Maternal metabolic profiling across body mass index groups: An exploratory longitudinal study

INTRODUCTION

Increased BMI has been identified as a risk factor for most pregnancy complications, but the underlying metabolic factors mediating the detrimental effects of BMI are largely unknown. We aimed to compare metabolic profiles in overweight/obese women (body mass index [BMI] ≥ 25 kg/m2 ) and normal weight/underweight women (BMI < 25 kg/m2 ) across gestation. We also explored how gestational weight gain (GWG) affected maternal metabolic profiles.

MATERIAL AND METHODS

Exploratory nested case-control study based on a prospective longitudinal cohort of women who were healthy prior to pregnancy and gave birth at Oslo University Hospital from 2002 to 2008. The sample consisted of 48 women who were overweight/obese and 59 normal-weight/underweight women. Plasma samples from four time points in pregnancy (weeks 14-16, 22-24, 30-32 and 36-38) were analyzed by nuclear magnetic resonance spectroscopy and 91 metabolites were measured. Linear regression models were fitted for each of the metabolites at each time point.

RESULTS

Overweight or obese women had higher levels of lipids in very-low-density lipoprotein (VLDL), total triglycerides, triglycerides in VLDL, total fatty acids, monounsaturated fatty acids, saturated fatty acids, leucine, valine, and total branched-chain amino acids in pregnancy weeks 14-16 compared to underweight and normal-weight women. Docosahexaenoic acid and degree of unsaturation were significantly lower in overweight/obese women in pregnancy weeks 36-38. In addition, overweight or obese women had higher particle concentration of XXL-VLDL and glycoprotein acetyls (GlycA) at weeks 14-16 and 30-32. GWG did not seem to affect the metabolic profile, regardless of BMI group when BMI was treated as a dichotomous variable, ≥25 kg/m2 (yes/no).

CONCLUSIONS

Overweight or obese women had smaller pregnancy-related metabolic alterations than normal-weight/underweight women. There was a trend toward higher triglyceride and VLDL particle concentration in overweight/obese women. As this was a hypothesis-generating study, the similarities with late-onset pre-eclampsia warrant further investigation. The unfavorable development of fatty acid composition in overweight/obese women, with possible implication for the offspring, should also be studied further in the future.

Reliability and agreement in intrapartum fetal heart rate monitoring interpretation: A systematic review

INTRODUCTION

Fetal heart rate (FHR) monitoring is routine in intrapartum care worldwide and one of the most common obstetrical procedures. Intrapartum FHR monitoring helps assess fetal wellbeing and interpretation of the FHR help form decisions for clinical management and intervention. It relies on the observers' subjective assessments, with variation in interpretations leading to variations in intrapartum care. The purpose of this systematic review was to summarize and evaluate extant inter- and intrarater reliability research on the human interpretation of intrapartum FHR monitoring.

MATERIAL AND METHODS

We searched for the terms "fetal heart rate monitoring," "interpretation agreement" and related concepts on Embase, Medline, Maternity and Infant Care Database and CINAHL. The last search was made on January 31, 2022. The protocol for the study was prospectively registered in PROSPERO (CRD42021260937). Studies that assess inter- and intrarater reliability and agreement of health professionals' intrapartum FHR monitoring were included and studies including other assessment of fetal wellbeing excluded. We extracted data in reviewer pairs using quality appraisal tool for studies of diagnostic reliability (QAREL) forms. The data retrieved from the studies are presented as narrative synthesis and in additional tables.

RESULTS

Forty-nine articles concerning continuous FHR monitoring were included in the study. For interrater reliability and agreement, in total 577 raters assessed 6315 CTG tracings. There was considerable heterogeneity in quality and measures across the included articles. We found higher reliability and agreement for the basic FHR features than for overall classification and higher agreement for intrarater reliability and agreement than for their interrater counterparts.

CONCLUSIONS

There is great variation in reliability and agreement measures for continuous intrapartum FHR monitoring, implying that intrapartum CTG should be used with caution for clinical decision making given its questionable reliability. We found few high-quality studies and noted methodological concerns in the studies. We recommend a more standardized approach to future reliability studies on FHR monitoring.