M. Voigt

Obesity and pregnancy--a risk profile.

AIM We aimed to illustrate the relationship between maternal obesity during pregnancy and maternal and fetal outcomes. We examined the influence of maternal BMI at the beginning of pregnancy on risks of pregnancy and birth, and on the somatic classification of the neonates. MATERIAL AND METHODS In our retrospective cohort study we included 499,267 singleton pregnancies taken from the German perinatal statistics of 1998-2000. 51,506 obese pregnant women (BMI >or= 30) were compared to 320,148 pregnant women of normal weight (BMI 18.50-24.99). We divided obesity into 3 BMI-categories: BMI = 30.00-34.99, BMI = 35.00-39.99, and BMI >or= 40.00. We defined small-for-gestational-age (SGA), appropriate-for-gestational-age (AGA), and large-for-gestational-age (LGA) status by birth weight percentiles. RESULTS 10.3 % of all pregnant women had a BMI >or= 30.00 and 0.8 % had a BMI >or= 40.00. The frequency of hypertension increased with the extent of obesity: 7.1 % (BMI = 30.00-34.99), 12.5 % (BMI = 35.00-39.99) and 18.3 % (BMI >or= 40.00) compared to 1.2 % (BMI 18.50-24.99). Cephalopelvic disproportion was found in 6.8 % (BMI >or= 40.00) compared to 2.8 % (BMI 18.50-24.99). Fetal macrosomia occurred in 24.8 % (BMI >or= 40.00) compared to 7.9 % in the control group. Rates of pre-eclampsia, gestational diabetes, and fetal structural anomalies also increased with maternal BMI. Women with different BMIs differed in parity but not in age. CONCLUSIONS Obesity during pregnancy is associated with a range of maternal and fetal adverse outcomes. Pregnancy in obese women therefore calls for close monitoring and careful planning of delivery. Pre-conceptional weight reduction should be considered.

Morbid obesity: Pregnancy risks, birth risks and status of the newborn

In perinatal medicine, severe obesity of the mother occurs in approximately 1% of cases. This is a problem of increasing importance because of the rising prevalence of juvenile obesity. Our retrospective cohort study aimed at characterising high-risk pregnancies associated with morbid obesity (body mass index [BMI]> or =40). This is of interest not only from an epidemiological perspective and for developing guidelines for clinical care but also from an anthropological point of view. We analysed the German perinatal statistics of the years 1998-2000 with data from more than 500,000 pregnancies. Pregnant women with coexistent morbid obesity were compared to a normal weight reference sample with regard to gestational, perinatal and neonatal risks. Birth weight percentiles were used to classify the neonates according to size (hypotrophy if <10th, hypertrophy/foetal macrosomia if >90th). The obtained risk profile for morbidly obese pregnant women primarily showed pregnancy related diseases, such as hypertension, pre-eclampsia and gestational diabetes. Hypertension and signs of foetal hypoxaemia occurred at higher frequencies with morbid obesity. Hypertrophic neonates were born 3.3 times more often to obese mothers than to mothers of the normal weight. At a BMI> or =40 the rates of complications such as pre-eclampsia, gestational diabetes, impending foetal hypoxaemia, foetal macrosomia, as well as neonatal infections and hyperbilirubinaemia were significantly higher. Obesity and maternal comorbidities, accounted for a higher rate of caesarean sections of up to 38.4% at a BMI> or =45. All differences were highly significant. Preconceptionally, the therapeutic approach should be weight reduction.

[New percentile values for the anthropometric dimensions of singleton neonates: analysis of perinatal survey data of 2007-2011 from all 16 states of Germany].

AIM The aim of this study was to derive percentile values for birth weight, length, head circumference, and weight for length for singleton neonates based on the German perinatal survey of 2007-2011 (using data from all 16 states of Germany). We also compared these new percentile values with the percentile values of 1995-2000 that so far have been considered standard values. MATERIAL AND METHODS Data of 3 187 920 singleton neonates from the German perinatal survey of the years 2007-2011 were kindly provided to us by the AQUA Institute in Göttingen, Germany. Sex specific percentile values were calculated using cumulative frequencies. Percentile values at birth were computed for the 3(rd), 10(th), 25(th), 50(th), 75(th), 90(th), and 97(th) percentiles for 21-43 completed weeks of gestation. Percentile curves and tabulated values for the years 2007-2011 were compared with the published values of 1995-2000. RESULTS AND DISCUSSION Overall the new percentile curves closely resemble the previous ones. Minimal differences can be found for the 10(th) percentile and generally for early weeks of gestation. Values for the 10(th) percentile in the 2007-2011 dataset are somewhat higher than values of 1995-2000 for birth weight, length, and weight for length. CONCLUSIONS We recommend the use of these new percentile values instead of the old ones.

