The recently released fifth Confidential Inquiry into Maternal Mortality report indicates that 4867 women died during or within 42 days of childbirth in the period 2008 and 2010 - more than in any of the previous reporting periods.
The report is commissioned by government and compiled by doctors who make up the national committee on confidential inquiries into maternal deaths.
They investigate the cause of death of every woman who dies giving birth or within 42 days of doing so. This excludes deaths unrelated to pregnancy.
The biggest cause of maternal deaths was HIV-related infections, followed by obstetric haemorrhage (bleeding from the womb) and complications caused by high blood pressure.
Despite South Africa's recent success in rolling out the world's largest antiretroviral programme and increasing life expectancy by six years, HIV complications remained the biggest killer of South Africa's mothers - nearly 40.5% of maternal deaths were due to HIV-related infections such as TB.
The report implies that some of the deaths could have been prevented as the expectant mothers were diagnosed with HIV and could have been started on ARV therapy.
HIV Clinicians' Society president professor Francesca Conradie said mothers were not receiving antenatal care after becoming pregnant or ARVs quickly enough.
She said women who were serious about falling pregnant needed to test for HIV first, and then be placed on treatment as soon as they knew they were pregnant and had tested positive.
"Many of the deaths were preventable ... not by the healthcare system but by the women themselves," she said.
The biggest cause of preventable deaths was obstetric haemorrhage, occurring most often during or after a Caesarean section.
These deaths usually occurred at district hospitals.
Hypertension, the third-biggest killer, affected teenage mothers most.
When healthcare workers were to blame it was due to misdiagnosis and delays in referring patients to better care facilities.
In 22% of all cases where resuscitation was used, the procedure was "sub-optimal".
"A recurring theme in previous Saving Mothers reports and this report is the need to improve the training of all nurses and doctors to deal effectively with obstetric emergencies," the commitee said.
Health Department spokesman Joe Maila said: "The department had always been concerned about deaths during pregnancy.
"Pregnant women need to make sure they go to clinics as soon as possible so healthcare workers can detect any complications in time."