Differential effects of growth restriction and immaturity on predicted psychomotor development at 4 years of age in preterm infants.

BACKGROUND: Fetal growth restriction and immaturity are associated with poor neurocognitive development and child psychopathology affecting educational success at school and beyond. However, the differential effects of either obstetrical risk factor on predicted psychomotor development have not yet been deciphered. OBJECTIVE: This study aimed to separately study the impact of growth restriction and that of immaturity on predicted psychomotor development at the preschool age of 4.3 (standard deviation, 0.8) years using birthweight percentiles in a prospective cohort of preterm infants born at ≤37+6/7 weeks of gestation. Differences between small for gestational age newborns with intrauterine growth restriction and those without were described. We examined predicted total psychomotor development score, predicted developmental disability index, calculated morphometric vitality index, and predicted intelligence quotient, Porteus Maze test score, and neurologic examination optimality score in 854 preterm infants from a large prospective screening cohort (cranial ultrasound screening, n=5,301). STUDY DESIGN: This was a prospective cranial ultrasound screening study with a single-center cohort observational design (data collection done from 1984-1988, analysis done in 2022). The study included 5,301 live-born infants, of whom 854 (16.1%) were preterm infants (≤37+6/7 weeks' gestation), and was conducted on the day of discharge of the mother at 5 to 8 days postpartum from a level 3 perinatal center. Predicted psychomotor development, as assessed by the predicted total psychomotor development score, predicted developmental disability index, calculated morphometric vitality index, predicted intelligence quotient, Porteus Maze test score, and neurologic examination optimality score were calculated. We related psychomotor development indices and measures to gestational age in 3 groups of birthweight percentiles (ie, 10%, 50%, and 90% for small, appropriate, and large for gestational age newborns, respectively) using linear regression analysis, analysis of variance, multivariate analysis of variance, and t test procedures. RESULTS: The key result of our study is the observation that in preterm infants born at ≤37+6/7 weeks of gestation, growth restriction as compared with immaturity is the prime risk factor for impairment of overall predicted psychomotor development, intelligence quotient, Porteus Maze test results, and neurologic examination optimality score at the preschool age of 4.3 (standard deviation, 0.8) years (P<.001). This is particularly true for intrauterine growth restriction. These detrimental effects of growth restriction become more prominent with decreasing gestational age (P<.001). As expected, growth restriction in preterm infants born at ≤37+6/7 weeks of gestation was associated with a number of obstetrical risk factors, including hypertension in pregnancy (P<.001), multiple pregnancy (P<.001), pathologic cardiotocography (P=.001), and low pH (P=.007), increased pCO2 (P=.009), and poor pO2 (P<.001) in umbilical arterial blood. Of note, there were no differences in cerebral hemorrhage or white matter damage among small, appropriate, and large for gestational age birthweight percentile groups, suggesting an independent mechanism of brain injury caused by preterm growth restriction resulting in poor psychomotor development. CONCLUSION: Compared with immaturity, growth restriction in preterm infants has more intense detrimental effects on psychomotor development, necessitating improved risk stratification. This finding has implications for clinical management, parental consultation, and early intervention strategies to improve school performance, educational success, and mental health in children. The mechanisms of brain injury specific to growth restriction in preterm infants require further elucidation.

[Individualized Somatic Classification of Newborns Using Birth Weight Percentiles Based On Maternal Body Height and Weight (Results of a Validation Study)]. / Individuelle somatische Klassifikation von Neugeborenen auf der Grundlage von Körperhöhe und Körpergewicht der Mutter (Ergebnisse einer Validierungsstudie).

