Rationale and design of ePPOP-ID: a multicenter randomized controlled trial using an electronic-personalized program for obesity in pregnancy to improve delivery.

BACKGROUND: Pre-pregnancy obesity and excessive gestational weight gain (GWG) are established risk factors for adverse pregnancy, delivery and birth outcomes. Pregnancy is an ideal moment for nutritional interventions in order to establish healthier lifestyle behaviors in women at high risk of obstetric and neonatal complications. METHODS: Electronic-Personalized Program for Obesity during Pregnancy to Improve Delivery (ePPOP-ID) is an open multicenter randomized controlled trial which will assess the efficacy of an e-health web-based platform offering a personalized lifestyle program to obese pregnant women in order to reduce the rate of labor procedures and delivery interventions in comparison to standard care. A total of 860 eligible pregnant women will be recruited in 18 centers in France between 12 and 22 weeks of gestation, randomized into the intervention or the control arm and followed until 10 weeks of postpartum. The intervention is based on nutrition, eating behavior, physical activity, motivation and well-being advices in which personalization is central, as well as the use of a mobile/tablet application. Inputs includes data from the medical record of participants (medical history, anthropometric data), from the web platform (questionnaires on dietary habits, eating behavior, physical activity and motivation in both groups), and adherence to the program (time of connection for the intervention group only). Data are collected at inclusion, 32 weeks, delivery and 10 weeks postpartum. As primary outcome, we will use a composite endpoint score of obstetrical interventions during labor and delivery, defined as caesarean section and instrumental delivery (forceps and vacuum extractor). Secondary outcomes will consist of data routinely collected as part of usual antenatal and perinatal care, such as GWG, hypertension, preeclampsia, as well as fetal and neonatal outcomes including premature birth, gestational age at birth, birth weight, macrosomia, Apgar score, arterial umbilical cord pH, neonatal traumatism, hyperbilirubinemia, respiratory distress syndrome, transfer in neonatal intensive care unit, and neonatal adiposity. Post-natal outcomes will be duration of breastfeeding, maternal weight retention and child weight at postnatal visit. DISCUSSION: The findings of the ePPOP-ID trial will help design e-health intervention program for obese women in pregnancy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02924636 / October 5th 2016.

Prospective study of Hepatitis E Virus infection among pregnant women in France.

BACKGROUND: Hepatitis E Virus (HEV) infection has a poor prognosis among pregnant women from high endemic countries. HEV-prevalence and incidence among pregnant women is unknown in high-income countries such as France. This prospective study was conducted to assess HEV infection in this setting. FINDINGS: An overall HEV prevalence of 7.74% was observed among 315 pregnant women. Seroprevalence was higher in south than in north of France (29.3% vs. 3.6%, p < 0.0001), and women with detectable IgG were older. No IgG seroconversion or IgM detection were observed during pregnancy. CONCLUSIONS: Data suggest that HEV infection is a rare occurrence during pregnancy even in regions of western countries with high seroprevalence rates.

Statistical Mechanics of the Human Placenta: A Stationary State of a Near-Equilibrium System in a Linear Regime.

All near-equilibrium systems under linear regime evolve to stationary states in which there is constant entropy production rate. In an open chemical system that exchanges matter and energy with the exterior, we can identify both the energy and entropy flows associated with the exchange of matter and energy. This can be achieved by applying statistical mechanics (SM), which links the microscopic properties of a system to its bulk properties. In the case of contractile tissues such as human placenta, Huxley's equations offer a phenomenological formalism for applying SM. SM was investigated in human placental stem villi (PSV) (n = 40). PSV were stimulated by means of KCl exposure (n = 20) and tetanic electrical stimulation (n = 20). This made it possible to determine statistical entropy (S), internal energy (E), affinity (A), thermodynamic force (A / T) (T: temperature), thermodynamic flow (v) and entropy production rate (A / T x v). We found that PSV operated near equilibrium, i.e., A ≺≺ 2500 J/mol and in a stationary linear regime, i.e., (A / T) varied linearly with v. As v was dramatically low, entropy production rate which quantified irreversibility of chemical processes appeared to be the lowest ever observed in any contractile system.

Ultraslow myosin molecular motors of placental contractile stem villi in humans.

Human placental stem villi (PSV) present contractile properties. In vitro mechanics were investigated in 40 human PSV. Contraction of PSV was induced by both KCl exposure (n = 20) and electrical tetanic stimulation (n = 20). Isotonic contractions were registered at several load levels ranging from zero-load up to isometric load. The tension-velocity relationship was found to be hyperbolic. This made it possible to apply the A. Huxley formalism for determining the rate constants for myosin cross-bridge (CB) attachment and detachment, CB single force, catalytic constant, myosin content, and maximum myosin ATPase activity. These molecular characteristics of myosin CBs did not differ under either KCl exposure or tetanus. A comparative approach was established from studies previously published in the literature and driven by mean of a similar method. As compared to that described in mammalian striated muscles, we showed that in human PSV, myosin CB rate constants for attachment and detachment were about 103 times lower whereas myosin ATPase activity was 105 times lower. Up to now, CB kinetics of contractile cells arranged along the long axis of the placental sheath appeared to be the slowest ever observed in any mammalian contractile tissue.

Mechanics and energetics of myosin molecular motors from nonpregnant human myometrium.

Mechanical properties of spontaneously contracting isolated nonpregnant human myometrium (NPHM) were investigated throughout the whole continuum of load from zero load up to isometry. This made it possible to assess the three-dimensional tension-velocity-length (T-V-L) relationship characterizing the level of contractility and to determine crossbridge (CB) kinetics of myosin molecular motors. Seventy-seven muscle strips were obtained from hysterectomy in 42 nonpregnant patients. Contraction and relaxation parameters were measured during spontaneous mechanical activity. The isotonic tension-peak velocity (T-V) relationship was hyperbolic in 30 cases and nonhyperbolic in 47 cases. When the T-V relationship was hyperbolic, the Huxley formalism could be used to calculate CB kinetics and CB unitary force. At the whole muscle level and for a given isotonic load level, part of the V-L phase plane showed a common pathway, so that a given instantaneous length corresponded to only one possible instantaneous velocity, independent of time and initial length. At the molecular level, rate constants for CB attachment and detachment were dramatically low, ∼100 times lower than those of striated muscles, and ∼5 to 10 times lower than those of other smooth muscles. The CB unitary force was ∼1.4 ± 0.1 pN. NPHM shared similar basic contractile properties with striated muscles, reflected in the three-dimensional T-V-L relationship characterizing the contractile level. Low CB attachment and detachment rate constants made it possible to generate normal CB unitary force and normal muscle tension in NPHM, even though it contracted extremely slowly compared with other muscles.