In the review of hospital data from 1999 to 2004 of more than 500,000 mothers, researchers came to know that the ratio of adverse maternal complications have risen up to four percent.

The rate of complications after pregnancy, in 1999 was 11.5 in 1000 deliveries the complications include renal failure, loss of blood, or jee

In the 2004 the maternal complications elevated to the 13.8 percent.

Researchers also noticed that the increase in complications was typically in the women who suffered excessive blood loss (haemorrhaging) after delivery.

It is still unclear why postpartum haemorrhage increasing over time. Even the women who delivered in the hospitals exhibited the similar trend.

“The trend has been observed internationally but the still unable to find out the underlying cause,” lead researcher Dr. Christine L. Roberts said.

Theoretically speaking, increased maternal age, frequency of C-section or birth of twins could be the reasons behind, researchers added.

Researchers analyzed that the overweight women were on the high risk of postpartum bleeding, but there is no data have been collected so far.

The poor management form the doctor’s end, at the time of delivery could also be the reason, researchers speculated.