Background and Objectives: This meta-analysis aimed to determine whether pre-implantation uterine artery (UtA) Doppler measurements are associated with clinical pregnancy in women undergoing assisted reproductive technologies (ART). Materials and Methods: A systematic search of MEDLINE, Scopus, and the Cochrane Library from inception until 25 March 2025 was conducted to identify relevant studies. Additional records were retrieved through grey literature searching and manual reference checks. Eligible publications were observational studies or clinical trials that evaluated UtA Doppler indices prior to embryo transfer in adult women undergoing ART. Studies were required to report on clinical pregnancy rates, while those enrolling participants under 18 years of age, lacking Doppler data, or providing no pregnancy endpoints were excluded. Three reviewers independently assessed study quality using the Newcastle–Ottawa Scale and the Quality in Prognosis Studies tool. Meta-analyses were performed using a random-effects model to calculate mean differences (MDs) with 95% confidence intervals (CIs). Heterogeneity was examined via Cochran’s Q and the I² statistic. Sensitivity analyses excluded studies at high risk of bias. Results: In total, 12 studies met the inclusion criteria, including a population of 3317 women. Women who achieved clinical pregnancy had a lower mean UtA pulsatility index (PI) (MD, −0.26; 95% CI, −0.46 to −0.06) and a higher peak systolic velocity (PSV) (MD, 8.59; 95% CI, 2.31 to 14.87) than those who did not conceive. Subgroup analyses showed that UtA PI measured during the menstrual cycle was lower in clinical pregnancy cases (MD, −0.38; 95% CI, −0.66 to −0.10). Measurements on the day of hCG administration or the day before showed a non-significant difference in UtA PI (MD, −0.43; 95% CI, −1.03 to 0.17), while assessments on the day of embryo transfer showed no significant difference between groups (MD, −0.02; 95% CI, −0.28 to 0.24). Conclusions: This meta-analysis suggests that lower UtA PI and higher PSV prior to embryo transfer are associated with higher clinical pregnancy rates in ART, particularly when measurements are taken during the menstrual cycle. Although these findings highlight a potential role for uterine hemodynamics in successful clinical pregnancy, UtA Doppler alone may not be a reliable predictor. Future studies should focus on earlier-cycle Doppler measurements and their integration into multifactorial models to improve prognostic accuracy.

Background/Objectives: Uterine artery pulsatility index (UtA-PI) is a key biomarker of placental function, but its clinical interpretation in assisted reproductive technology (ART) pregnancies is uncertain. This meta-analysis aimed to assess trimester- and method-specific UtA-PI differences between ART and spontaneous conceptions (SC) and to examine associated risks for preeclampsia (PE) and small-for-gestational-age (SGA) neonates to contextualize its findings. Methods: A systematic search of MEDLINE, Scopus, and the Cochrane Library was conducted through 25 June 2025. We included observational studies comparing UtA-PI and perinatal outcomes in singleton ART versus SC pregnancies. The primary outcome was the standardized mean difference (SMD) in first (until the 13⁺⁶ gestational week) and second trimester (14⁺⁰–23⁺⁶ gestational weeks) UtA-PI measurements; secondary outcomes were PE and SGA rates. Analyses were stratified by ART modalities. Random-effects models were used, and study quality was evaluated using the Newcastle–Ottawa Scale and risk of bias with QUIPS tool (INPLASY registration: INPLASY202560104). Results: Thirteen cohort studies were included. Overall, ART pregnancies had significantly lower UtA-PI values than SC in both the first (SMD = −0.28; 95% CI: −0.53 to −0.03) and second trimesters (SMD = −0.20; 95% CI: −0.36 to −0.04). These reductions were driven by oocyte donation (first-trimester SMD = −0.70; 95% CI: −1.21 to −0.18; second-trimester SMD = −0.46; 95% CI: −0.65 to −0.26) and artificial cycle frozen embryo transfers (ET) (first-trimester SMD = −0.69; 95% CI: −1.00 to −0.39). These lower UtA-PI values typically suggest better placental perfusion and a lower risk of placental related complications. However, ART pregnancies had an elevated overall risk for PE (risk ratio [RR] = 2.32; 95% CI: 1.72 to 3.12), with the highest risk in oocyte donation (RR = 6.11; 95% CI: 3.35 to 11.17) and artificial cycle frozen ET (RR = 3.45; 95% CI: 1.51 to 7.90). Conclusions: ART pregnancies, particularly from oocyte donation and artificial cycle frozen ET, show lower UtA-PI values despite a significantly elevated risk for PE. This finding suggests that mechanisms other than placental perfusion contribute to PE development. Clinically, the ART method is an independent risk factor for PE, and UtA-PI interpretation should be adjusted accordingly. Further research is crucial to elucidate the underlying pathophysiology.

