We sought to investigate whether early mid pregnancy visceral and subcutaneous fat depths measured by ultrasound were associated with infant birth size, independent of early pregnancy BMI. A cohort study was performed at Uppsala University Hospital, Sweden, between 2015–2018. Visceral and subcutaneous fat depths were measured at the early second-trimester anomaly scan in 2498 women, giving birth to singleton, term infants. Primary outcomes were birthweight and LGA (birthweight standard deviation score > 90th percentile in the cohort). Linear and logistic regression models were used, adjusted for BMI, age, smoking, parity, maternal country of birth, gestational age and infant sex. A 5-mm increase in visceral fat depth was associated with an increase in birthweight of 8.3 g [95% confidence interval (CI) 2.5 − 14.1 g], after adjustments, and a 6% increase in the adjusted odds of having an infant born LGA (OR 1.06, CI 1.02–1.11). There was no association between subcutaneous fat depth and birthweight or LGA after covariate adjustments. Hence, visceral fat depth measured by ultrasound in early mid pregnancy was associated with excessive fetal growth, independent of early pregnancy BMI, and may be useful in models for predicting LGA infants.

Overweight and obesity during pregnancy are risk factors for a large number of perinatal complications, both for the mother and the infant. Risk stratification and early interventions are therefore highly clinically important to minimize future complications. Currently, body mass index (BMI) in early pregnancy is used for risk stratification of pregnant women, but a disadvantage of BMI is that it does not distinguish muscle from fat tissue and central from peripheral adiposity. Maternal fat distribution is suggested to be a better predictor than BMI of obesity-related adverse pregnancy outcomes, with central adiposity posing a greater risk than peripheral subcutaneous fat. With this study, we aimed to systematically review the evidence of what impact maternal central adiposity in early to mid-pregnancy or at most 365 days prior to conception has on infant anthropometry and perinatal morbidity. The databases PubMed/MEDLINE, Web of Science Core Collection, CINAHL, SCOPUS, Clinical Trials, and Open Grey were searched from inception until November 2019. Eligible studies assessed the association between maternal central adiposity, in early to mid-pregnancy or at most 365 days prior to conception, and any of the following infant outcomes: preterm delivery (< 37 weeks of gestation), birthweight, macrosomia, large for gestational age, congenital malformations, hypoglycemia, hyperbilirubinemia, care at neonatal intensive care unit, and death. Two authors independently screened titles and abstracts, read the included full-text studies, and extracted data. The Newcastle-Ottawa Quality Assessment Scale for cohort studies was used to evaluate the quality of and risk of bias in the studies. A total of 720 records were identified, 20 full-text studies assessed for eligibility, and 10 cohort studies included in the review. The results suggest that central adiposity in early to mid-pregnancy or at most 365 days prior to conception may contribute to increased birthweight and increased likelihood of delivery by cesarean section. There is also some evidence of associations between central adiposity and preterm delivery (< 37 weeks of gestation), and admission to neonatal intensive care unit. A meta-analysis was not possible to perform due to substantial heterogeneity among the included studies regarding the exposure, outcome, and statistical methods used. Hence, central adiposity in early to mid-pregnancy or at most 365 days prior to conception could be a possible risk marker in addition to BMI for risk stratification of pregnant women. However, since the topic is only scarcely researched, and the results not unanimous, more studies are needed to further clarify the associations between maternal central adiposity and adverse neonatal complications, before any altered recommendations of guidelines could be made. To enable a future meta-analysis, studies using similar methods for central adiposity assessment,and similar outcome measures, are required.

