TABLE 1.

Representative studies on inflammation and immune function related to early pregnancy.

Disease/pathology	Author/years	Description	Roles of inflammation/findings
Ovulation	Duffy (review)/2019 35	LH a surge and inflammatory response	Beneficial inflammation
	Buyalos/1992 37	IL‐6 level in the follicular fluid	Beneficial inflammation
	Wang/1992 38	TNFα in the follicular fluid	Beneficial inflammation
	Nishimura/1998 41	M‐CSF in the follicular fluid	Beneficial inflammation
	Al‐Alem/2015 42	Leukocytes and chemokines	Beneficial inflammation
	Kryczek/2005 46	Chemokine and T cells	Beneficial inflammation
	Nio‐Kobayashi/2015 47	Chemokine and macrophages	Beneficial inflammation
	Cohen‐Fredarow/2014 51	Dendritic cells	Both pro‐ and anti‐inflammatory effects
LUF b	Shibata/2016 59	Administration of G‐CSF	Beneficial effect of inflammation for preventing LUF
	Brannstrom/1995 60	Neutrophils	Beneficial effect of inflammation for preventing LUF
PCOS c	Escobar‐Morreale (review)/2011 63	C‐reactive protein	Harmful inflammation
	Cirillo/2020 67	HMGB1 d	Harmful inflammation induced by HMGB1
Placenta formation/fetal growth	Griffith/2017 31	Inflammation at attachment	Beneficial inflammation at attachment of embryo
	Granot (review)/2012 70	Inflammatory cytokines and Th1 inflammatory response in implantation	Beneficial inflammation in implantation
	Ashkar/2000 76	IFN‐γ in placental formation	Beneficial role of IFN‐γ
	Valero‐Pacheco/2022 166	IL‐33 in placental formation	Beneficial role of IL‐33 in placenta formation and fetal growth
CE e	Matteo/2009 111	Abnormal distribution of NK cell subsets	Harmful inflammation
	Tortorella/2014 112	Elevation of IL‐6 and TNF‐α levels	Harmful inflammation
	Wang/2019 113	Autophagy dysregulation and Th17 dominancy	Harmful effects of Th17 dominanct in CE
	Kitazawa/2021 114	Accumulation of Th1 cells	Harmful inflammation
Endometrial microbiota disturbance	Moreno/2016 124	Dominancy of Lactobacillus	Beneficial effects of Lactobacillus
	Hashimoto/2019 126	Eubiosis and dysbiosis related to Lactobacillus	No differences between eubiosis and dysbiosis for implantation
	Yoshida/2021 127	L. crispatus	Beneficial role of L. crispatus in trophoblast invasion
	Kadogami/2023 128	L. iners	Low implantation rate in L. iners dominant state
Immunological disorder	Saito (review)/2010 137	Th1/Th2/Th17/Treg f balance	Pregnancy complications and disruption of immune balance
	Fukui/2008 143	NK cell cytotoxicity	Harmful inflammation in RIF g
	Ledee (review)/2016 93	IL‐18/TWEAK h and IL‐15/Fn‐14 i balance	Importance of appropriate balance

^a LH, luteinizing hormone.

^b LUF, luteinized unruptured follicle.

^c PCOS, polycystic ovary syndrome.

^d HMGB1, high‐mobility group box 1.

^e CE, chronic endometritis.

^f Treg, regulatory T.

^g RIF, repeated implantation failure.

^h TWEAK, tumor necrosis factor‐like weak inducer of apoptosis.

ⁱ Fn, fibroblast growth factor‐inducible molecule 14.