Plasma volume in normal and sickle cell pregnancy

Afolabi, Bosede (2011) Plasma volume in normal and sickle cell pregnancy. DM thesis, University of Nottingham.

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Abstract

Plasma volume (PV) rises by up to 50% in normal pregnancy, a phenomenon associated with a favourable pregnancy outcome. A previous study of pregnant women with sickle cell (haemoglobin SS) disorder found that PV paradoxically contracts in late pregnancy.

A cross-sectional study was performed to determine PV (Evans blue method) and volume regulatory hormones and electrolytes in pregnant women with haemoglobin (Hb) SS and in non-pregnant and Hb AA controls.

PV rose in pregnant HbAA and was significantly correlated with plasma angiotensinogen. Non-pregnant Hb SS women had supranormal PV measurements and reduced glomerular filtration rate (GFR). Their PV did not rise in pregnancy and was not correlated with angiotensinogen. Their plasma renin concentration also failed to rise significantly by 36 weeks gestation and was significantly less than in Hb AA pregnancy although aldosterone concentration was raised as expected.

A general vasoconstriction in pregnancy can cause inactivation of the renin-angiotensin system and could explain this, with aldosterone being elevated by non Angiotensin II dependent stimulation such as plasma potassium, which was significantly higher in the pregnant Hb SS women. Further studies demonstrating a deficiency of vasodilator substances in pregnant Hb SS women will strengthen this hypothesis.

Item Type:Thesis (DM)
Supervisors:Broughton-Pipkin, F.
Faculties/Schools:UK Campuses > Faculty of Medicine and Health Sciences > School of Clinical Sciences
ID Code:2073
Deposited By:Dr Bosede Afolabi
Deposited On:18 Jan 2012 11:21
Last Modified:18 Jan 2012 11:21

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