Does continuing oral magnesium supplementation until delivery affect labor and puerperium outcome?
OBJECTIVE
To determine the labor and puerperal impact of continuing oral magnesium supplementation until delivery.


METHODS
Single-center study with matched controls. In 40 pairs of healthy women with vaginally delivered singleton pregnancies, matched for maternal age, race and parity, maternal and neonatal outcome endpoints were compared in those receiving continuous oral magnesium aspartate supplementation 15-30 mmol/d for at least 4 weeks until delivery (for constipation, calf cramps, preterm contraction without cervical effacement or additional tocolytics) versus non-supplemented controls.


RESULTS
In the magnesium group labor was nonsignificantly longer (stage 1: 326.0+/-187.5 min versus 276.7+/-140.8 min, P = 0.19; stage 2: 52.0+/-44.5 min versus 43.5+/-44.0 min, P = 0.40) and maximum oxytocin dose nonsignificantly higher (14.5+/-9.4 [median 12.0; n=15] versus 10.5+/-6.9 [median 7.5] mU/min, P = 0.28; n = 10). Fewer women had afterpains (12 versus 20, P=0.11), required spasmolysis (3 versus 14, P = 0.005), or could breastfeed their infants exclusively at discharge (24 versus 34, P = 0.04).


CONCLUSIONS
Continuing oral magnesium supplementation until delivery does not significantly prolong labor or increase the oxytocin requirement, but it significantly impairs breastfeeding competence.
Meier
Barbara
B
Department of Obstetrics, Zurich University Hospital, Frauenklinikstrasse 10, CH-8091, Zurich, Switzerland.
Huch
Renate
R
Zimmermann
Roland
R
von Mandach
Ursula
U
D000284:Administration, Oral; D000328:Adult; D005260:Female; D006801:Humans; D007743:Labor, Obstetric / Q000187:drug effects*; D007775:Lactation Disorders / Q000139:chemically induced*; D008274:Magnesium / Q000494:pharmacology* / Q000627:therapeutic use; D009465:Neuromuscular Agents / Q000494:pharmacology* / Q000627:therapeutic use; D007744:Obstetric Labor Complications / Q000139:chemically induced; D049590:Postpartum Period / Q000187:drug effects*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000188:drug therapy; D011256:Pregnancy Outcome; D011644:Puerperal Disorders / Q000139:chemically induced; D013997:Time Factors
D009465:Neuromuscular Agents; D008274:Magnesium