The relation between environmental temperature and oxygen consumption in the new-born baby

1. Oxygen consumption (V(O2)) has been measured serially in sixty-eight infants during the first 10-35 days of life, when naked in a Perspex metabolic chamber, by recording the changes in circulating gas volume. Air speed in the chamber was 4-5 cm/sec, and absolute humidity approximately 18 mm Hg.2. When environmental temperature (T(E)) was 35-38 degrees C minimal V(O2) rose from 5 to 7 ml.O(2)/kg.min during the first 2 days of life in infants weighing over 2.5 kg, and more slowly in the first 7-10 days in infants under 2 kg at birth.3. Physical activity and V(O2) both increased when T(E) fell below 33 degrees C: the increase appeared to be linearly and inversely related to T(E), but the rise in heat production was seldom enough to prevent a fall in rectal temperature. In infants over 2.5 kg at birth the mean increase amounted to 0.56 ml.O(2)/kg.min for each 1 degrees C fall in T(E) when 4-12 hours old, and 1.27 ml.O(2)/kg.min when between 4 and 20 days old. In infants weighing 1-2 kg at birth the mean increase was similar in the first 12 hr, but the coefficient rose more gradually with age.4. The maximum V(O2) in infants over 2.5 kg at birth and over 2 days old was about 2(1/2) times the minimum V(O2); the maximum was rather lower in most infants of low birth weight.5. In seven infants who were motionless and apparently asleep after sedation with chloral hydrate, the increase in V(O2) at low T(E) was reduced but still significant.6. It is concluded that the new-born baby responds to a cool environment with a considerable immediate increase in heat production; visible muscular activity appears to account for only part of this increase.     

The post-natal changes in minimal metabolic rate in the pig

1. Minimal metabolic rate was measured as oxygen consumption in new-born pigs when environmental temperature was rising and passing through thermal neutrality.2. Three different periods were observed in 20 days after birth. The first period included the time from birth to 82 hr and was characterized by a continuous rise in minimal metabolic rate from 9.4 to 16.0 ml. O(2)/kg.min (70% increase). The second period extended from 82 hr to 9.5 days with values near to 16 ml. O(2)/kg.min. The third period beginning on the eleventh day lasted until observations ceased on the twentieth day and was characterized by a 25-30% fall in minimal metabolic rate when compared with the second period.3. Minimal metabolic rates from the second and third period were proportional to body weight and not to the surface area. Exponential factors for body weight were 0.93 and 0.96 for the second and third periods respectively.4. Rectal temperature rose from 38.6 degrees C on the first day to 39.3 degrees C on the second and 39.5 degrees C on the fourth day after birth.5. Environmental temperature associated with minimal metabolic rate showed a general tendency to fall from 36.5 in the first 4 days to between 33 and 34 degrees C in the following days.6. Age rather than body weight is the decisive factor influencing changes in minimal metabolic rate in the new-born pig.     

Paternal sperm concentration and growth and cognitive development in children born with a gestational age more than 32 weeks after assisted reproductive therapy

BACKGROUND: A possible impact of paternal sperm quality on the outcome in children born after assisted reproductive technologies, especially ICSI, has been discussed. The objective of this study was to assess whether sperm concentration has any influence on growth and cognitive development in children born with a gestational age more than 32 weeks after ICSI or IVF. METHODS: Singleton children born after ICSI (n = 492) or IVF (n = 265) from five European countries were examined at age 5 years. The ICSI group was divided into five subgroups according to paternal sperm origin and sperm concentration: (1) epididymal and testicular sperm group, (2) ejaculated sperm < 1 x 10(6)/ml, (3) ejaculated sperm 1-4.99 x 10(6)/ml, (4) ejaculated sperm 5-19.99 x 10(6)/ml and (5) ejaculated sperm > or = 20 x 10(6)/ml. The IVF group was divided into two subgroups: (1) < 20 x 10(6)/ml and (2) > or = 20 x 10(6)/ml. Growth parameters at birth and age 5 were evaluated. Cognitive development was assessed with the Wechsler Preschool and Primary Scale of Intelligence-Revised. RESULTS: No significant difference was found for gestational age, birth weight and birth weight standard deviation scores (SDS) between the ICSI and IVF sperm groups. No significant difference in height and weight at age 5 or SDS weight or height or BMIs at age 5 was found. There was no significant difference in total intelligence quotient (IQ)--performance or verbal IQ--between the groups. CONCLUSION: We found no indication that growth and cognitive development in ICSI and IVF children differed depending on paternal sperm concentration.     

