SMFM 2021: Selected Scientific Advances

March 15, 2021
Cynthia Gyamfi-Bannerman, MD

This year’s annual meeting of the Society for Maternal-Fetal Medicine (SMFM) will go down in history as one to remember.

Not only was the meeting held on a virtual platform during a pandemic, the science was incredible, as 21 of the 101 orals presented were randomized controlled trials. The meeting focused on health equity and addressing health care disparities, with a special forum on racism and respectful care.

In no particular order, here are some of the highlights from SMFM 2021:

1. Defining anemia in pregnancy by race contributes to worse outcomes for Black women.

Rebecca Hamm, MD, showed how the ACOG definition of anemia by race, using a lower cutoff for Black women, resulted in a larger proportion of them presenting with anemia at delivery. This prospective cohort study found that Black women had 75% of the odds of presenting to deliver with a hemoglobin level of < 11 g/dL, and that presenting with a hemoglobin level of < 11 was associated with a 3-fold increase in the likelihood of transfusion. The conclusion recommends removing race-based thresholds defining anemia.

2. COVID-19 in pregnancy is worse for women with severe symptoms and comorbidities.

This National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network study of pregnant individuals with coronavirus disease 2019 (COVID-19) found that women with severe COVID-19 had worse obstetric outcomes.

3. “No call” results in NIPT are associated with an increased risk of adverse pregnancy outcomes.

Mary Norton, MD, and colleagues analyzed first trimester noninvasive prenatal testing “no call” results and found an association with a higher rate of preterm delivery and preeclampsia as well as an increased risk for aneuploidy.

4. Half-dose betamethasone was not noninferior to full-dose for respiratory distress syndrome.

The BETADOSE study from France tested a lower dose (12mg x 1 dose, rather than 12 mg q 24 hours x 2 doses) of betamethasone for fetal lung maturity. The study found that neonatal survival and complications did not differ by group, however, the rate of respiratory distress syndrome was 3 percentage points higher in the single-dose group.

5. Prophylactic manual rotation of persistent occiput posterior presentation decreased operative delivery.

In this randomized trial from 4 centers in France, investigators found that manual rotation in the early second stage of labor decreased the operative vaginal delivery rate by about 30%. The 5-minute Apgar score was also higher in neonates of participants who were manually rotated.

6. Application of the CDC’s Social Vulnerability Index determined likelihood of preterm birth.

Investigators analyzed electronic medical records of 50,998 women in the University of North Carolina health system from 2014 to 2020. Each woman’s home address was geocoded and assigned to a Census tract and linked to the Centers for Disease Control and Prevention’s (CDC) publicly available Social Vulnerability Index (SVI). The study found that women who delivered prematurely were more likely to live in an area with a higher overall SVI and higher social vulnerability in each SVI theme. The authors suggested that if individual communities can identify areas of relative weakness where additional support is needed, that may improve pregnancy outcomes.

7. Six hours of Foley catheter placement resulted in shorter time to delivery.

Sarah Lassey, MD, presented on the timing of Foley Cook catheter removal (6 hours versus 12 hours) for induction with oxytocin. The study found that removal at 6 hours was associated with a shorter time to delivery with no difference in cesarean rates.

8. Placental transfer of SARS-CoV-2 specific antibodies may occur from mothers to newborns.

Investigators reported placental transfer of the spike protein of SARS-CoV-2 from mothers to their newborns when they sampled cord blood of pregnancies complicated by COVID-19. The group said that the significance of this finding was unclear, as they were doing future studies to look at the functionality of these antibodies.

9. Communication and linguistic barriers are associated with a higher rate of obstetric morbidity.

Investigators asked where communication or linguistic barriers would affect pregnancy outcomes when counseling is an important part of the care, such as with diabetes. They found a higher rate of pregnancy morbidities in individuals with evidence of communication or linguistic barriers, as measured by a predefined scoring system, but these differences were not noted in non-diabetic pregnancies.

10. The effect of sleep-disordered breathing in pregnancy on endothelial and metabolic dysfunction was not measurable by angiogenic markers or uterine artery Dopplers.

Investigators sought to determine whether the association between sleep-disordered breathing (SDB) and preeclampsia could be predicted by measuring angiogenic factors such as angiogenic domain using soluble endoglin, soluble FMS-like tyrosine kinase 1, and placental growth factor. They found that these factors did not correlate with SDB, however, they did find that mean arterial pressure was elevated with an early pregnancy diagnosis of SDB.