Same-day pregnancy test provides valuable guidance to pre-surgery patients

June 16, 2008

The first trimester of any pregnancy is a precarious time, as about 15 percent of women who know they are pregnant will spontaneously miscarry. This risk increases when pregnant women undergo surgery, which is why Hospital for Special Surgery (HSS) in New York instituted a same-day pregnancy testing protocol. A study published in the April issue of Anesthesia and Analgesia shows that this protocol is effective in identifying unknown pregnancies to the benefit of the patient, the physician and the hospital.

"There are no standard recommendations and it is my sense that most places do not have a protocol like this in effect," said Richard L. Kahn, M.D., attending anesthesiologist at Hospital for Special Surgery and lead author of the study. "But the majority of the surgeries HSS performs are elective. By testing all women of child-bearing age on the same day of their surgery we can make sure that the patient has all the facts to make the best informed decision."

The doctors found of 2,588 women tested, five patients had a positive pregnancy test. All of the patients postponed surgery and only one was a false positive.

The American Society of Anesthesiologists gives individual hospitals and physicians the opportunity to define and institute their own policies in regards to pre-operation pregnancy testing. Like many hospitals, Hospital for Special Surgery had been conducting some tests a week before the scheduled surgery, but it wasn't a consistent protocol.

"Pregnancy hormone levels can change within the week leading up to surgery, and HSS was concerned that it was missing some pregnancies," said Dr. Kahn. "We instituted the new policy in November 2004 and the study looked at the cost-benefit ratio within the first full year, January 2005 – January 2006, that the protocol was in effect."

While there is no conclusive evidence, there are associated pregnancy risks with any surgery. Both the stress the mother is under during surgery or the anesthesia could contribute to a spontaneous miscarriage or to an increased chance of birth defects. Doctors at Hospital for Special Surgery always explain the risks to patients who are pregnant, but if the patient herself doesn't know she is pregnant she may not spend much time weighing the risks.

The direct cost associated with each urine pregnancy test is $5.03. Therefore, it cost HSS $3,273 in lab and labor costs to detect each unrecognized pregnancy, though this does not include the indirect costs associated with a cancelled surgery. However, if a woman who didn't know she was pregnant went on to either lose the pregnancy or have a child with a birth defect, the unknown role that anesthesia and surgery may have played in this can be devastating to patient and physician. The benefit of eliminating this possibility, Dr. Kahn said, is more than enough to justify the cost of testing and inconvenience of a postponed surgery.

"Based on the outcome of this study, the same-day pregnancy testing is still in effect at HSS," said Dr. Kahn. "If I were to move to another hospital that did not perform same-day pregnancy testing, I would work to institute a similar policy. What it comes down to is providing the best care for our patients, and I believe this protocol allows us to do that."

Source: Hospital for Special Surgery