Patent Ductus Arteriosus Closure in Prematurities Weighing Less than 1 Kg by Subaxillary Mini-thoracotomy

The surgical closure of patent ductus arteriosus (PDA) is provided more frequently in extremely low birth weight babies who are usually deemed unsuitable for pharmacological closure. We have adopted subaxillary mini-thoracotomy in order to lessen surgical trauma in these babies; and its clinical results were analyzed. From April 2004 to August 2008, out of 50 babies at the neonatal intensive care unit who underwent the surgical closure of PDA, 22 premature babies weighing less than 1 kg at operation were included in the study. Eleven babies were males and mean gestational age was 27 weeks ranging from 23⁺³ to 30⁺² weeks. Mean body weight at operation was 816 g ranging from 490 to 989 g and average age at operation was 17.9±11.9 days. Of them, 17 babies (72%) were ventilator dependent preoperatively, as compared with 13 out of 28 (46%) babies that weighed more than 1 kg (P<0.05). Four babies did not survive to discharge. Among 28 babies who were heavier than 1 kg, there were only one death. However, the mortality difference was not statistically significant (P=0.11). All mortalities were caused by inherent problems of prematurity and co-morbidities. Out of 17 babies who had been ventilator dependent preoperatively, 13 weaned off successfully at 17.0±23.9 days after the operation. The baby patients heavier than 1 kg weaned at 6.0±5.3 days (P=0.27). Surgical outcome of simple and less invasive subaxillary mini-thoracotomy was satisfactory; the surgery is highly recommended for ductal closure in extremely low weight premature babies.     

广西农村壮族66798例新生儿出生体重分析

目的研究农村壮族新生儿出生体重与胎儿性别、胎龄、孕母年龄的关系,为农村壮族孕产期保健和儿童保健提供基础资料。方法回顾性分析农村住院分娩的66798例壮族新生儿出生体重及其相关因素。结果壮族新生儿出生体重平均值五年无变化（P〉0.05）,平均值为（3.00±0.41）kg,其中五年间壮族男婴平均出生体重大于壮族女婴（P〈0.05）;出生体重随胎龄增长而增加,早产儿组平均体重只有（2.32±0.44）kg;孕母的年龄〈20岁的新生儿出生平均体重低于其他组。结论进一步研究广西农村壮族新生儿出生体重的影响因素,减少早育和早产,提高农村壮族地区孕产期保健和儿童保健工作质量,是广西＂十一五＂期间乃至更长时间孕产期保健和儿童保健工作的重点。     

Placental Cytokine and Chemokine Profiles Reflect Pregnancy Outcomes in Women Exposed to Plasmodium falciparum Infection

Pregnancy-associated malaria (PAM) can lead to severe complications for both mother and baby. Certain placental cytokine/chemokine profiles have been shown to reflect poor pregnancy outcomes, including maternal anemia and low birth weight. In intervillous plasma samples from 400 Beninese women living in an area where Plasmodium falciparum is endemic, we quantified 16 cytokines/chemokines. We assessed their profiles in groups with PAM, with maternal anemia, with preterm births, or with a low birth weight for gestational age. Repeated ultrasound measurements ensured that prematurity and low birth weight were highly accurate. Preliminary analyses revealed trends for lower cytokine/chemokine concentrations in placental plasma associated both with babies with low birth weight for gestational age and with P. falciparum infection during pregnancy, while, as a function of the latter, the concentration of gamma interferon (IFN-γ)-inducible protein 10 (IP-10) was higher. Multivariate analyses showed that (i) higher placental plasma interleukin-10 (IL-10) levels were associated with P. falciparum infections and (ii) independently of P. falciparum infections, lower concentrations of both IFN-γ and IL-5 were associated with low birth weight for gestational age. Our data further strengthen the idea that IL-10 and IP-10 could be useful diagnostic markers of P. falciparum infection during pregnancy. The concentrations of cytokines/chemokines in placental plasma may represent previously unrecognized markers of poor fetal growth.     