INTRODUCTION: Birth weight is influenced by maternal anthropometry. The SGA-rate of newborns of short and light mothers (<158 cm,<53 kg) and the LGA-rate of tall and heavy mothers (>177 cm,>79 kg) are overestimated. The LGA-rate of newborns of shorter mothers and the SGA-rate of taller mothers are underestimated. Individualized birth weight percentiles (IBWP) based on 18 maternal groups (6 groups of height combined with 3 groups of weight), sex and weeks of gestation have been published. The aim of this study is to validate IBWP by evaluating SGA-, AGA-, and LGA-rates using perinatal data. METHODS: The validation study compares IBWP (1995 to 2000, n=2.2 million singletons) with percentile values from two German cohorts (i: 1995 to 2000; n=2.3 million and ii: 2007 to 2011, n=3.2 million singletons) using newborns from the Lower Saxony Perinatal Survey (n=0.56 million singleton newborns, 2001 to 2009). SGA-, AGA-, and LGA-rates were calculated using R statistical analysis. RESULTS: Common percentile charts based on the total population 1995-2000 and 2007-2011 yielded SGA-rates among shorter mothers of 21.1 to 21.6% and LGA-rates of 2.0 to 3.1%. In taller mothers, SGA-rates were 3.3 to 3.5% and LGA-rates were 26.6 to 27.1%. IBWP achieved SGA-rates of 9.0% and LGA-rates of 11.4 to 11.6% in shorter mothers and SGA- and LGA-rates of 10% in taller mothers. DISCUSSION: IBWP consider the maternal size for estimation of the fetal growth potential and achieve expected SGA- and LGA-rates of 10%. Consideration of individual growth potential avoids underestimation and overestimation of SGA- and LGA-rates. It aided analyses of birth weight with IBWP simplify the assessment of the nutritional status.

The impact of parity and maternal obesity on the fetal outcomes of a non-selected Lower Saxony population.

OBJECTIVES: Maternal obesity during pregnancy is associated with adverse intrauterine events and fetal outcomes and may increase the risk of obesity and metabolic disease development in offspring. Higher parity, regardless of socioeconomic status, is associated with increased maternal body mass index (BMI). In this study, we examined the relationship between parity, maternal obesity, and fetal outcomes in a large sample of mother-neonate pairs from Lower Saxony, Germany. METHODS: This retrospective cohort study examined pseudonymized data of a non-selected singleton cohort from Lower Saxony's statewide quality assurance initiative. 448,963 cases were included. Newborn outcomes were assessed in relation to maternal BMI and parity. RESULTS: Maternal obesity was associated with an increased risk of placental insufficiency, chorioamnionitis, and fetal distress while giving birth. This effect was present across all parity groups. Fetal presentation did not differ between BMI groups, except for the increased risk of high longitudinal position and shoulder dystocia in obese women. Maternal obesity was also associated with an increased risk of premature birth, low arterial cord blood pH and low 5-min APGAR scores. CONCLUSIONS: Maternal obesity increases the risk of adverse neonatal outcomes. There is a positive correlation between parity and increased maternal BMI. Weight-dependent fetal risk factors increase with parity, while parity-dependent outcomes occur less frequently in multipara. Prevention and intervention programs for women planning to become pregnant can be promising measures to reduce pregnancy and birth complications.

Obesity in pregnant women: a 20-year analysis of the German experience.

BACKGROUND/OBJECTIVE: To investigate the longitudinal development of maternal body weight and analyze the influence of obesity on obstetrics during more than two decades in Germany. SUBJECTS/METHODS: Data collected from the Federal state of Schleswig-Holstein (German Perinatal Survey) were analyzed with regard to the dynamics of maternal anthropometric variables (body weight, BMI) between 1995-7 and 2004-17. In total 335,511 mothers substantiated the presented study-collective. The statistical analysis was performed using IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY. RESULTS: Maternal BMI advanced significantly over the study period. Among a rise in mean periconceptional body weight (67.6-72.0 kg), the segment of obese women increased disproportionately (in average 9.4-19.2%). Despite the observed trend to late giving birth (mean maternal age 1995: 29.3 vs. 30.7 years in 2017), it was not advanced maternal age but parity that influenced the continuous increase in maternal weight (mean maternal body weight 1995-7: primi- bi-, multiparae 67.4, 68.3 and 69.0 kg vs. 2004-17: primi- bi-, multiparae 70.0, 71.5 and 73.2 kg respectively). CONCLUSION: Obesity is a major problem on health issues in obstetrics. Advancing maternal BMI, increasing mother's age and derived prenatal risks considerably complicate pregnancy and delivery. It has to be emphasized that its consequences do not end with delivery or childbed, but represent a livelong burden to the mother and their offspring. Hence, multimodal strategies to reduce/control periconceptional body weight are mandatory.

The cumulative impact of parity on the body mass index (BMI) in a non-selected Lower Saxony population.

