Does a body mass index greater than 25kg/m2 increase maternal and neonatal morbidity? A French historical cohort study.

OBJECTIVES: To evaluate, in a French multicenter cohort, the risk of C-section based on a high pre-pregnancy body mass index (BMI). Secondary objectives were to assess the risk of elective C-section, severe post-partum hemorrhage (>1L), severe perineal tears (3rd and 4th degree) and neonatal complications according to pre-pregnancy BMI. STUDY DESIGN: This historical cohort study analyzed records from the French AUDIPOG perinatal database. Inclusion criteria were deliveries≥22 weeks (or with a birth weight≥500g). Women with BMI<18.5kg/m2 (n=31,766) were excluded. After these exclusions, the study sample included 314,851 women between 1999 and 2009. Patients were classified among four BMI subgroups (normal: 18.5-24.9kg/m2, overweight: 25-29.9kg/m2, class I and II obesity: 30-39.9kg/m2 and class III obesity:≥40kg/m2). BMI was calculated using pre-pregnancy self-reported weight. Results were expressed as crude and adjusted relative risks (aRR). RESULTS: A C-section occurred in 16.4%, 22.7%, 28.8% and 39.4% of normal BMI, overweight, obese and class III obese women, respectively (P<10-4). aRR of C-section increased with BMI: 1.26 [95%CI: 1.22-1.30] for BMI between 25-29.9kg/m2; 1.39 [95%CI: 1.34-1.45] for BMI between 30-39.9kg/m2 and 1.72 [95%CI: 1.57-1.90] for BMI≥40kg/m2; but not the elective C-section. Neonatal complications were more frequent with increasing maternal BMI (BMI 25-29.9: aRR=1.09 [95%CI: 1.06-1.12]; BMI 30-39.9: aRR=1.20 [95%CI: 1.16-1.25]; BMI≥40: aRR=1.33 [95%CI: 1.21-1.45]). CONCLUSION: Our study confirmed that pre-pregnancy BMI is an important factor to consider because its elevation is associated with adverse obstetrical outcomes, especially cesarean delivery and neonatal complications.

Inter-observer reliability of 4 fetal heart rate classifications.

OBJECTIVE: Different classification of fetal heart rate (FHR) pattern have been proposed: FHR classified as either "reassuring" or "non-reassuring", the National Institute of Child Health and Human Development (NICHD) published in 2008 a 3-tier system, the French College of Gynecology and Obstetrics (CNGOF) recommended in 2013 a 5-tier system and recently in 2015, the Federation International of Gynecology and Obstetrics (FIGO) proposed a new classification based on a 3-tier system. Our objective was to assess the inter-observer reliability of these 4 existing classifications. STUDY DESIGN: Four observers reviewed 100 FHR without clinical information. FHR were obtained from term singleton pregnancies. Fetal heart rate patterns were classified by one 2-tier ("reassuring vs. non-reassuring"), two 3-tier (NICHD 2008 and FIGO 2015), and one 5-tier (CNGOF 2013) fetal heart classifications. RESULTS: The global agreement between observers was moderate for each classification: 0.58 (0.40-0.74) for the 2-tier, 0.48 (0.37-0.58) for the NICHD 2008, 0.58 (0.53-0.63) for the CNGOF 2013 and 0.59 (0.49-0.67) for the FIGO 2015 classification. When FHR was classified as reassuring, it was classified as normal in 85.5% for the NICHD 2008 and in 94.5% for the FIGO 2015. For the CNGOF 2013, 65.0% were classified as normal and 32.5% as quasi normal. There was strong concordance between FIGO category I and "reassuring" FHR (kappa=0.95). CONCLUSION: Inter-observer agreement of FHR interpretation is moderate whatever the classification used. To evaluate the superior interest of one classification, it will be interesting to compare their impact on need of second line techniques and on neonatal outcome.

Influence of ECG sampling rate in fetal heart rate variability analysis.

