Effect of parental anthropometric parameters on neonatal birth weight and birth length

Data on 550 healthy pregnant women, 550 healthy fathers and their healthy term neonates born from singleton pregnancies (37(+0) through 41(+6) week) during a one-year period were reviewed. Maternal mean age was 27.7 +/- 9.37 years, mean pregestational weight 64.0 +/- 9.50 kg, mean gestational weight gain 15.4 +/- 4.33 kg, mean height 169.7 +/- 5.81 cm, and mean gestational age 40.1 +/- 0.95 weeks. Paternal mean age was 31.4 +/- 6.22 years, mean weight 84.6 +/- 10.35 kg, and mean height 182.8 +/- 6.84 cm. Mean birth weight was 3,709.8 +/- 500.48 g and 3,562.5 +/- 443.02 g, and mean birth length 51.5 +/- 1.91 cm and 50.7 +/- 1.62 cm in male and female newborns, respectively, yielding a birth weight greater by 147.3 g and birth length by 0.8 cm in the former. Study variables showed statistically significant correlations: maternal age contributed to the significant correlation between maternal weight and parity, maternal pregestational weight, weight at delivery, gestational weight gain and body height correlated significantly with neonatal birth weight and birth length, gestational age correlated significantly with neonatal weight and length (p = 0.01 all), parity had no major impact (p > 0.05). Paternal height and weight correlated significantly with neonatal birth weight and birth length (p = 0.01). Study results pointed to a significant correlation of maternal pregestational weight, gestational weight gain and body height, and of paternal weight and height with the neonate birth weight and birth length.     

中华山蝠的生长发育及年龄估算

1997 年5 ～9 月,采用标志重捕法对中华山蝠的生长发育进行研究,共观察幼蝠388 只次(雄性184 只次,雌性204 只次),结果显示:中华山蝠幼蝠20 d 前体重和前臂长均呈直线增长,日平均生长率分别为0.57 g/d 与1.36 mm/d, 回归方程为:体重=3.05 + 0.57×日龄, 前臂长= 15.49+1.36×日龄。20 d后增长减慢, 大约5 周龄后开始飞行,初飞幼蝠与成体的体重差异显著,前臂长与成蝠差异不显著。中华山蝠幼体生长与Logistic、Von Bertalanffy 及Compertz 3 种生长曲线模型的拟合度均较高, R² 值超过0.93。前臂长的增长用Logistic曲线拟合最合适,体重的增长用Von Bertalanffy 曲线拟合最合适。根据前臂长以及第四掌骨与指骨间软骨的发育模式,得到出生后1 ～ 76 d幼蝠的年龄鉴定方程式。当前臂长≤43.32 mm时,日龄= -10.77 +0.71 × 前臂长;当前臂长> 43.32 mm时, 日龄= 71.10 - 9.89 ×第四掌骨与指骨间软骨长。      

Use of fetal biometry to determine fetal age in late pregnancy in llamas

Sixty-three pregnant llamas of known breeding date were used in this study. Forty-six of them were submitted to surgery between 186 and 320 days of gestation (52-91% of average gestation period, respectively). Under general anesthesia their fetuses were exteriorized and fetal weight (W), biparietal diameter (BPD) and femoral (F), tarsus-hoof (T-H), tibial (T)) and fronto-occipital (F-O) length were determined. Additionally, the same variables were determined on 16 newborn llamas. The weight was measured in kg and the length in cm. All the collected data was entered into a spreadsheet and different regression analyses as a function of gestational age (GA) were assessed. The best fit equations and their correlation for linear regression were the following: GA=169.448+16.66(*)W, r=0.99; GA=-51.713+44.77(*)BPD, r=0.88; GA=-72.139+39.48(*)F-O, r=0.71; GA=39.304+8.35(*)T-H, r=0.97; GA=91.276+8.23(*)T, r=0.86; GA=102.029+9.94(*)F, r=0.91. For multiple regression, the dependent variable GA can be predicted by the following equation: GA=67.462+11.163(*)W+20.297(*)BPD. Results of the present study indicated measured variables to be highly correlated with GA. This could be useful on daily basis in clinical examination of the neonates, in assessment of fetal growth and well being with cesarean sections, in the determination of GA in late gestation abortions, and in perinatal and reproductive research in the llama.     

