Influence of elective preterm delivery on birthweight and head circumference standards.

We calculated new birthweight and head circumference centiles for boys and girls between 24 and 42 weeks'' gestation from 20,713 singleton live births at our hospital between 1978 and 1984. Among the 803 babies born at or before 34 weeks'' gestation, 28% were delivered electively for fetal problems; they were considerably lighter than babies born after spontaneous preterm labour. In contrast, they showed only a small deficit in head circumference, possibly due to a brain sparing effect in growth retarded infants. Electively delivered preterm infants cause a bias in birthweight and head circumference centiles and we recommend that these babies should be excluded when these centiles are calculated.     

Size at Birth of Infants in a Saudi Maternity Hospital

ABSTRACT. The size at birth was assessed of Saudi infants who were delivered in the main Maternity hospital in Riyadh and who represented a large proportion of infants born in the city. The mean (SD) weight, length and head circumference at birth of Saudi singletons were 3226 (534) g, 49.5 (2.0) cm and 34.5 (1.5) cm, respectively. Of all infants 5.9 percent were born preterm. The proportion of low birthweight infants was 7.9 percent, of which 44 percent were born at or past term. Teenage mothers had a low birthweight rate of 15.2 percent and primipara of 13.9 percent, however. Of all singletons 2.2 percent were small for gestational age and 3.7 percent of term infants had a Ponderal index <3rd percentile of the standard. During the final weeks of gestation the fetal growth rate was similar to that of Western populations. Compared with other developing countries the birth weight distribution was favorable and seemed to be influenced to a smaller extent than in these countries by socioeconomic and environmental factors.     

Birthweight centiles in preterm infants reappraised

The relationship between birthweight, gestation and obstetric and neonatal course was examined for 444 live births at 25-31 weeks gestation in 5 centres from 1982 to 1984 and comparative data were obtained from 121 infants below 32 weeks born in 1968-1972. The rate of 'interventive' deliveries by elective caesarean section, at this gestation, performed largely for conditions associated with poor intrauterine growth, has risen over 10-fold in the past decade, now accounting for 42% of deliveries at 30 weeks. This may explain in part a secular trend towards reduced birthweight for gestation in preterm infants. Electively delivered infants were significantly lighter than those delivered spontaneously and were responsible for substantial skewing and lowering of overall birthweight centiles. In contrast, the infant's sex, whether or not the infant survived following live birth, and whether gestational age was assessed by maternal dates or by clinical estimation (including ultrasound), all made no significant difference to birthweight centiles. A new birthweight centile chart is presented for infants less than 32 weeks, based only on spontaneous deliveries. This chart differs considerably from those commonly used in Britain and, we suggest, provides a realistic standard for identifying abnormal intrauterine growth.     

84例早产适于胎龄儿第一年体格追赶生长纵向评估

目的：分析早产适于胎龄儿1岁以内的追赶生长特点,探讨其追赶生长规律。方法：选择84名胎龄28～36周的早产适于胎龄儿（男44例,女40例）作为研究对象,对其0～12月内的体重、身长及头围分别按实际月龄足月儿生长标准和纠正月龄标准进行Z评分评估并分析。结果：早产适于胎龄儿1岁内体重、身长和头围均出现追赶性生长,且增长最快的阶段均在实际月龄0～3月,体重追赶速度优于身长追赶速度。结论：生后前3个月是早产适于胎龄儿的快速生长期;体重与身长的变化存在不平衡性。     

早产儿校正24月龄内生长轨迹研究（英文翻译）

目的分析早产儿校正24 月龄内生长轨迹,以了解早产儿的生长趋势和规律。方法基于互联网+ 随访系统建立早产儿随访数据库,纳入2018 年4 月至2021 年4 月3 188 例早产儿,收集其出生及校正1、3、6、 12、18、24 月龄时的身长、体重、头围数据。按不同的围生期因素分组,绘制生长曲线,并与21 世纪国际胎儿和新生儿生长联合会（International Fetal and Newborn Growth Consortium for the 21st Century,INTERGROWTH-21st）标准和世界卫生组织（World Health Organization,WHO） 标准进行比较。结果按不同的围生期因素分组的各组早产儿体重、身长、头围曲线均在校正6 月龄内快速上升,校正6 月龄后增长速度减缓。按实际月龄比较,各出生胎龄组早产儿（<28 周、28~31⁺⁶周、32~33⁺⁶周、34~36⁺⁶周） 身长曲线在实际9 月龄后逐渐与WHO 曲线重合（P=0.082）,<32 周早产儿的体重和头围则一直落后于WHO 曲线（P<0.001）。校正月龄后,不同出生胎龄组早产儿（<28 周、28~31⁺⁶周、32~33⁺⁶周、34~36⁺⁶周） 的体格生长曲线基本重合（P>0.05）。超低出生体重儿和小于胎龄儿的身长、体重、头围曲线均低于INTERGROWTH-21st 标准和WHO 标准（P<0.05）。结论早产儿在校正6 月龄内体格增长速度较快,校正6 月龄后增长速度减缓。胎龄越小,体重和头围追赶的时间越长。应重点关注超早产儿、超低出生体重儿和小于胎龄儿的体格生长。     

