In the United States, about 176,000 cycles of assisted reproductive technology were reported during 2012, resulting in the birth of 65,160 babies. ART, as this procedure is commonly called, requires harvesting eggs from a woman’s ovaries and then either donating them to someone else or returning them, newly fertilized, to her own body. An original study finds complication rates from ART to be low overall, with ovarian hyperstimulation syndrome being the most common risk of all.

This syndrome is an “over-response to the use of ovulation induction medications that has the potential to be dangerous if not managed proactively,” said Dr. Jennifer Kawwass, co-author of the study and assistant professor at Emory University School of Medicine, in her email to Medical Daily.

What Causes Ovarian Hyperstimulation Syndrome?

To accomplish in vitro fertilization, a woman needs to take a drug. Medication is required to stimulate her ovaries to produce eggs. Clomiphene citrate (Clomid), a synthetic hormone, is the most commonly used drug for this purpose; less often, an aromatase inhibitor named letrozole (Femara) may be used. In either case, how much of the drug a woman needs is a matter of art as much as science. Too much may cause ovarian hyperstimulation syndrome (OHSS), where a woman’s ovaries become swollen and painful. Severe OHSS causes rapid weight gain, abdominal pain, vomiting, and shortness of breath. Even worse symptoms may occur in the rarest of cases.

Because assisted reproductive technology (ART) is on the rise, Kawwass and her colleagues wanted answers to a key question: What complications occur and how often? For the current study, then, Kawwass and her co-researchers used the Centers for Disease Control and Prevention National ART Surveillance System (NASS) to calculate the incidence in complications for both mothers and donors during cycles of ART.

For 1,135,206 mothers who used their own eggs, the most commonly reported patient complication was OHSS (about 154 for every 10,000 procedures), followed by hospitalizations (about 35 for every 10,000 procedures). All other complications remained below 10 for every 10,000 cycles.  Additionally, the rates of these complications, OHSS and hospitalization, declined over the study period between 2000 and 2011.

For donors, reported complications were even less frequent. Among the 112,254 cycles of donor ART, the most common complication was, once again, OHSS (averaging 31 for every 10,000 cycles) with hospitalization the second most frequent (11 for every 10,000 cycles). All other complications for donors averaged below five for every 10,000 cycles.  

Not every health care practice is required to report its ART complication rates. While the authors suggest underreporting “must be considered” when interpreting this research, Kawwass noted in her email to Medical Daily, “it is reassuring, however, that seven to 10 percent of reporting clinics undergo annual data validation.”  

Source: Kawwass JF, Kissin DM, Kulkarni AD, et al. Safety of Assisted Reproductive Technology in the United States, 2000-2011. JAMA. 2014.