影响脐带血采集质量的相关性因素分析

目的回顾性分析影响脐带血采集质量的母婴因素和采集处理因素。 方法记录389份脐带血的采集量、母亲年龄、孕龄、新生儿体重、分娩方式、新生儿性别、胎次及脐带血采集至计数间隔以及采集方式。用KX-21型全自动血液分析仪进行细胞计数并计算有核细胞总数（TNC）。采用Pearson相关和Spearman秩相关进行相关性分析,采用t检验、Mann-Whitney U检验、方差分析及Kruskal-Wallis H检验进行分组比较,分析影响脐带血采集量和TNC的相关因素。? 结果脐带血采集量与TNC显著相关（r = 0.723,P < 0.001）,脐带血采集量大于80 ml时的TNC显著高于低体积者。在母婴因素中,母亲年龄与采集量及TNC差异均无统计学意义;孕龄与采集量负相关（r = -0.119,P = 0.019）,而与TNC正相关（r = 0.138,P = 0.007）,足月儿脐带血的TNC显著高于早产儿（P = 0.038）;婴儿出生体重与采集量及TNC均正相关（r = 0.236,P < 0.001;r = 0.275,P < 0.001）,体重较大婴儿脐带血的采集量和TNC均显著高于体重较小者（P?< 0.001）;剖宫产的脐带血采集量虽高于阴道分娩（P < 0.001）,但其TNC不及阴道分娩;男婴与女婴在脐带血采集量和TNC之间无显著差异。在采集处理因素中,脐带血采集至计数的时间间隔与采集量及TNC均无显著相关。 结论为提高脐带血的保存质量,应侧重选择胎儿体重较大、经阴道分娩的产妇作为脐带血供者,实验室应首先处理采集量较大的脐带血。     

十种菊科外来入侵种连萼瘦果风力传播的特性

借助风力传播连萼瘦果, 是菊科入侵种最普遍的自然扩散方式, 而其适应风力传播的特性与入侵性关系的研究还未得到足够的重视。阐明种子本身的风力传播特性与入侵潜力间的关系, 可以为深入理解外来入侵种的入侵机制以及入侵种的控制提供理论依据。该研究以10种菊科入侵种为研究对象, 测量其连萼瘦果的形态特征, 测定它们在静止空气中的垂直沉降速度和模拟风力条件下的水平扩散距离, 分析比较连萼瘦果的形态性状与沉降速度、水平扩散距离以及这些菊科入侵种在国内入侵范围的相关性。结果表明, 根据连萼瘦果的形态特征, 将这10个入侵种分为强、中和弱风传播3类; 连萼瘦果的重量和冠毛特征对垂直沉降速度和水平扩散距离均有显著影响, 对垂直沉降速度影响最大的因素是冠毛长度和冠毛上的小刺对数, 对水平扩散距离影响最大的因素是连萼瘦果的重量和冠毛长度。在垂直沉降速度和水平扩散距离间存在极显著负相关性(r = -0.806, p = 0.005), 表明沉降速度越慢, 借风力水平移动的距离越远。这些入侵种的发生程度与沉降速度间存在显著负相关性(r = -0.721, p = 0.019), 而与水平扩散距离之间存在着极显著正相关性(r = 0.927, p = 0.000), 说明水平扩散距离比垂直沉降速度更适合作为评估菊科入侵种入侵能力的指标。根据上述研究结果, 提出了南京市需重点防范胜红蓟(Agratum conyzoides)和牛膝菊(Galinsoga parviflora)等菊科入侵种的建议。     

Thyrotropin measured by the immunoradiometric assay in low birth weight infants

In 37 infants, the blood levels of TSH were determined by the immunoradiometric assay (IRMA) and the relation between TSH and thyroid hormone was evaluated. The ranges of gestational age (weeks) and birth weight (g) of infants were 28-42 and 982-3,650, respectively. The birth weights of 19 infants were below 2,500 g. The free T4 levels in the low birth weight (LBW) infants were lower than those of the normal infants and significantly correlated to the birth weight (r = 0.64, P less than 0.01) and gestational age (r = 0.58, P less than 0.01). In addition, free T4 levels were significantly correlated to the levels of total T4 (r = 0.66, P less than 0.01). The concentrations of TSH measured by IRMA method were significantly correlated to those of free T4 (r = 0.51, P less than 0.01). From these data, we consider that the transient hypothyroxinemia observed frequently in LBW infants might be a physiological reaction regulated by hypothalamus and that thyroid hormone treatment should be avoided.     