Cardiac arrhythmias are prevalent complications in pregnancy, yet their precise association with acute maternal cardiovascular morbidity and mortality remains unclear due to heterogeneous evidence. This systematic review and meta-analysis evaluated the impact of maternal arrhythmias on acute cardiovascular outcomes. We searched Medline, Scopus, and Cochrane databases for observational studies comparing pregnant women with arrhythmias to those without. Random-effects meta-analyses were used to calculate pooled risk ratios (RR) for maternal mortality and major adverse cardiovascular events (MACE). Eleven studies comprising 76,028 pregnancies with arrhythmias and over 82 million controls were included. Analysis of data, primarily derived from large administrative cohorts with low absolute event rates, indicated that arrhythmias were significantly associated with increased all-cause maternal mortality (0.78% vs. 0.01%; RR 31.94; adjusted RR 8.91) and a composite of MACE (2.90% vs. 0.03%; RR 6.48). Supraventricular tachycardia and atrial fibrillation were associated with an increased likelihood of adverse outcomes. Notably, the relative risk of mortality and heart failure in women with arrhythmias versus controls was significantly higher in the general obstetric population around delivery than in women with known structural heart disease, suggesting a “sentinel event” phenomenon. Thromboembolic events were also 15 times more likely in the arrhythmia group. Cardiac arrhythmias during pregnancy are associated with substantial maternal morbidity and mortality. New-onset arrhythmias may warrant comprehensive cardiac evaluation, as they may unmask underlying pathology and precipitate severe hemodynamic compromise, particularly in women without prior cardiac history.

Introduction: The prevalence of maternal arrhythmias is increasing with advanced maternal age. Current evidence regarding the association between maternal arrhythmias and pregnancy outcomes remains inconsistent. This meta-analysis aimed to define the associations between adverse pregnancy outcomes and specific maternal arrhythmias. Methods: We conducted a systematic review and meta-analysis using the PRISMA guidelines. We searched MEDLINE, Scopus, and Cochrane on the 4th of November 2025 for cohort and case–control studies comparing pregnant women with cardiac arrhythmias to those without. Primary outcomes included preeclampsia, stillbirth, preterm delivery, and small-for-gestational-age (SGA) neonates. Data were pooled using random-effects models with subgroup analyses by arrhythmia type. Results: Nineteen studies were included. Maternal arrhythmias were associated with a significantly increased risk of preeclampsia (RR = 1.46, 95% CI [1.10, 1.93]), preterm delivery (RR = 1.39, 95% CI [1.12, 1.72]), and stillbirth (RR = 2.09, 95% CI [1.11, 3.91]). Ventricular tachycardia/fibrillation was linked to the most severe outcomes, including a four-fold increase in stillbirth (RR = 4.20, 95% CI [3.75, 4.71]) and a fifteen-fold increase in neonatal death (RR = 15.47, 95% CI [3.45, 69.45]). Supraventricular tachycardia was independently associated with preeclampsia (aRR = 1.14, 95% CI [1.04, 1.24]), preterm delivery (aRR = 1.76, 95% CI [1.39, 2.23]), and SGA neonates (aRR = 5.93, 95% CI [1.23, 28.55]). Risks were notably higher in the general population compared to women with known heart disease, supporting an “unmasking” of occult vulnerability. Conclusions: Maternal arrhythmias are associated with distinct fetal risks beyond maternal hemodynamics. Ventricular tachycardia was associated with severe outcomes, likely reflecting acute compromise, while supraventricular tachycardia was linked to signs of chronic vascular dysfunction. These findings suggest arrhythmias as possible sentinels for placental insufficiency, necessitating enhanced surveillance.