Measured intelligence in offspring of oral and nonoral contraceptive users ABELARDO

FUERTES-DELA

GUILLERMO

SANTIAGO,

ISHVER San Juan,

S. Puerto

BANGDIWALA,

HABA,

M.D.,

D.P.H.,

F.A.C.O.G.

M.D. PH.D.,

F.A.S.A

Rico

A study has been made of measures of intelligence of21 0 children (5 to 8 years of age) born to mothers who used oral and nonoral contraceptives pregestationally. Ninety-six OJ these children were born to mothers who used oral contraceptives, and one hundred and fourteen were born to mothers who used uaginal contraceptive methods. The intelligence of the children was measured in the form of the full-scale 1.4. score by the Wechsler Intelligence Scale for Children (WISC) adapted and normalized for Puerto Rico by the Puerto Rico Department of Education. A three-factor analysis of variance was performed on the data collected for comparison of the two groups. It was observed that there was no signaficant dzfference between the average IQ. scores of children born to mothers using oral contraceptives arid those born to the mothxrs wing nonoral contraceptives. The average 1.4. in children of tk oral contraceptive group was 85.04 and that in children of the nonoral contraceptive group was 85.54. Distributions for both groups were also found to be similar. No signiJicant dayferences between means were observed for sex, age, and interactions with the exception of the age and sex interaction, where, again, no speca$c, meanin& trend could be established. The average IQ. in the sample fell veTy close to the center of the “normal” range of the WISC, Puerto Rican adaptation. The results of the study do not offer any evidence as to the effect of the we of oral contraceptives on the intelligence measure (by the WISC) of the offspring born to mother,\ using them pregestationally. The children under study, on an average, are of "normal" intelligence as maamred by the Puerto Rican intelligence standards.

THE ORAL CONTRACEPTIVE, commonly “the pill,” has been employed more and method of family planning. As its use different segments of society are asking about its possible effects on women and their

known as more as a increases, themselves offspring.

Some of the effects on mothers and fetuses have been mentioned in previous studies.“-’ Numerous art,icles in the lay press also have focused attention on the alleged harmful effects of the contraceptive pill. Some have claimed congenital and physical defects and low intelligence quotients in the offspring of mothers who have received antenatal norethynodrel.” ’ However, one of the specific questions remaining unanswered was whether the administration of oral contraceptive steroids immediately prior to pregnancy had any relationship to the intelligence of the child. A review of the available literature, up to 1971, indicated that this subject, although mentioned in a few articles, had not been formally investigated. This made evident the need for research directed toward identifying and understanding in a more scientific way the effects of oral contraceptives on the intelligence of children born to mothers who used them. The present report reveals some important

From the Department of Obstetrics and Gynecology, and the Department of Psych&y, University of Puerto Rico School of Medicine, and the Department of Graduate Studies, University of Puerto Rico. Supported in part by a grant from G. D. Searle 63 Co., P. 0. Box 5110, Chicago, Illinois 60680, and a special wignnwnt from the Puerto Rico Legislature through Senator Luis Izquierdo-Mora, M.D., President of the Finance Commission of the Puerto Rico Senate. Received for publication Acceptid

December

September

30, 1975.

24, 1975.

Reprint requests: Dr. Abe&do Fuertes-de la Haba, Director, Maternal Health Program, Offtie A-886, Medical Sciences Bldg., G. P. 0. Box 5067, SnnJuan, Puerto Rico 00936.

980

Volume Number

125 7

findings of a controlled experiment being carried out in the Maternal Health Program at the University of Puerto Rico Medical School.