OBJECTIVES: During the last decade obesity has been continuously rising in adults in industrial countries. The increased occurrence of perinatal complications caused by maternal obesity poses a major challenge for obstetricians during pregnancy and childbirth. This study aims to examine the association between parity, pregnancy, birth risks, and body mass index (BMI) of women from Lower Saxony, Germany. METHODS: This retrospective cohort study examined pseudonymized data of a non-selected singleton cohort from Lower Saxony's statewide quality assurance initiative. Mothers were categorized according to BMI as normal weight (18.5 to <25 kg/m2) or obese (≥30 kg/m2). RESULTS: Most of the mothers in this study population were either in their first (33.9%) or second pregnancy (43.4%). The mean age of women giving birth for the first time was 28.3 years. Maternal age increased with increasing parity. The proportion of pregnant women with a BMI over 30 was 11% in primiparous women, 14.3% in second para, 17.3% in third para and 24.1% in fourth para or more women. Increasing parity was positively correlated with the incidence of classical diseases related to obesity, namely diabetes mellitus, gestational diabetes, hypertension, pregnancy-related hypertension and urinary protein excretion. An increased risk of primary or secondary cesarean section was observed in the obese women, particularly during the first deliveries. CONCLUSIONS: There is a positive and significant correlation between parity and increased maternal BMI. The highest weight gain happens during the first pregnancy. The rate of operative deliveries and complications during delivery is increased in obese pregnant women.

Impact of nicotine and maternal BMI on fetal birth weight.

BACKGROUND: According to the World Health Organization, smoking is the most important risk factor for adverse pregnancy outcomes in industrialized nations. As the individual factors (body mass index - BMI (kg/m2) - and cigarette consumption) have been extensively investigated in pregnancy, we aimed to establish how maternal BMI and nicotine interact with regard to perinatal outcomes and birth weight. METHODS: Data from 110.047 singleton pregnancies, achieved from the German Perinatal Survey in Schleswig-Holstein and registered between 2010 and 2017 were analyzed in August 2018 concerning maternal BMI and smoking. The BMI was taken from the maternity log. Information concerning the smoking status were self-reported and further subdivided into the following four categories: a) non-smokers; b) 1-7 cigarettes/day; c) 8-14 cigarettes/ day; and d) ≥ 15 cigarettes/ day. Furthermore, we classified women by their BMI into underweight, normal weight, overweight and obese. Comparisons between non-smokers and the respective smoking group, and their relationship with maternal BMI were performed by the t-test (birth weight). A P-value ≤0.05 was considered to indicate statistical significance. RESULTS: A number of 97.092 women (88.2%) were non-smokers and 12.955 (11.8%) were smokers. Furthermore 10.3% of women of normal weight smoked during pregnancy, but both high and low BMI were associated with a high prevalence of smoking. The proportion of smokers was highest (18.1%) among underweight women (BMI ≤ 18.5 kg/m2). A large number of smokers (15.5%) were registered in the obesity group (BMI ≥ 30 kg/m2). Mean birth weight (≥ 37 + 0 gestational age) increased with increasing maternal BMI, and was reduced by smoking for every BMI category. The differences between smokers and non-smokers were always highly significant (p < 0.001). Mean birth weight varied between 2995 g in underweight frequent smokers and 3607 g in obese non-smokers. CONCLUSION: Both maternal BMI and smoking during pregnancy influences the birth weight and therefore pregnancy outcome. Smoking during pregnancy was significantly associated with low birth weight. Pregnant women should be advised to cease or at least reduce smoking in order to improve the birth weight of the newborn and to minimize child morbidities.

Impact of smoking and fetal gender on preterm delivery.

According to the World Health Organization, smoking is the most important risk factor for adverse pregnancy outcomes in industrialized nations. We aimed to establish how fetal gender and smoking interact with regard to perinatal outcomes, especially preterm delivery. Data from 220,339 singleton pregnancies, obtained from the German Perinatal Survey in Schleswig-Holstein and registered between 2004 and 2017 were analyzed in regard to smoking behavior, fetal gender, and preterm delivery. The rate of preterm births was directly proportional to the women's consumption of nicotine. The rate of preterm deliveries was 6.8% among nonsmokers, and 13.2% in women who were very heavy smokers (≥22 cigarettes/day). Very heavy smoking (≥22 cigarettes/day) had a marked impact on extremely preterm births (<28 weeks of gestation) and very preterm births (28-31 weeks of gestation). Preterm births increased by 1.2% from heavy smokers to very heavy smokers; the differences between the other groups ranged between 0.1% and 0.4%. Fetal gender also had an impact on preterm birth: male infants were predominant in nearly all groups of women who delivered preterm infants. Smoking during pregnancy and male gender are both risk factors for preterm delivery. Fetal gender should be given greater attention as one of the several risk factors of preterm birth. Due to the high rate of morbidity among preterm infants and enormous costs for the healthcare system, women should be encouraged to cease or at least reduce smoking during pregnancy.