Oxygen consumption during pouch development of the macropod marsupial Setonix brachyurus

1. Measurements of O(2) consumption at 9 or 10 temperatures in the 20-40 degrees C ambient temperature range were made on joeys with ages selected to cover the 180-day period of pouch occupancy.2. The rate of O(2) consumption of joeys younger than 100 days increased directly with ambient temperature.3. After 100 days of age the O(2) consumption rate at low temperatures rose and at about 140 days of age a constant rate was maintained over the full ambient temperature range.4. Heat transfer from joey to mother commenced after 100 days of age.5. At 150-180 days of age the rate of O(2) consumption at 20 degrees C was approximately 12 times greater than at ages less than 100 days. A thermal neutral zone was established in the range 32-36 degrees C by joeys older than 150 days.6. At the usual pouch temperature of 36.5 degrees C, O(2) consumption per unit wet body weight rose from 12 ml./kg.min at birth to 17 ml./kg.min at the end of pouch life. On a unit dry body weight basis it fell from 120 to 56 ml./kg.min. This decline parallels the decrease in growth rate.     

Prognosis of neonates in pregnant women with systemic lupus erythematosus

PURPOSE: The effects of maternal systemic lupus erythematosus (SLE) on neonatal prognosis were examined by comparing clinical features of full-term babies born to lupus mothers and age- and parity-matched controls. PATIENTS AND METHODS: From January 2000 to December 2005, 39 singletons were born to 37 SLE women. Excluding 11 cases of prematurity and preeclampsia, 28 full-term neonates formed the lupus group. The control group included 66 full-term babies. The retrospective study examined medical records and compared gestational age, birth weight, days of hospital stay, small for gestational age (SGA) frequency, Apgar scores < 7, and parity. Lupus neonates were tested for anti-nuclear antibody (ANA) and platelet count, and electrocardiogram was performed. RESULTS: Average gestational age (38 vs. 39 weeks, p < 0.05) and birth weight (2,775 vs. 3,263g, p < 0.05) were significantly different between the SLE and control groups. SGA frequency was higher in the SLE group (25% vs. 4.5%, p < 0.05). No significant difference was observed in Apgar score, birth weight, gestational age, SGA frequency, and platelet count between lupus subgroups formed based on anti-dsDNA antibody levels and antiphospholipid antibody status. CONCLUSION: The association of maternal ANAs, antiphospholipid antibodies, and drug history with neonatal prognosis could not be elucidated. However, even in uncomplicated pregnancies, maternal lupus is disadvantageous for gestational age, birth weight, and SGA frequency.     

Birthweight and gestational age by ethnic group, England and Wales 2005: introducing new data on births

Low birthweight babies and babies born preterm are at increased risk of morbidity and mortality in the first year of life, as well as in the longer-term. Since information on ethnic group is not recorded at birth registration in England and Wales, it has not been possible to produce routine statistics on birthweight or gestational age by ethnic group. A new system, introduced in 2002, for allocating NHS numbers at birth (NN4B) provided the opportunity to obtain ethnic group information. The NN4B record includes information on the ethnic group of the baby classified according to the 2001 Census categories. This paper presents the first analyses of ethnic differences in birthweight and gestational age at birth for England and Wales as a whole. Utilising NN4B records linked with birth registration records for all births occurring in England and Wales in 2005, birthweight and gestational age distributions, including the percentages low birthweight and preterm, are compared between ethnic groups. The paper also examines how parental socio-demographic circumstances vary by ethnic group.     

