"Hypertension in Pregnancy Intervention Trial At Term" and "Disproportionate Intrauterine Growth Intervention Trial At Term" Studies.

In 2003, in the context of a national research funding program in which obstetric research was prioritized, several perinatal centers took the initiative to jointly submit a number of applications to the subsidy programs of Effectiveness Research and Prevention of ZonMw. This has led to the funding of the Obstetric Consortium with several projects, including the "Hypertension in Pregnancy Intervention Trial At Term" and the "Disproportionate Intrauterine Growth Intervention Trial At Term" studies. The studies showed that induction of labor for hypertension and growth restriction at term was the appropriate management. Subsequent implementation improved maternal and perinatal outcomes.

Transmission and dynamics of mother-infant gut viruses during pregnancy and early life.

Early development of the gut ecosystem is crucial for lifelong health. While infant gut bacterial communities have been studied extensively, the infant gut virome remains under-explored. To study the development of the infant gut virome over time and the factors that shape it, we longitudinally assess the composition of gut viruses and their bacterial hosts in 30 women during and after pregnancy and in their 32 infants during their first year of life. Using shotgun metagenomic sequencing applied to dsDNA extracted from Virus-Like Particles (VLPs) and bacteria, we generate 205 VLP metaviromes and 322 total metagenomes. With this data, we show that while the maternal gut virome composition remains stable during late pregnancy and after birth, the infant gut virome is dynamic in the first year of life. Notably, infant gut viromes contain a higher abundance of active temperate phages compared to maternal gut viromes, which decreases over the first year of life. Moreover, we show that the feeding mode and place of delivery influence the gut virome composition of infants. Lastly, we provide evidence of co-transmission of viral and bacterial strains from mothers to infants, demonstrating that infants acquire some of their virome from their mother's gut.

Medical findings and congenital anomalies in Vermeer's paintings.

The 17th century was a time of scientific discovery in Europe. Leading academic centers provided the general population with an opportunity to view anatomic dissections of human bodies. Rather than portray idealized versions of individuals, Dutch painters were committed to accurately representing their models. This was true for Johannes Vermeer. The 2023 exhibition of Vermeer's paintings at the Rijksmuseum in Amsterdam provided an unprecedented opportunity to observe 28 of his 37 existing paintings simultaneously in person. Here the authors suggest that in at least eight paintings a visibly pregnant woman is present. Vermeer's wife was pregnant or lactating most of the time during their 22-year marriage. Further, evidence of specific medical findings and congenital anomalies such as polydactyly, ectrodactyly, alopecia, kyphosis, and hyperthyroidism were observed in the paintings. These have not been previously reported in the medical or art history literature.

Cost-effectiveness analysis of a first-trimester screening test for preterm preeclampsia in the Netherlands.

OBJECTIVES: The risk of preterm preeclampsia (PT PE) can significantly be reduced by starting acetylsalicylic acid ≤ 16 weeks of gestational age. First trimester predictive models based on maternal risk factors to effectively start this therapy lacked sufficient power, but recent studies showed that these models can be improved by including test results of biochemical and/or -physical markers. To investigate whether testing a biochemical marker in the first trimester is cost-effective in the Netherlands, a cost-effectiveness analysis was performed in this study. STUDY DESIGN: The outcome of this study was expressed as an incremental cost-effectiveness ratio (ICER) with as effect prevented PT PE cases. To evaluate the impact of each model parameter and to determine model uncertainties, both univariate and probabilistic sensitivity analyses were performed. RESULTS: When compared to the baseline strategy, the test strategy is estimated to save almost 4 million euros per year on a national scale and at the same time this would prevent an additional 228 PT PE cases. The sensitivity analyses showed that the major drivers of the result are the costs to monitor a high-risk pregnancy and the specificity and that most of the model simulations were in the southeast quadrant: cost saving and more prevented complications. CONCLUSIONS: This study showed that a first-trimester test strategy to screen for PT PE in the first trimester is potentially cost-effective in the Dutch healthcare setting. The fact that the specificity is a major driver of the ICER indicates the importance for a (new) screening model to correctly classify low-risk pregnancies.

