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

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.

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.

Pregnancy management and outcome in patients with four different tetrahydrobiopterin disorders

INTRODUCTION

Inborn errors of tetrahydrobiopterin (BH4) biosynthesis or recycling are a group of very rare neurometabolic diseases. Following growing awareness and improved availability of drug treatment the number of patients with BH4 disorders reaching adulthood is constantly increasing. Pregnancy care of patients with these disorders is therefore a new challenge for clinicians.

METHODS

This retrospective study summarises for the first time clinical and biochemical monitoring data of 16 pregnancies in seven women with different disorders of BH4 metabolism and evaluates treatment regimens before and during pregnancy in relation to the obstetrical outcome and paediatric follow-up.

RESULTS

Worsening of pre-existing neurological symptoms or occurrence of new symptoms during pregnancy was not observed in most of the cases. Treatment regimens remained mostly unchanged. Pregnancies were not complicated by disease-specific features. Organ abnormalities, miscarriage, prematurity, IUGR and chromosomal changes were occasionally reported, without showing any association with the standard drug treatment for BH4 deficiencies.

CONCLUSION

Although our data on 16 pregnancies in seven patients did not present any association of standard drug treatment with an increased rate of pregnancy complications, abnormal obstetrical or paediatric outcome, an intensive clinical and biochemical supervision by a multidisciplinary team before, during and after the pregnancy in any BH4 deficiency is essential since available data on pregnancies in patients with BH4 deficiencies is limited.

Monitoring postnatal growth of preterm infants: present and future

BACKGROUND

There is no consensus with regard to which charts are most suitable for monitoring the postnatal growth of preterm infants.

OBJECTIVE

We aimed to assess the strategies used to develop existing postnatal growth charts for preterm infants and their methodologic quality.

DESIGN

A systematic review of observational longitudinal studies, having as their primary objective the creation of postnatal growth charts for preterm infants, was conducted. Thirty-eight items distributed in 3 methodologic domains ("study design," "statistical methods," and "reporting methods") were assessed in each study. Each item was scored as a "low" or "high" risk of bias. Two reviewers independently selected the studies, assessed the risk of bias, and extracted data. A total quality score [(number of "low risk" of bias marks/total number of items assessed) × 100%] was calculated for each study. Median (range, IQR) quality scores for each methodologic domain and for all included studies were computed.

RESULTS

Sixty-one studies met the inclusion criteria. Twenty-seven (44.3%) of the 61 studies scored ≥50%, of which 10 scored >60% and only 1 scored >66%. The median (range, IQR) quality score for the 61 included studies was 47% (26-75%, 34-56%). The scores for the domains study design, statistical methods, and reporting methods were 44% (19-67%, 33-52%), 25% (0-88%, 13-38%), and 33% (0-100%, 0-33%), respectively. The most common shortcomings were observed in items related to anthropometric measures (the main variable of interest), gestational age estimation, follow-up duration, reporting of postnatal care and morbidities, assessment of outliers, covariates, and chart presentation.

CONCLUSIONS

The overall methodologic quality of existing longitudinal studies was fair to low. To overcome these problems, the Preterm Postnatal Follow-up Study, 1 of the 3 main components of The International Fetal and Newborn Growth Consortium for the 21st Century Project, was designed to construct preterm postnatal growth standards from a prospective cohort of "healthy" pregnancies and preterm newborns without evidence of fetal growth restriction.

Obesity or Underweight-What is Worse in Pregnancy?

OBJECTIVE

This study was conducted to compare underweight and obese women and their weight gain during pregnancy on fetomaternal outcome.

METHOD

This is a prospective, non-interventional, observational study on 1000 women (BMI between 20 and 30 were excluded). Women attending ANC OPD with singleton pregnancy at or before 16 weeks were included and BMI calculated in early pregnancy. Their weight gain during pregnancy was noted. Any complications in the mother or perinate were noted.

RESULTS

Incidence of obesity in our institute was 17 % and that of underweight was 18 %. Pre-eclampsia, gestational hypertensions, gestational DM, antepartum hemorrhage, all were more common among obese women, while anemia was more common in the underweight. Post-dated pregnancy, induction of labor, cesarean delivery, and postpartum complications were more common in obese women. Fetal complications were also higher in obese patients.

CONCLUSION

Lower as well as higher prepregnancy BMI is an independent risk factor that is associated with increased morbidity and mortality in both the mother and the fetus.

Exploring the relationship between maternal body mass index and offspring birth weight: Analysis of routinely collected data from 1967 to 2010 in Aberdeen, Scotland

A retrospective cohort study was undertaken to assess the relationship between maternal body mass index (BMI) and neonatal birth weight. Data were extracted from Aberdeen Maternity and Neonatal Databank on all deliveries (n = 94049) occurring between 1967 and 2010. Compared with mothers whose weight was in the normal range, the adjusted odds of delivering a high-birth-weight infant were 0.63 (95% confidence interval: 0.59, 0.67), 1.44 (1.39, 1.50); 1.83 (1.72, 1.95); 2.22 (2.04, 2.43) in underweight, overweight, obese and morbidly obese mothers, respectively. Similarly, the adjusted odds of delivering a low-birth-weight baby decreased with increasing maternal BMI from 1.38 (1.23, 1.55) in underweight women to 0.80 (0.72, 0.89) in overweight women; 0.78 (0.67, 0.93) in obese and 0.56 (0.44, 0.71) in morbidly obese mothers. These relationships were only evident after adjustment for gestational age, presumably because higher maternal BMI is also, in some cases, associated with pre-term deliveries.