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

Abstract 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.

Dependence of neonatal small and large for gestational age rates on maternal height and weight--an analysis of the German Perinatal Survey.

Abstract Neonatal anthropometric data reflect intrauterine development and correlate with postnatal outcome. Therefore, classification of neonates by body dimensions, using gestational age-adjusted population percentiles, is clinically practiced. However, neonatal anthropometric variables are also influenced by maternal constitution and the extent of this influence is currently unknown. We analyzed small for gestational age (SGA) and large for gestational age (LGA) rates according to maternal height and weight. We used data of about 2.3 million singleton pregnancies from the German Perinatal Survey of 1995–2000. A close correlation between maternal and neonatal anthropometric data was found; SGA rates were inversely proportional and LGA rates were directly proportional to maternal height, weight, and body mass index. Neonates of small and light mothers (<155 cm, <50 kg) had, according to the presently used classification scheme, an SGA rate of 25.3% and an LGA rate of 1.7%, respectively. Newborns to tall and heavy women (>179 cm, >89 kg) had a much lower SGA rate (3.1%) and a much higher LGA rate (30.6%). Neonatal body length and head circumference depended on maternal stature in a similar way. Some neonates who are “appropriate” for their gestational age in that they achieve their genetically determined growth potential are therefore apparently misclassified as SGA or LGA.

The Influence of Smoking during Pregnancy on Fetal Growth

BACKGROUND Smoking is the most important risk factor for adverse pregnancy outcomes in industrialized nations and is associated with, amongst other adverse effects, a higher rate of small-for-gestational-age (SGA) neonates. The rate of SGA neonates born before 32 weeks and its association with smoking have so far not been the focus of attention. MATERIAL AND METHODS Using data of 643,288 primiparous women from the German perinatal statistics of 1995-2000, we aimed to investigate this relationship. We also analyzed our data according to daily cigarette consumption. RESULTS We found that smoking during pregnancy was strongly associated with lower birth weight and higher SGA rates. This effect was especially pronounced in women >or=31 years. There was clear dose dependence with regard to daily cigarette consumption. An increase in SGA rates in smokers versus non-smokers can already be seen for very early preterm deliveries (31 weeks of gestation or less). CONCLUSIONS Our results allow the definition of groups of women who are at higher risk of SGA births. We show that especially older primiparous women (aged >or=31 years) who smoke >10 cigarettes a day are at increased risk of experiencing fetal growth restriction.

The Combined Effect of Maternal Body Mass Index and Smoking Status on Perinatal Outcomes - An Analysis of the German Perinatal Survey

BACKGROUND Maternal body mass index (BMI) outside the normal range and smoking are both associated with adverse perinatal outcomes, but their interaction needs further investigation. AIM The aim of this study was to analyse the combined effects of smoking and BMI on birth weight, preterm birth rate, the somatic development of neonates, and complications of pregnancy. MATERIAL AND METHODS Data from 508 926 singleton pregnancies from the German Perinatal Survey of 1998-2000 were analysed according to maternal BMI and smoking. RESULTS Preterm birth rates were higher for non-smoking underweight (8.3%) and obese women (6.7%) than for normal weight (6.0%) or overweight women (5.6%); rates were higher in smokers than in non-smokers for every BMI category. The mean birth weight increased with increasing BMI and was decreased by smoking; it was 2,964 g in underweight smokers and 3,556 g in obese non-smokers. Small for gestational age (SGA) rates were least in obese women and highest in underweight women; large for gestational age (LGA) rates varied in the opposite direction. In smokers SGA rates were higher than in non-smokers for every BMI category and LGA rates were always lower. Hypertension, proteinuria, oedema, and pre-eclampsia/eclampsia were more common as BMI increased but were always lower in smokers. Pre-eclampsia/eclampsia occurred in 0.7% of underweight smokers but in 9.6% of obese non-smokers. CONCLUSIONS Smoking and low maternal BMI in combination can cause high rates of preterm birth and SGA neonates as well as low mean birth weight. Although smoking offers some apparent benefit regarding LGA rates and pre-eclampsia this should not distract from its overall adverse influence.