Accuracy of canine parturition date prediction using fetal measurements obtained by ultrasonography

The length of canine gestation is 65 days from the luteinizing hormone (LH) surge. Early and accurate determination of canine gestational age is useful for predicting and managing parturition. We performed a retrospective study on fetal measurements obtained by transabdominal ultrasonographic examination of 83 bitches (32 breeds) to estimate gestational age. Gestational age was estimated using two published tables correlating either (1). embryonic vesicle diameter (EVD), crown-rump length (CRL), body diameter (BD), and biparietal diameter (HD) to the LH surge in mid-gestational beagles or (2). BD and HD to parturition in late-gestation retrievers. Parturition date was predicted by obtaining the difference between the gestational age estimate and 65 days. Bitches were divided into four body weight (BW) groups based on nonpregnant body weight: small (9-20 kg), large (>20-40 kg), and giant (>40 kg). Mean+/-S.D. litter size (LS) was calculated for each BW group. The BW groups were then divided into small, average, or large LS groups. The accuracy of the prediction was not affected by LS but was affected by maternal body weight for small and giant BW groups only. When adjusted for weight, the accuracy of prediction within +/-1 day and +/-2 day intervals was 75 and 87%, respectively. Using stepwise logisitic regression, the most accurate prediction of parturition date was obtained when fetuses were measured at 30 days after the LH surge, regardless of body weight or LS. Parturition date predictions made after 39 days of gestation using only biparietal and BD fetal measurements were <50% accurate within +/-2 days.     

Relation of cord blood thyroxine and thyrotropin levels to gestational age and birth weight.

A program of screening cord blood for evidence of primary neonatal hypothyroidism was implemented in a general hospital. In 13 months 3456 newborns were screened: the thyroxine (T4) and triiodothyronine (T3) concentrations were measured in cord blood samples, and when the T4 level was below 8.0 micrograms/dl thyrotropin was also assayed in the sample. The two-tier program was effective. One hypothyroid newborn was detected and treated. More boys than girls had T4 levels below 8.0 micrograms/dl (9.7% v. 4.7%). The T4 level correlated with birth weight slightly better in the boys (r = 0.28 v. 0.21), and in the boys this correlation was stronger when the birth weight was lower. Regression analysis of the data for 54 sets of twins indicated that the T4 level was more strongly related to gestational age than to birth weight.     

Synthetic standards for body weight

Growth charts represent body stature, body weight, and body mass index (BMI) from birth to maturity. Due to secular changes in these parameters, growth charts tend to become outdated, and must be revised from time to time. Recently, we developed alternative strategies that facilitate developing and renewing growth charts, and suggested synthetic standards for body stature. The increasing prevalence of obesity has made it necessary to develop similar techniques also for monitoring body weight and BMI. Two-hundred-and-forty historic and modern growth studies (108 studies of male growth, 132 studies of female growth) were selected from 22 European, 6 American, 3 African, and 6 Asian nations, published between 1831 and 2001. The studies contained annual information on weight and stature, either between birth and 6 years, or between 6 years and maturity, or information on the whole age range between birth and maturity. Since historic studies up to the mid-20th century usually ignore the fact that body weight (in contrast to body stature) is not normally distributed, a group of 92 more recent studies (45 male, 47 female), published between 1943 and 2001, presenting centiles for weight, was chosen for additional analysis. Furthermore, the skewness of body weight distributions, was investigated in original raw data of body weight obtained from five well reputed longitudinal growth studies, performed at Jena, Germany, Lublin, Poland, Paris, France, Prague, Czech Republic, and Zürich, Switzerland. Average body stature and average weight differ markedly between different populations. But within the same population, both parameters are closely interrelated. In males, birth length and weight correlated with r = 0.503, stature and weight correlated with r = 0.873 at the age of 2 years; with r = 0.882 at the age of 6 years; with r = 0.935 at the age of 14 years, and with r = 0.891 at the age of 18 years. Similar results were obtained in females. At birth, length and weight correlated with r = 0.619. Stature and weight correlated with r = 0.863 at the age of 2; with r = 0.912 at the age of 6; with r = 0.935 at the age of 12; and with r = 0.918 at the age of 15 years. Tables of linear regression coefficients for relative stature and weight at all ages enable the reversal of the process of the meta-analysis and allow the generation of synthetic growth references for stature and weight. Synthetic reference charts help in the revision of current growth charts without much additional effort, and may be used for populations for which autochthonous growth standards are not available.     

