Short description:

Use of assisted reproductive technology (ART) continues to increase in the United States and globally. In an effort to improve patient safety, stimulation protocols have become less aggressive, oocyte retrieval has transitioned from laparoscopic to transvaginal, and pregnancy rates have improved.1 However, limited data exist regarding the incidence of maternal complications.2 We explored incidence and trends in reported patient and donor complications in fresh ART cycles using the US Centers for Disease Control and Prevention National ART Surveillance System (NASS).

Link to the journal

Abstract taken from PubMed

Methods:

NASS is a federally mandated reporting system that collects cycle-level ART procedure information.3 As of 2011, NASS included 97% of cycles and 94% of all US ART clinics. Annually, 7% to 10% of reporting clinics undergo data validation (does not include complication variables).

Reported complications (defined as having been directly related to ART and occurring within 12 weeks of cycle initiation) include infection, hemorrhage requiring transfusion, moderate or severe ovarian hyperstimulation syndrome (OHSS), medication adverse event, anesthetic complication, hospitalization, patient death within 12 weeks of stimulation, and other complications. We report severe OHSS and severe or moderate OHSS in a single category because the delineation between categories is subjective. We also report maternal death prior to infant birth.

Separate analyses using SAS version 9.3 (SAS Institute Inc) and SUDAAN version 11.0 (RTI International) were performed for autologous and donor cycles. We report complications (absolute numbers and rates/10 000 cycles annually) and maternal death prior to infant birth/100 000 ART-conceived live births from 2000-2011. The 2-sided α level was .05. Bivariable linear regression (complication rate as outcome, calendar year as explanatory variable) was used to assess trends over time.

The Centers for Disease Control and Prevention institutional review board approved this study; a waiver of informed consent was obtained.

Results:

Among 1 135 206 autologous cycles, the most commonly reported patient complications were OHSS (peak of 153.5/10 000 autologous cycles; 95% CI, 146.0-161.3) and hospitalizations (peak of 34.8/10 000 autologous cycles; 95% CI, 30.9-39.3); rates of other complications remained below 10/10 000 cycles (Table 1). Rates declined from 2000-2011 for reported medication adverse events (P = .02) and hospitalizations (P < .001); no other significant trends were detected among reported infections, hemorrhages, OHSS, severe OHSS, anesthetic-related complications, and deaths within 12 weeks of stimulation start or during pregnancy (P > .10 for trend for all tests).

Fifty-eight total deaths were reported (18 stimulation-related and 40 maternal deaths prior to infant birth). No temporal patterns were noted. Of the 40 maternal deaths, 16 women carried a singleton, 16 carried twins, 2 carried triplets or higher-order multiples, and 6 did not report plurality. The maternal death rate ranged from 1.6 per 100 000 ART-conceived live births in 2008 to 14.2 in 2004.

Reported complications following donor ART cycles (n = 112 254) were less frequent; none showed a significant trend (P > .05 for trend for all tests; Table 2). The most common donor complications were OHSS (peak of 31.0/10 000 cycles; 95% CI, 22.9-44.3) and hospitalizations (peak of 10.5/10 000 cycles; 95% CI, 5.5-20.1). Rates of other complications remained below 5/10 000 cycles. No donor deaths were reported; 13 maternal deaths prior to infant birth were reported among oocyte donor recipients.

Discussion:

In the United States from 2000-2011, autologous and donor ART procedures were associated with low reported stimulation and surgical complication risks; no concerning trends or patterns were identified. The most frequently reported complication among autologous and donor cycles was OHSS, though less frequent in donor cycles. Obstetric mortality was rare. The lack of significant change in most adverse events may reflect the low baseline rate of such occurrences, making it harder to detect temporal change. This study is the first, to our knowledge, to quantify US ART-associated patient risks. A 1984-2008 report from the Netherlands found a higher ART-related maternal death rate (42.5/100 000 pregnancies) compared with our study (peak of 14.2/100 000 pregnancies).5 Underreporting of complications remains an inherent limitation of surveillance systems6 and must be considered when interpreting our findings. Additionally, our outcomes are cycle-based rather than patient-based, validation does not include complication variables, and available data do not explain the noted trends. Increased awareness of the most common complication, OHSS, may prompt additional study to characterize predictors of this and other adverse events to inform the development of effective approaches necessary to decrease complication occurrence.