Early pregnancy biomarker discovery study for spontaneous preterm birth.

(1) OBJECTIVE: discover new candidate biomarkers for spontaneous preterm birth in early pregnancy samples. When fully clinically validated, early pregnancy biomarkers for sPTB give the possibility to intervene or monitor high-risk pregnancies more intensively through, as example, pelvic exams, ultrasound or sonographic cervical length surveillance. (2) STUDY DESIGN: Early pregnancy serum samples of eight spontaneous extreme and very preterm birth cases (<32 weeks of gestational age) without any symptoms of preeclampsia and fetal growth restriction and eight uncomplicated pregnancies were analyzed by liquid chromatography mass spectrometry (LC-MS). Thirteen proteins, which were differentially expressed according to the LC-MS data, were subsequently selected for confirmation by enzyme-linked immunosorbent assay (ELISA). (3) RESULTS: Differential expression of four candidate biomarkers was confirmed by ELISA with decreased early pregnancy levels of gelsolin and fibulin-1 and increased levels of c-reactive protein and complement C5 in the preterm birth group. (4) CONCLUSIONS: The confirmed candidate biomarkers are all to some extent related to inflammatory pathways and/or the complement system. This supports the hypothesis that both play a role in extreme and very preterm birth without any symptoms of preeclampsia and fetal growth restriction. The predictive value of complement C5, c-reactive protein, fibulin-1 and gelsolin should, therefore, be validated in another cohort with early pregnancy samples.

Preeclampsia-induced alterations in brain and liver gene expression and DNA methylation patterns in fetal mice.

Exposure to pregnancy complications, including preeclampsia (PE), has lifelong influences on offspring's health. We have previously reported that experimental PE, induced in mice by administration of adenoviral sFlt1 at gestational day 8.5 combined with LPS at day 10.5, results in symmetrical growth restriction in female and asymmetrical growth restriction in male offspring. Here, we characterize the molecular phenotype of the fetal brain and liver with respect to gene transcription and DNA methylation at the end of gestation.In fetal brain and liver, expression and DNA methylation of several key regulatory genes is altered by PE exposure, mostly independent of fetal sex. These alterations point toward a decreased gluconeogenesis in the liver and stimulated neurogenesis in the brain, potentially affecting long-term brain and liver function. The observed sex-specific growth restriction pattern is not reflected in the molecular data, showing that PE, rather than tissue growth, drives the molecular phenotype of PE-exposed offspring.

Distribution of decidual mast cells in fetal growth restriction and stillbirth at (near) term.

INTRODUCTION: Placental pathology and pregnancy complications are associated with unfavorable regulation of the maternal immune system. Although much research has been performed towards the role of immune cells like macrophages and T cells in this context, little is known about the presence and function of mast cells (MC). MC can be sub classified in tryptase-positive (MCT) and tryptase- and chymase-positive (MCTC). This study investigates the presence of MC in the decidua of pregnancies complicated by fetal growth restriction (FGR) and stillbirth (SB). METHODS: Placental tissue from FGR (n = 250), SB (n = 64) and healthy pregnancies (n = 42) was included. Histopathological lesions were classified according to the Amsterdam Placental Workshop Group criteria. Tissue sections were stained for tryptase and chymase. Decidual MC were counted manually, and the results were expressed as number of cells/mm2 decidual tissue. RESULTS: A significant lower median number of MCTC was found in the decidua of FGR (0.40 per mm2; p < 0.001) and SB (0.51 per mm2; p < 0.05) compared to healthy controls (1.04 per mm2). No difference in MCT number (1.19 per mm2, 1.88 per mm2 and 1.37 per mm2 respectively) was seen between the groups. There was no difference in number of MCT and MCTC between placental pathological lesions. DISCUSSION: Our findings suggest a shift in decidual MC balance towards MCT in pregnancy complications. No difference in numbers of MC subtypes was found to be related to histopathologic lesions.

