Does CVS in Twin Pregnancies Increase the Risk of Fetal Loss?
BACKGROUND AND PURPOSE:
The risk of fetal loss following chorionic villus sampling (CVS) in twin pregnancies has not been extensively tested, and previous studies have reported conflicting results
Gil et al. (Ultrasound in Obstetrics and Gynecology, 2021) estimated the risk of fetal loss associated with CVS in twin pregnancy
Multicenter cohort study
8 fetal medicine units in the UK, Spain, Italy, Bulgaria and Portugal
Women with twin pregnancies undergoing ultrasound examination at 11 to 13 weeks
Following propensity score matching, pregnancies that underwent CVS were compared to those that did not (1:1 ratio) | Adjusted for the confounding bias between the two study groups (CVS vs no CVS)
Risk of death of ≥1 fetus
8581 twin pregnancies
Had CVS: 445
There were fewer deaths of one or two fetuses at any stage during pregnancy in the group that did not undergo CVS (P<0.001)
The propensity score algorithm matched 258 cases that had CVS with 258 non-CVS
There was no significant difference in fetal loss between the propensity matched groups
OR 0.81 (95% CI, 0.48 to 1.35); P=0.415
However, there was a significant interaction between the risk of fetal loss after CVS and the background risk of fetal loss
When the background risk was higher, the risk of fetal loss after CVS decreased
OR 0.46 (95% CI 0.23 to 0.90)
When the background risk was lower, the risk of fetal loss after CVS increased
OR 2.45 (95% CI, 0.95 to 7.13)
These effects were significantly different
P of interaction=0.005
Prior risk of fetal loss and risk following CVS
Background risk = 6% (approximately the same as in the original non-CVS population): No change in fetal loss risk after CVS
Background risk was ≥6%: Risk was paradoxically reduced
Background risk was <6%: Risk increased exponentially (e.g., if background risk of fetal loss was 2.0%, relative risk was 2.8 and the posterior risk was 5.6%)
Overall, there was no difference in fetal loss between CVS and non-CVS exposed twin pregnancies following adjustments for confounding
However, twin pregnancies at lower risk for fetal loss prior to CVS had a paradoxical increased risk for fetal loss following CVS vs those at higher risk where this relationship was reversed
The authors state
The risk factors for fetal loss are similar to those that make CVS necessary and, in women at high prior risk of fetal loss, the risk of fetal loss following the invasive test could paradoxically be lower than if they did not have the invasive test, for the simple reason that prenatal diagnosis often converts spontaneous loss of a chromosomally abnormal fetus into pregnancy termination
OBG Project CME requires a modern web browser (Internet Explorer 10+, Mozilla Firefox, Apple Safari, Google Chrome, Microsoft Edge). Certain educational activities may require additional software to view multimedia, presentation, or printable versions of their content. These activities will be marked as such and will provide links to the required software. That software may be: Adobe Flash, Apple QuickTime, Adobe Acrobat, Microsoft PowerPoint, Windows Media Player, or Real Networks Real One Player.
Disclosure of Unlabeled Use
This educational activity may contain discussion of published and/or investigational uses of agents that are not indicated by the FDA. The planners of this activity do not recommend the use of any agent outside of the labeled indications.
The opinions expressed in the educational activity are those of the faculty and do not necessarily represent the views of the planners. Please refer to the official prescribing information for each product for discussion of approved indications, contraindications, and warnings.
Participants have an implied responsibility to use the newly acquired information to enhance patient outcomes and their own professional development. The information
presented in this activity is not meant to serve as a guideline for patient management. Any procedures, medications, or other courses of diagnosis or treatment discussed or suggested in this activity should not be used by clinicians without evaluation of their patient’s conditions and possible contraindications and/or dangers in use, review of any applicable manufacturer’s product information, and comparison with recommendations of other authorities.
Jointly provided by
NOT ENOUGH CME HOURS
It appears you don't have enough CME Hours to take this Post-Test. Feel free to buy additional CME hours or upgrade your current CME subscription plan