Growth in the first year of life: how early can one predict size at twelve months among small-for-dates and large-for-dates babies?

Within groups of small-for-dates (SFD) and large-for-dates (LFD) babies there is great diversity in their postnatal growth patterns. We analysed our data to find out how soon, and for which dimensions, could predictions of size at one year be reasonably made. Among LFD babies a strong correlation (r=0.644) was found between head circumference at birth and 12 months. Comparable values for weight and length were present by 3 months. In the SFD group, correlations of the same order were achieved for all three dimensions at the age of 4 months.

Neurological development of small-for-gestational age babies during the first year of life.

137 small-for-gestational age (SGA) infants were examined in the neonatal period and at 2, 6 and 12 months. At each age a structured assessment was used for which a score denoting neurological maturation could be given. The SGA infants were significantly retarded compared with average-for-gestational age (AGA) infants from 2 months onwards. Within the SGA group the mean scores for boys, those who were first-born, breast-fed and/or born to mothers who smoked during pregnancy were in each case significantly higher than the rest at 6 and 12 months. Maternal smoking influenced all aspects of development at 12 months; whereas sex and method of infant feeding mainly affected the motor items, and birth order only those that were socially oriented. Positive associations were found between changes in somatic measures and changes in neurological scores from birth through to 6 months. Infants who grew faster also matured faster during this period of time, and vice versa. Positive correlations were found between size and scores at 2 and 6 months, but not at 12 months.

Growth and proportionality in early childhood. III. Differences between babies of low birthweight in well-nourished and malnourished populations.

The growth patterns from birth to 7 yr of four groups of children are compared. They comprise: small-for-gestational age children in a highly favoured community born to (A) short mothers, (B) mothers of average height for their population; Guatemalan children living in a community where mild to moderate protein-calorie malnutrition was endemic. Data on a sample of children whose birthweights covered the normal range for gestational age were used as reference standards. At all ages and for almost all measures they were significantly larger than children in the other three groups. No differences were found between the boys in groups A and B; but girls in group A were lighter and shorter from 18 mth onwards. The Guatemalans were shorter and had smaller heads than group A from 12 mth onwards; and the boys were also lighter. No differences were found between the Guatemalans and group A for chest circumference in either sex from 2 yr onwards. Deficits in size at 4 yr of the Guatemalans compared with the Reference Sample ranged from 8.8% for stature, 6.8% head circumference, 5.9% weight, down to 3.9% for chest circumference. The differences between the four groups may broadly be taken to represent those due to low birthweight for gestational age, lower genetic potential, postnatal malnutrition, and their cumulative effects. Our findings offer a new perspective on their varying contributions to growth in size and shape during early childhood.

Small-for-dates babies, gestational age, and developmental ability at 7 years.

One hundred sixteen small-for-dates (SFD) children, whose progress had been monitored prospectively from birth, completed a comprehensive developmental assessment at age 7 years. There was an inverse relationship between their developmental scores at 7 years and gestational age at birth. Further analyses showed that the negative associations were stronger when biological factors commonly associated with the birth of SFD babies were absent. SFD babies are often delivered electively before term because of their increased risks of intrauterine death. The infant's ability to withstand the perinatal metamorphosis is usually assured, prior to intervention. Our findings indicate that, among SFD children in general, prolongation of pregnancy beyond about 36 weeks is not associated with an improved long-term prognosis. When pathological factors are operant, delivery before term may enhance the chances of these babies achieving their full developmental potential in later childhood.

Proportionality of small-for-gestational age babies at birth: perinatal associations and postnatal sequelae.

Head and chest circumference and crown-rump length measurements were obtained for 413 small-for-gestational age (SGA) infants at birth; and head-chest, head-crown-rump and chest-crown rump ratios derived. There was an inverse correlation between head-chest ratios and gestational age, and boys had higher ratios than girls. First-born infants, and those whose mothers had pre-eclampsia had higher ratios than the rest, and higher ratios were associated with instrumental delivery. Higher ratios were also found for girls (but not boys) born to women of above average weight, and those who suffered birth asphyxia or other problems in the neonatal period. When adjustment was made for confounding between variables gestational age and sex were the only factors making a significant contribution to the variance in head-chest ratios at birth. SGA babies with relatively high head-chest ratios at birth grew faster than those with lower ratios during the first 6 mth of life. Girls with above-average ratios were heavier and had larger heads at the age of 7 yr, but no differences were found for either sex in any aspect of developmental ability at 7 yr associated with head-chest ratios at birth.

Growth and proportionality in early childhood. I. Within population variations.