Cholestasis in a neonatal intensive care unit

A retrospective study of 17 babies admitted to the neonatal intensive care unit of the Royal Maternity Hospital, Belfast, was undertaken to determine the causes and prognosis of conjugated hyperbilirubinaemia (direct fraction greater than 20% of total) over a five year period. Mean gestational age was 29 weeks and mean birth weight was 1,240g with a 2:1 male preponderance. All babies had a complicated clinical course involving prolonged periods of parenteral nutrition and many episodes of sepsis. Liver damage was not found to be a contributory factor to death in any baby who died before the age of one year. Bilirubin levels in the survivors had returned to normal within one year. No permanent pathological cause of cholestasis, such as biliary atresia, was ascribable to any of the cases, indicating that extensive investigation to exclude anatomical causes in this population is unlikely to prove rewarding.     

H-reflex and motor nerve conduction studies in growth retarded newborn babies

OBJECTIVE: To demonstrate the accelerated postnatal maturation/myelination in growth retarded babies compensating the deficit suffered by them during intrauterine life. METHODS: We studied 16 babies within the first 3 days of birth. These included 6 full term appropriate for gestational age babies (FT AGA) and 10 full term intrauterine growth retarded (FT IUGR). A separate group of 16 babies was examined at 2 months of age. In this group 7 were FT AGA and 9 were FT IUGR at the time of birth. H-reflex latency (HRL), motor nerve conduction velocity (MNCV) and H-reflex excitability (H/M) were measured in the right lower limb. Anthropometric measurements of the babies were also recorded meticulously. All the babies were neurologically normal on clinical evaluation. RESULT: At birth, MNCV was significantly lower in FT IUGR babies compared to FT AGA babies. However at the age of 2 months the MNCV of both FT AGA and FT IUGR was comparable. Other parameters (HRL and H/M) in the IUGR babies were comparable with normal babies both at birth and 2 months of age. In FT IUGR babies crown-heel length and weight was significantly lower than FT AGA babies both at the time of birth and at 2 months of age. CONCLUSION AND SIGNIFICANCE: The findings suggest that FT IUGR babies demonstrate accelerated postnatal peripheral neural maturation. At 2 months of age, the motor nerve conduction velocity of these growth retarded babies was comparable to that observed in normal AGA babies of similar age. This provides an insight into the functional aspect of the proven theories of decreased peripheral myelination in FT IUGR babies with subsequent rapid postnatal myelination that renders these babies neurologically equivalent to FT AGA babies despite not achieving comparable anthropometric parameters.     

Maternal early second trimester pregnancy weight in relation to birth outcome among Bengalee Hindus of Kolkata,India

Objective: The study examined to what degree maternal early second trimester pregnancy weight is useful and efficient in predicting birth outcome of Bengalee women.

Subjects and methods: The cross-sectional retrospective study was conducted in a government general hospital in South Kolkata, India. This hospital serves the needs of people belonging to lower and lower middle class socio-economic groups. Data were collected by one-to-one interview for confirmation of age, history of last menstrual period (LMP) including medical disorders. Mother's weight was recorded at 14–18 weeks of pregnancy from the history of LMP. Birth weight was measured within 24?h of delivery and gestational age was assessed by Ballard's method using newborn physical and neurological maturity scoring. Of the 331 Bengalees, 295 mother–baby pairs met the recruitment criteria and were included in this study.

Result: Mean?±?SD maternal early second trimester pregnancy weight and birth weight were 45.9?±?7.0?kg and 2612?±?371?g, respectively. The difference in mean weight (3.74?kg) between mothers who delivered low birth weight (LBW) and normal birth weight (NBW) babies was statistically significant (t?=?4.497, p?<?0.001). Overall, the prevalence of LBW was nearly 34%. A higher incidence of LBW and lower mean birth weight was observed in first quartile or low weight (≤40?kg) mothers. The rate of LBW decreased (χ²?=?14.47, p?<?0.01) and mean birth weight increased significantly with increasing maternal weight (F?=?9.218, p?<?0.001). Risk ratio (RR) for LBW, intrauterine growth retardation (IUGR) and preterm birth in low weight (first quartile or <40.0?kg) mothers were 2.72 (95% confidence interval (CI): 1.45–5.10), 3.54 (95% CI: 1.17–10.74) and 1.97 (95% CI: 0.56–6.90), respectively, compared with heavier (>50.0?kg) mothers. Finally, the present data showed that the maternal weight of <46.0?kg is the best cut-off for detecting LBW with 66% sensitivity and 75% negative predictive power.

Conclusion: The findings suggest a positive association between maternal early second trimester pregnancy weight and birth outcome. The present study provided an efficient cut-off point for detecting LBW. Antenatal caregivers in health institutions and community health workers in the field can use this cut-off value for screening pregnant women at early second trimester.     

The relation between body size and maximum and minimum metabolic rates in the new-born pig

1. Measurements of rates of oxygen consumption were made on a total of sixty-two Large White pigs aged between 1 hr and 6 days, with a range of body weight from 0.75 to 2.40 kg.2. The maximum rate was determined from the continuous estimation of oxygen consumption as the environmental temperature fell past the point at which the maximum occurred.3. The minimum rate was determined both as the environmental temperature rose through the zone of thermal neutrality, and from measurements at thermal neutrality.4. In animals aged 1-6 days the mean maximum rate was 49.0 ml. O(2)/kg.min, and the mean minimum was 15.3 ml. O(2)/kg.min. Both rates were proportional to body weight and not to surface area.5. Pigs less than 1 day old exhibited lower maximum and minimum rates than the older pigs.     

Hepatocyte growth factor concentration in the early second-trimester amniotic fluid does not predict fetal growth at birth.

The purpose of this study was to evaluate whether hepatocyte growth factor (HGF) concentrations in the early second-trimester amniotic fluid predict fetal growth at birth. HGF and insulin-like growth factor-I (IGF-I) concentrations in the early second-trimester amniotic fluid were measured in 12 pregnancies with small for gestational age (SGA) infants, 84 pregnancies with appropriate for gestational age (AGA) infants, and eight pregnancies with large for gestational age (LGA) infants. HGF concentrations were measured from the early second-trimester amniotic fluid samples using an enzyme-linked immunosorbent assay. IGF-I concentrations were measured from the early second-trimester amniotic fluid samples using an immunoradiometric assay. Maternal age in AGA group (34.2 +/- 5.5 years) was significantly lower than in SGA (37.9 +/- 3.0 years) and LGA (37.6 +/- 3.3 years) groups (P < 0.05). There were no significant differences for parity or gestational age at amniocentesis among the groups. There were significant differences for birth age, birth weight, neonatal height, and placental weight among the groups (P < 0.05). HGF concentrations in SGA, AGA and LGA groups were 16.9 +/- 6.6, 16.7 +/- 9.0 and 20.2 +/- 14.8 ng/ml respectively (not significant). There was no correlation between amniotic fluid HGF concentrations and birth weight, height or placental weight. There were also no significant differences for amniotic fluid IGF-I concentrations among the three groups. These results suggest that differences in HGF concentrations in the early second-trimester amniotic fluid do not predict fetal growth at birth. Further study is needed to clarify the role of high HGF concentrations in early second-trimester amniotic fluid during pregnancy.     

