French Speaking Free University of Brussels, Brussels, Belgium

Transcription

1 FERTILITY AND STERILITY VOL. 80, NO. 6, DECEMBER 2003 Copyright 2003 American Society for Reproductive Medicine Published by Elsevier Inc. Printed on acid-free paper in U.S.A. A prospective longitudinal study of the physical, psychomotor, and intellectual development of singleton children up to 5 years who were conceived by intracytoplasmic sperm injection compared with children conceived spontaneously and by in vitro fertilization Isabelle Place, M.Sc., a and Yvon Englert, Ph.D. a,b French Speaking Free University of Brussels, Brussels, Belgium Received October 10, 2002; revised and accepted June 16, Supported by a grant from the Belgian National Fund for Scientific Research, for which I.P. is a scientific collaborator. Reprint requests: Isabelle Place, M.Sc., Erasme Hospital, Fertility Clinic, 808 Route de Lennik, 1070 Brussels, Belgium (FAX: ; iplace@ulb.ac.be). a Research Laboratory on Human Reproduction, Faculty of Medicine. b Fertility Clinic, Erasme Hospital /03/$30.00 doi: /j.fertnstert Objective: To assess the somatic, psychomotor, and intellectual development of children conceived through intracytoplasmic single sperm injection (ICSI) over the whole preschool period. Design: Prospective, controlled, cohort study. Setting: Fertility clinic in Brussels, Belgium. Patient(s): Sixty-six ICSI-conceived children prospectively compared with 52 IVF-conceived and 59 spontaneously conceived children. All children were full-term singletons. Intervention(s): Home visits by a trained psychologist. Standardized interviews. Assessments using the revised Brunet-Lézine scale and the revised Wechsler preschool and primary scale of intelligence. Main Outcome Measure(s): Physical growth and general health. Formal developmental and intellectual assessments. Result(s): Children conceived by ICSI were healthy: no significant differences appeared in the incidence of combined congenital malformations (11.3%), health problems (44.1%), surgical interventions (18.6%), and hospitalizations (6.8%), nor for the developmental assessments (mean developmental quotient at 9 months: 93.9; at 18 months: 102.0). For the intellectual assessments, the between-group differences disappeared when adjusted for levels of parental education (mean intelligence quotient at 3 years: 97.0; at 5 years: 103.3). Conclusion(s): This pilot study shows that throughout the preschool period, ICSI-conceived children have psychomotor and intellectual development similar to that of IVF-conceived and spontaneously conceived children. These conclusions need to be confirmed by multicenter studies. (Fertil Steril 2003;80: by American Society for Reproductive Medicine.) Key Words: Child development, ICSI, psychomotor development, intellectual outcome For several decades, medical intervention in the field of infertility has been increasing. Depending on the sources, 10% to 20% of the population now consults for infertility problems. Dazzling progress in the field of biology of reproduction helped develop several new medically assisted procreation procedures. Many couples who would have remained infertile in the past can now have children. Throughout the world, 300,000 children have been conceived by IVF, and in Belgium, 2,000 children are conceived outside of the womb each year, which represents 2% of annual births. Although first introduced in the early 1990s, the new intracytoplasmic single sperm injection procedure (ICSI) is currently performed in hundreds of IVF centers worldwide, and it is likely that tens of thousands of children have been born after this procedure. The arrival of the microinjection procedure into the field of assisted reproduction helped clinicians obtain embryos in cases of severe 1388

2 male infertility that up until now were with little or no therapeutic hope, allowing previously infertile men to become the genetic fathers of their offspring. This technique bypasses all natural sperm selection processes and thus raises a countless number of questions regarding the physical, intellectual, and psychological outcome of these children because of the putative additional risks related to either the invasive nature of the ICSI procedure or to the use of poor-quality semen. Long-term implications for life expectancy, health, or fertility of ICSI-conceived children are of course unknown. The need to assess the health of children born after ICSI has become a major concern over the last several years, but the use of the ICSI technique has advanced at such a pace that studies on the long-term outcome of ICSI-conceived children have lagged far behind. Up until now data have been scarce; only a few studies have specifically addressed follow-up of the health and development of ICSI-conceived children with direct evaluation of the children (1 7). To date, all of the published studies concern children who are 2 years old, and most of them involve a bias (absence of demographic information, absence of control groups, or control groups obtained by buddy matching ), all of which amounts to a contradiction of results. Some studies appeared to show no additional risk after ICSI (3, 5 7), whereas one study suggested a mild mental development delay of 1-year-old ICSI infants, especially boys (4). The fertility laboratory of the Erasme Hospital obtained its first birth by this technique in The laboratory has since been actively participating in the