Data on the postnatal growth patterns of 238 small-for-gestational age (SGA) and 241 large-for-gestational age (LGA) babies are presented. Three proportionality ratios were selected; and their changes in shape, by these indices, during the first 7 years are compared with a random sample of 284 children drawn from the same population. Highly significant differences (P less than 0.001) were found between the mean head-chest and head-length ratios for both sexes at birth; but mean chest-length ratios did not differ. Our findings show that these three measures of proportionality differ in their patterns of change over time; in the influence of birthweight group on their absolute values at each age; and the influence of sex within birthweight groups. At 7 years SGA children still had the highest and LGA children the lowest head-chest and head-stature ratios, and the differences were significant (P less than 0.01) for girls. This was mainly due to the relatively small heads of LGA girls. 46% of our sample had a head-chest ratio above unity at the age of 2 years. The "rule of thumb" criterion for the identification of malnourished children, based on the general principle that mean chest circumference overtakes head circumference by the age of 12 months, should not be too strictly applied.

Associations between size and development at four years among children who were small-for-dates and large-for-dates at birth.

Associations were sought between somatic measures and developmental status at 4 years among groups of children who had been small-for-dates (SFD), average-for-dates (AFD) and large-for-dates (LFD) at birth. When the three groups were combined, and adjustment made for sex, social class and series, a significant correlation was found between head circumference and total scores. Within the SFD and AFD groups no correlations were found between any somatic measures and aspects of development; and the only significant finding in the LFD group was a negative correlation between weight-for-height and total developmental scores. The somatic measures were then divided into three subgroups comprising children who had small, average, and large values for that measure, and developmental scores for each subgroup were computed. Within all three birthweight groups significant differences were found for head circumference: those with relatively small heads having lower scores than the rest.

Small-for-dates babies at the age of four years: health, handicap and developmental status.

221 small-for-dates (SFD) and 244 average-for-dates (AFD) children were personally examined at birth, and seen thereafter at regular intervals up to 4 years, when a thorough assessment was made. There was an excess of SFD children with major congenital abnormalities; but no difference between the groups in the number of children who were handicapped without congenital abnormality. Their general health was good, and the prevalence of specific disease or major ill-health did not differ. SFD girls seemed to have less acute hearing than AFD girls; but there was not difference for boys. The prevalence of squint, impaired vision, speech defects, and abnormalities of gross and fine motor movements were equally low in both groups. At 4 years the mean scores for five sectors of development were significantly lower in the SFD than the AFD group. Within group analyses of 16 variables and their effects on developmental scores showed no associations in either group according to maternal height and weight, birthweights of previous siblings, the presence or not of hypertension and pre-eclampsia, bleeding during pregnancy, asphyxia and injury at birth, or birth order. Within each group the net effect of the remaining eight factors was assessed; adjustment being made for the other seven variables. In the SFD group social class and method of delivery made a significant contribution to total scores. In the AFD group significant differences were found according to social class, sex, gestational age at birth and smoking. Method of infant feeding just failed to achieve significance. When all the children were considered together, and birthweight group included as an additional variable, no significant differences remained between the SFD and AFD groups for any sector of development.

Large-for-dates babies at the age of four years: health, handicap and developmental status.

236 Average-for-dates (AFD) and 212 large-for-dates (LFD) children were personally examined at birth, and seen thereafter at regular intervals up to 4 yr, when a thorough assessment was made. No differences were found in the prevalence of handicap, health problems, speech and hearing defects, impaired vision or squint; and abnormalities of gross and fine-motor movements were equally low in both groups. At 4 yr the mean scores for five sectors of development were slightly higher in the LFD group, and the difference in total scores was significant; but when adjustment was made for sex and social class the difference became insignificant. Within group analyses of 16 variables and their effects on developmental scores showed no associations in either group according to maternal weight, height and siblings birthweight; hypertension, pre-eclampsia or bleeding during pregnancy; asphyxia or injury at birth. Within each group the net effect of eight factors was assessed; adjustment being made for the other seven variables. In the AFD group significant differences in total scores were found according to sex, social class, smoking, and method of infant feeding. In the LFD group social class and method of delivery made a significant contribution to total scores.

Children of deviant birthweight at the age of seven years: health, handicap, size and developmental status.

