Influence of maternal obesity and metabolic and vascular mediators in twin-twin transfusion syndrome

Placental architectural characteristics following laser ablation within monochorionic twins complicated by twin-twin transfusion syndrome: A systematic review and meta-analysis of outcomes

INTRODUCTION

Twin-twin transfusion syndrome (TTTS) complicates approximately 10%-15% of all monochorionic twin pregnancies. The aim of this review was to evaluate the placental architectural characteristics within TTTS twins following laser and elucidate their impact on fetal outcomes and operative success.

MATERIAL AND METHODS

Five databases were searched from inception to August 2023. Studies detailing post-delivery placental analysis within TTTS twins post-laser were included. Studies were categorized into two main groups: (1) residual anastomoses following laser and (2) abnormal cord insertion: either velamentous and/or marginal or proximate. The primary outcome was to determine the proportion of TTTS placentas with residual anastomoses and abnormal cord insertions post-laser. Secondary outcomes included assessing residual anastomoses on post-laser fetal outcomes and assessing the relationship between abnormal cord insertion and TTTS development. Study bias was critiqued using the Joanna Briggs Institute checklists and Cochrane risk of bias tool. Random-effects meta-analysis was used, and results were reported as pooled proportions or odds ratio (OR) with 95% confidence interval (CI). PROSPERO registration: CRD42023476875.

RESULTS

Twenty-six studies, comprising 4013 monochorionic twins, were included for analysis. The proportion of TTTS placentas with residual anastomoses following laser was 24% (95% CI, 0.12-0.41), with a mean and standard deviation of 4.03 ± 2.95 anastomoses per placenta. Post-laser residual anastomoses were significantly associated with intrauterine fetal death (OR, 2.38 [95% CI, 1.33-4.26]), neonatal death (OR, 3.37 [95% CI, 1.65-6.88]), recurrent TTTS (OR, 24.33 [95% CI, 6.64-89.12]), and twin anemia polycythemia sequence (OR, 13.54 [95% CI, 6.36-28.85]). Combined abnormal cord (velamentous and marginal), velamentous cord, and marginal cord insertions within one or both twins following laser were reported at rates of 49% (95% CI, 0.39-0.59), 27% (95% CI, 0.18-0.38), and 28% (95% CI, 0.21-0.36), respectively. Combined, velamentous and marginal cord insertions were not significantly associated with TTTS twins requiring laser (p = 0.72, p = 0.38, and p = 0.71, respectively) versus non-TTTS monochorionic twins.

CONCLUSIONS

To the best of our knowledge, this is the first review to conjointly explore outcomes of residual anastomoses and abnormal cord insertions within TTTS twins following laser. A large prospective study is necessitated to assess the relationship between abnormal cord insertion and residual anastomoses development post-laser.

The Association of Prepregnancy Body Mass Index with Pregnancy Outcomes in Chinese Women

Our study was to evaluate the association between prepregnancy body mass index (BMI) and pregnancy outcomes. A total of 1546 women who attended prenatal care clinics and delivered at the Peking University International Hospital, Beijing, China, from October 2018 to April 2020 was included. This research explored gestational, perinatal, and postpartum outcomes, including gestational diabetes, anemia, preeclampsia, preterm premature rupture of membranes (PPROM), and postpartum hemorrhage. Participants were divided into underweight (BMI < 18.5 kg/m²), normal weight (18.5 kg/m² ≤ BMI ≤ 23.9 kg/m²), overweight (24 kg/m² ≤ BMI ≤ 27.9 kg/m²), and obese (BMI ≥ 28 kg/m²) groups. Logistic regression analysis was used to analyze the association between prepregnancy BMI and pregnancy outcomes, and odds ratio (OR) with 95% confidence interval (95% CI) was calculated. After adjusting potential confounders, the risk of PPROM was higher in the underweight group than the normal weight group (OR = 1.864, 95% CI: 1.269-2.737, P < 0.01). Prepregnancy obesity was associated with higher odds of gestational diabetes (OR = 2.649, 95% CI: 1.701-4.126, P < 0.001) and preeclampsia (OR = 3.654, 95% CI: 1.420-9.404, P < 0.01) than the normal weight group, whereas it correlated with the lower risk of anemia (OR = 0.300, 95% CI: 0.128-0.704, P < 0.01). Our findings may provide evidence for the importance of keeping normal weight for Chinese women when preparing for pregnancy.