Biomaterial Database

Serum calcium concentrations in human pregnancy. 1977

R M Pitkin, and M P Gebhardt

Total and ionic calcium concentrations were measured in maternal serum from nonpregnant (N=30), pregnant (N=137), and early puerperal (N=17) women. In this cross-sectional study, total calcium levels (measured by atomic absorption spectrophotometry) exhibited the previously described pattern of a decline beginning in the first trimester and continuing until approximately 32 weeks, with a slight terminal rise from thence to term. Mean (+/-SD) values for the three trimesters were 4.80 (+/- 0.13), 4.56 (+/- 0.14), and 4.46 (+/-0.16) mEq. per liter, respectively, with all differences statistically significant. Ionic calcium levels (measured by calcium flow-through electrode) declined to a lesser (though still statistically significant) degree; mean (+/- S.D.) values for the three trimesters were 2.33 (+/-0.07), 2.28 (+/-0.08), and 2.24 (+/-0.06) mEq. per liter, respectively. Because of the differential rates of fall, the proportion of total calcium represented by the ionic component increased progressively during gestation. The results indicate that the major portion of the characteristic decline in maternal serum total calcium concentration with pregnancy reflects changes in the nonionized (albumin-bound) fraction while the ionic portion declines only slightly. The concentration of calcium ions in serum is maintained within a very narrow physiologic range throughout gestation.

UI	MeSH Term	Description	Entries
D007477	Ions	An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
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
D011262	Pregnancy Trimester, Second	The middle third of a human PREGNANCY, from the beginning of the 15th through the 28th completed week (99 to 196 days) of gestation.	Midtrimester,Pregnancy, Second Trimester,Trimester, Second,Midtrimesters,Pregnancies, Second Trimester,Pregnancy Trimesters, Second,Second Pregnancy Trimester,Second Pregnancy Trimesters,Second Trimester,Second Trimester Pregnancies,Second Trimester Pregnancy,Second Trimesters,Trimesters, Second
D011263	Pregnancy Trimester, Third	The last third of a human PREGNANCY, from the beginning of the 29th through the 42nd completed week (197 to 294 days) of gestation.	Pregnancy, Third Trimester,Trimester, Third,Last Trimester,Last Trimesters,Pregnancies, Third Trimester,Pregnancy Trimesters, Third,Third Pregnancy Trimester,Third Pregnancy Trimesters,Third Trimester,Third Trimester Pregnancies,Third Trimester Pregnancy,Third Trimesters,Trimester, Last,Trimesters, Last,Trimesters, Third
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D049590	Postpartum Period	In females, the period that is shortly after giving birth (PARTURITION).	Puerperium,Postpartum,Postpartum Women,Period, Postpartum,Women, Postpartum