Cardiac growth in staged human fetuses: an allometric approach

The human cardiac growth was studied on 30 staged fetuses (gestational age ranged from 10 to 38 weeks post conception, WPC). The hearts were quantitatively evaluated considering their weight and the following linear parameters: the pulmonary (da.p.) and aortic (dA) internal diameters, the right (VR) and left (VL) ventricular wall thickness, the ventricular width (dV), and the length "sulcus terminalis-apex cordis" (Lst-apex). The data were correlated with the gestational age by using the allometric method (Y = bX alpha). The equations and the growth curves are presented. In the fetal life, we observe that the body weight is 134 times larger than the heart weight, the Lst-apex is 1.07 times larger than the dV, the da.p. is 1.50 times larger than the dA, and the VL is 1.19 times larger than the VR.     

Maturation of the pituitary-thyroid axis during the perinatal period.

To clarify the maturation process of the pituitary-thyroid axis during the perinatal period, thyrotropin (TSH) response to thyrotropin releasing hormone (TRH) and serum thyroid hormone levels were examined in 26 healthy infants of 30 to 40 weeks gestation. A TRH stimulation test was performed on 10 to 20 postnatal days. Basal concentrations of serum thyroxine (T4), free thyroxine (free T4) and triiodothyronine (T3) were positively correlated to gestational age and birth weight (p less than 0.001-0.01). Seven infants of 30 to 35 gestational weeks demonstrated an exaggerated TSH response to TRH (49.7 +/- 6.7 microU/ml versus 22.1 +/- 4.8 microU/ml, p less than 0.001), which was gradually reduced with gestational age and normalized after 37 weeks gestation. A similar decrease in TSH responsiveness to TRH was also observed longitudinally in all of 5 high responders repeatedly examined. There was a negative correlation between basal or peak TSH concentrations and postconceptional age in high responders (r = -0.59 p less than 0.05, r = -0.66 p less than 0.01), whereas in the normal responders TSH response, remained at a constant level during 31 to 43 postconceptional weeks. On the other hand, there was no correlation between basal or peak TSH levels and serum thyroid hormones. These results indicate that (1) maturation of the pituitary-thyroid axis is intrinsically controlled by gestational age rather than by serum thyroid hormone levels, (2) hypersecretion of TSH in preterm infants induces a progressive increase in serum thyroid hormones, and (3) although there is individual variation in the maturation process, the feedback regulation of the pituitary-thyroid axis matures by approximately the 37th gestational week.     

Sexual dimorphism in growth in the relative length of the forearm and relative knee height during adolescence

There are numerous studies concerning sexual dimorphism in body proportions, but only a few have investigated growth in the relative length of particular segments of the upper and lower limbs during adolescence. The aim of the study is an assessment of sex differences of longitudinal growth in the relative length of the forearm and knee height among adolescents. Sample involved 121 boys and 111 girls, participants of the Wroclaw Growth Study, examined annually between 8 and 18 years of age. Sexual dimorphism in six ratios: forearm length and knee height relatively to: trunk, height, and limb length were analyzed using a two‐way analysis of variance with repeated measurements. The sex and age relative to an estimate of maturity timing (3 years before, and after age class at peak height velocity [PHV]) were independent variables. All of the ratios showed significant sex differences in interaction with age relative to age at PHV. The relative length of the forearm, in boys, did not change significantly with the years relative to age at PHV, whereas in girls, was the lowest in the two first age classes and afterward significantly increased just 1 year before and during the adolescent growth spurt, remaining unchanged in further age classes. For relative knee height no clear pattern for sex differences was noticed. It is proposed that relatively longer forearms, particularly in relation to the trunk in girls, could have evolved as an adaptation to more efficient infant carrying and protection during breastfeeding.     

不同胎龄早产儿早期凝血指标的变化及其临床意义

目的:研究不同胎龄早产儿早期凝血指标的变化及其临床意义。方法:选取2012年1月至2017年7月期间我院出生的新生儿392例为研究对象。根据新生儿胎龄的不同分为早期早产儿组(胎龄27~31周)78例、中期早产儿组(胎龄32~33周)102例、晚期早产儿组(胎龄34~36周)116例以及足月新生儿组(胎龄37~42周)96例。四组新生儿出生后2h内抽取静脉血检测凝血指标,包括凝血酶原时间(PT)、活化部分凝血酶原时间(APTT)、纤维蛋白原(FIB),并应用Pearson相关性分析分析新生儿胎龄与上述各项凝血指标水平的相关性。结果:早期早产儿组、中期早产儿组、晚期早产儿组、足月新生儿组的出生体重以及胎龄呈逐渐上升趋势,不同组别新生儿的出生体重以及胎龄差异均有统计学意义(P0.05)。早期早产儿组、中期早产儿组、晚期早产儿组、足月新生儿组PT、APTT均呈逐渐下降趋势,FIB呈逐渐上升趋势,不同组别新生儿PT、APTT、FIB差异均有统计学意义(P0.05)。Pearson相关性分析显示,新生儿胎龄与PT、APTT呈负相关(r=-0.567、-0.691,P=0.000、0.000),而新生儿胎龄与FIB水平呈正相关(r=0.623,P=0.000)。结论:不同胎龄早产儿早期凝血功能存在异常变化,新生儿胎龄与PT、APTT均呈负相关关系,与FIB呈正相关关系,临床应予以重视,及时检测其凝血指标,必要时应予以干预治疗。     

Estimation of gestational age in Egyptian native goats by ultrasonographic fetometry

The main aim of the present study was to estimate the gestational age of Egyptian goats by B-mode ultrasound measurement of embryonic or fetal parts throughout pregnancy. Trans-rectal (TR) ultrasonography (7 MHz) was carried out on 15 pregnant Egyptian does at Day 10 post mating on alternate days until Day 25 and then once at 3-5-day intervals until Day 50. Trans-abdominal (TA) ultrasonography (3.5-5 MHz) was carried out on the same animals from Days 25 to 130 at 3-5-day intervals. After imaging the embryo or the fetus, the following parameters were measured: length of the embryo or fetus (CRL), heart rate (FHR), biparital diameter (BPD), trunk diameter (TD), placentome size (PS), umbilical cord diameter (UCD) and femur length (FL). The average of days at which the embryonic vesicle was first determined by TR and TA ultrasonography was 16.98+/-1.97 and 27.87+/-3.48, respectively. The embryo proper with a beating heart was first determined by TR and TA ultrasonography at an average of 22.36+/-2.66 and 30.36+/-4.75 days, respectively. All the fetal measures were significantly (P<0.0001) correlated with the gestational age. With the exception of fetal heart rate (R(2)=0.551), all the measured fetal structures were highly correlated (R(2)> or =90) with the gestational age. In conclusion, the age of embryo or fetus in Egyptian does can be estimated by ultrasound measuring the crown rump length, biparital diameter, trunk diameter, placentome size, umbilical cord diameter and femur length.     

Proximal intestinal absorption of calcium is elevated in proportion to growth rate but not bone mass is small for gestational age piglets

During the first year of life, body calcium content increases faster in relation to body size than any other time during growth. Studies have shown postnatal growth and bone mineralization differences between appropriate for gestational age and small for gestational age infants. The objective of this study was to compare duodenal calcium transport using intestinal ligated loop technique in 21-day-old small for gestational age (birth weight of <1.2 kg) and appropriate for gestational age piglets (birth weight of > or =1.4 kg). Piglets were fed liquid formula between day 5 and 21 of life and monitored daily for weight gain. At day 21 calcium absorption was measured followed by measurement of bone mass using dual energy x-ray absorptiometry. Small for gestational age piglets had greater calcium absorption and growth rate than appropriate for gestational age piglets. Birth weight was negatively related to weight gain and calcium absorption. Weight gain was positively related to calcium absorption. Appropriate for gestational age piglets had significantly higher whole body bone mineral content than small for gestational age piglets even after correction for body size. Whole body bone mineral content was positively correlated with birth weight and negatively correlated with calcium absorption. These observations suggest that small for gestational age piglets are capable of absorbing elevated amounts of calcium in the proximal intestine in support of compensatory growth. However, at 21 days of age small for gestational age piglets are similar in size but have lower bone mass compared to appropriate for gestational age piglets.     