138 small-for-dates (SFD), 138 average-for-dates (AFD) and 136 large-for-dates (LFD) children who had been followed up from birth were examined at the age of 7 years. Nine children had major congenital abnormalities (SFD 5, AFD 2, LFD 2). In addition gross and/or fine motor incoordination was noted in 25 children (SFD 9, AFD 10, LFD 6). There were no differences between the groups in the incidence of chronic or specific ill-health, hearing, sight and speech defects. Highly significant differences were found between the groups for weight, height, head circumference and triceps skinfold thickness; and significant differences were also found between the total developmental scores in the three groups. In every case SFD children had the lowest and LFD children the highest mean values. Within each group analyses were made of 22 parental, pregnancy, perinatal and postnatal factors which might affect growth or development. The net effects of those factors for which significant differences had been found were then assessed, adjustment being made for confounding between variables. In all three groups the children's genetic potential for size was strongly evident by this age, and boys had larger heads than girls. All three groups showed the powerful influence of social class on intellectual ability; and sex on gross and fine-motor function. The other main contributor to developmental differences in the AFD group was gestational age. In the SFD group maternal hypertension was associated with slightly decreased intellectual ability, and in all areas first-born SFD children performed better than subsequent born. Among LFD children instrumental delivery had an adverse effect on all areas of ability, and first-born children had higher intellectual scores. When all the children were considered together and birthweight included as an additional variable the differences in developmental scores between the groups were much reduced. In the SFD and LFD groups some significant correlations were found between size and developmental scores; but none were found among AFD children.

Growth and proportionality in early childhood. II. Some population differences.

The postnatal growth patterns of children in four different populations are compared with a sample born and brought up in Oxford. Three indices of proportionality were investigated. Among the three caucasian groups Swedish children had the smallest heads and tallest stature, resulting in particularly low head-chest and head-stature ratios. Denver children had unusually small chest from 2 years onwards; their head-chest ratios were significantly higher than those in Oxford, but head-stature and chest-stature ratios were lower. Japanese children were smaller than Oxford children in all dimensions; but apart from some minor fluctuations they were similar in shape by all three indices used. Guatemalan children of both sexes had extremely high chest-stature ratios from 3 years onwards. Head-stature ratios were also raised, but to a lesser extent. Compared with children in more highly-favoured communities their stature and head circumference were reduced more than weight and chest circumference.

Hypertension during pregnancy, with and without specific hypotensive treatment. I. Perinatal factors and neonatal morbidity.

In a prospective study, women who were hypertensive before the 28th wk of gestation were randomly allocated into two groups: those who received specific hypotensive therapy (Ht) and those who did not (Hu). The outcome was compared with a random sample of the hospital population (S) ascertained after delivery. In both hypertensive groups there was a higher incidence of clinical signs of possible fetal distress and instrumental delivery. Although there was no difference between the groups in the distribution of birthweight above and below the mean for gestational age, the treated hypertensive group had an excess of infants with relatively smaller head circumferences for their gestational age compared with both the untreated hypertensive group and the hospital sample. Tube-feeding was also more frequent in the treated hypertensive group. In the untreated hypertensive group there were more infants whose neurological status was categorized as questionable or abnormal in the neonatal period, compared with the sample. The different problems encountered by infants in the two hypertensive groups emphasized the need for further study of these babies. Their development during the first year of life will be examined in a subsequent paper.

Hypertension during pregnancy, with and without specific hypotensive treatment. II. The growth and development of the infant in the first year of life.

The growth and development of three groups of infants were prospectively assessed from birth to 12 mth. In two groups the mothers had been hypertensive before the 28th wk of gestation; one group was randomly allocated to specific hypotensive therapy, the other group was allocated to no specific treatment. The third group was a sample of the hospital population. General health, and the incidence of sight and hearing problems did not differ. Infants in the treated hypertensive group had had more perinatal problems, and there was an excess of infants with relatively small heads for their gestational age at birth. At 6 mth their heads were still smaller than the hospital sample, but by the age of 1 yr the difference was no longer present. The neurological status of infants in the untreated hypertensive group was less favourable in the neonatal period, and there was still an excess of infants in this group rated questionable on neurological assessment at the age of 12 mth. In both hypertensive groups there was an excess of infants with delayed fine-motor function at 6 mth, and in the untreated group there was an excess with delayed gross-motor function at 12 mth compared with the hospital sample. Our varied findings draw attention to the dangers of assessing the effects of different pregnancy conditions in terms of neonatal mortality and morbidity alone. Our date indicate that follow-up should extend for longer than 12 mth when the effects of adverse pregnancy factors and their management are under consideration. Further evaluation will be made when these children are 4 yr old.

Hand preference: its provenance, development, and associations with intellectual ability at the age of 7.5 years.