Evaluation of maternal parameters as risk factors for premature birth (individual and combined effects)

OBJECTIVE We aimed to examine the individual and combined effects of nine maternal parameters (biological, medical, and social) on rates of prematurity. Our objective was to provide obstetricians with a way of screening women for likely premature deliveries. METHODS We conducted a retrospective analysis on the data of about 2.3 million pregnancies taken from the German perinatal statistics of 1995-2000. Rates of prematurity were calculated with single and multi-dimensional analyses on the basis of nine maternal parameters (age, weight, height, number of previous live births, stillbirths, miscarriages and terminations of pregnancy, smoking status, previous premature delivery). The following combinations of parameters were investigated in particular: rates of prematurity according to the number of previous stillbirths, miscarriages, and terminations; rates of prematurity according to the number of previous live births and maternal age, height and weight. We also included daily cigarette consumption and previous premature deliveries in our analyses. RESULTS The rate of prematurity (< or =36 weeks of gestation) in our population was 7.0%; the rate of moderately early premature deliveries (32-36 weeks) was 5.9%, and the rate of very early premature deliveries (< or =31 weeks) was 1.1%. Our multi-dimensional analyses revealed rates of prematurity (< or =36 weeks) between 5.1% and 27.5% depending on the combination of parameters. We found the highest rate of prematurity of 27.5% in women with the following combination of parameters: > or =1 stillbirth, > or =2 terminations of pregnancy and > or =2 miscarriages. A rather high risk of premature delivery (>11%) was also found for elderly (> or =40 years) grand multiparous women as well as small (< or =155 cm) and slim women (< or =45 kg). CONCLUSIONS We have shown that certain combinations of maternal parameters are associated with a high risk of premature deliveries (>10%). The risk table that we present here may assist in predicting premature delivery.

Zum Einfluss von vorausgegangenen Schwangerschaftsabbrüchen, Aborten und Totgeburten auf die Rate Neugeborener mit niedrigem Geburtsgewicht und Frühgeborener sowie auf die somatische Klassifikation der Neugeborenen

AIM The influence of previous interruptions, miscarriages and IUFD on the IUGR and preterm rate as well as on the somatic staging (gestational age and birth weight) of the new born is a subject of controversial discussion in the literature. The present paper attempts to quantify these risks of the medical history. 2 282 412 singleton pregnancies of the period 1995 to 2000 were evaluated from the German Perinatal Database. For the analysis 1 065 202 pregnancies (46.7 %) of those mothers without any live birth in the medical history were assessed. To exclude any influence from previous abortions patients with previous miscarriages and IUFDs were excluded. The control collective were new borns whose mothers had suffered neither from miscarriages nor from abortions or IUFD. RESULTS Previous interruptions, miscarriages and IUFD influence the rate of new borns with low birth weight and increase the rate of prematurity. With increasing numbers of isolated or combined risks in the medical history, the rate of newborns with a low birth weight or with prematurity is increased. The lowest risk was found after one interruption, the highest rate with two or more IUFDs. Interruptions, miscarriages or IUFD are not risk factors for IUGR or SGA. CONCLUSION Previous interruptions, miscarriages and IUFD are relevant risk factors for prematurity and are related with low birth weight of the new borns. Pregnant women with such risk factors have to been considered as risk pregnancies and need intensive surveillance.

Weight gain in pregnancy according to maternal height and weight.

Abstract Weight gain during pregnancy is of great importance for the health of mother and child. There is considerable individual variability with regard to the weight gain, with maternal height and pre-pregnancy body weight being important determinants. We aim to assess the usefulness of the maternal body mass index (BMI) and other ways of combining maternal weight and height in predicting weight gain during pregnancy. We analyzed data of more than 2.2 million pregnancies taken from the German perinatal statistics of 1995–2000. We found that BMI is not useful as a predictor of weight gain during pregnancy. We developed an alternative system of using maternal weight and height to predict weight gain by classifying pregnant women according to their weight and height. This allows an assessment of weight gain by comparing a given pregnant woman to other women with similar weights and heights.