Leptin values in placental cord blood of human newborns with normal intrauterine growth after 30-42 weeks of gestation

OBJECTIVE: To evaluate leptin values in placental cord blood of newborns with normal intrauterine growth after 30-42 weeks of gestation. DESIGN: Leptin, a protein encoded by the ob gene, plays an important role in the regulation of feeding behaviour and energy balance in rodents, primates and humans. The presence of leptin in human amniotic fluid and cord blood has recently been reported in human gestations at term and the possible role of leptin in human fetal growth suggested. However, little is known of leptin synthesis during human foetal development. Thus, the aim of our work was to measure leptin (RIA, Linco Research, Inc.) in placental cord blood of human newborns at different fetal ages. PATIENTS: One hundred and twenty-six healthy newborns with normal intrauterine growth were studied. Twenty-nine were preterm (15 males and 14 females; gestational age: 30-36 weeks) and 99 were at term (49 males and 48 females; gestational age: 37-42 weeks). RESULTS: Leptin values increase progressively throughout gestation from 1.30 +/- 0.53 ng/ml at 30 weeks of gestation to 7.98 +/- 4.96 ng/ml (mean +/- SD) at term, and correlate positively with birth weight (r = 0.56, p < 0. 005, n = 126), length (r = 0.37, p < 0.005, n = 126), BMI (r = 0.57, p < 0.005, n = 126), head circumference (r = 0.37, p < 0.005, n = 126), gestational age (r = 0.48, p < 0.005, n = 126) and placental weight (r = 0.38, p < 0.003, n = 59). Leptin values are statistically significantly lower (p < 0.005) preterm (median: 2.05 ng/ml; range: 0.7-8.3 ng/ml) than at term (median: 7.0 ng/ml; range: 1.1-28.1 ng/ml). Leptin values are also significantly (p < 0.005) higher in females (median: 7.2 ng/ml; range: 0.9-23.6 ng/ml, n = 62) than in males (median: 4.8 ng/ml; range: 0.7-28.1 ng/ml, n = 64), although there are no differences in weight (2,864 +/- 536 g in females vs. 2,937 +/- 744 g in males). Multiple regression analysis shows weight to be a positive sex-independent predictor of serum leptin values (p < 0.0005). Sex also proves to be a predictor of leptin, independently of weight and is higher in females than in males (p < 0.003). CONCLUSION: Leptin is present in placental human cord blood after 30-42 weeks of gestation. Newborn weight and sex are independent predictors of leptin values.     

Assessing the Causal Relationship of Maternal Height on Birth Size and Gestational Age at Birth: A Mendelian Randomization Analysis

Background

Observational epidemiological studies indicate that maternal height is associated with gestational age at birth and fetal growth measures (i.e., shorter mothers deliver infants at earlier gestational ages with lower birth weight and birth length). Different mechanisms have been postulated to explain these associations. This study aimed to investigate the casual relationships behind the strong association of maternal height with fetal growth measures (i.e., birth length and birth weight) and gestational age by a Mendelian randomization approach.

Methods and Findings

We conducted a Mendelian randomization analysis using phenotype and genome-wide single nucleotide polymorphism (SNP) data of 3,485 mother/infant pairs from birth cohorts collected from three Nordic countries (Finland, Denmark, and Norway). We constructed a genetic score based on 697 SNPs known to be associated with adult height to index maternal height. To avoid confounding due to genetic sharing between mother and infant, we inferred parental transmission of the height-associated SNPs and utilized the haplotype genetic score derived from nontransmitted alleles as a valid genetic instrument for maternal height. In observational analysis, maternal height was significantly associated with birth length (p = 6.31 × 10⁻⁹), birth weight (p = 2.19 × 10⁻¹⁵), and gestational age (p = 1.51 × 10⁻⁷). Our parental-specific haplotype score association analysis revealed that birth length and birth weight were significantly associated with the maternal transmitted haplotype score as well as the paternal transmitted haplotype score. Their association with the maternal nontransmitted haplotype score was far less significant, indicating a major fetal genetic influence on these fetal growth measures. In contrast, gestational age was significantly associated with the nontransmitted haplotype score (p = 0.0424) and demonstrated a significant (p = 0.0234) causal effect of every 1 cm increase in maternal height resulting in ~0.4 more gestational d. Limitations of this study include potential influences in causal inference by biological pleiotropy, assortative mating, and the nonrandom sampling of study subjects.