Individualized sex-specific birth weight percentiles for gestational age based on maternal height and weight.

OBJECTIVES: The maternal body size affects birth weight. The impact on birth weight percentiles is unknown. The objective of the study was to develop birth weight percentiles based on maternal height and weight. METHODS: This observational study analyzed 2.2 million singletons from the German Perinatal Survey. Data were stratified into 18 maternal height and weight groups. Sex-specific birth weight percentiles were calculated from 31 to 42 weeks and compared to percentiles from the complete dataset using the GAMLSS package for R statistics. RESULTS: Birth weight percentiles not considering maternal size showed 22% incidence of small for gestational age (SGA) and 2% incidence of large for gestational age (LGA) for the subgroup of newborns from petite mothers, compared to a 4% SGA and 26% LGA newborns from big mothers. The novel percentiles based on 18 groups stratified by maternal height and weight for both sexes showed significant differences between identical original percentiles. The differences were up to almost 800 g between identical percentiles for petite and big mothers. The 97th and 50th percentile from the group of petite mothers almost overlap with the 50th and 3rd percentile from the group of big mothers. CONCLUSIONS: There is a clinically significant difference in birth weight percentiles when stratified by maternal height and weight. It could be hypothesized that birth weight charts stratified by maternal anthropometry could provide higher specificity and more individual prediction of perinatal risks. The new percentiles may be used to evaluate estimated fetal as well as birth weight.

Individualized birth length and head circumference percentile charts based on maternal body weight and height.

Objectives Measurement of birth length and birth head circumference is part of the newborn assessment. Both measurements aid in distinguishing between proportionate and disproportionate small and large for gestational age newborns. It had been shown that birth weight is related to maternal height and weight. This study aims to analyze birth length and birth head circumference percentiles based on maternal stature. Methods This observational study analyzed birth length and birth head circumference percentiles of 2.3 million newborns stratified by maternal height and weight from the first obstetric assessment. Percentiles were calculated for sex and 22-43 gestational weeks for all infants. Eighteen subgroups based on six maternal height and three weight strata were defined and percentiles calculated from 32 to 42 gestational weeks using GAMLSS package for R. Results Newborns of mothers with height <158 cm and weight <53 kg (short stature) had a rate of preterm birth of 9%, compared to 5% in the tall stature group (height >177 cm, weight >79 kg). Small stature mothers were 1.7 years younger. Birth length differed by several centimeters for the same percentiles between groups of short and tall stature mothers, whereas birth head circumference differed up to 1.2 cm. The largest deviation of birth length was between the 97th percentiles. For male newborns born at term, birth length at the 97th percentile differed by 3.2 cm, at the 50th percentile by 2.7 cm and at the third percentile by 2.5 cm. Conclusions Birth length and birth head circumference are related to maternal height and weight. To more completely assess newborns, the maternal size should be considered.

Identification of growth patterns of preterm and small-for-gestational age children from birth to 4 years - do they catch up?

Background A legitimate indication for growth hormone (GH) therapy in children born too light or short at birth [small-for-gestational age (SGA)] exists in Germany and the European Union only if special criteria are met. Methods We conducted a longitudinal, multi-centered study on full-term appropriate-for-gestational age (AGA, n=1496) and pre-term born SGA (n=173) and full-term SGA children (n=891) in Germany from 2006 to 2010. We analyzed height, weight, body mass index (BMI) and head circumference. Results Pre-term or full-term born SGA children were shorter, lighter and had a lower BMI from birth until 3 years of age than full-term AGA children. The growth velocity of the analyzed anthropometric measurements was significantly higher in pre-term and full-term SGA children exclusively in the first 2 years of life than in AGA children. The criteria for GH treatment were fulfilled by 12.1% of pre-term SGA children compared to only 1.3% of full-term SGA children. Conclusion For children that do not catch up growth within the first 2 years of life, an earlier start of GH treatment should be considered, because a catch-up growth later than 2 years of life does not exist. Pre-term SGA-born children more frequently fulfill the criteria for GH treatment than full-term SGA children.