Longitudinal follow-up of height up to five years of age in infants born preterm small for gestational age; comparison to full-term small for gestational age infants

OBJECTIVE: This aims to conduct a comparative study of the height catch-up rate in preterm small for gestational age (SGA) infants during early childhood by gestational age and identify the factors affecting short stature in comparison to full-term SGA infants. METHODS: 449 SGA infants (214 full-term infants, 73 infants with gestation of less than 32 weeks, and 162 infants with gestation of more than 32 weeks but less than 37 weeks) from 25 institutions in Japan were assessed for catch-up (> or = -2SD) rate in growth by measuring for length/height at 1 year, 3 years and 5 years of age and the risk factors for no catch-up (< -2SD) at 5 years. RESULTS: The overall length/height catch-up rate was 68% at 1 year, 89% at 3 years and 88% at 5 years. The catch-up rate at 3 and 5 years of age in the group with gestation of less than 32 weeks had a rate of 74%, which was significantly less than the other two groups (approximately 90%). A significant factor associated with short stature at 5 years in the group with gestation of less than 32 weeks was the lower length SD score at time of birth, and for preterm infants born more than 32 weeks of gestation and full-term infants, significant factors were the lower maternal height and head circumference at birth. CONCLUSION: SGA infants born less than 32 weeks of gestation had a higher risk of no catch-up and different factors affecting catch-up compared to preterm SGA infants of gestation more than 32 weeks and full-term SGA infants.     

Standards for skinfold thickness in British newborn infants.

Standards of triceps and subscapular skinfold thicknesses for 1293 Caucasian newborn infants of gestational ages 37-42 weeks, and of 0-25 kg birthweight intervals between 2-25 and 4-5 kg are presented. Female infants had a greater skinfold thickness than males, and the subscapular skinfold was greater than the triceps. The skinfold thickness in both males and females declined after 40 weeks of gestation.     

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.     

Neurosensory outcome and growth at three years in extremely low birthweight infants: follow-up results from the Swedish national prospective study

A prospective national investigation comprising 633 extremely low birthweight (ELBW) infants born alive in the 2-y period 1990-1992 with a birthweight of ≤1000 g and gestational age of ≥23 completed weeks was conducted regarding neurosensory outcome and growth. Three-hundred and sixty-two (98%) surviving ELBW infants were assessed at a median age of 36 months, using a specially designed protocol. At follow-up, mean height, weight and head circumference in both boys and girls were significantly lower than the reference values. The incidence of cerebral palsy was 7% among all children and 14%, 10% and 3% in children born at 23-24, 25-26 and ≥27 gestational weeks, respectively. At least one obvious handicap was present in 14%, 9% and 3% of these three groups of children, respectively. After adjustment for gestational age, a significantly increased risk of handicap was found in children with intraventricular haemorrhage grade ≥3 and/or periventricular leucomalacia and in children with retinopathy of prematurity stage ≥3. The results show that more than 90% of ELBW children born at ≥25 completed gestational weeks were without neurosensory handicap at 36 months of corrected age. In infants born at 23-24 weeks of gestation, both survival and long-term outcome were less favourable.     

Why is there a modifying effect of gestational age on risk factors for cerebral palsy?

