Serum IgG at birth in preterm appropriate- and small-for-gestational age newborns

Serum IgG at birth was estimated in 31 preterm and 33 full term newborns, grouped according to their weight-for-gestational age. Preterm small-for-gestational age neonates were found to have significantly reduced IgG levels as compared to preterm appropriate-for-gestational age and full term small-for-gestational age newborns. It is suggested that preterms with intra-uterine growth retardation are most suitable for exogenous IgG supplementation to reduce neonatal and postneonatal susceptibility to infections.     

Proteins in preterm and term milk from mothers delivering appropriate or small-for-gestational age infants

The concentrations of total protein, secretory immunoglobulin A (IgA), lactotransferrin (LTF) and serum albumin (SA) were measured in sequential samples of colostrum, transitional and mature milk from 53 mothers divided into four groups according to gestational age and birthweight of their infants. Individual proteins were determined by single radial immunodiffusion. From the covariance analysis of data controlling for the day of lactation and the milk volume it was found that these covariables were significantly negative correlated with total protein and IgA. The concentration of LTF was also significantly negative correlated with the day but positively with the volume; whereas the contrary occurs for SA although the correlation was not significant for the volume. Differences in the total protein and IgA contents have been found among the mothers. The LTF content varied among the groups. Mean protein contents did not change in a similar way in all groups during lactation. Preterm milk maintained a more constant level of proteins.     

Brainstem auditory-evoked responses to different rates of clicks in small-for-gestational age preterm infants at term

AIM: To clarify further the influence of intrauterine growth retardation (IUGR) on early neural development. METHODS: In 30 small-for-gestational age (SGA) preterm infants at term, brainstem auditory-evoked responses (BAERs) were recorded with clicks of different repetition rates. All infants had a birthweight < 3rd centile, without any other major perinatal complications. RESULTS: Compared with the BAER in 36 appropriate-for-gestational age (AGA) term infants, the preterm SGA infants did not show any abnormalities at 21 s(-1) clicks, except for a slight increase in wave III amplitude. At 51 s(-1) clicks, there was an increase in III-V/I-III interval ratio (ANOVA p < 0.05). At 91 s(-1), the I-III interval shortened, whereas the III-V interval and III-V/I-III interval ratio increased (all p < 0.05). Wave V amplitude tended to increase slightly at all repetition rates of clicks used, although this increase did not reach statistical significance. The III-V interval and III-V/I-III interval ratio in the preterm SGA infants at different click rates correlated inversely with occipitofrontal head circumference at the time of testing, i.e. the smaller the head the longer the III-V interval (all p < 0.01). Wave III amplitude at 21 s(-1) also correlated inversely with head circumference (p < 0.01), suggesting that the slight increase in this amplitude in the preterm SGA infants is related to their relatively small head size. CONCLUSION: There were no major abnormalities in the BAER up to 91 s(-1) clicks at term in preterm SGA infants. The slight increase in III-V interval at high-rate stimulation suggests a subtle degree of central neural dysfunction, which is associated with small head size following IUGR.     

Catch-up growth up to ten years of age in children born very preterm or with very low birth weight

Background  

Improved survival due to advances in neonatal care has brought issues such as postnatal growth and development more to the focus of our attention. Most studies report stunting in children born very preterm and/or small for gestational age. In this article we study the growth pattern of these children and aim to identify factors associated with postnatal catch-up growth.     

Extrauterine growth restriction in preterm infants of gestational age < or =32 weeks

BACKGROUND: Extrauterine growth restriction (EUGR) in low-birthweight (LBW) infants affects their growth and developmental prognoses as well as their incidence of adult diseases. The aim of the present paper was to determine the frequency and contributing factors of EUGR in infants > or =32 weeks of gestational age. METHODS: The subjects consisted of 416 infants from 22 facilities born between February and October 2002, whose gestational age was > or =32 weeks. For EUGR assessment, subjects whose body measurements in the 37-42 week postmenstrual age (PMA) period were below the 10th percentile of the standard normal distribution, were selected. RESULTS: EUGR incidence rates for weight, length, and head circumference were 57%, 49%, and 6%. In appropriate-for-gestational-age infants, a negative correlation was found between number of gestational weeks and EUGR incidence rates for weight, length, and head circumference, but in small-for-gestational-age infants this was true only for head circumference. Lower gestational age and age in days to achieve complete feeding were among the shared factors contributing to EUGR incidence for weight, length, and head circumference. The significant factors for EUGR incidence for weight and length included whether the infant was small for gestational age, whether oxygen was administered at 36 weeks PMA, age in days at which breast-feeding was initiated, and age in days when the infant regained birthweight. CONCLUSIONS: The growth retardation of preterm LBW infants in the neonatal intensive care unit continues to pose challenges. Relevant factors other than gestational age include intrauterine growth restriction, severe chronic lung disease, and poor nutrition.     