collection of empirical data on the security of the microinjection procedure. Data have been gathered concerning the outcome of ICSI pregnancies, births, the rates of major and minor congenital malformations, and karyotypes of ICSI-conceived children in comparison with those resulting from IVF (8, 9). After these prenatal and postnatal analyses, the objective was to conjointly assess over the whole preschool period the somatic condition as well as the psychomotor, intellectual, emotional, and behavioral development of ICSI-conceived children. This prospective longitudinal study was aimed at providing answers to the legitimate questions raised by parents, healthcare professionals, and policy makers on the issue of the long-term outcome of ICSI-conceived children. MATERIALS AND METHODS The study compared ICSI-conceived children with children conceived by conventional IVF and with spontaneously conceived children. The comparison of the ICSI-conceived children with the second control group (spontaneously conceived children) allowed us to see whether differences appeared between these children and children conceived without any medical assistance. As for the IVF-conceived children, these are usually children that parents have been awaiting for a long time, so the parental investment is similar to that of ICSI-conceived children. This subtle comparison with the first control group thus allowed us to compare the effects of male infertility (ICSI group) with the effects of female infertility (IVF group) and to see the influence of the couples infertility on the children s development. Selection and Matching Criteria The population samples were families who resorted to IVF or ICSI treatments at the fertility clinic of the Erasme hospital. For the spontaneously conceived children, families who gave birth in the maternity ward of the Erasme Hospital were contacted. Indications for the ICSI procedure were either abnormal semen parameters or fertilization failure in previous IVF attempts. Immature spermatozoa surgically obtained from the epididymis and the testis were used successfully for three couples who were included in the study. The conventional IVF procedure as well as the ICSI procedure used by the fertility clinic of the Erasme hospital were described elsewhere (10, 11). For the ICSI and IVF groups, the head of the fertility clinic wrote to these families well after the birth of the child and asked for their consent to participate in a prospective study that included a clinical follow-up of their child. Before contacting the families of the spontaneously conceived children, preliminary agreement from their gynecologist was obtained. The letter of consent addressed to these families was signed by the head of the fertility clinic as well as by their gynecologist. All children included in the study were full-term singletons so as to test the possible influence of the ICSI procedure without having the interference of other difficulties associated with multiple births and prematurity, known to influence children s early development (12). For the same reasons, pregnancies obtained after frozen and thawed ETs (either IVF or ICSI) as well as children with a birth weight of 2,500 g were excluded from the study. Moreover, it would have been very difficult to appropriately match the control groups for variables such as prematurity, low birth weights, as well as multiple births. The mean gestational age for all three groups was 39.7 weeks (SD, 1.23). The mean birth weight of the girls in all three groups was 3,237 g (SD, ), and for the boys, it was 3,334 g (SD ). The age of the mothers was between 20 and 40 years. There were no particular restrictions in regard to paternal age. The population sample was Belgian for at least one of the partners and was European and residing in Belgium for 3 years for the other partner. This measure was to limit the possible sociocultural divergences, especially for cultures far from our own, with regard to the representation and investment given to pregnancies and to children as well as in regard to the division of family roles. It was also used to overcome the linguistic barriers. All full-term singleton children conceived by ICSI that fell into the inclusion criteria over 24 months from April FERTILITY & STERILITY 1389

3 1998 to March 2000 were contacted. The control groups were matched as closely as possible with the ICSI group with respect to birth date, age and sex of the child, age of the mother, social class, ethnic background, family size, and birth order of the child. Procedure This research project received the consent of the Ethical Commission of the Erasme Hospital (approval 97.53). The aim was to study the whole preschool period in 4 years time. Assessments were done in two different age groups: children between 0 and 2 years of age and children between 3 and 5 years of age. The aim was also to see each child at two of the following timepoints: 9 months, 18 months, 3 years, and/or 5 years. The follow-up rate, excluding those who were seen for the first time at 5 years of age (n 12), as well as those who could not be traced, was 91% for the ICSI-conceived children, 93% for the IVF-conceived children, and 84% for the spontaneously conceived children. This very high response rate minimizes the bias that commonly occurs in longitudinal studies of greater attrition among families who are experiencing personal or parenting problems. A similar proportion