Rates of trauma to both mother and baby during vaginal deliveries have increased in Canada in recent years, especially when forceps are used, according to a new study by the University of British Columbia.
Operative vaginal deliveries – using forceps or vacuum – have declined over the past few decades in the United States and Canada while cesarean delivery rates have increased. These trends have led to recommendations to increase operative vaginal delivery rates to counter high numbers of cesarean deliveries, although both types of births carry risks.
The study, published in CMAJ (Canadian Medical Association Journal) looked at almost 2 million hospital deliveries in four Canadian provinces – Alberta, Manitoba, Ontario and Saskatchewan – between 2004 to 2014.
Obstetric trauma from operative vaginal deliveries — such as injury to the mother’s perineum, bladder or cervix— increased in first-time mothers from 16.6 per cent to 19.4 per cent, and from 13.8 per cent to 18.7 per cent in women with a prior cesarean delivery. Severe perineal tearing accounted for 87 per cent of the cases of obstetric trauma among operative vaginal deliveries.
“Severe perineal tearing can cause significant long-term complications for women because such injuries can lead to impaired control of the bladder and bowel function as well as pelvic organ prolapse, one of the most common reasons for gynaecologic surgery,” says lead author Giulia Muraca, a postdoctoral fellow in the Department of Obstetrics and Gynaecology and the School of Population and Public Health.
The largest increases in obstetric trauma occurred in forceps deliveries, going from 19.4 per cent in first-time mothers to 26.5 per cent. In women with a previous cesarean delivery, the obstetric trauma rate following forceps delivery increased from 16.6 per cent to 25.6 per cent over the same period.
Based on the researchers’ modelling, a 1 per cent increase in the operative vaginal delivery rate in Canada may result in over 700 additional cases of obstetric trauma per year among first-time mothers alone.
The rate of severe trauma to the baby following operative vaginal delivery also increased in women delivering their first child, from 4.5 to 6.8 per 1000 deliveries from 2004 to 2014 and from 6.5 to 10.6 per 1000 deliveries in women with a previous vaginal delivery.
“These trends may be due to a decline in expertise, due to poor selection of candidates for operative vaginal delivery, or perhaps because operative vaginal delivery is being reserved for the most severe cases,” says Dr. Muraca.
While rates of operative vaginal delivery have declined in Canada and the U.S., the Canadian increases in trauma to the mom and baby from these types of procedures contrast with declining rates of trauma in the United States.
The push to reduce cesarean deliveries by relying more on operative vaginal delivery should be tempered by the knowledge that the latter carries its own risks, Dr. Muraca says.
“These results should make policy-makers cautious about recommending increased operative vaginal delivery without improving training, skill and oversight associated with operative vaginal delivery,” she says.
In a related commentary, Christopher Ng, a Clinical Instructor in the UBC Department of Obstetrics and Gynaecology, urged caution in in moving away completely from operative vaginal delivery.
“It is not easy to find the optimal balance of risks and benefits among operative vaginal delivery, trial of labour after cesarean, and cesarean delivery,” writes Dr. Ng, who works at Langley Memorial Hospital. “Unfortunately, that discussion may be cut short as we run the real risk of having the skills for operative vaginal delivery wither as a result of the difficulty in training future providers.”