Multicenter trial on the efficacy of HBIG and vaccine in preventing perinatal hepatitis B. Final report

In an attempt to interrupt perinatal transmission of hepatitis B, 92 infants born to HBsAg carrier mothers (49 to HBeAg-positive mothers, 30 to anti-HBe-positive with abnormally elevated ALT levels, and 13 to HBeAg/anti-HBe-negative mothers) received 0.5 ml/kg BW of HBIG at birth and at 1 month of age. Three IM injections of hepatitis B vaccine were given at 3, 4, and 9 months of life. All babies who were given the three doses of vaccine developed an active anti-HBs response: of these, 53 (62.3%) had antibody titers higher than 1,000 mIU/ml, 29 (34.2%) had levels between 100 and 1,000 mIU/ml, and the other three (3.5%) were below 100 mIU/ml. At the end of the 2-year follow-up, these three poor responders became anti-HBs negative, whereas the others still had antibody. All but three babies were protected by HBIG plus vaccine treatment. Two chronic HBV infections occurred within 6 months of life presumably because the babies were already infected when prophylaxis started. The third baby became an HBsAg carrier at 9 months of age in spite of a previous response to the vaccine. Simultaneous presence of HBsAg of y specificity and anti-HBs (anti-a) was still detectable at 24 months of age. The vaccine was well tolerated. Passive plus active immunization is an effective procedure for preventing perinatally transmitted HBV infection.     

Maximal aerobic power in children and adolescents of Beijing,China

The maximal aerobic power of 463 Chinese children and adolescents, 10–19 years, is described. The absolute values of maximal oxygen intake (V̇O₂max) in boys and girls were 1.75–3.26 and 1.44–2.10 L/min, respectively. Relative values of V̇O₂max per unit stature (V̇O₂max/stature) were 12.35–19.42 ml/cm.min for boys and 10.18–13.42 ml/cm.min for girls, values per unit weight (V̇O₂max/weight) were 48.60–56.59 ml/kg.min for boys and 39.34–45.56 ml/kg.min for girls, and values per estimated unit lean body mass (V̇O₂max/lean-body-mass) were 58.98–65.28 ml/kg.min for boys and 54.90–59.04 ml/kg.min for girls. Maximal values of oxygen pulse (V̇O₂max/HRmax) were 8.58–16.67 ml/beat for boys and 6.88–10.35 ml/beat for girls. In early adolescence, V̇O₂max, V̇O₂max/stature, and V̇O₂max/HRmax increased with chronological age, but the increment was less in girls. In contrast, V̇O₂max/weight and V̇O₂max/LBM did not increase with age in boys and girls. All indicators of V̇O₂max were lager in boys than in girls. © 1996 Wiley-Liss, Inc.     

Electrophysiological studies in newborns with reference to gestation and anthropometry

Fourteen full term appropriate for gestational age (FT-AGA) and 11 preterm appropriate for gestational age (PT-AGA) newborns and their mothers constituted study subjects. The mothers were subjected to hemoglobin and serum albumin estimations. Offsprings were subjected to measurements of weight, crown heel length and head circumference along with motor nerve conduction velocity (MNCV) and H-reflex latency (H-RL) at right median nerve. The MNCV was found to be significantly lower and H-RL significantly higher in PT-AGA babies compared to FT-AGA babies. The gestation, crown heel length of baby and maternal serum albumin status were found to be significant independent variables. Multiple regression equations have been derived using these parameters as determinative variables. These equations explained much higher per cent variation than explained by simple regression equations.     

Maternal early second trimester pregnancy weight in relation to birth outcome among Bengalee Hindus of Kolkata, India

