The following is a summary of “Lactogenesis and breastfeeding after immediate vs. delayed birth-hospitalization insertion of etonogestrel contraceptive implant: a noninferiority trial,” published in the January 2023 issue of Obsterics and Gynecology by Henkel, et al.

Lactation may be affected if progestin-based contraception is started before the progesterone level drops necessary to initiate lactogenesis stage II. Previous research demonstrated that starting progestin-based contraception in the postnatal period before birth-hospitalization discharge had no negative impact on starting or continuing nursing compared to starting it during the outpatient interval. The effects of starting the etonogestrel contraceptive implant in the early postnatal period right away in the delivery room had not yet been studied with regard to nursing. For a study, researchers sought to compare the effects of etonogestrel contraceptive implant placement in the delivery room vs delayed birth-hospitalization on breastfeeding results.

The noninferiority randomized controlled experiment was conducted to see if the insertion time of the etonogestrel implant during the birth-hospitalization affected the time to lactogenesis stage II (the start of profuse milk production). Pregnant women were randomly randomized to get their insertion between 0 and 2 hours (in the delivery room) or 24 and 48 hours (in a delayed setting). Participants were proficient in English or Spanish, expected to breastfeed, requested a contraceptive implant for postpartum contraception, and had no allergies or contraindications to the etonogestrel implant. At enrolment, they gathered demographic data and planned to breastfeed. Using a validated technique, the onset of lactogenesis stage II was monitored every day. In a per-protocol analysis, the noninferiority margin for the mean difference in time to lactogenesis stage II was established at 12 hours. Additional electronic surveys were used to gather information on breastfeeding and continued use of a contraceptive at 2, 4, 3, and 12 months.

They enrolled and randomly assigned 95 participants; 77 participants (n=38 in the delivery room group and n=39 in the delayed group) were included in the modified intention-to-treat analysis after 18 participants were excluded due to withdrawal of consent, changes in contraceptive or breastfeeding plans, or failure to provide primary outcome data. 8 patients who received the etonogestrel implant outside the protocol windows were excluded, and 2 patients from the delivery room group received the etonogestrel implant at 24 to 48 hours and were analyzed with the delayed group. A total of 69 participants (n=35 delivery room, n=34 delayed) were included in the as-treated analysis. In terms of age, gestational age, and prior nursing experience, participants were comparable between groups. In terms of time to lactogenesis stage II, delivery room insertion was not worse than delayed birth-hospitalization insertion (delivery room [mean±standard deviation], 65±25 hours; delayed, 73±61 hours; mean difference, −9 hours; 95% CI, −27 to 10). Beginning on postpartum day 3, lactogenesis stage II did not differ substantially across the groups. 5.5% (n=2) of individuals in the delayed group had lactation failure. There were no differences in continued or exclusive breastfeeding rates across the groups throughout the first postpartum year. At 12 months, most users were still using the implant, with no group differences.

Regardless of whether a woman intended to breastfeed, etonogestrel contraceptive implant insertion in the delivery room did not delay the start of lactogenesis compared to initiation later in the birth-hospitalization. For this reason, it should be routinely offered as part of person-centered postpartum contraceptive counseling.

Reference: ajog.org/article/S0002-9378(22)00644-5/fulltext