The Society for Maternal-Fetal Medicine (SMFM) released a list this month of 5 procedures that ob/gyns should question. The list is part of the American Board of Internal Medicine Foundation's Choosing Wisely® campaign, an initiative launched in 2012 that is meant to encourage physicians to question the benefit of some commonly used tests and procedures.
To help ob/gyns understand the recommendations and how they apply to clinical practice, Medscape asked guidelines coauthor and SMFM President Vincenzo Berghella, MD, to discuss them in more detail. Dr. Berghella is Professor of Obstetrics and Gynecology and Director of Maternal-Fetal Medicine at Jefferson Medical College and Director of the Maternal-Fetal Medicine Fellowship Program at Thomas Jefferson University.
Inherited Thrombophilia Evaluation
The Recommendation: Don't do an inherited thrombophilia evaluation for women with histories of pregnancy loss, intrauterine growth restriction (IUGR), preeclampsia, and abruption.
The Rationale: There isn't enough evidence to show an association between the inherited thrombophilias and adverse pregnancy outcomes. Testing for antiphospholipid antibodies should be limited to lupus anticoagulant, anticardiolipin antibodies, and beta-2 glycoprotein antibodies.
Dr. Berghella's Bottom Line: Antiphospholipid antibodies have been shown to be associated with pregnancy loss or early pregnancy failure, and if tests are positive, we can treat these women with aspirin and heparin. There is no evidence, however, to show that if you test patients for thrombophilia, it will improve or change outcomes.
Cerclage Placement
The Recommendation: Don't place a cerclage in women with a short cervix who are pregnant with twins.
The Rationale: These women are at high risk for delivering preterm, but data, including a meta-analysis published on this issue, shows that a cerclage is not only ineffective, but also may be associated with an increase in preterm births.
Dr. Berghella's Bottom Line: This is not an uncommon procedure. However, twins are not born prematurely because the cervix is weak, but because the uterus is growing so much more quickly than in singleton pregnancies. There are really no data out there showing that cerclage helps in this situation.
Noninvasive Prenatal Testing
The Recommendation: Don't offer noninvasive prenatal testing (NIPT) to low-risk patients or make irreversible decisions on the basis of the results of this screening test.
The Rationale: NIPT has only been adequately evaluated in high-risk pregnancies, defined as maternal age older than 35 years; positive screening; sonographic findings suggestive of aneuploidy; translocation carrier at increased risk for trisomy 13, 18 or 21; or prior pregnancy with a trisomy 13, 18, or 21. In addition, pretest counseling must be provided, and a positive NIPT result should be confirmed with invasive diagnostic testing.
Dr. Berghella's Bottom Line: We have a lot of data on high-risk patients, but not enough to show that the test is useful for low-risk women. One of the worries we all have is that as we screen for more things, how will we interpret the results? Right now, we screen for trisomy 13, 18, and 21, but in a few years it may be possible to screen the whole genotype of the baby. I think it will get more complex in the future, but for now, it's still pretty straightforward.
Screening for IUGR
The Recommendation: Don't screen for IUGR with Doppler blood flow studies.
The Rationale: Studies have shown inconsistent results regarding the benefit of Doppler blood flow studies for IUGR screening. Once the diagnosis is suspected, however, umbilical artery Doppler flow studies are beneficial.
Dr. Berghella's Bottom Line: The diagnosis of IUGR is made by ultrasonography. Once you have calculated an estimated fetal weight less than the 10th percentile, then it becomes important to use Doppler to monitor blood flow and to confirm that there's plenty of blood going back and forth from the placenta to the fetus and vice versa. It doesn't make sense to use Doppler in pregnancies for which IUGR is not suspected.
Progestogens for Preterm Birth
The Recommendation: Don't use progestogens for preterm birth prevention in uncomplicated multifetal gestations.
The Rationale: Progestogens haven't proven to reduce the incidence of preterm birth in women with uncomplicated multifetal gestations.
Dr. Berghella's Bottom Line: Intramuscular and vaginal progesterone have been shown to be effective in singleton pregnancies, but research done on multifetal pregnancies has produced negative results.