Biomaterial Database

Maternal physiologic adaptations to early human pregnancy. 1988

J F Clapp, and B L Seaward, and R H Sleamaker, and J Hiser

Department of Obstetrics and Gynecology, University of Vermont College of Medicine, Burlington 05405.

This study was designed to test the hypothesis that significant maternal physiologic adaptations to pregnancy take place in multiple systems long before they are functionally necessary (during the embryonic period). To test this hypothesis, 20 women were studied serially before pregnancy and in the seventh and fifteenth postconceptional week of an accurately dated, clinically normal, singleton pregnancy. By the seventh week, significant changes were noted in body composition and cardiopulmonary and metabolic functions. Body fat and plasma volume increased 2% and 11%, respectively, accounting for all of the observed 2 kg weight gain. With the patient standing at rest after eating, heart rate increased 13 beats/min (16%) while mean arterial pressure fell 8 mm Hg (9%). Minute ventilation rose 24% and oxygen consumption increased by 27 ml/min, or 10%. The postprandial respiratory exchange ratio also increased, from 0.78 to 0.83; the whole blood glucose level was unchanged at rest, although there was a 15% decrease in whole blood lactate levels. We conclude that our hypothesis is correct, which suggests these adaptations are preparative and may have diagnostic value.

UI	MeSH Term	Description	Entries
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D010953	Plasma Volume	Volume of PLASMA in the circulation. It is usually measured by INDICATOR DILUTION TECHNIQUES.	Blood Plasma Volume,Blood Plasma Volumes,Plasma Volumes,Volume, Blood Plasma,Volume, Plasma,Volumes, Blood Plasma,Volumes, Plasma
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011261	Pregnancy Trimester, First	The beginning third of a human PREGNANCY, from the first day of the last normal menstrual period (MENSTRUATION) through the completion of 14 weeks (98 days) of gestation.	Early Placental Phase,Pregnancy, First Trimester,Trimester, First,Early Placental Phases,First Pregnancy Trimester,First Pregnancy Trimesters,First Trimester,First Trimester Pregnancies,First Trimester Pregnancy,First Trimesters,Phase, Early Placental,Phases, Early Placental,Placental Phase, Early,Placental Phases, Early,Pregnancies, First Trimester,Pregnancy Trimesters, First,Trimesters, First
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
D001823	Body Composition	The relative amounts of various components in the body, such as percentage of body fat.	Body Compositions,Composition, Body,Compositions, Body
D005260	Female		Females
D006400	Hematocrit	The volume of packed RED BLOOD CELLS in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, ANEMIA shows a low value; POLYCYTHEMIA, a high value.	Erythrocyte Volume, Packed,Packed Red-Cell Volume,Erythrocyte Volumes, Packed,Hematocrits,Packed Erythrocyte Volume,Packed Erythrocyte Volumes,Packed Red Cell Volume,Packed Red-Cell Volumes,Red-Cell Volume, Packed,Red-Cell Volumes, Packed,Volume, Packed Erythrocyte,Volume, Packed Red-Cell,Volumes, Packed Erythrocyte,Volumes, Packed Red-Cell
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic