abortions in the compatible matings is 9.22% and that in the incompatible matings is 13.28%.The difference between these percentages is not statistically significant CX: = 2.4123, P < 0.05).
TABLE 3
DLstribution of pregnancies in ARO mating t w e s SE N u of' pregnancies i x
2.
0
1
3
2
6
6
4
5
8
11
of
Prob. of abort
Vanance ul nu. uf
mean nu. of
ppr preg.
of preg.
preg.
5 6
0.19 0.12
1.56 2.14
0.42 0.35
9 8
0.15 0.09
2.85 4.52 -
-
0.19 1.19 1.84 2.73
0.22 0.55 0.27 0.16
2.38 1.48
1.54 0.27
Mean Total no. of abort preg pcrprrg.
Nu. of niatmgs
Tata! nu. uf' prea
9 18 1 20 23 1 4 4 26 106
27 51 3 61 92 4 13 9 87 347
3.00 2.83 3.00 3.05 4.00 4.00 3.25 2.25 3.35 3.27
-
-
4 32
0.05 0.09
11 21 6 12 15 5 7 77
36 72 21 32 47 14 19 241
3.27 3.43 3.50 2.67 3.13 2.80 2.17 3.13
5 8 3 6 5 2 3 32
0.14 0.11 0.14 0.19 0.11 0.14
Compatible matings
AXA BXB ABXAB A x 0 B x O AB X 0 AB x A AR X B O x 0
- 1
-
2
-
4 3 1 - 1 - - 4 7 1 2 1 - - -
1 - -
-
-
5 4
Total
-
-
- _ - -
7 3
-
2 410 6 2 Total 110233420 7 Incompatible matings
O x A OXB OxAB AXB BXA AxAB BxAR
-
2 1 1 - 1 -7 2 4 - - I I - - - - - - - 3 1 - _ - - _ 1 2 I - - - - 3 2
_ -
1 1 - 8 I 1 1
2 2 1 - 1 7 3 6 - - - 3 3 - - - - - 2 4 3 2 I - - - - 1 4 6 1 2 1 - - - - 2 2 I - - - - - - 4 2 1 0 423251211 1 1 -
1
5 4
-
- - -
_ _ - -
-
-
~-
-
-~
-
1.39 1.72
0.34 0.34
1.54
0.14
-
0.16 0.13
-
0.38 0.44
-
TABLE 1
Distribution of Ziuing chddrrrz i n ABO mating tvpes Nu. of children j
x ::
n
I
2
1 1
5 7
3
4
'Total no ul children
no. of children
- - - 1 1 3
20 23 1 4 4 26 106
20 42 3 50 81 4 13 9 81 303
2.22 2.33 3.00 2.50 3.52 4.00 3.25 2.25 3.12 2.86
1 1 3 - - - - - 1 - - - - - 5 1 -
11 21 6 12 15 5 7 77
30 64 18 26 41 12 16 207
2.73 3.05 3.00 2.17 2.73 2.40 2.29 2.69
5
6
10
No o f mntings
MP'iIl
Variance of children
Y.E.
us
llleali ,I