Method The subjects for the study were obtained from the Maternal Health Study Program which was designed in 1961 to study the incidence of genital and breast cancer in women who were taking progestational agents. Subjects admitted to the study program met basic minimum qualifications such as: age 21 to 39 years old, at least one normal pregnancy, and no prior use of oral contraceptives or intrauterine contraceptive devices. Each candidate, before admission to the program agreed to use the contraceptive to be prescribed. Once a woman was found eligible, and prior to the physical examination, she was assigned at random to the experimental (oral contraceptive) or the control (nonoral contraceptive) group* which she was to follow throughout the experiment. The 5,465 subjects of the present study were admitted to one of the clinics in the project between 1961 and 1969. The randomization procedure assigned 2,741 women (50.16 percent) to the study group (oral contraceptive) and 2,724 (49.84 per cent) to the control group (nonoral contraceptive). A comparison of several socioeconomic characteristics of the randomly selected subjects for our two groups such as age, education, family income, occupation, etc., showed that both groups (oral and nonoral contraceptive) were identical and, therefore, comparable.6 The next step was to identify the mothers who had offspring after admission to the study. These were mostly voluntary pregnancies, since there were no cases of contraception failure among the oral group. During the period 1961 to 1969, 398 children were born to the 5,465 women. Of the 398 children, 229 (57.54 per cent) were between ages 5 and 8 at the time of the study, an age range suitable for the psychological tests to be used. Of these 229 children, 210 were included in the study. The other nineteen patients (11 users of oral contraceptives and 8 users of nonoral contraceptives) were excluded either because the children were dead or because they had moved out to other communities and therefore were lost to study. The subjects of the study were distributed as follows: 96 children (41 boys and 55 girls) were in the group *The oral contraceptive group used norethynodrel, 5 mg., and mestranol. 0.075 mn. (Enovid. G. D. SearIe & Co.). The total steroid dosage wax j.75 mg. Per tablet. The control group used vaginal methods such as diaphragms, prophylactics, suppositories, etc.

Intelligence of offspring of contraceptive users

Table I. Analysis scores

of the full-scale

Degrees of freedom

Source of uariancc

Contraceptive treatment (C) Sex (S) Age (4 C-S interaction C-A interaction S-A interaction C-S-A interaction Error Total *Sign&cant

of variance

1

Mear2 square

981

I.Q.

F ratio

11.05

0.07

1 2 1 2 2 2 198

237.86 153.2 1 183.09 36.71 655.55 407.77 150.19

1.58 1.02 1.22 0.24 4.37* 2.72

i&i

156.35

at 5 per cent level.

whose mothers used oral contraceptives, and 114 (60 boys and 54 girls) were in that of the women who used nonoral contraceptives. The average ages of the two groups were 6.1 years for the study group (oral contraceptives) and 6.2 years for the control group (nonoral contraceptives). Each child was referred at random to one of the two psychologists* who administered a full-scale intelligence test. The test used in the study was the Wechsler Intelligence Scale for Children (WISC) (Escala de Intehgencia Wechsler para Niiros) which is translated and adapted for Puerto Rico by the Department of Education of the Commonwealth of Puerto Rico! This test is not a literal translation of the English WISC. It has been adapted after several experimental studies, in 1951, which suggested revisions appropriate to the Puerto Rican language and cultural environment. The test was normalized by Dr. Pablo Rota, then Director of the Evaluation Office of the Department of Education, in consultation with the author of the test, David Wechsler, and the Psychological Corporation of New York. In administering the test, the psychologists followed the manual prepared by David Wechsler for the test in Spanish.‘” For the purpose of the study, a three-factor (treatment group X sex X age) analysis of variance was performed on the full-scale Intelligence Quotient (I.Q.) scores.

Findings The analysis of the data revealed that the 96 children of the oral contraceptive group had an average I.Q. score of 85.08 (with a standard deviation of 13.66), *The usvcholoeists were both Puerto Rican and had their M.A.‘s in’ Psycholggy from recognized United States universities; they were experienced and trained to administer psychological tests.

982

Fuertes-de

la Haba,

Santiago,

Table II. Means and standard nonoral contraceptive groups

and Bangdiwala

deviations (SD.) of WISC (Puerto by sex and age Treatment

Age oj childrnz &an)

Rico) I.Q. scores for children

---

group

Oral /-O~lt?WptiLV

of’ oral a11c1

! Nonoral contrucPptiz,v

! Both grorlp~ fWi gWql\ ctrctl c(‘x

Boy

Cd\

BOY.,

Girls

BqYJ

No. Mean S.D.

9 81.44 9.42

12 85.33 19.24

11 82.91 10.11

6 84.50 6.24

20 82.25 9.83

No. Mean SD. 7-8 NO. Mean SD.

18 88.50 11.63

26 83.69 11.82

28 87.75 10.85

34 86.53 11.07

46 88.04 11.17

60 85.30 11.49

106

:64.00 9.29

17 92.82 12.93

21 83.24 9.60

14 84.7 1 16.08

35 80.34 10.12

3I 89.16 14.99

66 84.48

41 82.68 11.78

55 86.87 14.66

60 85.28 10.55

54 85.83 12.22

101 84.23 11.14

I 09 86.36 13.51

GirL7

.5

6

Mean S.D.