of boys and girls was wanted in each group. All the consenting families were seen at home. All the interviews as well as all the developmental and intellectual assessments were done by the same clinical psychologist trained in the study techniques. Information was collected by a tape-recorded standardized interview with the mothers using an adaptation (13) of the technique developed by Quinton and Rutter (14). Information was gathered on the family background, the history of the couple s infertility, the pregnancy, the birth and the child s physical development, his or her medical history, as well as demographic information on the family. The type of information collected during the interviews made it impossible for the psychologist to be blind to family type when assessing the children. The mothers also completed a questionnaire covering diseases and functional disorders (15). In this questionnaire, the mother described the child s feeding and sleeping behavior. The interviewer then rated the mother s report according to operationally defined degrees of normality or deviance of the behavior. To avoid overreliance on self-report questionnaires in which parents might try to present their child in the best possible way, a multimethod design was used to gather information from several sources (parents, doctors, medical records) and by means of a variety of techniques (standardized questionnaires, standardized interviews, developmental and intellectual assessments). To complete the medical investigation, a detailed questionnaire was filled out by the child s pediatrician. A 70% response rate was obtained; this rate was similar in all three groups. The child s health records were consulted whenever possible. Information on major and minor malformations were gathered from all these sources. Major malformation was defined as a condition requiring surgical correction or causing functional impairment (16). The children were formally assessed at 9 and 18 months using the revised (in 1997) Brunet-Lézine scale (17, 18). This scale assesses the current developmental functioning of infants and young children and consists of four subscales. The subscales assess the following: [1] posture: the child s movements in dorsal, ventral, sitting, lying, and standing positions; [2] coordination: oculomotor coordination and prehension abilities; [3] language skills: comprehension and expression abilities; and [4] socialization: self-awareness, relations to others, gestures, gesticulations, mimicry, and adaptation to social situations. The child s performance on these scales determines a developmental quotient (DQ). The mean score is 100 (SD, 15). The children were formally assessed at 3 and 5 years of age using the revised Wechsler preschool and primary scales of intelligence (WPPSI-R; revised in 1995) (19, 20). This scale assesses the intellectual development of children and consists of two subscales evaluating performance and verbal skills. The child s performance on these scales determines an intelligence quotient (IQ). The mean score is 100 (SD, 15). Performance on both the Brunet-Lézine and the WPPSI-R scales is classified as follows: a score of 115 indicates an accelerated performance, of 85 to 114 indicates a performance within normal limits, of 70 to 84 indicates a mildly delayed performance, and of 69 indicates a significantly delayed performance. Statistical analysis was done with the SPSS statistical package (version 10, SPSS Inc., Chicago, IL). Group comparisons were analyzed with 2 or Fisher s exact test for categorical data and with Student s t test, one-way analysis of variance, or multivariate analysis of variance (including adjustment for covariates) for continuous variables. All levels of significance were two-tailed. RESULTS Sixty-six ICSI couples agreed to participate (70% acceptance). Fifty-two couples who underwent an IVF treatment (60% acceptance) and 59 couples who conceived spontaneously (40% acceptance) consented. Nonacceptance was often due to practical reasons such as lack of free time. On the whole, parents of children conceived by ICSI had similar characteristics to those of children conceived by IVF and to those of spontaneously conceived children. No group difference was found for mother s age or for father s age: the mean maternal age was 31.9 years (SD, 3.78), and the mean paternal age was 34.9 years (SD, 6.25). Ninety percent of all couples were married; the other 10% were living together. Two couples split up in the interval before the second interview (1 ICSI-conceiving couple and 1 spontaneously conceiving couple). Families matched for all the criteria except for levels of education of the parents and 1390 Place et al. Intellectual outcome of ICSI children Vol. 80, No. 6, December 2003