First trimester serum biomarker discovery study for early onset, preterm onset and preeclampsia at term.

INTRODUCTION: Preeclampsia (PE) is a heterogeneous syndrome during pregnancy and postpartum and it is subdivided in this study into early onset (<34 weeks), preterm onset (34-37 weeks) and PE at term (>37 weeks). First trimester models currently lack a sufficient power to predict PE, but inclusion of biochemical markers shows an improvement of their predictive power. The aim of this study was to perform a biomarker discovery study in order to find possible novel first trimester biomarkers for each PE subtype. Further, our findings were related to available literature and the possible role of the proteins in the development of preeclampsia was discussed. METHODS: In this study, 9 early onset (<34 weeks), 8 preterm onset (34-37 weeks), 6 PE at term (>37 weeks) and 23 control samples were drawn between 11 and 14 weeks gestational age. Serum samples were prepared for liquid chromatography mass spectrometry analysis and protein data were exported for statistical analyses. All differentially expressed proteins were further evaluated by searching literature in MEDLINE, Embase and Web of science and differential expression of two proteins, which were not yet associated with PE, was verified through enzyme-linked immunosorbent assay (ELISA). RESULTS: After statistical analysis, six, four and eight proteins were differently expressed in early onset, preterm onset and PE at term, respectively. After exclusion of antibody fragments, only nine proteins remained. Seven out of these nine proteins were already in literature associated with preeclampsia and only three of them were described as differentially expressed in the first trimester or early second trimester of preeclamptic pregnancies. Differential expression of Apolipoprotein D (ApoD), which was not yet associated with PE, was confirmed by ELISA in both early and preterm onset PE in the first trimester. DISCUSSION: In this study, two main observations were made. First, some of the differentially expressed proteins have a role in the same biological pathway, such as the acute phase response or endometrium receptivity, and their differential expression was observed in all three PE subtypes. This observation supports the hypothesis that classification of PE could be more accurate when subtyping is based on the etiology and/or phenotype instead of the arbitrary parameter gestational age at onset or delivery. Second, seven differential expressed proteins were already associated in literature with preeclampsia, but this association was for only three of them observed in the first trimester. In addition, ApoD was not yet associated with PE in other studies and, moreover, its differential expression was confirmed by ELISA. Therefore the predictive power of these proteins in the first trimester is worth evaluating in a larger and more heterogeneous cohort.

Differential Placental DNA Methylation of NR3C1 in Extremely Preterm Infants With Poorer Neurological Functioning.

Background: Understanding underlying mechanisms of neurodevelopmental impairment following preterm birth may enhance opportunities for targeted interventions. We aimed to assess whether placental DNA methylation of selected genes affected early neurological functioning in preterm infants. Methods: We included 43 infants, with gestational age <30 weeks and/or birth weight <1,000 g and placental samples at birth. We selected genes based on their associations with several prenatal conditions that may be related to poor neurodevelopmental outcomes. We determined DNA methylation using pyrosequencing, and neurological functioning at 3 months post-term using Prechtl's General Movement Assessment, including the Motor Optimality Score-Revised (MOS-R). Results: Twenty-four infants had atypical MOS-R, 19 infants had near-optimal MOS-R. We identified differences in average methylation of NR3C1 (encoding for the glucocorticoid receptor) [3.3% (95%-CI: 2.4%-3.9%) for near-optimal vs. 2.3% (95%-CI: 1.7%-3.0%), p = 0.008 for atypical], and at three of the five individual CpG-sites. For EPO, SLC6A3, TLR4, VEGFA, LEP and HSD11B2 we found no differences between the groups. Conclusion: Hypomethylation of NR3C1 in placental tissue is associated with poorer neurological functioning at 3 months post-term in extremely preterm infants. Alleviating stress during pregnancy and its impact on preterm infants and their neurodevelopmental outcomes should be further investigated.

Altered neurodevelopmental DNA methylation status after fetal growth restriction with brain-sparing.