OBJECTIVE: The study examined to what degree maternal early second trimester pregnancy weight is useful and efficient in predicting birth outcome of Bengalee women. SUBJECTS AND METHODS: The cross-sectional retrospective study was conducted in a government general hospital in South Kolkata, India. This hospital serves the needs of people belonging to lower and lower middle class socio-economic groups. Data were collected by one-to-one interview for confirmation of age, history of last menstrual period (LMP) including medical disorders. Mother's weight was recorded at 14-18 weeks of pregnancy from the history of LMP. Birth weight was measured within 24h of delivery and gestational age was assessed by Ballard's method using newborn physical and neurological maturity scoring. Of the 331 Bengalees, 295 mother-baby pairs met the recruitment criteria and were included in this study. RESULT: Mean +/- SD maternal early second trimester pregnancy weight and birth weight were 45.9+/-7.0kg and 2612+/-371g, respectively. The difference in mean weight (3.74kg) between mothers who delivered low birth weight (LBW) and normal birth weight (NBW) babies was statistically significant (t = 4.497, p < 0.001). Overall, the prevalence of LBW was nearly 34%. A higher incidence of LBW and lower mean birth weight was observed in first quartile or low weight (< or =40 kg) mothers. The rate of LBW decreased (chi2 =14.47, p<0.01) and mean birth weight increased significantly with increasing maternal weight (F=9.218, p<0.001). Risk ratio (RR) for LBW, intrauterine growth retardation (IUGR) and preterm birth in low weight (first quartile or <40.0 kg) mothers were 2.72 (95% confidence interval (CI): 1.45-5.10), 3.54 (95% CI: 1.17-10.74) and 1.97 (95% CI: 0.56-6.90), respectively, compared with heavier (>50.0kg) mothers. Finally, the present data showed that the maternal weight of <46.0 kg is the best cut-off for detecting LBW with 66% sensitivity and 75% negative predictive power. CONCLUSION: The findings suggest a positive association between maternal early second trimester pregnancy weight and birth outcome. The present study provided an efficient cut-off point for detecting LBW. Antenatal caregivers in health institutions and community health workers in the field can use this cut-off value for screening pregnant women at early second trimester.     

New growth charts: soy, cow, and breast milk comparison

Weight and length measurements were recorded for 1583 babies during the 1st year of life. The population sample was fairly constant and composed of children from white, middle and upper income families seen in the private practice of 11 pediatricians in Dallas, Texas. This study was part of a larger research effort to determine how diets during the 1st 6 months affect subsequent development of allergy. The babies were subdivided into 3 groups according to family history for allergy and 3 groups according to diet (cow, breast or soy milk) during the 1st 6 months. After examination at birth, the babies were reexamined monthly up to 6 months of age and bimonthly thereafter up to age 1. Nearly 22,000 observations were made in all. Tables and charts were constructed showing mean weight and length measurements plotted from birth through 38 weeks against 24 possible combinations of sex, family allergy history, and diet. No significant difference was detectable between subgroups when differences in birth weight were taken into account. Compared with the Iowa norms for infant growth which were established from measurements taken 1926-49, these babies grew taller in the 1st year of life; weight differences were minimal. Revised infant growth charts, more consistent with today's growth patterns, are needed.     

Ethnic and environmental factors affecting fetal growth in Papua New Guinea

We studied 738 live singleton births in Papua New Guinea to examine the contribution of ethnic origin and environmental factors to birth weight and gestation. Maternal history, examination and post-partum anthropometry, infant anthropometry and clinical gestational assessment were performed, and placental blood slides and histology were examined. Mothers from Highlands provinces who delivered on the coast had larger babies (mean birthweight 3.34 SD 0.48 kg) than either indigenous coastal mothers (mean 3.10 SD 0.51 kg) or those migrating to Port Moresby from other coastal regions (mean 3.14 SD 0.51 kg). This was due to a combination of longer gestation and better intrauterine growth (assessed by birthweight standard deviation scores). Gestation was slightly longer in Highlands mothers delivering on the coast compared with those delivering in the Highlands, but birthweight standard deviation scores were unchanged. Malarial infection of the placenta was almost never found. Stepwise regression analysis showed that parity, maternal height, Highlands origin and maternal body mass index (weight/height2) were all significant predictors of birthweight standard deviation score, while maternal body mass index and Highlands origin were predictors of gestational length. We conclude that Highland mothers have a tendency to deliver heavier babies, and do not demonstrate the fetal growth-retarding effects of altitude seen in other races. Although the incidence of low birthweight was only 7.1% in our study, we found that indices of maternal nutrition were predictors of birth weight.