4 TABLE 1 Medical characteristics of the ICSI, IVF, and SC children. Medical Outcome ICSI a (n 66) IVF a (n 52) SC a (n 59) P Congenital malformations ( 2 ) 7 (10.6) 5 (9.6) 8 (13.6).787 Major congenital malformations ( 2 ) 5 (7.6) 3 (5.8) 3 (5.1).837 Intensive care at birth (Fisher s exact) 4 (6.1) 1 (1.9) 4 (6.8) ICSI/IVF.382 ICSI/SC.000 IVF/SC.369 Breast-feeding ( 2 ) 51 (77.3) 34 (65.4) 43 (72.9).356 Breast-feeding duration Mean SD Mean SD Mean SD Confidence intervals (one-way ANOVA) 15.8m m m to Minor health problems ( 2 ) 28 (42.4) 25 (48.1) 25 (42.4).717 Minor surgical interventions ( 2 ) 16 (24.2) 9 (17.3) 8 (13.6).297 Long-term hospitalizations ( 2 ) 8 (12.1) 2 (3.8) 2 (3.4).093 Note: ANOVA analysis of variance; ISCI intracytoplasmic sperm injection; SC subcutaneous. a All data are n (%) unless otherwise specified. length of the relationship. The mean length of the relationship was 9.0 years (SD, 4.23), but it was significantly longer in the IVF group (ICSI conception: 9.1 [SD, 3.80]; IVF conception: 10.1 [SD, 4.35]; spontaneous conception: 8.1 [SD, 4.43]). Parents of the spontaneously conceived children had the highest level of education overall: 55% of the mothers and 52% of the fathers had a university degree, whereas only 23% of the assisted reproduction mothers and 33% of the fathers had one. The groups did not differ significantly in social class, although there was a trend toward a lower socioeconomic status in the assisted reproduction families. More than 95% of all fathers worked full-time. Seventyeight percent of all the women worked, of whom 72.5% worked full-time. The mean length of infertility was 66.0 months (SD, 40.69) and 75.2 months (SD, 39.95) for the ICSI and the IVF couples, respectively, which was not a significant difference between the two groups. Ninety-eight percent of the spontaneously conceived children were desired children: 2% were, however, unexpected and undesired. The groups did not differ significantly in family size (the mean number of children per family was 1.9 [SD, 1.1]). The number of single children was similar in each group: 43% of all the target children were single children. For the children who had siblings, there was no significant group difference for birth order of the target child (mean numerical position in family, 1.7 [SD, 1.1]). There was a similar proportion of boys (42.4%) and girls (57.6%) in each family type. Obstetrical Outcome The global number of complications during pregnancy did not differ significantly between the three groups (ICSI conception: 30.3%; IVF conception: 21.2%; spontaneous conception: 15.3%; p.127). These complications were first-trimester hemorrhages, bleeding after placenta previa or placental abruption, pregnancy-induced hypertension and/or pre-eclampsia, and hospitalizations for other medical reasons. The number of cesarean sections was similar in all three groups (ICSI conception: 19.7%; IVF conception: 11.5%; spontaneous conception: 11.9%; p.348); the mean cesarean section rate was 14.7%. More than 95% of all fathers were present at the time of birth. The mean maternal resting period was 3.3 months (SD, 3.6). Medical Outcome At birth, heights and head circumferences were similar in all three groups: the mean birth height of girls was 49.8 cm (SD, 1.72), and of boys, it was 50.3 cm (SD, 1.78); and the mean birth head circumference was 34.3 cm (SD, 1.63) for girls and 35.0 cm (SD, 1.31) for boys. Weights and heights at 9 months, 18 months, 3 years, and 5 years were plotted on reference curves (21). They were within the normal ranges and showed no incidence of slow physical growth (Fig. 1). There was no significant group difference in the incidence of combined (both minor and major) congenital malformations (11.3%; Table 1). The malformation rates for ICSIconceived children in our study appeared to be higher than the expected ranges (16, 22, 23). One particular malformation was disproportionately frequent in the ICSI-conceived group: the inguinal hernia. In seven ICSI-conceived children, the following malformations were noted (throughout this paragraph, malformations listed in italic print are those that required a surgical correction): a sixth finger on the left hand, a retro-auricular dermoid cyst, a hypospadias with an inguinal hernia, two inguinal hernias, a cryptorchidism, and an angioma (nevus flammeus). In five IVF-conceived children the following malformations were noted: an umbilical hernia, a left hip dysplasia, a trigger thumb with a cavernous angioma at the neck, a cryptorchidism, and a cleft lip and FERTILITY & STERILITY 1391

5 FIGURE 1 Mean heights and weights of the ICSI, IVF, and spontaneously conceived boys (A) and girls (B). X marks, conceived by ICSI; shaded circles, conceived by IVF; filled squares, spontaneously conceived. palate. In eight spontaneously conceived children, the following malformations were noted: a cryptorchidism with a patent foramen ovale, a hypospadias, a left hip dysplasia, a preauricular fistula, an umbilical hernia, a hiatal hernia, and two angiomas (nevus flammeus). There was no significant group difference in the need for intensive care at birth (5.1%) (Table 1). Intensive care mostly consisted of several days of observation in the neonatal service rather than of actual interventions or treatments. The children were under observation for minor digestive problems, hypoglycemia, and low Apgar scores as well as for a suspicion of cardiac murmur. Two spontaneously conceived children needed more intensive surveillance: one child for a hyaline membrane disease and the other for a pyloric stenosis. The number of mothers who breast-fed (72.3%), as well as the duration of breast-feeding, was similar in the three family types (19.2 weeks [SD, 16.73]; range, weeks; Table 1). There were no more health problems in the ICSI group at all four ages than in the other groups (42.4%; Table 1). The main difficulties appeared mostly in the early ages and were minor digestive problems; long apnea monitoring; repetitive ear, nose, and throat infections as well as allergies. No particular somatic complaint was disproportionately frequent. Less than 