Analysis of the German Perinatal Survey of the Years 2007-2011 and Comparison with Data From 1995-1997: Maternal Characteristics

Background and Aim: We have previously presented analyses of data obtained from the German Perinatal Survey for the years 1995-1997. Here we present an analysis of data from the years 2007-2011 and compare the data to the previous data from the 1990s. Material and Methods: For the years 1995-1997, the data on 1 815 318 singleton pregnancies were provided by the Chambers of Physicians of all the states of Germany except Baden-Württemberg. For the years 2007-2011, the data on 3 187 920 singleton pregnancies from the German Perinatal Survey (all states of Germany) were obtained from the AQUA Institute in Göttingen, Germany. SPSS was used for data analysis. Plausibility checks were performed on the data. Results: Mean maternal age has increased over the years, from 28.7 years in 1995 to 30.2 years in 2011. We observed a decrease in smoking. While not all cases included data on maternal smoking after the pregnancy was known, when the cases with data on smoking were analysed, in 1995-1997 23.5 % of pregnant women were smokers compared to 11.2 % smokers in 2007-2011. Maternal body mass index (BMI) also changed; 8.2 % of women were obese (BMI: 30-40 kg/m²), while 13.0 % were obese in 2011. In 1995, 0.6 % of women were morbidly obese (BMI ≥ 40 kg/m²) compared to 1.8 % of women in 2011. The mean maternal body weight at the time of the first obstetric consultation also increased from 65.9 kg in 1995 to 68.7 kg in 2011. Conclusions: While the decrease in the number of women smoking over time is clearly a positive development, increasing maternal age and obesity present challenges in clinical practice.

The independent effects of second hand smoke exposure and maternal body mass index on the anthropometric measurements of the newborn

Background

Exposure to tobacco smoke during pregnancy, whether as active smoking or by exposure to secondhand smoke (SHS), is associated with adverse pregnancy outcomes including low birth weight (LBW) and small for gestational age infants due to the effect of tobacco on the anthropometric measurements of the newborn. This effect might be masked by maternal obesity as it increases fetal weight. The objectives of this study were to estimate the independent effects of maternal exposure to SHS and maternal body mass index (BMI) on the anthropometric measurements and on the prevalence of macrosomia and LBW among term infants.

Methods

Data were collected from women in the postnatal ward following delivery. Participants were stratified into six groups based on the BMI (underweight <18 kg/m², non-obese 18–29.9 kg/m², and obese ≥30 kg/m²) and the SHS exposure status (exposed and non- exposed), to examine the independent effects of BMI and SHS on infants’ anthropometry. Multiple regression analysis was used to explore the independent associations between the six groups and the risk of delivering a macrosomic or LBW infant.

Results

Infants of women exposed to SHS had significantly reduced anthropometric measurements compared to infants of unexposed women. The odds of delivering a macrosomic baby increased to 9-fold for women with BMI of ≥30 kg/m² compared to non-obese women; odds ratio (OR) 9.18, 95% Confidence Interval (CI) (1.01, 9.37); p = 0.04, this risk was attenuated to 1.5-fold in women exposed to SHS, OR 1.53, 95% CI (1.19, 12.1); p < 0.0001. The odds of delivering an LBW infant were more than doubled in underweight women compared to non-obese women, OR 2.15, 95% CI (1.001, 4.57); p = 0.034, and were further increased to almost 3-fold for women who were exposed to SHS, OR 2.71, 95% CI (1.82,4.045); p = 0.02.

Conclusion

Exposure to SHS was associated with reduced anthropometric measurements of the newborn and increased rate of LBW infants, irrespective of maternal BMI. Maternal obesity was associated with increased risk of delivering a macrosomic infant; conversely maternal underweight was associated with increased risk of delivering an LBW infant.

Validating the weight gain of preterm infants between the reference growth curve of the fetus and the term infant

BACKGROUND

Current fetal-infant growth references have an obvious growth disjuncture around 40 week gestation overlapping where the fetal and infant growth references are combined. Graphical smoothening of the disjuncture to connect the matching percentile curves has never been validated. This study was designed to compare weight gain patterns of contemporary preterm infants with a fetal-infant growth reference (derived from a meta-analysis) to validate the previous smoothening assumptions and inform the revision of the Fenton chart.

METHODS

Growth and descriptive data of preterm infants (23 to 31 weeks) from birth through 10 weeks post term age were collected in three cities in Canada and the USA between 2001 and 2010 (n = 977). Preterm infants were grouped by gestational age into 23-25, 26-28, and 29-31 weeks. Comparisons were made between the weight data of the preterm cohort and the fetal-infant growth reference.

