Labour analgesia; Molecular pathway and the role of nanocarriers: a systematic review

Figures & data

Figure 1. Epidural anesthesia.

Figure 2. Opioid receptor signalling. αG: protein alpha subunit, arrestin phosphorylation-dependent GPCR scaffold; βγ: G-protein beta-gamma subunit; cAMP: cyclic adenosine monophosphate; ERK ½: extra-cellular signal-regulated kinase; JNK: c-Jun N-terminal kinase; p38: p38 MAPK; P: phosphorylation.

Table 1. A118G Variant of OPRM1 in labour analgesia.

Genetic variant	Clinical context	Intervention	Outcome		Case number	Genotype			Ref
				Ethnicity		AA	AG	GG
OPRM1A118G	Labor analgesia (CSE) (N = 224, Swiss)	Spinal fentanyl (2.5–30 mcg	304A homozygous require significantly more fentanyl for labour analgesia Analgesia requested at greater cervical dilatation Lower ED50 (1.5- to 2-fold) in women with G118	Caucasian	223	150	62	11	[55]
OPRM1A118G	Labor analgesia (Epidural) (N = 57, )	Epidural sufentanil (16–27 mcg)	Lower ED50 in women with G118 allele	Italian	57	33	23	1	[58]
OPRM1A118G	Labour pain	Analgesia (all types)	No association between G-allele carriers and labour pain-related behaviour	Swedish	672	541	119	12	[54]
OPRM1A118G	Labour analgesia	Spinal fentanyl (25 mcg)	No effect of G118 on duration of spinal analgesia	American	190	144	34	12	[57]

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