Jean-Claude Forest

Breastfeeding initiation: impact of obesity in a large Canadian perinatal cohort study.

Objective To evaluate incidence of breastfeeding initiation according to maternal pre-pregnancy body mass index (BMI) in “Grossesse en Santé”, a large prospective birth cohort in Quebec City. Methods Breastfeeding initiation in the post-partum period, pre-pregnancy BMI, sociodemographic determinants and obstetrical and neonatal factors were collected from years 2005 to 2010 in 6592 women with single pregnancies. Prenatal non-intention to breastfeed was documented in a subgroup of the cohort (years 2009–2010). Log-binomial regression analyses were performed to assess relative risk (RR) of non-initiation of breastfeeding between maternal BMI categories in models including pre- and post-natal determinants, after exclusion of variables with a mediating effect. Results Twenty percent (20%) of obese women did not initiate breastfeeding in the post-natal period at hospital compared to 12% for normal weight women. Compared with those having a normal pre-pregnancy BMI, obese women had a higher risk of non-initiation of breastfeeding (RRunadj 1.69, 95% CI 1.44–1.98), even after adjustment for prenatal and sociodemographic factors (RRadj 1.26, 95% CI 1.08–1.46). Furthermore, the risk of non-initiation of breastfeeding in obese women still remained higher after introduction of per- and post-natal factors (RR 1.22, 95% CI 1.04–1.42). The prenatal non-intention to breastfeed was strongly associated with the non-initiation of breastfeeding for all categories of BMI. Conclusion Maternal obesity is associated with a two-fold rate of non-initiation of breastfeeding. Considering the benefits of breastfeeding and the increasing obesity rate, adapted interventions and specialized support should target both pre- and immediate post-natal periods in this population.

Screening for pre-eclampsia early in pregnancy: performance of a multivariable model combining clinical characteristics and biochemical markers.

To investigate the performance of a multivariable model combining a priori clinical characteristics and biomarkers to detect, early in pregnancy, women at higher risk of developing pre‐eclampsia (PE).

Association between first-trimester placental volume and birth weight

OBJECTIVEnTo estimate the correlation between first-trimester placental volume, birth weight, small-for-gestational-age (SGA), and preeclampsia.nnnMETHODSnA prospective study of women with singleton pregnancy at 11-13 weeks of gestation was conducted. First-trimester placental volume was measured using three-dimensional ultrasound and reported as multiple of median (MoM) for gestational age. Participants were followed until delivery where birth weight, placental weight, and occurrence of preeclampsia were collected. Non-parametric analyses were performed.nnnRESULTSnWe reached a complete follow-up for 543 eligible women. First-trimester placental volume was significantly correlated with birth weight (correlation coefficient: 0.18; p < 0.0001) and placental weight (cc: 0.22; p < 0.0001) adjusted for gestational age. First-trimester placental volume was smaller in women who delivered SGA neonates (median MoM: 0.79; interquartile range: 0.62-1.00; p < 0.001) and greater in women who delivered large-for-gestational-age neonates (median MoM: 1.13; 0.95-1.49; p < 0.001) when compared to women with neonates between the 10th and 90th percentile (median MoM: 1.00; 0.81-1.25). First-trimester placental volume was not associated with the risk of preeclampsia (cc: 0.01; p = 0.87).nnnCONCLUSIONnFirst-trimester placental volume is strongly associated with fetal and placental growth. However, we did not observe a correlation between placental volume and the risk of preeclampsia.

Validation of early risk-prediction models for gestational diabetes based on clinical characteristics

AIMSnGestational diabetes (GDM) is generally diagnosed late in pregnancy, precluding early preventive interventions. This study aims to validate, in a large Caucasian population of pregnant women, models based on clinical characteristics proposed in the literature to identify, early in pregnancy, those at high risk of developing GDM in order to facilitate follow up and prevention.nnnMETHODSnThis is a cohort study including 7929 pregnant women recruited prospectively at their first prenatal visit. Clinical information was obtained by a self-administered questionnaire and extraction of data from the medical records. The performance of four proposed clinical risk-prediction models was evaluated for identifying women who developed GDM and those who required insulin therapy.nnnRESULTSnThe four models yielded areas under the receiver operating characteristic curve (AUC) between 0.668 and 0.756 for the identification of women who developed GDM, a performance similar to those obtained in the original studies. The best performing model, based on ethnicity, body-mass index, family history of diabetes and past history of GDM, resulted in sensitivity, specificity and AUC of 73% (66-79), 81% (80-82) and 0.824 (0.793-0.855), respectively, for the identification of GDM cases requiring insulin therapy.nnnCONCLUSIONSnExternal validation of four risk-prediction models based exclusively on clinical characteristics yielded a performance similar to those observed in the original studies. In our cohort, the strategy seems particularly promising for the early prediction of GDM requiring insulin therapy. Addition of recently proposed biochemical markers to such models has the potential to reach a performance justifying clinical utilization.

Soluble Fms-like tyrosine kinase-1 to placental growth factor ratio in mid-pregnancy as a predictor of preterm preeclampsia in asymptomatic pregnant women.