RESULTS

Median weight gain curves of the three preterm gestational age groups were almost identical and remained between the 3rd and the 50th percentiles of the fetal-infant-growth-reference from birth through 10 weeks post term. The growth velocity of the preterm infants decreased in a pattern similar to the decreased velocity of the fetus and term infant estimates, from a high of 17-18 g/kg/day between 31-34 weeks to rates of 4-5 g/kg/day by 50 weeks in each gestational age group. The greatest discrepancy in weight gain velocity between the preterm infants and the fetal estimate was between 37 and 40 weeks; preterm infants grew more rapidly than the fetus. The infants in this study regained their birthweight earlier compared to those in the 1999 National Institute of Child Health and Human Development report.

CONCLUSION

The weight gain velocity of preterm infants through the period of growth data disjuncture between 37 and 50 weeks gestation is consistent with and thus validates the smoothening assumptions made between preterm and post-term growth references.

A systematic review and meta-analysis to revise the Fenton growth chart for preterm infants

Background

The aim of this study was to revise the 2003 Fenton Preterm Growth Chart, specifically to: a) harmonize the preterm growth chart with the new World Health Organization (WHO) Growth Standard, b) smooth the data between the preterm and WHO estimates, informed by the Preterm Multicentre Growth (PreM Growth) study while maintaining data integrity from 22 to 36 and at 50 weeks, and to c) re-scale the chart x-axis to actual age (rather than completed weeks) to support growth monitoring.

Methods

Systematic review, meta-analysis, and growth chart development. We systematically searched published and unpublished literature to find population-based preterm size at birth measurement (weight, length, and/or head circumference) references, from developed countries with: Corrected gestational ages through infant assessment and/or statistical correction; Data percentiles as low as 24 weeks gestational age or lower; Sample with greater than 500 infants less than 30 weeks. Growth curves for males and females were produced using cubic splines to 50 weeks post menstrual age. LMS parameters (skew, median, and standard deviation) were calculated.

Results

Six large population-based surveys of size at preterm birth representing 3,986,456 births (34,639 births < 30 weeks) from countries Germany, United States, Italy, Australia, Scotland, and Canada were combined in meta-analyses. Smooth growth chart curves were developed, while ensuring close agreement with the data between 24 and 36 weeks and at 50 weeks.

Conclusions

The revised sex-specific actual-age growth charts are based on the recommended growth goal for preterm infants, the fetus, followed by the term infant. These preterm growth charts, with the disjunction between these datasets smoothing informed by the international PreM Growth study, may support an improved transition of preterm infant growth monitoring to the WHO growth charts.

Pregestational body mass index is related to neonatal abdominal circumference at birth--a Danish population-based study

OBJECTIVES

To examine the impact of maternal pregestational body mass index (BMI) and smoking on neonatal abdominal circumference (AC) and weight at birth. To define reference curves for birth AC and weight in offspring of healthy, nonsmoking, normal weight women.

DESIGN

Population-based study.

SETTING

Data from the Danish Medical Birth Registry.

POPULATION

All live singletons without congenital malformations in Denmark 2004-10.

METHODS

Data on 366,886 singletons at 35(+0) to 41(+6) weeks(+days) of gestation were extracted and analysed using multivariate linear regressions.

MAIN OUTCOME MEASURES

Birth AC and weight in relation to pregestational maternal BMI, maternal smoking and medical conditions (any).

RESULTS

Birth AC and weight increased with increasing pregestational BMI, and decreased with smoking (P < 0.0001). Reference curves were created for offspring of healthy, nonsmoking mothers with normal pregestational BMI. Mean AC ranged from 30.1 cm and 30.2 cm at 35 weeks of gestation to 33.9 cm and 34.1 cm at 41 weeks of gestation, for girls and boys, respectively. Mean birthweight ranged from 2581 and 2666 g at 35 weeks to 3705 and 3852 g at 41 weeks of gestation for girls and boys, respectively. Pregestational BMI correlated more to the Z score of birthweight than to the Z score of AC (P < 0.0001).

CONCLUSION

Birth AC and weight are affected by maternal smoking status and pregestational BMI. Pregestational BMI correlated more to birthweight than to AC. Using data from healthy, nonsmoking mothers with normal pregestational BMI we have provided new reference curves for birth AC and birthweight.

Smoking during pregnancy influences the maternal immune response in mice and humans

OBJECTIVE

During pregnancy the maternal immune system has to adapt its response to accommodate the fetus. The objective of this study was to analyze the effects of smoking on the maternal immune system.

STUDY DESIGN

First-trimester decidual tissue and peripheral blood of smoking and nonsmoking women were analyzed by real time reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry. A mouse model was used to further analyze the effects of smoking. Murine tissue was analyzed by flow cytometry, real-time RT-PCR, and immunohistochemistry.

RESULTS

Smoking caused lower percentages of viable pups in mice and lower birthweights in humans. Smoking mothers, both mice and human, had more natural killer cells and inflammatory macrophages locally, whereas systemically they had lower percentages of regulatory T cells than nonsmoking controls.

CONCLUSION

Maternal smoke exposure during pregnancy influences local and systemic immune responses in both women and mice. Such changes may be involved in adverse pregnancy outcomes in smoking individuals.