OBJECTIVE: To investigate risk factors for cerebral palsy in relation to gestational age. DESIGN: Three case-control studies within a geographically defined cohort. SETTING: The former Oxfordshire Health Authority. PARTICIPANTS: A total of 235 singleton children with cerebral palsy not of postnatal origin, born between 1984 and 1993, identified from the Oxford Register of Early Childhood Impairment; 646 controls matched for gestation in three bands: or=37 weeks. RESULTS: Markers of intrapartum hypoxia and infection were associated with an increased risk of cerebral palsy in term and preterm infants. The odds ratio (OR) for hypoxia was 12.2 (95% confidence interval 1.2 to 119) at or=37 weeks. Corresponding ORs for neonatal sepsis were 3.1 (1.8 to 5.4) and 10.6 (2.1 to 51.9). In contrast, pre-eclampsia carried an increased risk of cerebral palsy at >or=37 weeks (OR 5.1 (2.2 to 12.0)) but a decreased risk at 相似文献   

Velocity of head growth during the perinatal period

Growth velocity of head circumference was studied longitudinally in different gestational age groups of 222 appropriate-weight-for-dates (AFD) and 94 small-for-dates (SFD) healthy infants during the first 5 months of life. Term AFD and SFD infants showed a steady slowing of growth rate of head circumference from birth. In contrast, preterm AFD infants of less than 36 weeks' gestation showed an increasing velocity of growth followed by slowing, with maximum velocity occurring between 30 and 40 days after birth. The shorter the postconceptional age at birth the later maximum velocity occurred. However, those preterm AFD infants of between 30 and 33 weeks' gestation who were given a high caloric feed showed a similar velocity curve to that of infants of 34-37 weeks of gestation. Cross-sectional data were used to estimate growth velocity of head circumference in the fetus. Two conclusions emerged. First, there is a slowing of head growth velocity from 31 weeks' gestation in utero, and second, term infants show a marked increase in volocity after birth. Though the occurrence of maximum velocity of head growth is delayed in the preterm infant, the net effect is such that at a given postconceptional age his head circumference is greater than that of the term infant, at least within the first 5 postnatal months.     

The association of growth impairment with neurodevelopmental outcome at eight years of age in very preterm children

BACKGROUND: The relative contributions of poor growth before and after birth in very preterm infants to subsequent outcomes at school-age are not certain. AIMS: To determine the associations between weight and head circumference, at birth and postnatally, with cognitive, academic and motor outcomes at age 8 years for very preterm children free of neurosensory impairment. STUDY DESIGN: This was a regional cohort study from the state of Victoria, Australia. SUBJECTS: 179 very preterm infants (<28 weeks' gestational age) born in 1991 and 1992 who were free of neurosensory impairment. OUTCOME MEASURES: At 8 years of age children had cognitive, academic and motor assessments. Weight and head circumference data were collected at birth, at the time of discharge (weight only), at 2 years of age and at 8 years of age, and growth restriction was calculated using Z-scores (standard deviation scores) relative to the expected mean for age. RESULTS: Very preterm children were significantly lighter and had smaller head circumferences than the reference group at all ages. Weight at any age was mostly unrelated to any outcomes. While head circumference at birth was not related to school-aged outcomes, smaller head circumferences at ages 2 and 8 years were associated with poorer performance in most outcome measures. Catch-up growth in weight in early childhood was not associated with 8-year outcomes. CONCLUSIONS: Intrauterine growth restriction was not substantially associated with neurodevelopmental status at age 8. Weight after birth had little influence, but head circumference became more important in early childhood.     

Incidence of retinopathy of prematurity requiring treatment in infants born greater than 30 weeks' gestation and with a birthweight greater than 1250 g from 1998 to 2002: a regional study

AIM: To ascertain the prevalence of significant Retinopathy of Prematurity (ROP) and ROP requiring treatment in infants born greater than 30 weeks gestation and with a birthweight greater than 1250 g, utilising the Neonatal Intensive Care Units' (NICUS) data collection from 1998 to 2002. Second, to determine whether infants delivered at more than 30 weeks gestation or with a birthweight greater than 1250 g require ROP screening. METHODS: A review of the New South Wales and Australian Capital Territory NICUS data collection from 1998 to 2002 was performed. Infants of gestational age 31-33 weeks and with a birthweight greater than 1250 g were included. A review was performed of these infants to ascertain stage of ROP, threshold disease and treatment for ROP. RESULTS: 2292 infants were greater than 30 weeks and had a birthweight greater than 1250 g. Of these 1386 (60%) were not examined or died prior to eye examination. No ROP was noted in 888 of the 904 infants examined (98%), 13 infants had stage 1 (1.4%), five infants stage 2 (0.6%) and no infant had stage 3 ROP. No infant developed stage 3 ROP, required treatment for ROP or had threshold disease. CONCLUSION: In this regional study of infants greater than 30 weeks gestation and with a birthweight greater than 1250 g, the prevalence of any ROP was low (2.0%). This study supports evidence from other studies that screening for ROP could be restricted, at least within our referral network, to infants less than 30 completed weeks and a birthweight less than 1250 g.     