This study aimed to investigate how maternal birthweight is related to early pregnancy obesity, gestational diabetes mellitus (GDM), and offspring birthweight. Females born term and singleton in Sweden between 1973 and 1995 (N = 305,893) were studied at their first pregnancy. Information regarding their birthweight, early pregnancy body mass index, and pregnancy complications was retrieved from the Swedish Medical Birth Register, as were data on their mothers and offspring. High maternal birthweights (2–3 standard deviation scores (SDS) and >3 SDS) were associated with greater odds of early pregnancy obesity, odds ratio (OR) 1.52 (95% confidence interval (CI) 1.42–1.63) and OR 2.06 (CI 1.71–2.49), respectively. A low maternal birthweight (<2 SDS) was associated with greater odds of GDM (OR 2.49, CI 2.00–3.12). No association was found between high maternal birthweight and GDM. A maternal birthweight 2–3 SDS was associated with offspring birthweight 2–3 SDS (OR 3.83, CI 3.44–4.26), and >3 SDS (OR 3.55, CI 2.54–4.97). Corresponding ORs for a maternal birthweight >3 SDS were 5.38 (CI 4.12–7.01) and 6.98 (CI 3.57–13.65), respectively. In conclusion, a high maternal birthweight was positively associated with early pregnancy obesity and offspring macrosomia. A low, but not a high maternal birthweight, was associated with GDM.

The objective of this study was to evaluate the associations of 92 maternal blood-based proteins with increased infant birth size. The study was performed at the Uppsala University Hospital, Sweden, and included 857 mother and child dyads. The mean age of the women was 30.3 years, and 53.2% were nulliparous. Blood samples were collected at mean 18 + 2 weeks’ gestation, and the Olink cardiovascular II panel was used to measure 92 proteins, either known to be or suspected to be markers of cardiovascular and inflammatory disease in humans. Multiple linear regression models adjusted for maternal age, parity, pre-conception BMI, height, and smoking were performed to evaluate the association of each individual protein with infant birth size. We also performed sex-stratified analyses. Eight proteins (Matrix metalloproteinase-12 (MMP-12), Prostasin (PRSS8), Adrenomedullin (ADM), Pappalysin-1 (PAPP-A), Angiotensin-converting enzyme 2 (ACE2), Sortilin (SORT1), Lectin-like oxidized LDL receptor 1 (LOX-1), and Thrombomodulin (TM)) were associated with infant birth size after false discovery rate adjustment. In the analyses including only female infants, ten proteins (MMP-12, Growth/differentiation factor 2 (GDF-2), PRSS8, SORT1, ADM, Interleukin-1 receptor antagonist protein (IL-1ra), Leptin (LEP), ACE2, TM, and Tumor necrosis factor receptor superfamily member 11A (TNFRSF11A)) were associated with infant birth size. Two proteins (PAPP-A and PRSS8) were associated with infant birth size among male infants. Our study suggests several proteins as potential biomarkers for increased birth weight, and our findings could act as a base for future research to identify new potential markers that could be added to improve screening for large infants.

This study investigated whether maternal central adiposity and body mass index (BMI) were associated with neonatal hypoglycemia and adverse neonatal outcomes. A cohort study was performed at Uppsala University Hospital, Sweden, between 2015 and 2018. Visceral and subcutaneous fat depths were measured by ultrasound at the early second-trimester anomaly scan in 2771 women giving birth to singleton infants. Body mass index was assessed in early pregnancy. Logistic regression models were performed. Adjustments were made for age, BMI (not in model with BMI as exposure), smoking, maternal country of birth, and parity. Outcomes were neonatal hypoglycemia (blood glucose concentration < 2.6 mmol/l), a composite of adverse neonatal outcomes (Apgar < 7 at 5 min of age, or umbilical artery pH ≤ 7.0, or admission to neonatal intensive care unit), and the components of the composite outcome. Visceral and subcutaneous fat depths measured by ultrasound in early mid pregnancy were not associated with any of the outcomes in adjusted analyses. For every unit increase in BMI, the likelihood of neonatal hypoglycemia increased by 5% (aOR 1.05, 95% CI 1.01–1.10), the composite outcome by 5% (aOR 1.05, 95% CI 1.01–1.08), and admission to neonatal intensive care unit by 6% (aOR 1.06, 95% CI 1.02–1.10).