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. 2013 Jan;17(1):50-9.
doi: 10.4103/2230-8210.107841.

Endocrinology of parturition

Sunil K Kota  1 , Kotni Gayatri, Sruti Jammula, Siva K Kota, S V S Krishna, Lalit K Meher, Kirtikumar D Modi
Affiliations

Endocrinology of parturition

Sunil K Kota et al. Indian J Endocrinol Metab. 2013 Jan.

Abstract

The myometrium must remain relatively quiescent during pregnancy to accommodate growth and development of the feto-placental unit, and then must transform into a highly coordinated, strongly contracting organ at the time of labour for successful expulsion of the new born. The control of timing of labour is complex involving interactions between mother, fetus and the placenta. The timely onset of labour and delivery is an important determinant of perinatal outcome. Both preterm birth (delivery before 37 week of gestation) and post term pregnancy (pregnancy continuing beyond 42 weeks) are both associated with a significant increase in perinatal morbidity and mortality. There are multiple paracrine/autocrine events, fetal hormonal changes and overlapping maternal/fetal control mechanisms for the triggering of parturition in women. Our current article reviews the mechanisms for uterine distension and reduced contractions during pregnancy and the parturition cascade responsible for the timely and spontaneous onset of labour at term. It also discusses the mechanisms of preterm labour and post term pregnancy and the clinical implications thereof.

Keywords: Endocrine; labour; parturition; term.

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Conflict of interest statement

Conflict of Interest: None declared

Figures

Figure 1
Figure 1
Endocrinological control of pregnancy and parturition in women. The balance between the effects of estrogen and progesterone is critical to maintenance of pregnancy and the onset of labor. Other important hormonal factors modulate this balance as shown in the scheme
Figure 2
Figure 2
Parturition cascade leading to labour induction at term. The induction of labour at term is reegulated by paracrine and autocrine factors acting in coordination promote uterine contraction. COX-2: Cyclooxygenase 2, OT: Oxytocin, PGDH: Prostaglandin dehydrogenase, PGEM: 13, 14-dihydro-15-keto-PGE2, PGFM: 13, 14-dihydro-15-keto-PGF2α, PLA2: Phospholipase A, SROM: Spontaneous rupture of the fetal membranes, 11β-HSD: 11β-hydroxysteroid dehydrogenase, 16-OH DHEAS: 16-hydroxy-dehydroepiandrostendione sulfate
Figure 3
Figure 3
Dual pathway by which the fetal genome controls the onset of labour through endocrine and mechanical signals. HPA-Hypothalamic Pituitary Adrenal, P-progesterone, E-estrogen
Figure 4
Figure 4
Maternal and fetal HPA axis and stress induced preterm birth. COX-2: Cyclooxygenase 2, MLCK: Myosin light chain kinase, OTR: Oxytocin receptors, PG: Prostaglandin, PGDH: Prostaglandin dehydrogenase
Figure 5
Figure 5
Inflammation of decidua-amniochorion and preterm labor. FasL: Fas ligand, CRH: Cortico Tropic Hormone, PG: Prostaglandin, MMP: Matrix Metallo Proteinase
Figure 6
Figure 6
Hemorrhage and preterm labor. ECM: Extracellular matrix, MMP: Matrix Metallo Proteinase, PAI-1: Plasminogen activator inhibitor 1, tPA: Tissue-type plasminogen activator, uPA: Urokinase plasminogen activator
See this image and copyright information in PMC

References

    1. Liggins GC. Initiation of labor. Biol Neonate. 1989;55:366–94. - PubMed
    1. Liggins GC, Fairclough RJ, Grieves SA, Kendall JZ, Knox BS. The mechanism of initiation of parturition in the ewe. Recent Prog Horm Res. 1973;29:111–59. - PubMed
    1. Flint AP, Anderson AB, Steele PA, Turnbull AC. The mechanism by which fetal cortisol controls the onset of parturition in the sheep. Biochem Soc Trans. 1975;3:1189–94.
    1. Thorburn GD, Hollingworth SA, Hooper SB. The trigger for parturition in sheep: Fetal hypothalamus or placenta? J Dev Physiol. 1991;15:71–9. - PubMed
    1. Matthews SG, Challis JR. Regulation of the hypothalamo -pituitary- adrenocortical axis in fetal sheep. Trends Endocrinol Metab. 1996;7:239–46. - PubMed