Abstract Background: This study aims to evaluate the performance of the soluble Fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio to predict early-onset, preterm and severe preeclampsia at mid-pregnancy in asymptomatic women. Methods: Based on a prospective cohort of 7929 pregnant women from the Quebec City metropolitan area, a nested case-control study was performed including 111 women who developed preeclampsia and 69 women with gestational hypertension matched with 338 normotensive women. Serum sFlt-1 and PlGF were measured between 20 and 32 weeks of gestation. The performance of the sFlt-1/PlGF ratio, expressed as raw values and multiples of the median (MoM) for the prediction of early-onset, preterm and severe preeclampsia was evaluated. Results: Women who developed preeclampsia had significantly higher MoM sFlt-1/PlGF ratio (p<0.001). In the early-onset preeclampsia group, the median of the MoM distribution was 24.0 and the area under the receiver operating characteristic curve (AUC) was 0.977, giving sensitivities of 77.8% and 88.9% at false-positive rates of 5% and 10%. Positive predictive values (PPV) were 2.5% and 1.5%, respectively. In a subset between 26 and 32 weeks of gestation, at a threshold of 30, the sFlt-1/PlGF ratio yielded 100% specificity and identified, respectively, 85.7% and 65.2% of women who developed early-onset and preterm preeclampsia. Conclusions: The sFlt-1/PlGF ratio has the potential to predict early-onset and preterm preeclampsia at mid-pregnancy in asymptomatic women. However, care must be paid to the prevalence of early-onset preeclampsia in the population since low prevalence reduces PPV and may hamper clinical utility.

Mid-Trimester Maternal Serum AFP and hCG as Markers of Preterm and Term Adverse Pregnancy Outcomes

OBJECTIVEnTo evaluate the predictive values of mid-trimester serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) for preterm and term placenta-mediated adverse pregnancy outcomes (PMAPOs).nnnMETHODSnWe extracted data for nulliparous women with a singleton pregnancy without aneuploidy or lethal fetal anomalies from a prospective cohort study. Maternal serum AFP and hCG measured between 13 and 17 weeks of gestation and expressed as multiples of the median (MoM) for gestational age were compared between women who developed a PMAPO (preeclampsia, intrauterine growth restriction, fetal death) before term or at term and women who did not develop any of these complications.nnnRESULTSnAmong 3466 nulliparous women, maternal serum AFP and hCG levels were available in 2110 and 2125 cases, respectively. Women who developed a PMAPO before term had a higher median level of serum AFP (1.4 vs. 1.1 MoM; P < 0.01) and hCG (1.3 vs. 1.1 MoM; P < 0.01) than controls. A serum hCG > 2.0 MoM was associated with a higher risk of PMAPO before term (RR 4.6; CI 95% 2.3 to 9.1) but had no impact on the risk of PMAPO at term (RR 1.1; CI 95% 0.7 to 1.7). Maternal serum AFP > 2.0 MoM was also associated with a significant increase in the risk of preterm PMAPO (RR 3.9; CI 95% 1.6 to 9.8) but not term PMAPO (RR 1.2; CI 95% 0.6 to 2.3).nnnCONCLUSIONnMaternal serum AFP or hCG > 2.0 MoM increases the risk of preterm PMAPO but not term PMAPO in our population. We suggest that women with elevated serum AFP or hCG should receive standard pregnancy care once they have reached 37 weeks of gestation if fetal growth is in the normal range.

Osteocalcin is Higher Across Pregnancy in Caucasian Women with Gestational Diabetes Mellitus

OBJECTIVEnThe purpose of this study was to investigate circulating concentrations of osteocalcin, a bone-derived protein, while accounting for 25-hydroxyvitamin D (25(OH)D) throughout pregnancy, and whether early gestation concentrations and changes in osteocalcin predict the subsequent diagnosis of gestational diabetes mellitus (GDM).nnnMETHODSnThis was a nested case-control study involving 48 GDM and 48 control pregnant Caucasian women (matched for age, season of conception, pre-pregnancy body mass index and pregnancy length). Maternal serum osteocalcin was measured by enzyme-linked immunosorbent assay and 25(OH)D by chemiluminescence throughout pregnancy (11-13 weeks, 24-28 weeks and predelivery). Differences between groups were compared by mixed model analysis of variance. Predictors of diagnosis of GDM were explored using generalized estimating equation models. Neonatal general health outcomes were also compared between groups.nnnRESULTSnSerum osteocalcin was higher across pregnancy (p=0.006) in women with GDM vs. controls, whereas serum 25(OH)D was not different (p=0.80). Both biomarkers increased with time across pregnancy (p<0.0001). However, serum osteocalcin during early pregnancy and changes in its concentration from early to mid gestation did not predict the development of GDM. There were no significant differences in anthropometry and APGAR (appearance, pulse, grimace, activity, respiration) scores in neonates of controls and cases.nnnCONCLUSIONSnSerum osteocalcin is elevated in Caucasian women with GDM throughout pregnancy, but was not predictive of the onset of GDM. Larger trials evaluating the role of osteocalcin and the development of GDM appear warranted.