Fetal hypoxia results in a fetal blood acidosis (pH<;7.10). In such a situation, the fetus develops several adaptation mechanisms regulated by the autonomic nervous system. Many studies demonstrated significant changes in heart rate variability in hypoxic fetuses. So, fetal heart rate variability analysis could be of precious help for fetal hypoxia prediction. Commonly used fetal heart rate variability analysis methods have been shown to be sensitive to the ECG signal sampling rate. Indeed, a low sampling rate could induce variability in the heart beat detection which will alter the heart rate variability estimation. In this paper, we introduce an original fetal heart rate variability analysis method. We hypothesize that this method will be less sensitive to ECG sampling frequency changes than common heart rate variability analysis methods. We then compared the results of this new heart rate variability analysis method with two different sampling frequencies (250-1000 Hz).

A new analysis of heart rate variability in the assessment of fetal parasympathetic activity: An experimental study in a fetal sheep model.

Analysis of heart rate variability (HRV) is a recognized tool in the assessment of autonomic nervous system (ANS) activity. Indeed, both time and spectral analysis techniques enable us to obtain indexes that are related to the way the ANS regulates the heart rate. However, these techniques are limited in terms of the lack of thresholds of the numerical indexes, which is primarily due to high inter-subject variability. We proposed a new fetal HRV analysis method related to the parasympathetic activity of the ANS. The aim of this study was to evaluate the performance of our method compared to commonly used HRV analysis, with regard to i) the ability to detect changes in ANS activity and ii) inter-subject variability. This study was performed in seven sheep fetuses. In order to evaluate the sensitivity and specificity of our index in evaluating parasympathetic activity, we directly administered 2.5 mg intravenous atropine, to inhibit parasympathetic tone, and 5 mg propranolol to block sympathetic activity. Our index, as well as time analysis (root mean square of the successive differences; RMSSD) and spectral analysis (high frequency (HF) and low frequency (LF) spectral components obtained via fast Fourier transform), were measured before and after injection. Inter-subject variability was estimated by the coefficient of variance (%CV). In order to evaluate the ability of HRV parameters to detect fetal parasympathetic decrease, we also estimated the effect size for each HRV parameter before and after injections. As expected, our index, the HF spectral component, and the RMSSD were reduced after the atropine injection. Moreover, our index presented a higher effect size. The %CV was far lower for our index than for RMSSD, HF, and LF. Although LF decreased after propranolol administration, fetal stress index, RMSSD, and HF were not significantly different, confirming the fact that those indexes are specific to the parasympathetic nervous system. In conclusion, our method appeared to be effective in detecting parasympathetic inhibition. Moreover, inter-subject variability was much lower, and effect size higher, with our method compared to other HRV analysis methods.

[Maternal obesity and pregnancy: Evolution of prevalence and of place of birth]. / Obésité maternelle et grossesse : évolution de la prévalence et du lieu d'accouchement à partir des données AUDIPOG.

OBJECTIVE: The primary objective was to describe the evolution of the prevalence of maternal obesity in France. The secondary objectives were to assess changes in the French regions and the place of birth according to type (public/private) and level of care. MATERIAL AND METHODS: Study based population of all births between 1999 and 2009 included in the AUDIPOG database. Our judgment criterion was the body mass index (BMI) divided into classes. RESULTS: Seventy-four thousand and forty-six pregnancies were included. The mean BMI was 22.9±4.5kg/m(2) with an increase between 1999-2001 and 2008-2009 (22.6±4.3kg/m(2) versus 23.1±4.7kg/m(2), P<10(-4)). North was the first region in terms of overweight patients (18%) and obese (10.2%). There was an increase of the birth rate in public maternity, and level II and III regardless of BMI class. Only the class of patients with a BMI ≥40kg/m(2) delivered more frequently in level III with an increase between the first and the last period of the study (20.8% versus 36.8%, P=0.02). CONCLUSION: The BMI is still increasing with more and more patients with a BMI ≥40kg/m(2) referred to level III. This raises the question of the organization of care and follow-up of these patients.