The relationship between placental characteristics and birthweight discordance in different types of selective intrauterine growth restriction in monochorionic diamniotic twins: A single‐center 7 year cohort study

Abstract

Objective: To clarify the relationships between placental characteristics and birthweight discordance in three types of selective intrauterine growth restriction (sIUGR) in monochorionic diamniotic twins. Methods: A retrospective cohort study was conducted between april 2013 and april 2020. Associations between placental characteristics and birthweight discordance were evaluated through multiple linear regression analyses with two models for each sIUGR type. Model A was adjusted for gestational age, Model B additionally adjusted for the impact of placental characteristics interacted. Results: In cases of type I sIUGR, birthweight discordance ratio was positively associated with placental territory discordance ratio [(β = 0.181,95%CI (0.072,0.290), p < 0.05), (β = 0.239,95%CI(0.125, 0.353), p < 0.05)] under both Model A and Model B. In-type II sIUGR [(β = −0.012,95%CI(-0.020, −0.004), p < 0.05) (β = −0.010,95%CI (−0.018, −0.002), p < 0.05)] and type III sIUGR [(β = −0.011,95%CI (−0.021, −0.001), p < 0.05), (β = −0.012,95%CI(-0.022, −0.003), p < 0.05)], birthweight discordance ratio was negatively associated with the total diameter of all the anastomoses as calculated with both Model A and Model B. Conclusion: Birthweight discordance is primarily related to placental territory discordance in type I sIUGR, whereas vascular anastomoses play important roles for growth-restricted fetal compensation in type II and III sIUGR. Key points What's already known about this topic? � Placental characteristics associate with the onset of selective intrauterine growth restriction What does this study add? � Birthweight discordance is primarily related to placental territory discordance in type I sIUGR, whereas vascular anastomoses play important roles for growth-restricted fetal compensation in type II and III sIUGR 1518 -Prenatal Diagnosis.

Impact of placental sharing and large bidirectional anastomoses on birthweight discordance in monochorionic twins: a retrospective cohort study in 449 cases

“…We did not find this effect in our population, potentially because of the nearly double amount of placentas with VV anastomoses that we were able to include. In a study performed by Wang et al, 19 the presence of VV anastomoses was found to be negatively correlated with BWD in type III sFGR when corrected for gestational age at diagnosis and delivery. We were unable to conclude the effect of VV diameter in the subgroup analysis of the UA Doppler flow patterns, as only 9 pEDF, 6 A/REDF, and 12 iA/REDF placentas had a VV anastomosis.…”

“…The hazard in comparing studies using the Gratacós classification is the different scoring methods that are widely used. Some studies classify a pregnancy as type II or type III when abnormal UA Doppler flow patterns were observed on a single occasion, 20 others use the final classification before delivery, 19 and others use the most prevalent type of flows as we have done now and in the past. 11 UA Doppler flow patterns are dynamic and can change over time, presenting difficulty in determining the "definitive" Gratacós type.…”

Laser therapy versus expectant management for selective fetal growth restriction in monochorionic twins: A systematic review

“…sFGR is thought to arise due to unequal amounts of placental tissue controlled by the twins 12 and is associated with velamentous cord insertion of the FGR twin 12 . As a result of this situation, FGR twins are often dependent on anastomoses which carry nutrients from the AGA twin's placental territory 13 . Finally, there is a difference between early sFGR and later sFGR, with the latter thought to result from late transfusion imbalance in some cases, an etiology more like twin‐twin transfusion syndrome 14 …”

“…12 As a result of this situation, FGR twins are often dependent on anastomoses which carry nutrients from the AGA twin's placental territory. 13 Finally, there is a difference between early sFGR and later sFGR, with the latter thought to result from late transfusion imbalance in some cases, an etiology more like twin-twin transfusion syndrome. 14 The optimal treatment for selective fetal growth restriction is unknown.…”

Investigation of the Association of Abdominal Circumference discordance and Estimated Fetal Weight discordance in twins with birth weight discordance

“…The incidence of respiratory distress syndrome, intraventricular hemorrhage, seizures, periventricular leukomalacia, sepsis, and necrotizing enterocolitis rose directly with the percentage of weight discordancy ( 17 , 18 ). Most discordancy surveillance begins after the first trimester ( 19 ).…”