Conclusions

Our results demonstrate that the observed association between maternal height and fetal growth measures (i.e., birth length and birth weight) is mainly defined by fetal genetics. In contrast, the association between maternal height and gestational age is more likely to be causal. In addition, our approach that utilizes the genetic score derived from the nontransmitted maternal haplotype as a genetic instrument is a novel extension to the Mendelian randomization methodology in casual inference between parental phenotype (or exposure) and outcomes in offspring.     

Allometry of hepatic weight growth in human staged fetuses

The growth of the hepatic weight was correlated to fetal parameters of maturity (gestational age, crown-rump length and weight) in 70 human fetuses ranging from 14 to 39 weeks post-conception using the allometric method. The growth of the hepatic weight presents moderate positive allometry relative to age and C-R length, and isometry relative to fetal weight. The coefficiens of correlation are very high (p less than 0.001, Table 1). This study presents growth curves of the hepatic weight useful in medical branches such as anatomy, forensic medicine, fetopathology, medical imagery, onstetrics and pediatrics.     

Hyperadiponectinemia in Newborns: Relationship with Leptin Levels and Birth Weight

Objective: Adiponectin is the only adipose‐specific hormone that, despite its exclusive production by adipose tissue, is reduced in obesity and is inversely correlated with leptin levels in adults. The aim of this study was to evaluate the adiponectin concentration in umbilical cord blood at different gestational ages and to investigate its possible associations with leptin levels and birth weight. Research Methods and Procedures: Umbilical cord blood was obtained from 132 newborns (male = 65, female = 67, gestational age: 35 to 42 weeks). The anthropometric variables of the newborns studied were birth weight, birth length, body weight/body length, and ponderal index. Adiponectin, insulin, and leptin levels were measured by radioimmunoassay methods. Results: Adiponectin levels in males were not different from those in females (24.10 ± 0.81 vs. 25.62 ± 0.84 μg/mL, p = 0.280). Adiponectin concentrations were positively correlated with birth weight (p < 0.05), birth length (p < 0.05), body weight/body length (p < 0.05), gestational age (p < 0.01), and leptin levels (p < 0.01). Discussion: These findings indicate that adiponectin is present in umbilical cord blood after 35 to 42 weeks of gestation, with higher levels than those usually found in adults, no gender differences, and a positive correlation with birth weight and leptin. These results suggest that not only could neonatal hyperadiponectinemia be associated with the increase of adiponectin production by fetal adipose tissue but also with a possible reduction in an unknown mechanism related to the suppression of adiponectin observed in adults.     

Low birth weight for gestational age associates with reduced glucose concentrations at birth, infancy and childhood

BACKGROUND/AIMS: Our aim was to investigate glucose homeostasis, insulin sensitivity and insulin-like growth factor (IGF) system status in children born small for gestational age (SGA). METHODS: A case-control study was carried out at birth, infancy and childhood, comparing SGA with children appropriate for gestational age strictly matched for age, gender, pubertal status and body mass index. Ninety newborns, 52 infants, and 68 children were studied. Fasting insulin (I(F)), fasting glucose (G(F)) to I(F) ratio (G(F)/I(F)), the homeostasis model assessment of insulin sensitivity, the quantitative insulin sensitivity check index, insulinogenic index and the triglyceride/high-density lipoprotein-cholesterol ratio were measured. IGF-I, IGF-binding protein-3 and the IGF-I/IGF-binding protein-3 molar ratio were assessed. RESULTS: Glucose concentrations were lower in SGA newborns (p < 0.0001), infants (p = 0.01), and children (p = 0.001). Birth weight correlated with glucose levels at birth (r = 0.59, p < 0.0001), 12 months (r = 0.29, p = 0.04) and childhood (r = 0.44, p < 0.0001). CONCLUSION: Our results provide evidence for a developmental adaptation of glucose metabolism in SGA children leading to reduced glucose concentrations.