86.49 ll.43

13.3Y

Both .sexe.~and all ages NO.

Mean S.D.

96 85.08 13.66

while the 114 children of the nonoral contraceptive group had an average 1.Q. score of 85.54 (with a standard deviation of 11.37). The difference (0.48) between the two averages is not statistically significant, as indicated by the F test in the analysis of variance (Table I). It may be noted that the I.Q. score in children of the “oral contraceptive” group ranged from a low score of 55 to a high of 133, while in the nonoral group it ranged from 54 to 118. The I.Q. scores for both groups were similar and essentially distributed normally. Thus, these data suggest that children of both groups (oral and nonoral contraceptive) were almost equal in I.Q. When the groups are combined, the average I.Q. of the 210 children was found to be 85.33 (standard deviation 12.47). This average score compares fairly well with the average I.Q. score of the children in Puerto Rico which is 88, according to a study made by the Department of Education, wherein it is established that the average I.Q. (88) of children in Puerto Rico is equivalent to the average 1.Q. (100) by the United States standards.” The results of the F test indicated that none of the main effects (treatment, sex, and age) were significant. Also among the interactions, only the sex and age

REFERENCES

1. Abdul-Karim, R. W., Druker, M., and Rizk. P.: Influence of estrogen on the cholinesterase content of fetal brain. Ohstet. Gynecol. 36: 719, 1970.

114 85.54 11.37

2 10 85.33 12.47

interaction was found to be significant at the 5 per cent level. However, when the average I.Q. scores between boy5 and girls within the age groups were compared. as indicated in Table II, no meanings coutd be assigned to these differences, as no specific trend could be noticed among the six means. For example, at age 5. the boys had an average I.Q. score 2.81 points lower than girls (82.25 versus 85.06); on the other hand, at the age of 6 (a year-older group), the boys had an average score 2.74 higher than the girls but, once again. the average of boys in the 7- to g-year-old group was lower by 8.82 points than that of the girls in that group. ‘I‘h~ls, even though the age-sex interaction averages show significant differences, no meaningful trend bk age or b) sex could be established. We gratefully acknowledge the helpfLl1 coutributiorl of Senator Luis Izquierdo-Mora, M.D., Dr. Samuel Rodriguez, Medical Director, Maternal lnfant Care Project, Mr. Jorge Dominguez, and Miss Carmen Lydia Romero (deceased), psychologists who performed thr tests on the children in the study. Appreciation is also expressed to Mrs. Nilda Martin de SuntirC for her contribution to the study.

2. Bongiovanni, A., and MaPadden, A. J.: Steroids during pregnancy and possible fetal conscquenc~es. Fcrtil. St&. 11: 181, 1960. 3. Kupperman, H. S.: Progesterone, and related steroids in

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4. 5. 6.

7.

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the management of recurrent abortion, presented at the Brooke Lodge Symposium, Brooke Lodge, Michigan, 1961, Brooke Lodge Press, p. 105. Burstein, R., and Wasserman, H. C.: The effect of Provera on the fetus. Obstet. Gynecol. 23: 931, 1964. Drillien, C. M.: The small for date infants: Etiology and prognosis, Pediatr. Clin. North Am. 17: 9, 1970. Fuertes-de la Haba, A., Bangdiwala, I., and Pelegrina, 1.: Success of randomization procedure in a controlled contraceptive experiment, J. Reprod. Med. 11: 142, 1973. Fuertes-de la Haba, A., Curet, J. O., Pelegrina, I., and Bangdiwala, I.: Thrombophlebitis among oral and non-

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oral contraceptive users, Obstet. Gynecol. 38: 259, 1971. 8. Fuertes-de la Haba, A., Pelegrina, I., Bangdiwala, I., and Hernandez-Cibes, J. J.: Changing patterns in cervical cytology among oral and non-oral contraceptive users, J. Reprod. Med. 10: 3, 1973. 9. Rota, P.: Problems of adapting intelligence scales from one culture to another, Department of Education, Commonwealth of Puerto Rico, 1955. 10. Wechsler, D.: Escala de Inteligencia Wechsler Para Nines, Departamento de Instruccidn, Estado Libre Asociado de Puerto Rico, 1970.

Measured intelligence in offspring of oral and nonoral contraceptive users.

Measured intelligence in offspring of oral and nonoral contraceptive users ABELARDO FUERTES-DELA GUILLERMO SANTIAGO, ISHVER San Juan, S. Puerto...
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