4% of all children had more serious health problems: in the ICSI-conceived group, one child contracted a pyelonephritis and another a purpura; in the IVF-conceived group, one child had a severe unexplained hypotonia of the inferior limbs and torso, and another contracted a bacteriemia; in the spontaneously conceived group, one child had a cerebellitis and another had an esophagus ulcer. Surgical interventions were carried out in 24.2% of ICSIconceived children, 17.3% of IVF-conceived children, and 13.6% of spontaneously conceived children (Table 1). These interventions were minor and mostly consisted of tonsillectomies, adenoid vegetation removal, tympanic drainage, the correction of the previously listed congenital malformations, as well as a pyloric stenosis and an appendicitis. The number of long-term hospitalizations ( 4 days) was higher in the ICSI group, but our data did not quite reach statistical significance (12.1%; Table 1). These longer hospitalizations were mostly to observe the child after a surgical intervention or after an infection. There was no difference in all three groups with regard to the number of pediatric consultations in the last 6 months: at 9 and 18 months, the mean number of consultations was 5.3 (SD, 3.24), and at 3 and 5 years of 1392 Place et al. Intellectual outcome of ICSI children Vol. 80, No. 6, December 2003

6 TABLE 2 Developmental assessments at 9 and 18 months of the ICSI, IVF, and SC children. Developmental outcome (test used: one-way ANOVA) ICSI (n 32) IVF (n 24) SC (n 26) Mean SD Mean SD Mean SD P Confidence intervals Posture Coordination months Language Sociability Developmental quotient (DQ) ICSI (n 46) IVF (n 32) SC (n 40) Posture Coordination months Language Sociability Developmental quotient (DQ) Note: ANOVA analysis of variance; ICSI intracytoplasmic sperm injection; SC subcutaneous. age it was 2.9 (SD, 2.59). The vast majority of these consultations were for pulmonary, skin, and/or otorhinolaryngology disorders. Eating and sleeping disorders were uncommon in all three groups: no disturbed eating or sleeping patterns appeared at all four ages. No discrepancy was identified regarding walking and talking achievements: the mean walking age was 13.3 months (SD, 1.99), and the mean talking age was 11.7 months (SD, 3.24). For the children who were slow in achieving these abilities, neither speech nor motor delays persisted at 2 years of age, except for the IVF-conceived child with a severe unexplained hypotonia of the inferior limbs and torso and one ICSI-conceived child with a severe speech delay that still persisted at 3 years of age. Developmental Outcome The results of the developmental assessments done at 9 and 18 months showed no significant between-group differences for the DQs as well as for all four subscales (Table 2). The ICSI group as a whole had good development in all the assessed areas. There was no significant association between the type of conception and the mean Brunet-Lézine score at either age. No significant effect of gender was observed: both boys and girls showed a similar pattern in development. We note however that the mean scores for all three groups at 9 months were lower than those for the Brunet-Lézine standardization sample. At 9 and 18 months, all three groups showed a similar distribution of the Brunet-Lézine DQ scores (Fig. 2). The developmental performances of 90% of all the children were well within the normal range (DQ: ). Less than 10% of the children at 9 months and 2% of the children at 18 months showed a mildly delayed performance. No child showed a significantly delayed performance. Intellectual Outcome At 3 and 5 years, the mean IQs as well as the subscale quotients were significantly lower for the two groups of assisted reproduction children in comparison with the spontaneously conceived children. The levels of education of the parents were included in the analyses as covariates because the correlations with the performance and verbal subscales and the overall IQs were highly significant. After adjustment for the covariates in the multivariate analyses, the betweengroup differences that appeared in the children s mean IQ scores as well as for both subscales disappeared (Table 3). These analyses showed no significant association between the type of conception and intellectual development. Again, no significant effect of gender was observed: boys and girls had similar performances in all the assessed areas. A slight shift to the left in the distribution of the IQ scores among the ICSI group as well as among the IVF group was observed at both ages (Fig. 3). At 3 years of age, 19.4% of ICSI-conceived children, 36.7% of IVF-conceived children, and 7.4% of spontaneously conceived children showed a mildly delayed performance (IQ range, 70 84), and a further 3.2% of ICSI-conceived children (representing one 3-year-old boy) showed a significantly delayed performance (IQ, 70). At 5 years of age, 6.6% of ICSI-conceived children showed a mildly delayed performance, and no child showed a significantly delayed performance. FERTILITY & STERILITY 1393