[Influence of Parental Body Measurements on Birth Weight of Eutrophic Term Newborns with Special Consideration of Paternal Body Measurements]. / Zum Einfluss von Körpermaßen der Eltern auf das Geburtsgewicht von eutrophen Termingeborenen (TG) unter besonderer Berücksichtigung der Körperhöhe und des Körpergewichts des Vaters.

A significant influence of maternal body height and weight on neonatal birth outcome has been confirmed before, whereas the influence of paternal traits is rather unknown. In order to analyze the correlation between parental body measurements and the birth weight of newborns, data of 1312 eutrophic term newborns and their parents were collected based on a multicenter study in 10 participating German maternity clinics. The collected data included the birth weight of the infants and the body height and weight of their parents. The results show a significant correlation between infant birth weight and maternal body height. Even with a constant body height and body weight of fathers in a range between 176-184 cm and 76-84 kg, taller mothers gave birth to children with a higher birth weight than shorter mothers. Furthermore, higher maternal body weight is also correlated with increased birth weights, although this correlation is attenuated in higher maternal weight groups. Data regarding body weight and body height of fathers showed similar results with regard to birth weight of the newborns. At a constant maternal body height (164-172 cm) and weight (56-64 kg), the body weight of newborns significantly correlates with the body height of fathers but not with their body weight. The multivariable regression analysis resulted in the following ranking of influence factors on the birth weight of newborns: 1) body height of mother, 2) body weight of mother, 3) body height of father. The results gave support to the assumption of a certain genetic influence of parental body stature on their neonates but argue for an even stronger impact of maternal environmental conditions on the developmental status of neonates.

Maternal body mass index and smoking during pregnancy do not affect the proportional sexual dimorphism for birth weight- an analysis of the German Perinatal Survey.

Background: Male sex has been reported as a risk factor for perinatal mortality. It can be hypothesized that smoking during pregnancy and low maternal pre-pregnancy body mass index (BMI) would lead to a higher proportion of growth restricted male compared to female newborns. The objective of the study was to analyze sex-specific differences in birth weight related to smoking and maternal BMI. Method: Data on maternal and newborn characteristics were obtained from the German Perinatal Survey. We analyzed data on 508,926 singleton pregnancies that had been collected in eight German federal states between 1998 and 2000. Women were classified according to the number of cigarettes smoked per day (non-smokers, 1-7, 8-14, ≥ 15) and by maternal BMI (< 18.5, 18.5-24.99, 25-29.99, ≥ 30 kg/m2) at the first obstetric consultation. Newborns were classified as small, appropriate, or large for gestational age based on birth weight below the 10th, between 10th and 90th, or above the 90th percentile, respectively. The proportional sexual dimorphism (PSD) was calculated as the female mean divided by the male mean ×100. Results: Smoking is related to a decrease in mean birth weight and an increase of in the SGA rate. Maternal BMI is positively related to the birth weight. However, the proportional sexual dimorphism for birth weight was not different with smoking or BMI. Conclusion: Smoking during pregnancy is related to lower birth weight, and high BMI is related to higher birth weight with no change in PSD.

Birth risks according to maternal height and weight - an analysis of the German Perinatal Survey.

Objective To investigate the variability in the prevalences of selected birth risks in women of different heights and weights. Methods Data from the German Perinatal Survey of 1998-2000 were analyzed: 503,468 cases contributed to our analysis of the prevalences of selected birth risks specified according to maternal weight groups, 502,562 cases contributed to our analysis according to maternal height groups and 43,928 cases contributed to our analysis of birth risks in women with a body mass index (BMI) of 21-23 kg/m2 but different heights and weights. Data analysis was performed using SPSS version 22. Results Some birth risks varied substantially by maternal height in women with a "normal" BMI of 21-23 kg/m2: the prevalence of post-term birth increased from 8.7% in women with a height of 150 cm to 13.5% in 185 cm tall women, the prevalence of preterm birth decreased from 5.9% (150 cm tall women) to 3.1% (185 cm tall women), a pathologic cardiotocography (CTG) or poor fetal heart sounds on auscultation occurred in 19.4% of the 150 cm tall women but only in 9.2% of 185 cm tall women and cephalopelvic disproportion decreased from 12.3% (150 cm tall women) to 1.2% (185 cm tall women). Analyses of women in different body height and weight groups (without restriction of BMI) likewise showed differences in the prevalences of some birth risks. Conclusion Birth risks may vary by height and weight in women with the same, "normal" BMI. BMI should not be the only way by which the impact of maternal height and weight is assessed with regard to perinatal outcomes such as birth risks.