It is under debate how preferential perfusion of the brain (brain-sparing) in fetal growth restriction (FGR) relates to long-term neurodevelopmental outcome. Epigenetic modification of neurotrophic genes by altered fetal oxygenation may be involved. To explore this theory, we performed a follow-up study of 21 FGR children, in whom we prospectively measured the prenatal cerebroplacental ratio (CPR) with Doppler sonography. At 4 years of age, we tested their neurodevelopmental outcome using the Wechsler Preschool and Primary Scale of Intelligence, the Child Behavior Checklist, and the Behavior Rating Inventory of Executive Function. In addition, we collected their buccal DNA to determine the methylation status at predefined genetic regions within the genes hypoxia-inducible factor-1 alpha (HIF1A), vascular endothelial growth factor A (VEGFA), erythropoietin (EPO), EPO-receptor (EPOR), brain-derived neurotrophic factor (BDNF), and neurotrophic tyrosine kinase, receptor, type 2 (NTRK2) by pyrosequencing. We found that FGR children with fetal brain-sparing (CPR <1, n = 8) demonstrated a trend (0.05 < p < 0.1) toward hypermethylation of HIF1A and VEGFA at their hypoxia-response element (HRE) compared with FGR children without fetal brain-sparing. Moreover, in cases with fetal brain-sparing, we observed statistically significant hypermethylation at a binding site for cyclic adenosine monophophate response element binding protein (CREB) of BDNF promoter exon 4 and hypomethylation at an HRE located within the NTRK2 promoter (both p <0.05). Hypermethylation of VEGFA was associated with a poorer Performance Intelligence Quotient, while hypermethylation of BDNF was associated with better inhibitory self-control (both p <0.05). These results led us to formulate the hypothesis that early oxygen-dependent epigenetic alterations due to hemodynamic alterations in FGR may be associated with altered neurodevelopmental outcome in later life. We recommend further studies to test this hypothesis.

Healthy and preeclamptic pregnancies show differences in Guanylate-Binding Protein-1 plasma levels.

The large interferon-inducible anti-angiogenic pro-inflammatory GTPase Guanylate Binding Protein-1 (GBP-1) is produced and secreted by activated endothelial cells and is highly induced by inflammatory cytokines and inhibited by angiogenic growth factors. During pregnancy a generalized mild inflammatory response is observed. During preeclampsia this generalized inflammatory response is even further activated and activation of the endothelium occurs. We hypothesized that GBP-1 is increased in healthy pregnancy and will be even further increased during preeclampsia. In the first experiment, plasma and placentas were collected from healthy and preeclamptic pregnancies. Plasma was also collected from non-pregnant women. For the second experiment longitudinal blood samples from women with a healthy or preeclamptic pregnancy were collected from the end of the first trimester until birth and one sample postpartum. The plasma GBP-1 levels were measured by ELISA and GBP-1 mRNA and protein levels in the placenta were tested by qPCR and immunohistochemistry. During pregnancy higher plasma concentrations of GBP-1 compared with non-pregnant women were observed. Surprisingly, during preeclampsia, plasma GBP-1 levels were lower than in control pregnancies and similar to the level of non-pregnant controls. Placental GBP-1 mRNA levels were not different between healthy and preeclamptic pregnancies and GBP-1 protein was virtually undetectable in the trophoblast by immunohistochemistry in placental tissue. Evaluation of longitudinal samples showed that plasma GBP-1 concentrations increased towards the end of pregnancy in healthy pregnancies, but not in preeclampsia. In line with our hypothesis, we found higher GBP-1 plasma levels during healthy pregnancy. However, plasma GBP-1 did not further increase during preeclampsia, but was stable. Further studies are needed to evaluate why GBP-1 does not increase during preeclampsia.

Pregnancy Outcomes and Maternal Insulin Sensitivity: Design and Rationale of a Multi-Center Longitudinal Study in Mother and Offspring (PROMIS).