7 FIGURE 2 Distribution of the Brunet-Lézine global developmental quotients (DQ) at 9 months (A) and at 18 months (B). Open bars, conceived by ICSI; hatched bars, conceived by IVF; filled bars, spontaneously conceived children. DISCUSSION Previous follow-up studies on the outcome of conventional IVF-conceived children showed that these children were developing normally (13, 23, 24): they did not present congenital anomalies, developmental difficulties, or relational problems more frequently than did children born spontaneously. Even the results of the latest study (25) on IVF adolescents were very reassuring. The same kind of longterm data are needed concerning the experimental microinjection treatment, for which data are scarce. In 1998, one disturbing study (4) assessed the outcome at the age of 1 year of 89 children who were conceived by ICSI, compared with IVF and SC children. Those investigators results showed that ICSI-conceived children, especially boys, were at increased risk of mild mental delays. Other studies, however (3, 5 7), showed that at ages 1 and 2 years, ICSI-conceived children had normal mental development. These studies only concerned very young children and included children from multiple pregnancies, from preterm deliveries, as well as from cryopreserved embryos, three conditions that may have influenced their results. Concern has been expressed about the development of children born from cryopreserved embryos. A Swedish study (26) indicated that growth, health, and psychomotor development were normal up to the age of 18 months. However, another study (27) found minor developmental deficits be- TABLE 3 Intellectual assessments at 3 and 5 years of the ICSI, IVF, and SC children. Intellectual outcome (tests used: one-way ANOVA/MANOVA) ICSI (n 31) IVF (n 19) SC (n 27) Mean SD Mean SD Mean SD P Confidence intervals P* Performance skills years Verbal skills Intelligence quotient (IQ) ICSI (n 15) IVF (n 17) SC (n 15) Performance skills years Verbal skills Intelligence quotient (IQ) Note: ANOVA analysis of variance; ISCI intracytoplasmic sperm injection; MANOVA multivariate analysis of variance; SC subcutaneous; P* P corrected for the levels of education of the parents Place et al. Intellectual outcome of ICSI children Vol. 80, No. 6, December 2003

8 FIGURE 3 Distribution of the WPPSI-R global IQs at 3 years (A) and at 5 years (B). Open bars, conceived by ICSI; hatched bars, conceived by IVF; filled bars, spontaneously conceived children. tween children conceived from cryopreserved embryos and those conceived spontaneously. Previous studies of obstetrical outcome in IVF (28, 29) have reported a higher incidence of multiple pregnancy with their complications (preterm delivery, low birth weights, and high rates of cesarean sections). It has been previously acknowledged that multiple and preterm births influence early development (12). For all the aforementioned reasons, we chose to focus on full-term singleton children. This prospective longitudinal study was the first study to assess children aged older than 2 years, thus allowing IQ measurements. It covered the same ages as previous studies to allow comparisons, but it spread out over the whole preschool period. The follow-up rate was high, which is known to favorably influence the reliability of the results. Although not significantly different, the higher incidence of complications during pregnancy as well as the slightly higher cesarean section rate in the assisted reproduction groups were consistent with the data from the literature (30). The main newborn medical outcome measures showed no significant differences when other parameters such as multiple births and prematurity were not associated. The malformation rates in our study were higher than in large published series but of course depend on the classifications used as well as the sample sizes. All surveys use different definitions for the coding of malformations that increase the inherent biases regarding the limits of definition. What was, however, important was that no significant difference appeared between the three family types in the incidence of both minor and major congenital malformations. Healthwise, ICSI-conceived children were shown to be developing quite well; the vast majority of the health problems that appeared were minor. Although not significantly different, the increased rates of observation of ICSI-conceived children in the neonatal service as well as when they were hospitalized might be interpreted as indicative of overprotection of a precious child because no actual increase in health disorders was observed. No particular somatic complaint was disproportionately frequent. No eating and sleeping disorders appeared. All this is reassuring because these kind of complaints and disorders in very young children are often signs of increased emotional vulnerability (31). These findings can cautiously be interpreted as positive signs reflecting the well-being of the children. The developmental assessments at 9 and 18 months did not reveal any significant between-group differences and showed that the ICSI group had good results in all the assessed areas. The analyses of the intellectual assessments done at 3 and 5 years showed between-group differences in the mean IQ scores. A slight shift to the left in the distribution of the IQ scores was observed for both assisted reproduction family types. After adjustment for the levels of education of the parents, these between-group differences disappeared. This shift in the distribution was similar to the one observed in the Bowen et al. (4) study. In this study, 15% of the ICSI-conceived children were in the mildly delayed range, and a further 2% had a significantly delayed performance. A subset analysis taking into account the fathers occupation and excluding all infants whose fathers had an unskilled occupation was done and continued to show the same between-group differences. These results (4) concerning the development of ICSIconceived children, in contradiction with the Bonduelle et al. (3) results, were followed by a wide-ranging debate (32) on the safety of the ICSI technique. These debates emphasized FERTILITY & STERILITY 1395

