Commentary: Efficacy of estradiol–dydrogesterone and auto-cross-linked hyaluronan gel in preventing intrauterine adhesions following missed miscarriage curettage: a retrospective observational study

The pr.mary concern regard.ng the val.d.ty of the study's conclus.ons stems from .ts retrospect.ve observat.onal des.gn w.thout the use of propens.ty score match.ng (PSM). In non-random.zed cl.n.cal sett.ngs, the allocat.on of pat.ents to an .ntervent.on group (ACP gel + hormones) versus a control group .s rarely random and .s often .nfluenced by ".nd.cat.on b.as." Cl.n.c.ans are more l.kely to ut.l.ze adjuvant prevent.ve measures .n pat.ents perce.ved to be at h.gher r.sk for IUA-for .nstance, those w.th a h.story of mult.ple curettages, ev.dence of .nfect.on, or d.ff.cult surger.es .nvolv.ng extens.ve endometr.al trauma.Conversely, w.thout r.gorously adjust.ng for basel.ne confound.ng var.ables (e.g., durat.on of surgery, operator exper.ence, or soc.oeconom.c status), .t .s challeng.ng to attr.bute the super.or outcomes solely to the pharmacolog.cal .ntervent.on. As noted .n methodolog.cal l.terature regard.ng observat.onal stud.es, fa.l.ng to balance these covar.ates can lead to b.ased est.mates of treatment effects (2). If the control group possessed a h.gher basel.ne r.sk or worse prognost.c factors that were not stat.st.cally adjusted for, the eff.cacy of the comb.ned therapy m.ght be overest.mated.A second cr.t.cal po.nt .s the nature of the control group. In th.s study, the control group rece.ved no spec.f.c preventat.ve .ntervent.on. However, the current landscape of postabort.ve care .s evolv.ng. Major .nternat.onal gu.del.nes, such as those by the AAGL and ESGE, acknowledge the role of post-operat.ve estrogen therapy .n promot.ng endometr.al regenerat.on and prevent.ng adhes.on recurrence, cons.der.ng .t a standard approach .n many cl.n.cal scenar.os (3).Compar.ng a novel "comb.ned tr.ple therapy" aga.nst a "no-treatment" arm creates a s.gn.f.cant contrast that may not reflect real-world cl.n.cal d.lemmas. The more cl.n.cally relevant quest.on .s not whether "someth.ng .s better than noth.ng," but whether the add.t.on of ACP gel to standard hormonal support prov.des an .ncremental benef.t. By ut.l.z.ng a control group that rece.ved no hormonal support, the study potent.ally conflates the wellknown benef.t of estrogen w.th the spec.f.c effect of the ACP gel. In conclus.on, wh.le I commend the authors for address.ng th.s challeng.ng cl.n.cal ent.ty, I urge cl.n.c.ans to .nterpret the magn.tude of the reported benef.t w.th caut.on unt.l val.dated by random.zed tr.als that control for select.on b.as and ut.l.ze an act.ve comparator group.