Maternal arterial desaturation with 15-methyl prostaglandin F2 alpha for uterine atony.

Over a six-month period, five women with severe uterine atony and postpartum hemorrhage developed marked maternal arterial oxygen desaturation within five to ten minutes of the administration of 15-methyl prostaglandin F2 alpha. The average fall from baseline was 10.4 +/- 5.4%, to a mean arterial oxygen saturation of 88.8 +/- 5.45%. The desaturation was accompanied by acute increases, averaging 20.7 +/- 5.9%, in the intrapulmonary shunt.