The development of 199 children was studied at regular intervals from birth to 7.5 years. On each occasion hand preference was recorded. Their preferred hand was evident in 89.4% right and 85.7% left-handers by 4 years. Analyses on 242 children seen at birth and 7.5 years showed no associations between left-handedness and nine factors representing different aspects of "birth stress." For 12 of 15 aspects of ability at 7.5 years left-handed children had slightly higher scores than right-handers. Pathological factors do not seem to feature in the provenance or consequences of left-handedness in a normal healthy population.

Proportionality changes in the first year of life; the influence of weight for gestational age at birth.

Data on 55 small-for-gestational age (SGA), 56 average-for-gestational age (AGA) and 55 large-for-gestational age (LGA) infants whose growth had been monitored regularly from birth to 12 months are presented. SGA head-chest ratios were high at birth; but by 6 months they were very similar to AGA ratios, with values just below unity. Head-length ratios showed a steady decrement; SGA infants having the highest and LGA infants the lowest values at all ages. Chest-length ratios showed little change up to 6 months, with a steady decrease thereafter. Stem-stature ratios showed a similar pattern; and were confined within a narrow margin from 6 months onwards. These changes seem to be target orientated. We suggest the goal is that proportionality which enables the infant to attain the upright stature; and thus to sit, stand and walk at the appropriate time.

Proportionality at birth. Associations with weight, gestational age and sex.

501 small (SGA), 330 average (AGA) and 460 large for gestational age (LGA) babies were measured at birth. Head-chest, head-crown-rump length, and chest-crown-rump length ratios were used to evaluate the changing patterns of proportionality with increasing gestational age. The SGA group showed strong negative correlations for head-chest and head-length ratios, and positive correlations for chest-length ratios. The patterns were similar in the AGA group, only less evident. For all three measures of proportionality, correlations with gestational age in the LGA group were close to zero. In each group boys had higher head-chest ratios than girls.

Constrained and unconstrained fetal growth: associations with some biological and pathological factors.

Data are presented on the birthweights of 1092 siblings and 5207 maternal and paternal relatives of 986 probands. Previous analyses had demonstrated the potency of a maternal regulator constraining fetal growth. Different patterns of birthweights were found in families ascertained, respectively, through very large and very small babies (Ounsted, Scott and Ounsted 1986). When the data were reanalyzed in respect of other biological and pathological factors affecting fetal growth rate the following findings emerged: (1) When pathological factors were associated with the proband pregnancy the typical patterns of pedigree birthweights were not so clearly manifest; (2) general associations were found between the mothers' own birthweights and their size as adults; (3) low maternal birthweight was the biological factor showing the highest risk associated with small babies. When the babies were large the risks associated with high maternal adult weight and parity were similar to those associated with high birthweight. Paternal factors also made a contribution to fast fetal growth rate when pathological factors were absent. These findings confirm our hypothesis that at the lower extreme of fetal growth rate maternal constraint is pre-potent. At the upper extreme, relaxation of constraint allows other biological factors to take up more of the variance.

Children of deviant birthweight: the influence of genetic and other factors on size at seven years.

138 small-for-gestational age (SGA), 138 average-for-gestational age (AGA) and 136 large-for-gestational age (LGA) children who had been followed up from birth were measured at the age of seven years. Parental measurements were also obtained. Significant differences for weight, height and head circumference of the children and their parents were found between the three groups. There were highly significant parent-child correlations for most somatic measures in all groups. Within each group the parental contribution to the variance in children's somatic measures was large; so also was the effect of sex on head circumference. Other biological and pathological factors made only a small contribution in any group.

Risk factors associated with small-for-dates and large-for-dates infants.

Relative risks were calculated to assess the potency of different factors associated with the two extremes of the birthweight distribution. Maternal height affected the chances of having a small-for-dates (SFD) or large-for-dates (LFD) baby to an equal and opposite extent; but the risks associated with maternal weight were greater for LFD than SFD infants. Smoking increased the SFD risk by 3.5 times, whereas the LFD risk was only reduced by a half. Pre-eclampsia was associated with a very high SFD risk (14.6); in the LFD group it was insignificantly raised. The LFD relative risk steadily rose with increasing parity, but in the SFD group it fluctuated around unity. Among multiparae the risks of an SFD or LFD infant when previous siblings had been of relatively low or high birthweight for gestational age, respectively, were much increased. Estimates of attributable risk showed that if pathological factors such as smoking, hypertensive disorders and congenital abnormalities could be completely eliminated the number of SFD babies in this population would be reduced by about 60%; conversely the number of LFD babies would be increased by about 30%.