Effects of calcium supplementation on uteroplacental and fetoplacental blood flow in low-calcium-intake mothers: a randomized controlled trial.
OBJECTIVE
We postulated that calcium supplementation of calcium-deficient pregnant women would lower vascular resistance in uteroplacental and fetoplacental circulations.


METHODS
Pulsatility index (PI) and resistance index (RI) (uterine and umbilical arteries) and presence of bilateral uterine artery diastolic notching were assessed by Doppler ultrasound between 20-36 weeks' gestation in 510 healthy, nulliparous Argentinean women with deficient calcium intake in a randomized, placebo-controlled, double-blinded trial.


RESULTS
Average umbilical and uterine artery RI and PI tended to be lower in the supplemented group at each study week. Differences became statistically significant for umbilical artery RI and PI from 32 and 36 weeks, respectively. Estimated probabilities of bilateral uterine artery diastolic notching trended toward lower values in calcium-supplemented women.


CONCLUSIONS
Calcium supplementation of pregnant women with deficient calcium intake may affect uteroplacental and fetoplacental blood flow by preserving the vasodilation of normal gestation.
Carroli
Guillermo
G
Centro Rosarino de Estudios Perinatales, Rosario, Argentina. gcarroli@crep.com.ar
Merialdi
Mario
M
Wojdyla
Daniel
D
Abalos
Edgardo
E
Campodonico
Liana
L
Yao
Shih-Ern
SE
Gonzalez
Rogelio
R
Deter
Russell
R
Lindheimer
Marshall
M
Van Look
Paul
P
D000293:Adolescent; D000328:Adult; D002136:Calcium, Dietary / Q000008:administration & dosage*; D019587:Dietary Supplements; D005260:Female; D005333:Fetus / Q000502:physiology*; D006801:Humans; D017078:Laser-Doppler Flowmetry; D010920:Placenta / Q000098:blood supply* / Q000000981:diagnostic imaging; D011247:Pregnancy; D012039:Regional Blood Flow / Q000187:drug effects; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014599:Uterus / Q000098:blood supply* / Q000000981:diagnostic imaging; D014655:Vascular Resistance / Q000187:drug effects* / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects / Q000528:radiation effects; D055815:Young Adult
D002136:Calcium, Dietary