The relationship between maternal age, body mass index, and the rate of preterm birth

Objective: The aim of the present study was to assess the influence of maternal age and maternal body mass index of early pregnancy on the risk of preterm delivery. Material and Methods: The study included 2.1 million liveborn single newborns with documented data at perinatal surveys. Statistical analyses were performed using the SPSS statistics program. Results: The risk of preterm births increased in obese women and in women with advanced age. Conclusion: Strategies should be developed to reduce preconceptional body mass index, and guidelines are required to help advise women who postponed childbearing.

Demographic influence on maternal weight gain during pregnancy: where will we end up?

PURPOSE: Maternal obesity is one of the most commonly occurring risk factors in obstetrics. Complications, such as gestational diabetes, venous thromboembolism, preeclampsia and many more, exist far more often in obese women than in pregnant women of normal weight. METHODS: Changes in maternal weight gain during pregnancy were analysed in Schleswig-Holstein between 1995 and 1997 and between 2004 and 2009. Between 1995 and 1997 data were drawn from 74,000 singleton pregnancies and between 2004 and 2009 from 118,000 pregnancies. The data centre of the University of Rostock performed the statistical analysis. RESULTS: Maternal weight at the time of first consultation with proof of pregnancy was 67.6 kg in 1995 and increased to 70.7 kg in 2009. This means an absolute difference of 3.1 kg. Maternal weight at the time of delivery changed from 80.8 to 84.9 kg in the same period. This is an absolute difference of 4.1 kg. Body weight is higher in 2009 than in 1995 across nearly all age groups. Even in younger women (aged 17 years and over) differences in weight can be registered. The obesity rate (BMI ≥ 30) in relation to maternal age was also analysed. In general, the rate of obesity is higher in 2009 than in 1995 across all age groups. CONCLUSIONS: These results show an increase in maternal weight gain during pregnancy over the last decades. However, the change in maternal weight is not dependent upon maternal age. The weight differences are consistent across nearly all age groups. Thus, age is not a risk factor for overweight and obesity.

Somatic development at birth as influenced by maternal characteristics - an analysis of the German Perinatal Survey.

We investigated the effects of maternal age, body weight, body height, weight gain during pregnancy, smoking during pregnancy, previous live births and being a single mother on somatic development at birth. We analysed data from the German Perinatal Survey for the years 1998-2000 from eight German federal states. We had available data on 508,926 singleton pregnancies and neonates in total; for 508,893 of which we could classify the neonates as small, appropriate or large for gestational age (SGA, AGA or LGA) based on the 10th and 90th birth weight percentiles. Multivariable regression analyses found statistically significant effects of a clinically relevant magnitude for smoking during pregnancy [odds ratio (OR) 2.9 for SGA births for women smoking >10 cigarettes per day], maternal height (OR 1.4 for SGA births for women <162 cm; OR 1.4 for LGA births for women >172 cm), maternal weight (OR 1.5 for SGA births for women <59 kg; OR 1.9 for LGA births for women >69 kg), weight gain during pregnancy (OR 1.9 for SGA births for women with a weight gain <8 kg; OR 2.0 for LGA births for women with a weight gain >18 kg) and previous live births (OR 2.1 for LGA births for women with one or more previous live births). Maternal age and being a single mother also had significant effects but their magnitude was small. Our analysis confirms the clinically relevant effects of smoking, maternal anthropometric measures and weight gain during pregnancy on neonatal somatic development.

Maternal body height is a stronger predictor of birth weight than ethnicity: analysis of birth weight percentile charts.

