Conference Coverage

LARC prolongs interpregnancy intervals but doesn’t cut preterm birth risk



The use of long-acting reversible contraceptive (LARC) methods reduces short interpregnancy intervals, but does not appear to reduce the risk of preterm birth when used between a first and second pregnancy, results of a retrospective cohort study suggest.

Dr. Sara E. Simonsen, a certified nurse-midwife at the University of Utah Hospital, Salt Lake City Sharon Worcester/MDedge News

Dr. Sara E. Simonsen

Of 35,754 women who had a first and second live birth between 2005 and 2015 and who received non-emergent care within 10 years of the first birth, 3,083 (9%) had evidence of interpregnancy LARC exposure and were significantly less likely to have short interpregnancy intervals than were 32,671 with either non-LARC contraceptive use or no record of contraceptive-related care (P less than .0001), Sara E. Simonsen, PhD, reported in a poster at the annual meeting of the American College of Obstetricians and Gynecologists.

Intervals in those with intrapartum LARC use were 12 months or less in 4% of women, 13-18 months in 8%, 19-24 months in 11%, and greater than 24 months in 13%.

However, preterm birth, which occurred in 7% of first births and 6% of second births, was not lower among those with LARC exposure vs. those with no contraceptive encounters after adjustment for interpregnancy interval and a number of demographic factors, including education, presence of father, mother’s age, Hispanic ethnicity, fetal anomalies, and preterm birth history (adjusted odds ratio, 1.13), said Dr. Simonsen, a certified nurse midwife at the University of Utah Hospital, Salt Lake City.

“Preterm birth, a live birth at less than 37 weeks’ gestation, is a major determinant of poor neonatal outcomes,” she and her colleagues wrote. “Short interpregnancy interval, defined as less than 18 months, is an important risk factor for preterm birth.”

Given the increasing number of U.S. women who use highly effective LARCs to space pregnancies, she and her colleagues performed a retrospective cohort study of electronic medical records from two large health systems and linked them with birth and fetal death records to explore the relationship between interpregnancy LARC and both interpregnancy interval and preterm birth in the subsequent pregnancy.

“We did find that women who used LARC between their pregnancies were less likely to have a short interpregnancy interval, but in adjusted models ... we found no association with intrapartum LARC use and preterm birth in the second birth,” Dr. Simonsen said during an e-poster presentation at the meeting.

In fact, preterm birth in the second birth was most strongly associated with a prior preterm birth – a finding consistent with the literature, she and her colleagues noted.

Although the findings are limited by the use of retrospective data not designed for research, the data came from a large population-based sample representing about 85% of Utah births, they said.

The findings suggest that while LARC use may not reduce preterm birth risk, it “may contribute favorably to outcomes to the extent that having optimal interpregnancy interval does,” they wrote.

“‘We feel that these findings support providers counseling women on the full range of contraception options in the postpartum and not pushing [intrauterine devices,]” Dr. Simonsen added.

The related topic of immediate postpartum LARC use was addressed by Eve Espey, MD, in a separate presentation at the meeting.

Dr .Espey, professor and chair of the department of obstetrics and gynecology and director of the family planning fellowship at the University of New Mexico, Albuquerque, reported that immediate postpartum insertion of an intrauterine device (IUD) is highly cost-effective despite an expulsion rate of between 10% and 30%. She also addressed the value of postpartum LARC for reducing rapid-repeat pregnancy rates.

Payment models for immediate postpartum LARC are “very cumbersome,” but at the university, a persistent effort over 4 years has led to success. Immediate postpartum LARC is offered to women with Medicaid coverage, and payment is received in about 97% of cases, she said, adding that efforts are underway to help other hospitals “troubleshoot the issues.”

The lack of private insurance coverage for immediate postpartum LARC remains a challenge, but Dr. Espey said she remains “super enthusiastic” about its use.

“I think it’s going to take another 5 years or so [for better coverage], and honestly I think what we really need is an inpatient LARC CPT code to make this happen,” she said, urging colleagues to advocate for that within their American College of Obstetricians and Gynecologists sections when possible.

Dr. Simonsen and Dr. Espey reported having no relevant disclosures.

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