Velocity of head growth during the perinatal period.

Growth velocity of head circumference was studied longitudinally in different gestational age groups of 222 appropriate-weight-for-dates (AFD) and 94 small-for-dates (SFD) healthy infants during the first 5 months of life. Term AFD and SFD infants showed a steady slowing of growth rate of head circumference from birth. In contrast, preterm AFD infants of less than 36 weeks'' gestation showed an increasing velocity of growth followed by slowing, with maximum velocity occurring between 30 and 40 days after birth. The shorter the postconceptional age at birth the later maximum velocity occurred. However, those preterm AFD infants of between 30 and 33 weeks'' gestation who were given a high caloric feed showed a similar velocity curve to that of infants of 34-37 weeks of gestation. Cross-sectional data were used to estimate growth velocity of head circumference in the fetus. Two conclusions emerged. First, there is a slowing of head growth velocity from 31 weeks'' gestation in utero, and second, term infants show a marked increase in volocity after birth. Though the occurrence of maximum velocity of head growth is delayed in the preterm infant, the net effect is such that at a given postconceptional age his head circumference is greater than that of the term infant, at least within the first 5 postnatal months.     

Neurological examination of preterm infants at term equivalent age

BACKGROUNDS: We previously reported the neurological findings of the Dubowitz neonatal examination in a cohort of 157 low-risk preterms born between 25 and 33 weeks gestational age (GA) and examined at term equivalent age (TEA). Median and range of scores were wider than those found in term-born infants and preterms showed a different neurological behaviour in specific items. However, the cohort number was too small to draw any definitive conclusion about the distribution of findings. AIMS: We provide normative data from a low-risk cohort of 380 preterm infants; we also assess the findings and their relationship to motor outcome in preterms with major cranial ultrasound (US) abnormality. STUDY DESIGN: We assessed, at TEA, 380 low-risk preterms born <35 weeks gestation (range 25-34.9, median 29) with normal 2 year motor outcome and 85 preterm infants with major US abnormality. RESULTS: At TEA low-risk preterms had less flexor limb tone, poorer head control but better visual following than term-born infants. For 28/34 of the neurological items the range and median scores were similar across gestational ages. In infants with major US lesions the range and median scores differed from low-risk preterms in 20/34 items; 40% of infants developing a diplegia and 80% developing a tetraplegia had >7 items outside the 90th centile; all infants with >12 items outside the 90th centile developed a tetraplegia. CONCLUSIONS: We provide reference values for the neurological examination of low-risk preterms at TEA. In infants with major US abnormality the number of items outside the 90th centile was an indicator of outcome severity.     

Dietary zinc intake and growth during infancy

Energy, protein, zinc intake, and weight and length were monitored at 3, 6, and 12 months in 50 preterm infants (corrected for gestational age) (mean birthweight, 1,054 +/- 234 g; mean gestation, 29 +/- 2.5 weeks) and 60 full-term infants (mean birthweight, 3,509 +/- 269 g; mean gestation, 40 +/- 1 weeks). Mean energy and protein intake (per kilogram body weight) was higher (p less than 0.05) for the preterm infants at all times and met the recommended levels for preterm infants. No significant differences in zinc intake (per kilogram body weight) between the two groups existed, and at 3 months, mean zinc intake in the preterm group (per kilogram body weight) was below the recommended level for full-term infants. At no time were the growth percentiles of the preterm group equal to those of the full-term group. Multiple regression equations predicting length at 3 months and weight at 12 months for all the infants were significant, the significant variables being length at birth and zinc intake (milligrams per day) at 3 months, and weight at birth and dietary zinc intake (milligrams per day) at 12 months, respectively. Results indicate that zinc intake played a more important role in explaining the length at 3 months and weight at 12 months than did any other variables, including intakes of protein and energy, gestational age, socioeconomic index of the father, midparent height, sex, and age of introduction of solid foods. Results thus support the suggestion that infants, especially those born prematurely, are at risk for inadequate intake of dietary zinc.     