Fetal and neonatal mortality of small-for-gestational age infants

Fetal and neonatal mortality of small-for-gestational age (SGA) infants in 1968–1982 were studied in the region of the University Central Hospital of Turku, Finland. During the study period, there were 254 fetal and 127 neonatal deaths in SGA infants. The fetal mortality rate of SGA infants declined from 49.9/1000 to 14.0/1000. The neonatal mortality rate of SGA infants declined from 23.8/1000 to 8.3/1000. The severely SGA infants with a birth weight below the 2.5th percentile had three times higher neonatal mortality rates than SGA infants with a birth weight between the 2.5th and the 10th percentiles. The main causes of fetal deaths were maternal diseases, placental and cord complications and fetal malnutrition, even though there was a decline in all these groups. Malformations remained the main cause of neonatal death during the study period, while there was a decline in deaths due to asphyxia and respiratory distress syndrome (RDS). The high mortality rates of SGA infants emphasize the need for early diagnosis and special attention during pregnancy, delivery and the neonatal period.Abbreviations SGA small-for-gestational age - AGA appropriate-for-gestational age - UCHT University Central Hospital of Turku - RDS respiratory distress syndrome     

Body size and early growth in appropriate- and large-for-gestational-age infants

AIMS: To study weight, length, body composition, sleeping energy expenditure (SEE), and respiratory quotient (RQ) at birth and at 5 mo of age in both adequate-for-gestational-age (AGA) and large-for-gestational-age (LGA) subjects; to compare the changes in body weight and body composition adjusting for gender, age, SEE, RQ and several maternal factors; to investigate the contribution of initial SEE and RQ to changes in body weight and body composition. METHODS: Sixty-nine neonates were recruited among term infants in the University Hospital of Verona, Italy. Forty-nine subjects participated until follow-up. At birth and follow-up, weight and length were measured and arm-fat area and arm-muscle area were calculated from triceps and subscapular skinfolds. SEE and RQ were measured by indirect calorimetry. RESULTS: At birth, weight, length, arm-muscle and arm-fat areas were significantly higher in LGA subjects than in AGA subjects. Weight status, SEE and RQ at birth did not explain the relative weight change after adjusting for gestational weight, placental weight, age at follow-up and gender. Arm-fat area and weight/length ratio at birth were negatively associated with relative changes in body weight after adjusting for the above variables (p < 0.05). CONCLUSION: Early growth from birth to 5 mo of life is significantly affected by body size and adiposity at birth. Fatter newborns had a slower growth rate than thinner newborns.     

Lymphocyte subpopulations in peripheral blood of small-for-gestational age and appropriate-for-gestational age preterm neonates

The lymphocyte subpopulations were investigated in peripheral blood of small-for-gestational age (SGA) and appropriate-for-gestational age (AGA) preterm newborns. In SGA newborns the number and percentage of T lymphocytes were reduced. Among the T lymphocytes, the number and percentage of T helper cells were significantly decreased. The cytotoxic/suppressor T cells were also reduced, but to a lesser extent.     

Catch-up growth of supine length/height of very low birth weight, small for gestational age preterm infants to adulthood

OBJECTIVE: To analyze linear growth of very low birth weight (VLBW), small for gestational age (SGA; < 10th percentile) preterm infants from birth as to catch-up or no catch-up growth. STUDY DESIGN: VLBW SGA preterm infants (n = 46) with primarily symmetric intrauterine growth restriction from the Bonn Longitudinal Study were compared with 62 appropriate for gestational age (AGA) VLBW preterm and 73 term infants and with their parents. RESULTS: Forty-six percent of VLBW SGA (21 of 46) had complete height catch-up by adult age, and most became taller than target height (TH) (15 of 21; 71%). The others did not catch up; most of them remained shorter than TH (18 of 25; 72%) after initial catch-up followed by catch-down growth. Mean adult height z-score was lower than that for birth length. Mean body mass index was similar in the catch-up and no catch-up groups (21.8 and 21.3, respectively) and lower than in the controls (23.2). Approximately 1/2 of the head circumference (HC) catch-up children achieved height catch-up as well. CONCLUSIONS: Height catch-up extended beyond age 6 years, independent of HC growth. We could not predict height catch-down or successful catch-up.     

Catch-up growth in very-low-birth-weight infants. Clinical correlates

Clinical correlates of catch-up growth were documented in 182 very-low-birth-weight (VLBW) infants (less than 1.5 kg) followed up prospectively until a corrected age of 33 months. At birth, 147 infants had weights appropriate for gestational age (AGA), and 35 were small for gestational age (SGA). The infants in each group were categorized as small if body weight was 2 SDs below the mean for age or appropriate if body weight was within 2 SDs of the mean at birth and at corrected ages of 40 weeks and 8, 21, and 33 months. Of the 147 AGA infants, 67 (46%) weighed less than 2 SDs of the mean for age at a corrected age of 40 weeks, 40 (27%) at 8 months, 28 (19%) at 21 months, and 25 (17%) at 33 months. Of the 35 SGA infants, 32 (91%) had subnormal weight at 40 weeks, 17 (49%) at 8 months and 21 months, and 16 (46%) at 33 months. Significant correlates of poor catch-up growth in the AGA group were birth weight, gestational age, severity of neonatal complications, poor neonatal head growth, and chronic physical and neurologic sequelae. In the infants in the SGA group, the correlates of poor catch-up growth were birth weight, multiple birth, and social class.     

Catch-up growth of head circumference of very low birth weight,small for gestational age preterm infants and mental development to adulthood

OBJECTIVE: To examine the influence of postnatal energy quotient (EQ, energy intake/kg body weight per day) on head circumference (HC) growth and mental development of very low birth weight (VLBW), small for gestational age (SGA, <10th percentile) preterm infants. STUDY DESIGN: SGA VLBW preterm infants (n = 46) with primarily symmetric intrauterine growth restriction were compared with 62 appropriate for gestational age (AGA) VLBW preterm infants and 73 term infants from the Bonn Longitudinal study. RESULTS: Twenty-seven of 46 (59%) of the SGA preterm infants showed complete HC catch-up growth by the age of 12 months, but mostly before 6 months after term (HC catch-up group). These infants had significantly higher mean EQs from day 2 to 10 than the group of 19 infants without HC catch-up (EQ, 95 vs 78). Mean EQs correlated significantly with developmental and intelligence quotients (DQ/IQ) from 18 months to 6 years. As adults, the HC of the HC catch-up group was not significantly different from that of the AGA preterm infants, the term infants, and their parents. The group without HC catch-up had smaller HC as adults. CONCLUSIONS: Our data suggest that early postnatal high-energy nutrient intake for SGA preterm infants is needed to promote HC catch-up growth and to prevent negative consequences of undernutrition.     

Pituitary-thyroid responsiveness to thyrotropin-releasing hormone in preterm and small-for-gestational age newborns.

A dose of 40 microgram TRH was injected intravenously in 12 preterm (PT) and 15 small-for-gestational age (SGA) babies (with advanced gestational ages) between 5 and 167 hours after birth. Serum-thyrotropin (TSH) was measured prior to and 30 and 180 min after TRH; serum-thyroxine (T4) and serum-triiodothyronine (T3) were measured prior to and 180 min after TRH. The percentage increase in serum-TSH in PT and SGA babies was comparable to that of fullterm newborns. The serum-TSH 30 min after TRH in SGA newborns was significantly correlated to basal TSH values, such a correlation could not be shown in the preterms. One SGA and four PT babies had a repeat TRH-test performed later in infancy: In all but one PT with a gestational age of 27 weeks the TSH rise was lower than in the neonatal period. The thyroid hormone responses after TRH were similar in the two groups of babies. The percentage increase above basal levels were: Median serum-T3 increase about 46% and median serum-T4 increase about 14%. It is concluded that in low-birth-weight newborn babies the pituitary TSH response to exogenous TRH was like that detected in fullterm newborns and more pronounced that later in infancy. The effect of endogenous TSH as measured by thyroid hormone increases was of the same magnitude as observed in fullterms and in adults.     

