Pre-eclampsia, small-for-gestational-age infants, preterm birth and recurrent miscarriage complicate a significant number of pregnancies. The vascular endothelial growth factor (VEGF) family of angiogenic growth factors is implicated in the pathophysiology of these complications. We aimed to elucidate the role of these angiogenic factors in placentation and to evaluate the predictive value of their protein concentrations and genetic variations in pregnancy complications. We performed a systematic search of PubMed, and retrieved original articles. The search included a combination of terms such as VEGF-A, placental growth factor (PlGF), kinase insert domain receptor, fms-like-tyrosine-kinase receptor 1, soluble fms-like-tyrosine-kinase receptor 1, pre-eclampsia, small-for-gestational-age infants, preterm birth, recurrent miscarriage, placenta, prediction and polymorphisms. This review summarizes the current knowledge of the roles of the VEGF family in early placentation and of the abnormalities in maternal plasma and placental expression of angiogenic proteins in adverse pregnancy outcomes compared with normal pregnancy. PlGF and sFLT-1 in combination with other clinical and biochemical markers in late first or second trimester appear to predict early-onset pre-eclampsia with a high sensitivity and specificity. However, VEGF family proteins do not have sufficient power to accurately predict late-onset pre-eclampsia, small-for-gestational age pregnancies or preterm birth. Functional polymorphisms in these angiogenic genes are implicated in pregnancy complications, but their contribution appears to be minor. Although the VEGF family has important roles in normal and complicated pregnancy, the current predictive value of the VEGF family as biomarkers appears to be limited to early-onset pre-eclampsia.

Preeclampsia is a common pregnancy complication, affecting 2% to 8% of pregnancies worldwide, and is an important cause of both maternal and fetal morbidity and mortality. Importantly, although aspirin and calcium are able to prevent preeclampsia in some women, there is no cure apart from delivery of the placenta and fetus, often necessitating iatrogenic preterm birth. Preclinical models of preeclampsia are widely used to investigate the causes and consequences of preeclampsia and to evaluate safety and efficacy of potential preventative and therapeutic interventions. In this review, we provide a summary of the published preclinical models of preeclampsia that meet human diagnostic criteria, including the development of maternal hypertension, together with new-onset proteinuria, maternal organ dysfunction, and uteroplacental dysfunction. We then discuss evidence from preclinical models for multiple causal factors of preeclampsia, including those implicated in early-onset and late-onset preeclampsia. Next, we discuss the impact of exposure to a preeclampsia-like environment for later maternal and progeny health. The presence of long-term impairment, particularly cardiovascular outcomes, in mothers and progeny after an experimentally induced preeclampsia-like pregnancy, implies that later onset or reduced severity of preeclampsia will improve later maternal and progeny health. Finally, we summarize published intervention studies in preclinical models and identify gaps in knowledge that we consider should be targets for future research.

Single nucleotide polymorphisms and pre‐ and peri‐conception folic acid (FA) supplementation and dietary data were used to identify one‐carbon metabolic factors associated with pregnancy outcomes in 3196 nulliparous women. In 325 participants, we also measured circulating folate, vitamin B12 and homocysteine. Pregnancy outcomes included preeclampsia (PE), gestational hypertension (GHT), small for gestational age (SGA), spontaneous preterm birth (sPTB) and gestational diabetes mellitus (GDM). Study findings show that maternal genotype MTHFR A1298C(CC) was associated with increased risk for PE, whereas TCN2 C766G(GG) had a reduced risk for sPTB. Paternal MTHFR A1298C(CC) and MTHFD1 G1958A(AA) genotypes were associated with reduced risk for sPTB, whereas MTHFR C677T(CT) genotype had an increased risk for GHT. FA supplementation was associated with higher serum folate and vitamin B12 concentrations, reduced uterine artery resistance index and increased birth weight. Women who supplemented with <800 μg daily FA at 15‐week gestation had a higher incidence of PE (10.3%) compared with women who did not supplement (6.1%) or who supplemented with ≥800 μg (5.4%) (P < .0001). Higher serum folate levels were found in women who later developed GDM compared with women with uncomplicated pregnancies (Mean ± SD: 37.6 ± 8 nmol L⁻¹ vs. 31.9 ± 11.2, P = .007). Fast food consumption was associated with increased risk for developing GDM, whereas low consumption of green leafy vegetables and fruit were independent risk factors for SGA and GDM and sPTB and SGA, respectively. In conclusion, maternal and paternal genotypes, together with maternal circulating folate and homocysteine concentrations, and pre‐ and early‐pregnancy dietary factors, are independent risk factors for pregnancy complications.

Gestational diabetes mellitus (GDM) is a pregnancy complication that affects one in seven pregnancies. Emerging evidence demonstrates that children born of pregnancies complicated by GDM may be at increased risk of cardiovascular disease (CVD) in adulthood. Therefore, the aim of this study was to determine cardiovascular risk factors in offspring exposed to GDM in utero. PubMed, CINAHL, SCOPUS, and EMBASE databases were searched. Information was extracted on established CVD risk factors including blood pressure, lipids, blood glucose, fasting insulin, body mass index (BMI), and endothelial/microvascular function. The review protocol is registered in PROSPERO (CRD42018094983). Prospective and retrospective studies comparing offspring exposed to GDM compared to controls (non-GDM pregnancies) were considered. We included studies that defined GDM based on the International Association of Diabetes and Pregnancy Study Groups (IADPSG) definition, or prior definitions. The PRISMA guidelines were followed in conducting this systematic review. Methodological quality was assessed using the Newcastle–Ottawa Quality Assessment Scale. Study selection, data extraction, and quality assessment were done by two independent reviewers. The data were pooled using a random-effects model. Of 59 eligible studies, 24 were included in the meta-analysis. Offspring exposed to GDM had higher systolic blood pressure (mean difference (MD): 1.75 mmHg, 95% CI 0.57–2.94; eight studies, 7264 participants), BMI z-score (MD 0.11, 95% CI 0.02–0.20; nine studies, 8759 participants), and glucose (standard MD 0.43, 95% CI 0.08–0.77; 11 studies, 6423 participants) than control participants. In conclusion, offspring exposed to GDM have elevated systolic blood pressure, BMI, and glucose. Those exposed to GDM in utero may benefit from early childhood blood pressure measurements.