Short-term outcome predictors in infants born at 23–24 gestational weeks

Aim: Outcome is uncertain in infants born at 23–24 gestational weeks. The aim of the present study was to identify possible early predictors of outcome in these infants.
Materials and Methods: Data from the Swedish medical birth register (MBR) for live-born infants with gestational ages (GAs) 23 and 24 weeks, born during the time-period 2000–2002, were analysed in relation to short-term outcomes, that is survival and survival without severe brain damage (intraventricular haemorrhage [IVH] grades 3 and 4 and/or periventricular leukomalacia [PVL]).
Results: In 57 infants born at 23 gestational weeks, survival was associated with birthweight (BW) (p = 0.018) and 5-min Apgar score (p = 0.020) on univariate analyses. In 99 infants born at 24 weeks of gestation, survival without severe brain damage correlated with BW (p = 0.039), birth type (singleton/multiple) (p = 0.017) and Apgar score at 1, 5 and 10 min (p = 0.028, 0.014 and 0.030, respectively). The best model for predicting survival without severe brain damage in infants born at 24 gestational weeks was based on 5-min Apgar score and birth type. The small number of live-born infants at 23 weeks of gestation did not allow for multiple logistic regression analyses.
Conclusion: The 5-min Apgar score is associated with short-term outcome in live-born infants at 23–24 gestational weeks. The association is stronger for infants born at 24 weeks of gestation.     

Short-term outcome predictors in infants born at 23-24 gestational weeks.

AIM: Outcome is uncertain in infants born at 23-24 gestational weeks. The aim of the present study was to identify possible early predictors of outcome in these infants. MATERIALS AND METHODS: Data from the Swedish medical birth register (MBR) for live-born infants with gestational ages (GAs) 23 and 24 weeks, born during the time-period 2000-2002, were analysed in relation to short-term outcomes, that is survival and survival without severe brain damage (intraventricular haemorrhage [IVH] grades 3 and 4 and/or periventricular leukomalacia [PVL]). RESULTS: In 57 infants born at 23 gestational weeks, survival was associated with birthweight (BW) (p = 0.018) and 5-min Apgar score (p = 0.020) on univariate analyses. In 99 infants born at 24 weeks of gestation, survival without severe brain damage correlated with BW (p = 0.039), birth type (singleton/multiple) (p = 0.017) and Apgar score at 1, 5 and 10 min (p = 0.028, 0.014 and 0.030, respectively). The best model for predicting survival without severe brain damage in infants born at 24 gestational weeks was based on 5-min Apgar score and birth type. The small number of live-born infants at 23 weeks of gestation did not allow for multiple logistic regression analyses. CONCLUSION: The 5-min Apgar score is associated with short-term outcome in live-born infants at 23-24 gestational weeks. The association is stronger for infants born at 24 weeks of gestation.     

Plasma Zinc Concentration and Catch Up Growth in Preterm Infants

Changes in plasma zinc concentration during the period of catch up growth were examined in 44 preterm infants. Blood samples were collected at birth, 6, 12 and 24 weeks. Plasma zinc concentration showed a mean of 13.6 μmol/l at birth and dropped to 9.8 μmol/l at 6 weeks and rose to 11.3 and 15.4 μmol/l at 12 and 24 weeks respectively. Plasma zinc concentrations showed significant correlation with weight velocity at 12 weeks. Male infants had significantly lower plasma zinc concentrations than females at 12 weeks. Infants of gestational age more than 32 weeks had lower plasma zinc concentrations at 12 and 24 weeks than those of earlier gestations. At the same time males were growing faster than females and also infants of gestational ages more than 32 weeks were growing faster than those born at earlier gestations. These observations, together with the finding that the decline in zinc occurred during the phase of rapid growth, suggest that growth is the predominant modulator of plasma zinc concentration.     

Neonatal outcome following early onset preterm premature rupture of the membranes--a case controlled study

A case-controlled study was performed to determine whether preterm premature rupture of the membranes (PPROM), particularly if occurring in the second trimester, increased the duration of ventilatory support or hospital admission. Infants born after membrane rupture of at least 24 hours duration and prior to 37 weeks of gestation were identified. It was possible to match for gestational age and birthweight 40 PPROM infants, 15 of whom had onset of rupture of the membranes (ROM) prior to 27 weeks of gestation, with a control (an infant whose mother had not suffered PPROM). A greater proportion of the mothers of the PPROM infants had received antenatal steroids (p<0.01), had an antepartum hemorrhage (p=0.06) or delivered vaginally (p<0.02). More PPROM infants had pulmonary hypoplasia (p<0.03) or infection (p<0.01). Overall, however, and if only those matched pairs where membrane rupture had occurred prior to 27 weeks of gestation were considered, there were no statistically significant differences in the duration of ventilatory support or hospital admission. Step-wise regression analysis confirmed that in the study population overall and in the matched pairs where membrane rupture had occurred at less than 27 weeks of gestation, neither the duration of ventilation nor hospital admission significantly related to PPROM. These findings have implications when counselling parents.