9 the necessity of standardization for parameters such as social class and parental education in case-control studies when evaluating children s psychomotor and intellectual development. The etiologies of mild and severe mental retardation are multiple and, to a certain extent, related to social class and degree of education of the parents. Cognitive evaluations in children have been in fact shown to be positively associated with parental educational level (especially maternal educational level) (33 35). In these articles was expressed the idea that the genetic potential of the child is expressed more fully when parents are better educated. This was linked to the degree of intellectual stimulation in the child s environment, which seems higher in a more educated family. Furthermore, level of parental education is also likely to be influenced by genetic factors. Thus, more highly educated parents are more likely to pass on genes related to higher IQ as well as provide more intellectually stimulating environments. In our study, multivariate regression analysis indicated that parental education level had a significant influence on the test result. To control for these differences thus seemed appropriate. In the Bowen et al. (4) study, the maternal education level and/or occupation were not taken into account in the subset analyses, although this could have explained the group differences. In our study, when looking at each child s performance separately, only one ICSI-conceived child, a 3-year-old boy, had an IQ of 70. It is noteworthy that this child has a younger spontaneously conceived brother (2 years old). This spontaneously conceived child presents similar developmental difficulties as his older ICSI-conceived brother. Both these children are being followed in a hospital close to their home: investigations are still underway as to the cause of these delays. Because both children are showing the same patterns of development, we can safely say that these delays are not related to the use of the ICSI procedure. In conclusion, to the question of whether ICSI has a detrimental effect on the outcome of ICSI offspring, this pilot study, which isolated the impact of the ICSI procedure, showed that these children were developing as well as spontaneously conceived children. Their growth and health appeared to be within the normal ranges, and they showed a similar psychomotor development in comparison with the 2 control groups. When analyzing the intellectual assessments, the fact that the between-group differences disappeared after adjustment for the levels of education of the parents shows how crucial it is not to underestimate the influence of such factors when evaluating child development. Our data tend to support the safety of the ICSI procedure: ICSI-conceived children do not seem at increased risk of intellectual impairment or learning difficulties, and this appears to be the case over the whole preschool period. To complete these medical and developmental data, we are currently assessing the emotional and behavioral development of ICSI-conceived children as well as the parent child relationships. Our study is a pilot study because it is the first study to assess the intellectual development (IQ) of ICSI-conceived children. The conclusions of this pioneer work now need to be confirmed on larger samples using large multicenter studies. For these studies to accurately answer the question of the safety of the ICSI procedure with regard to the development of ICSI-conceived children, it is essential that they take into account such pilot studies not only to give them an idea as to where a developmental difficulty might appear but also to give them an idea as to the sample size that they would need at a certain age. Large multicenter studies including several hundred children are also needed to allow low-frequency or more subtle differences to appear. Acknowledgments: The authors thank Philippe Révelard, Ph.D., for his role in the management of data and Jean-Louis Slachmuylder, M.Sc., for his role in the statistical analysis of data. The authors also thank all the families who participated in the study. References 1. Bonduelle M, Wilikens A, Buysse A, Van Assche E, Wisanto A, Devroey P, et al. Prospective follow-up study of 877 children born after intracytoplasmic sperm injection (ICSI), with ejaculated epididymal and testicular spermatozoa and after replacement of cryopreserved embryos obtained after ICSI. Hum Reprod 1996;11(Suppl 4): Bonduelle M, Wilikens A, Buysse A, Van Assche E, Devroey P, Van Steirteghem AC, et al. A follow-up study of children born after intracytoplasmic sperm injection (ICSI) with epididymal and testicular spermatozoa and after replacement of cryopreserved embryos obtained after ICSI. Hum Reprod 1998;13(Suppl 1): Bonduelle M, Joris H, Hofmans K, Liebaers I, Van Steirteghem A. Mental development of 201 ICSI children at 2 years of age. Lancet 1998;351: Bowen JR, Gibson FL, Leslie GI, Saunders DM. Medical and developmental outcome at 1 year for children conceived by intracytoplasmic