Background Anthropometric parameters such as birth weight (BW) and adult body height vary between ethnic groups. Ethnic-specific percentile charts are currently being used for the assessment of newborns. However, due to globalization and interethnic families, it is unclear which charts should be used. A correlation between a mother's height and her child's BW (1 cm accounts for a 17 g increase in BW) has been observed. The study aims to test differences in small for gestational age (SGA) and large for gestational age (LGA) rates, employing BW percentile charts based on maternal height between ethnic groups. Methods This retrospective study of 2.3 million mother/newborn pairs analyzed BW, gestational age, sex, maternal height and ethnicity from the German perinatal survey (1995-2000). These data were stratified for maternal height (≤157, 158-163, 164-169, 170-175, ≥176 cm) and region of origin (Germany, Central and Northern Europe, North America, Mediterranean region, Eastern Europe, Middle East and North Africa, and Asia excluding Middle East). Percentile charts were calculated for each maternal height group. Results The average BW and maternal height differ significantly between ethnic groups. On current percentile charts, newborns of taller mothers (≥176 cm) have a low rate of SGA and a high rate of LGA, whereas newborns of shorter mothers (≤157 cm) have a high rate of SGA and a low rate of LGA. When the BW data are stratified based on the maternal height, mothers of similar height from different ethnic groups show similar average BWs, SGA and LGA rates. Conclusion Maternal body height has a greater influence on BW than maternal ethnicity. The use of BW percentile charts for maternal height should be considered.

Misclassification of newborns due to systematic error in plotting birth weight percentile values.

OBJECTIVES: Higher than expected small for gestational age (SGA) rates and lower than expected large for gestational age (LGA) rates have been observed. A possible explanation is a leftward shift of percentile curves for birth weight due to a systematic error in plotting birth weight values in charts (ie, plotting weekly mean birth weight data at the beginning of the weeks). Our objectives were to assess how common this plotting error is and to analyze the effect of this error on SGA and LGA classification based on data from the German perinatal survey. METHODS: First, a systematic literature search for birth weight charts was performed, and the charts were analyzed for the plotting error. Second, percentile values (10th, 50th, and 90th) for 25 to 42 completed weeks of gestation were calculated from the data of 1181200 male singleton newborns (German perinatal survey, 1995-2000). Birth weight percentile curves were calculated with and without the plotting error, and the resulting SGA and LGA rates were analyzed. RESULTS: Fourteen of the 16 identified publications contained the systematic error in plotting. Using our calculated percentile curves, a leftward shift caused by the plotting error led to an SGA rate of 12.5% and an LGA rate of 7.7%; ∼5% of newborns were misclassified. CONCLUSIONS: Percentile charts should be examined for the described systematic error and, if necessary, corrected.

Somatic classification of neonates based on birth weight, length, and head circumference: quantification of the effects of maternal BMI and smoking.

We defined neonates as small, appropriate, or large for gestational age (SGA, AGA, LGA) based on birth weight, length, and head circumference. We analyzed the effects on the somatic classification of maternal body mass index (BMI) (<18.5, 18.5-24.99, 25.0-29.99, ≥ 30) and smoking during pregnancy (0, 1-7, 8-14, ≥ 15 cigarettes daily). Data were from the German Perinatal Survey (1998-2000; 433,669 cases). The following refers to the classification by birth weight. In the normal maternal weight population SGA rates increased with cigarette consumption: 9.8%, 17.8%, 21.6%, and 25.4% for non-smokers, and smokers of 1-7, 8-14, and ≥ 15 cigarettes daily, respectively. In non-smoking underweight women the SGA rate was 17.4%. In underweight smokers of ≥ 15 cigarettes daily the SGA rate was 38.5% [odds ratio 5.77, 95% confidence interval 5.10-6.53, compared with normal weight non-smokers]. In the normal maternal weight population, LGA rates were 9.9%, 5.3%, 4.6%, and 3.5% for non-smokers, and smokers of 1-7, 8-14, and ≥ 15 cigarettes daily, respectively. In the obese, LGA rates were 20.9% (non-smokers) and 11.4% (≥ 15 cigarettes). Similar findings were obtained for the somatic classifications based on birth length and head circumference. Results for the various combinations of maternal BMI and smoking status in the three classification systems are described. Our findings may assist in individualized risk assessment for SGA and LGA births.