The worldwide prevalence of overweight and obesity in women of reproductive age is rapidly increasing and a risk factor for the development of gestational diabetes (GDM). Excess adipose tissue reduces insulin sensitivity and may underlie adverse outcomes in both mother and child. The present paper describes the rationale and design of the PRegnancy Outcomes and Maternal Insulin Sensitivity (PROMIS) study, an exploratory cohort study to obtain detailed insights in insulin sensitivity and glucose metabolism during pregnancy and its relation to pregnancy outcomes including early infancy growth. We aim to recruit healthy pregnant women with a body mass index (BMI) ≥ 25 kg/m2 before 12 weeks of gestation in Northern Netherlands. A total of 130 woman will be checked on fasted (≤7.0 mmol/L) or random (≤11.0 mmol/L) blood glucose to exclude pregestational diabetes at inclusion. Subjects will be followed up to six months after giving birth, with a total of nine contact moments for data collection. Maternal data include postprandial measures following an oral meal tolerance test (MTT), conducted before 16 weeks and repeated around 24 weeks of gestation, followed by a standard oral glucose tolerance test before 28 weeks of gestation. The MTT is again performed around three months postpartum. Blood analysis is done for baseline and postprandial glucose and insulin, baseline lipid profile and several biomarkers of placental function. In addition, specific body circumferences, skinfold measures, and questionnaires about food intake, eating behavior, physical activity, meal test preference, mental health, and pregnancy complications will be obtained. Fetal data include assessment of growth, examined by sonography at week 28 and 32 of gestation. Neonatal and infant data consist of specific body circumferences, skinfolds, and body composition measurements, as well as questionnaires about eating behavior and complications up to 6 months after birth. The design of the PROMIS study will allow for detailed insights in the metabolic changes in the mother and their possible association with fetal and postnatal infant growth and body composition. We anticipate that the data from this cohort women with an elevated risk for the development of GDM may provide new insights to detect metabolic deviations already in early pregnancy. These data could inspire the development of new interventions that may improve the management of maternal, as well as offsrping complications from already early on in pregnancy with the aim to prevent adverse outcomes for mother and child.

Lifelines COVID-19 cohort: investigating COVID-19 infection and its health and societal impacts in a Dutch population-based cohort.

PURPOSE: The Lifelines COVID-19 cohort was set up to assess the psychological and societal impacts of the COVID-19 pandemic and investigate potential risk factors for COVID-19 within the Lifelines prospective population cohort. PARTICIPANTS: Participants were recruited from the 140 000 eligible participants of Lifelines and the Lifelines NEXT birth cohort, who are all residents of the three northern provinces of the Netherlands. Participants filled out detailed questionnaires about their physical and mental health and experiences on a weekly basis starting in late March 2020, and the cohort consists of everyone who filled in at least one questionnaire in the first 8 weeks of the project. FINDINGS TO DATE: >71 000 unique participants responded to the questionnaires at least once during the first 8 weeks, with >22 000 participants responding to seven questionnaires. Compiled questionnaire results are continuously updated and shared with the public through the Corona Barometer website. Early results included a clear signal that younger people living alone were experiencing greater levels of loneliness due to lockdown, and subsequent results showed the easing of anxiety as lockdown was eased in June 2020. FUTURE PLANS: Questionnaires were sent on a (bi)weekly basis starting in March 2020 and on a monthly basis starting July 2020, with plans for new questionnaire rounds to continue through 2020 and early 2021. Questionnaire frequency can be increased again for subsequent waves of infections. Cohort data will be used to address how the COVID-19 pandemic developed in the northern provinces of the Netherlands, which environmental and genetic risk factors predict disease susceptibility and severity and the psychological and societal impacts of the crisis. Cohort data are linked to the extensive health, lifestyle and sociodemographic data held for these participants by Lifelines, a 30-year project that started in 2006, and to data about participants held in national databases.

A possible role for HLA-G in development of uteroplacental acute atherosis in preeclampsia.

