Women who bleed heavily after giving birth aren't at any higher risk of most complications during their next pregnancy, according to a new UK study.
Postpartum haemorrhage typically occurs when the muscles in a woman's uterine wall don't contract correctly after childbirth.
Although that much bleeding can be scary, researchers said the new findings are "reassuring" for women hoping to have another child after a first-time haemorrhage.
"Intuitively, that would have been what I would expect also," said Dr. Laura Riley, an obstetrician at Massachusetts General Hospital in Boston.
"It's really all about that particular pregnancy that puts most people at risk for bleeding," such as having a big baby or a long induction time, she told Reuters Health.
Postpartum haemorrhage can be dangerous when a woman loses a quart or more of blood - which can lead to a quick drop in blood pressure and shock. Less blood loss isn't always concerning because pregnant women have more blood circulating to begin with, Riley said - but it can still cause anaemia.
Haemorrhage is treated with drugs such as oxytocin and misoprosotol, or with a blood transfusion.
The new study is based on data covering more than 34,000 women in Aberdeen, UK who gave birth between 1986 and 2005. Among those women, about 10 percent had a postpartum haemorrhage during their first childbirth.
Older and heavier new mums, as well as smokers, were more likely to have heavy bleeding, Dr. Gail Fullerton from Aberdeen Maternity Hospital and her colleagues found.
Most women who both had and hadn't had a postpartum haemorrhage went on to get pregnant a second time, an average of five years later. Those women also had a similar risk of miscarriage and other pregnancy complications, according to findings published in the obstetrics and gynaecology journal BJOG.
However, mothers who had heavy bleeding the first time around were more likely to bleed again: about 18 percent of them had another postpartum haemorrhage, compared to seven percent of women who didn't have extra bleeding during their first childbirth. That is consistent with past studies, the researchers said.
"Postpartum haemorrhage is a difficult time for women - it can be very, very stressful for women and their partners. And there is a worry that women may be put off from having a second pregnancy," Fullerton told Reuters Health. In that sense, she said, "the paper has been very reassuring."
Riley, who wasn't involved in the new research, said women who had one postpartum haemorrhage shouldn't be too worried about complications with future pregnancies.
The one exception, she added, is among women who have had multiple Caesarean sections in a row - in which case there is a higher risk of heavy blood loss.
She recommended women try to start their pregnancy at a healthy weight and not gain too much while pregnant to lower their chances of having a big baby. In addition, women should eat an iron-rich diet to build up their iron stores in case they do lose blood, Riley said.
"The most important thing is optimizing their blood level before they come into labour, keeping a healthy diet... and obviously keeping their weight down as much as possible," she said.