Basal Plate Myofibers and the Risk of Placenta Accreta Spectrum in the Subsequent Pregnancy: A Large Single-Center Cohort

Abstract

Objective We aimed to evaluate whether there is a significant association between a placental pathology diagnosis basal plate myofibers (BPMF) in an index pregnancy with placenta accreta spectrum (PAS) in the subsequent pregnancy.

Study Design We conducted a retrospective nested cohort study of all cases with a histopathological finding of BPMF between August 2012 and March 2020 at a single tertiary referral center. Data were collected for all subjects (cases and controls) with at least two consecutive pregnancies (the initial index pregnancy and at least one subsequent pregnancy) accompanied by a concomitant record of histopathological study of the placenta at our center. The primary outcome was pathologically confirmed PAS in the subsequent pregnancy. Data are presented as percentage or median, interquartile range accordingly.

Results A total of n = 1,344 participants were included, of which n = 119 (index cases) carried a contemporaneous histopathological diagnosis of BPMF during the index pregnancy and n = 1,225 did not (index controls). Among the index cases, patients with BPMF were older (31.0 [20, 42] vs. 29.0 [15, 43], p < 0.001), more likely to have undergone in vitro fertilization (IVF) for conception (10.9 vs. 3.8%, p = 0.001) and were of a more advanced gestational age at delivery (39.0 [25, 41] vs. 38.0 [20, 42], p = 0.006). In the subsequent pregnancy, the rate of PAS was significantly higher among the BPMF index cases (6.7 vs. 1.1%, p < 0.001). After adjusting for maternal age and IVF, a histopathological diagnosis of BPMF in an index pregnancy was shown to be a significant risk factor for PAS in the subsequent gestation (hazard ratio: 5.67 [95% confidence interval: 2.28, 14.06], p < 0.001).

Conclusion Our findings support that a histopathological diagnosis of BPMF is an independent risk factor for PAS in the subsequent pregnancy.

Key Points

• BPMF may indicate morbid adherence of placenta.

• Patients with BPMF were older and more likely to have undergone IVF for conception.

• The BPMF in the current pregnancy is an independent risk factor for PAS in the subsequent pregnancy.

Keywords

placenta accreta - basal plate myofibers - morbid adherent - microscopic placenta accreta

• References

• 1 Khong TY. The pathology of placenta accreta, a worldwide epidemic. J Clin Pathol 2008; 61 (12) 1243-1246
• 2 Einerson BD, Comstock J, Silver RM, Branch DW, Woodward PJ, Kennedy A. Placenta accreta spectrum disorder: uterine dehiscence, not placental invasion. Obstet Gynecol 2020; 135 (05) 1104-1111
• 3 Shamshirsaz AA, Fox KA, Salmanian B. et al. Maternal morbidity in patients with morbidly adherent placenta treated with and without a standardized multidisciplinary approach. Am J Obstet Gynecol 2015; 212 (02) 218.e1-218.e9
• 4 Hoffman MS, Karlnoski RA, Mangar D. et al. Morbidity associated with nonemergent hysterectomy for placenta accreta. Am J Obstet Gynecol 2010; 202 (06) 628.e1-628.e5
• 5 Matsuzaki S, Mandelbaum RS, Sangara RN. et al. Trends, characteristics, and outcomes of placenta accreta spectrum: a national study in the United States. Am J Obstet Gynecol 2021; 225 (05) 534.e1-534.e38
• 6 Hecht JL, Baergen R, Ernst LM. et al. Classification and reporting guidelines for the pathology diagnosis of placenta accreta spectrum (PAS) disorders: recommendations from an expert panel. Mod Pathol 2020; 33 (12) 2382-2396
• 7 Jauniaux E, Chantraine F, Silver RM, Langhoff-Roos J. FIGO Placenta Accreta Diagnosis and Management Expert Consensus Panel. FIGO consensus guidelines on placenta accreta spectrum disorders: epidemiology. Int J Gynaecol Obstet 2018; 140 (03) 265-273
• 8 Jauniaux E, Ayres-de-Campos D, Langhoff-Roos J, Fox KA, Collins S. FIGO Placenta Accreta Diagnosis and Management Expert Consensus Panel. FIGO classification for the clinical diagnosis of placenta accreta spectrum disorders. Int J Gynaecol Obstet 2019; 146 (01) 20-24
• 9 Khong TY, Werger AC. Myometrial fibers in the placental basal plate can confirm but do not necessarily indicate clinical placenta accreta. Am J Clin Pathol 2001; 116 (05) 703-708
• 10 Sherer DM, Salafia CM, Minior VK, Sanders M, Ernst L, Vintzileos AM. Placental basal plate myometrial fibers: clinical correlations of abnormally deep trophoblast invasion. Obstet Gynecol 1996; 87 (03) 444-449
• 11 Langston C, Kaplan C, Macpherson T. et al. Practice guideline for examination of the placenta. Arch Pathol Lab Med 1997; 121 (05) 449-476
• 12 Carusi DA. The placenta accreta spectrum: epidemiology and risk factors. Clin Obstet Gynecol 2018; 61 (04) 733-742
• 13 Silver RM, Landon MB, Rouse DJ. et al; National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Maternal morbidity associated with multiple repeat cesarean deliveries. Obstet Gynecol 2006; 107 (06) 1226-1232
• 14 Salmanian B, Fox KA, Arian SE. et al. In vitro fertilization as an independent risk factor for placenta accreta spectrum. Am J Obstet Gynecol 2020; 223 (04) 568.e1-56 -8.e5
• 15 Modest AM, Toth TL, Johnson KM, Shainker SA. Placenta accreta spectrum: in vitro fertilization and non-in vitro fertilization and placenta accreta spectrum in a Massachusetts cohort. Am J Perinatol 2021; 38 (14) 1533-1539
• 16 Linn RL, Miller ES, Lim G, Ernst LM. Adherent basal plate myometrial fibers in the delivered placenta as a risk factor for development of subsequent placenta accreta. Placenta 2015; 36 (12) 1419-1424
• 17 Stanek J, Drummond Z. Occult placenta accreta: the missing link in the diagnosis of abnormal placentation. Pediatr Dev Pathol 2007; 10 (04) 266-273
• 18 Miller ES, Linn RL, Ernst LM. Does the presence of placental basal plate myometrial fibres increase the risk of subsequent morbidly adherent placenta: a case-control study. BJOG 2016; 123 (13) 2140-2145