Women with obesity have increased risks for postpartum haemorrhage complications

Researchers at the University of South Florida Health (USF Health) and Tampa General Hospital (TGH), examining how obesity affected the management and outcomes of postpartum haemorrhage have reported that high-risk obstetric patients, such as women with obesity, may need some additional support or a different treatment protocol for postpartum haemorrhage. The findings, ‘The Impact of Obesity on the Management and Outcomes of Postpartum Hemorrhage’, were published in the American Journal of Perinatology.

"This study showed that we managed postpartum haemorrhage the same way for women who were obese and those who were not. That's good overall but the same medical treatment is not always equitable because the obese women still experienced worse outcomes," said study senior author, Dr Judette Louis, the James Ingram Endowed Professor and chair of Obstetrics and Gynecology at the USF Health Morsani College of Medicine and co-medical director of Women's and Children's Services at TGH.

The researchers conducted a retrospective analysis of all deliveries complicated by postpartum haemorrhage from February 2013 to January 2014, about 2.6% of the hospital's 9,890 deliveries during that period (a rate consistent with the national average). Controlling for confounding variables, they compared two groups of patients treated for postpartum haemorrhage: women with obesity and women normal weight or who were overweight. Both groups were similar in age, race, insurance status, and alcohol and tobacco use.

The reported that:

  • Patients with obesity were more likely to have had caesarean sections, a risk factor for haemorrhage complications, than women with normal weight or who were overweight.

  • Both groups were equally likely to receive the same medications (carboprost, methylergonovine and misoprostol) to treat excessive blood loss, but women with obesity tended to receive more than one of these uterotonic agents. The medications are administered to induce contractions when the uterus does not contract enough to shrink to normal size after childbirth. This condition, known as uterine atony, is a primary cause of postpartum haemorrhage.

  • Despite similar management, women with obesity experienced more of any severe haemorrhage-related complications (including shock, renal failure, transfusion-related lung injury and cardiac arrest) and they were more apt to sustain more than one of the serious complications.

  • While the need for blood transfusion was similar for both groups, women with obesity were more likely to have greater blood loss and require more units of transfused blood.

  • Although women with obesity were more often transferred to the operating room, the rates of intrauterine pressure balloon tamponade (a device used to promote uterine contraction), interventional radiology procedures, or hysterectomy were no different for women with obesity and women normal weight or who were overweight.

Some basic science and clinical studies investigating uterine contractions during labour indicate obesity can impair uterine tone, so that the reproductive organ may not react as quickly or well to contraction-inducing medications. The underlying reasons for this are undefined, but a disruption of the hormonal balance in obese women may contribute to the impaired uterine response to control bleeding.

The USF Health-TGH study points to the need for larger, multisite studies to better understand the different responses to treatment protocols for postpartum haemorrhage in women with obesity, she added. That includes looking into the possible physiological connections between obesity, pharmacokinetics of the treatment (how the body processes medications) and the impact on uterine atony.

"With higher rates of obesity affecting higher numbers of pregnant women each year, it is important to evaluate how this is affecting the management of obstetric complications," the study authors conclude. "This study shows that despite similar (postpartum haemorrhage) management, key differences do exist in outcomes based on obesity status. There are numerous directions for future research... many of which have the potential for significant clinical implications and improvement of maternal outcomes."