HLA-G, a non-classical HLA molecule expressed by extravillous trophoblasts, plays a role in the maternal immune tolerance towards fetal cells. HLA-G expression is regulated by genetic polymorphisms in the 3' untranslated region (3'UTR). Low levels of HLA-G in the maternal circulation and placental tissue are linked to preeclampsia. Our objective was to investigate whether variants of the 3'UTR of the HLA-G gene in mother and fetus are associated with acute atherosis, a pregnancy specific arterial lesion of the decidua basalis that is prevalent in preeclampsia. Paired maternal and fetal DNA samples from 83 normotensive and 83 preeclamptic pregnancies were analyzed. We sequenced the part of the HLA-G 3'UTR containing a 14-bp insertion/deletion region and seven single nucleotide polymorphisms (SNPs). Associations with acute atherosis were tested by logistic regression. The frequency of heterozygosity for the 14-bp polymorphism (Ins/Del) and the +3142 SNP (C/G) variant in the fetus are associated with acute atherosis in preeclampsia (66.7 % vs. 39.6 %, p = 0.039, and 69.0 % vs. 43.4 %, p = 0.024). Furthermore, the fetal UTR-3 haplotype, which encompasses the 14-bp deletion and the +3142G variant, is associated with acute atherosis in preeclampsia (15 % vs. 3.8 %, p = 0.016). In conclusion, HLA-G polymorphisms in the fetus are associated with acute atherosis. We hypothesize that these polymorphisms lead to altered HLA-G expression in the decidua basalis, affecting local feto-maternal immune tolerance and development of acute atherosis.

Introduction of Criterion-Based Audit of Postpartum Hemorrhage in a University Hospital in Eastern Ethiopia: Implementation and Considerations.

With postpartum hemorrhage (PPH) continuing to be the leading cause of maternal mortality in most low-resource settings, an audit of the quality of care in health facilities is essential. The purpose of this study was to identify areas of substandard care and establish recommendations for the management of PPH in Hiwot Fana Specialized University Hospital, eastern Ethiopia. Using standard criteria (n = 8) adapted to the local hospital setting, we audited 45 women with PPH admitted from August 2018 to March 2019. Four criteria were agreed as being low: IV line-setup (32 women, 71.1%), accurate postpartum vital sign monitoring (23 women, 51.1%), performing typing and cross-matching (22 women, 48.9%), and fluid intake/output chart maintenance (6 women, 13.3%). In only 3 out of 45 women (6.7%), all eight standard criteria were met. Deficiencies in the case of note documentation and clinical monitoring, non-availability of medical resources and blood for transfusion, as well as delays in clinical management were identified. The audit created awareness, resulting in self-reflection of current practice and promoted a sense of responsibility to improve care among hospital staff. Locally appropriate recommendations and an intervention plan based on available resources were formulated.

Perinatal death in a term fetal growth restriction randomized controlled trial: the paradox of prior risk and consent.

BACKGROUND: The disproportionate intrauterine growth intervention trial at term was an intention to treat analysis and compared labor induction with expectant monitoring in pregnancies complicated by fetal growth restriction at term and showed equivalence for neonatal outcomes. OBJECTIVE: To evaluate trial participation bias and to examine the generalizability of the results of an obstetrical randomized trial. STUDY DESIGN: We used data from participants and nonparticipants of a randomized controlled trial-the disproportionate intrauterine growth intervention trial at term (n=1116) -to perform a secondary analysis. This study compared induction of labor and expectant management in women with term growth restriction. Data were collected in the same manner for both groups. Baseline characteristics and neonatal and maternal outcomes were compared. The primary outcome was a composite measure of adverse neonatal outcome. Secondary outcomes were delivery by cesarean delivery and instrumental vaginal delivery; length of stay in the neonatal intensive care, neonatal ward, and the maternal hospital; and maternal morbidity. RESULTS: Nonparticipants were older, had a lower body mass index, had a higher level of education, smoked less, and preferred expectant management. The time between study inclusion and labor onset was shorter in participants than in nonparticipants. Notably, 4 perinatal deaths occurred among nonparticipants and none among participants. Among nonparticipants, there were more children born with a birthweight below the third centile. The nonparticipants who had expectant management were monitored less frequently than the participants in both the intervention and the expectant arm. CONCLUSION: We found less favorable outcomes and more perinatal deaths in nonparticipants. Protocol-driven management, differences between participants and nonparticipants, or the fact that nonparticipants had a preference for expectant management might explain the findings.