sperm injection. Lancet 1998;351: Sutcliffe AG, Taylor B, Li J, Thornton S, Grudzinskas JG, Lieberman BA. Children born after intracytoplasmic sperm injection: population control study. BMJ 1999;318: Sutcliffe AG, Taylor B, Saunders K, Thornton S, Lieberman BA, Grudzinskas JG. Outcome in the second year of life after in-vitro fertilisation by intracytoplasmic sperm injection: a UK case-control study. Lancet 2001;357: Leslie GI, Cohen J, Gibson FL, McMahon C, Maddison V, Saunders D, et al. ICSI children have normal development at school age [abstract no. 009]. In: Abstracts from the 18th annual meeting of ESHRE, Vienna, Austria. Human Reprod 2002;17: Govaerts I, Englert Y, Vamos E, Rodesch F. Sex chromosome abnormalities after intracytoplasmic sperm injection. Lancet 1995;346: Govaerts I, Devreker F, Koenig I, Place I, Van Den Bergh M, Englert Y. Comparison of pregnancy outcome after intracytoplasmic sperm injection and in vitro fertilization. Hum Reprod 1998;13: Berberoglugil P, Englert Y, Van den Bergh M, Rodesch C, Bertrand E, Biramane J. Abnormal sperm-mucus penetration test predicts low in vitro fertilization ability of apparently normal semen. Fertil Steril 1993;59: Van den Bergh M, Bertrand E, Biramane J, Englert Y. More experience with ICSI. Importance of breaking a spermatozoon s tail before intracytoplasmic injection: a prospective randomized trial. Hum Reprod 1995;10: Miceli PJ, Goeke-Morey MC, Whitman TL, Kolberg KS, Miller-Loncar C, White RD. Brief report: birth status, medical complications, and social environment: individual differences in development of preterm, low birth weight infants. J Pediatr Psychol 2000;25: Place et al. Intellectual outcome of ICSI children Vol. 80, No. 6, December 2003

10 13. Golombok S, Cook R, Bish A, Murray C. Families created by the new reproductive technologies: quality of parenting and social and emotional development of the children. Child Dev 1995;66: Quinton D, Rutter M. Parenting breakdown: the making and the breaking of intergenerational links. Alderschot, UK: Avebury Gower Publishing, Robert-Tissot C, Rusconi-Serpa S, Bachmann J-P, Besson G, Cramer B, Knauer D, et al. Le questionnaire Symptom Check-List Evaluation des troubles psychofonctionnels de la petite enfance. In: Lebovici S, Mazet P, Visier JP, eds. L évaluation des interactions précoces entre le bébé et ses partenaires. Paris: ESHEL, 1990: Bonduelle M, Legein J, Buysse A, Van Assche E, Wisanto A, Devroey P, et al. Prospective follow-up study of 423 children born after intracytoplasmic sperm injection. Hum Reprod 1996;11: Brunet O, Lézine I. Le développement psychologique de la petite enfance. Paris: PUF, Josse D. Brunet-Lézine révisé: échelle de développement psychomoteur de la première enfance. Issy-Les-Moulineaux, France: EAP, Wechsler D. Manual for the Wechsler preschool and primary scale of intelligence. New York: Psychological Corporation, Wechsler D. Manuel: echelle d intelligence de Wechsler pour la période préscolaire et primaire. Forme révisée. Paris: ECPA, Graffar M. La nécessité d études longitudinales de la croissance de l enfant. Acta Paediatr Belg 1958;4: Wennerholm UB, Bergh C, Hamberger L, Lundin K, Nilsson L, Wikland M, et al. Incidence of congenital malformations in children born after ICSI. Hum Reprod 2000;15: Westergaard HB, Johansen AMT, Erb K, Andersen AN. Danish national in-vitro fertilization registry 1994 and 1995: a controlled study of births, malformations and cytogenetic findings. Hum Reprod 1999;14: Cederblad M, Friberg B, Ploman F, Sjöberg NO, Stjernqvist K, Zackrisson E. Intelligence and behaviour in children born after in-vitro treatment. Hum Reprod 1996;11: Golombok S, MacCallum F, Goodman E. The test-tube generation: parent-child relationships and the psychological well-being of the IVF children at adolescence. Child Dev 2001;72: Wennerholm UB, Albertsson-Wikland K, Bergh C, Hamberger L, Niklasson A, Nilsson L, et al. Postnatal growth and health in children born after cryopreservation of embryos. Lancet 1998;351: Sutcliffe AG, Souza CWD, Cadman J, Richards B, McKinlay IA, Lieberman B. Outcome in children conceived from cryopreserved embryos. Arch Dis Child 1995;72: Tan SL, Doyle P, Campbell S, Beral V, Rizk B, Brinsden P, et al. Obstetric outcome of in vitro fertilization pregnancies compared with normally conceived pregnancies. Am J Obstet Gynecol 1992;167: Doyle P. The outcome of multiple pregnancy. Hum Reprod 1996; 11(Suppl 4): Maman E, Lunenfeld E, Levy A, Vardi H, Potashnik G. Obstetric outcome of singleton pregnancies conceived by in vitro fertilization and ovulation induction compared with those conceived spontaneously. Fertil Steril 1998;70: Manuel C, Facy F, Choquet M, Grandjean H, Czyba JC. Les risques psychologiques de la conception par insémination artificielle avec donneur (IAD) pour l enfant. Neuropsychol Enfant 1990;38: te Velde ER, van Baar AL, van Kooij RJ. Commentary: concerns about assisted reproduction. Lancet 1998;351: Sellers AH, Burns WJ, Guyrke J. Differences in young children s IQs on the Wechsler preschool and primary scale of intelligence revised as a function of stratification variables. Appl Neuropsychol 2002;9(2): Croen LA, Grether JK, Selvin S. The epidemiology of mental retardation of unknown cause. Pediatrics 2001;107:E Chapman DA, Scott KG, Mason CA. Early risk factors for mental retardation: role of maternal age and maternal education. Am J Ment Retard 2002;107(1): FERTILITY & STERILITY 1397