Intrauterine growth and gestational age in preterm infants with cerebral palsy

In a case-control study, gestational age and intrauterine growth of 191 preterm singleton infants 1971–1982 with cerebral palsy were compared to all preterm live-born singletons in Denmark in 1982 (N = 2203). The distribution of gestational age among preterm cases was slightly bimodal with maximum values at 29 and 32 weeks. The risk for cerebral palsy was highest in the infants with gestational age 28–30 weeks (OR = 5.6 (4.0 – 7.8), 95% confidence interval). Birth weight deviation, in the 34–36 weeks infants, expressed as the number of standard deviations from the mean birth weight for gestational age, was more negative in cases than in controls (P < 0.001). The frequency of small for gestational age (SGA) was 13% in cases and 9% in controls (OR = 1.5 (0.96 – 2.3), 95% confidence interval). The odds for cerebral palsy being SGA, was lower in 28–30 weeks (OR = 0.22 (0.06 – 0.86), 95% confidence interval), the same in 31–33 weeks (OR = 0.83 (0.35 – 2.0), 95% confidence interval) and higher in 34–36 weeks (OR = 5.2 (2.9 – 9.5), 95% confidence interval). In conclusion, preterm infants with cerebral palsy are born earlier than other preterm infants. Small for gestational age is associated with cerebral palsy in preterm infants only above 33 weeks.     

Catch-up growth in 166 small-for- gestational age premature infants weighing less than 1,000 g at birth

Catch-up growth was studied in 166 children born with an extremely low birth weight (<1,000 g) and small-for-gestational age (SGA, <10th percentile birth weight for gestational age). Of these children 159 were followed up for between 4 and 18 years (median 9 years). Group A, SGA <10th percentile of Lubchenco curves only; group B, <10th percentile of Mamelle's curves but >5th percentile, and group C, <5th percentile of Mammelle's curves. Catch-up growth was considered to be achieved when height, weight, and head circumference (HC) reached -2 SD of French reference data and remained above this limit afterwards. Catch-up growth in height was achieved in 126/156 children or 81% (group A 88%; group B 84%; group C 74%), before 3 years of age in 100/127 (78%). Seven children below -2 SD received growth hormone (1 child who caught up was excluded from the results). Catch-up growth in weight was achieved in 126/159 children or 79% (group A 86%; group B 82%; group C 73%), before 3 years of age in 87/126 (69%). Catch-up growth in HC was achieved in 126/156 or 81% (group A 78%; group B 92%; group C 77%), before 3 years of age in 102/127 (80%). Overall catch-up growth was achieved for all three parameters in 65% of children, two of three parameters in 19%, and one of three parameters in 8%. Eleven children never caught up on any parameter. While weight is a lesser concern and HC is not liable to intervention, a greater number of short children might benefit from growth hormone therapy.     

Serum concentrations of thyroxine-binding globulin, prealbumin and albumin in healthy fullterm, small-for-gestational age and preterm newborn infants.

Simultaneous serum concentrations of thyroxine-binding globulin (TBG), prealbumin (TBPA) and albumin (Alb) were measured in 130 fullterm, 32 small-for-gestational age and 25 preterm infants during their first six days of life. In all infants serum concentrations of TBG were higher and serum TBPA and Alb were lower than in male adults. Even higher serum TBG levels were found in the mothers. There was no correlation between serum concentrations in paired maternal and cord sera. In infants with birth weights appropriate for gestation serum TBG, TBPA, and Alb concentrations increased progressively with gestational age. In small-for-gestational age infants born at term serum concentrations of TBG and Alb were lower than those in fullterm, but higher than those in premature newborns. Serum TBPA in small-for-gestational age babies was even lower than seen in prematures. A positive correlation was found between thyroid hormones and TBG concentrations, not between serum TBPA and thyroid hormones. The ratios between serum concentration of thyroid hormones and proteins might indicate that more thyroid hormonebinding sites are occupied in fullterm than in low birth-weight newborns. However, the main reason for the different serum levels of thyroid hormones in fullterm, small-for-gestational age and preterm babies is probably the various serum TBG concentrations demonstrated in these infants.