Mid-gestation low-dose LPS administration results in female-specific excessive weight gain upon a western style diet in mouse offspring.

Gestational complications, including preeclampsia and gestational diabetes, have long-term adverse consequences for offspring's metabolic and cardiovascular health. A low-grade systemic inflammatory response is likely mediating this. Here, we examine the consequences of LPS-induced gestational inflammation on offspring's health in adulthood. LPS was administered to pregnant C57Bl/6J mice on gestational day 10.5. Maternal plasma metabolomics showed oxidative stress, remaining for at least 5 days after LPS administration, likely mediating the consequences for the offspring. From weaning on, all offspring was fed a control diet; from 12 to 24 weeks of age, half of the offspring received a western-style diet (WSD). The combination of LPS-exposure and WSD resulted in hyperphagia and increased body weight and body fat mass in the female offspring. This was accompanied by changes in glucose tolerance, leptin and insulin levels and gene expression in liver and adipose tissue. In the hypothalamus, expression of genes involved in food intake regulation was slightly changed. We speculate that altered food intake behaviour is a result of dysregulation of hypothalamic signalling. Our results add to understanding of how maternal inflammation can mediate long-term health consequences for the offspring. This is relevant to many gestational complications with a pro-inflammatory reaction in place.

Altered Levels of Decidual Immune Cell Subsets in Fetal Growth Restriction, Stillbirth, and Placental Pathology.

Immune cells are critically involved in placental development and functioning, and inadequate regulation of the maternal immune system is associated with placental pathology and pregnancy complications. This study aimed to explore numbers of decidual immune cells in pregnancies complicated with fetal growth restriction (FGR) and stillbirth (SB), and in placentas with histopathological lesions: maternal vascular malperfusion (MVM), fetal vascular malperfusion (FVM), delayed villous maturation (DVM), chorioamnionitis (CA), and villitis of unknown etiology (VUE). Placental tissue from FGR (n = 250), SB (n = 64), and healthy pregnancies (n = 42) was included. Histopathological lesions were classified according to criteria developed by the Amsterdam Placental Workshop Group. Tissue slides were stained for CD68 (macrophages), CD206 (M2-like macrophages), CD3 (T cells), FOXP3 [regulatory T (Treg) cells], and CD56 [natural killer (NK) cells]. Cell numbers were analyzed in the decidua basalis using computerized morphometry. The Mann-Whitney U-test and Kruskal Wallis test with the Dunn's as post-hoc test were used for statistical analysis. Numbers of CD68+ macrophages were higher in FGR compared to healthy pregnancies (p < 0.001), accompanied by lower CD206+/CD68+ ratios (p < 0.01). In addition, in FGR higher numbers of FOXP3+ Treg cells were seen (p < 0.01) with elevated FOXP3+/CD3+ ratios (p < 0.01). Similarly, in SB elevated FOXP3+ Treg cells were found (p < 0.05) with a higher FOXP3+/CD3+ ratio (p < 0.01). Furthermore, a trend toward higher numbers of CD68+ macrophages was found (p < 0.1) in SB. Numbers of CD3+ and FOXP3+ cells were higher in placentas with VUE compared to placentas without lesions (p < 0.01 and p < 0.001), accompanied by higher FOXP3+/CD3+ ratios (p < 0.01). Elevated numbers of macrophages with a lower M2/total macrophage ratio in FGR suggest a role for a macrophage surplus in its pathogenesis and could specifically indicate involvement of inflammatory macrophages. Higher numbers of FOXP3+ Treg cells with higher Treg/total T cell ratios in VUE may be associated with impaired maternal-fetal tolerance and a compensatory response of Treg cells. The abundant presence of placental lesions in the FGR and SB cohorts might explain the increase of Treg/total T cell ratios in these groups. More functionality studies of the observed altered immune cell subsets are needed.