Is grand multiparity an independent predictor of pregnancy risk? A retrospective observational study

To the Editor: As a “grand multip” myself, I turned with interest to Humphrey’s recently published study of grand multiparity and pregnancy risk at Cairns Base Hospital.1 However, I cannot support his conclusions.

Throughout the period of the study, most grand multiparous women giving birth at this hospital were actively managed in the third stage of labour with a regimen designed to prevent postpartum haemorrhage (intravenous ergometrine/oxytocin). Women of lesser parity were also given preventive therapy, but generally in lower doses and less consistently. This is a major confounding factor not addressed in Humphrey’s study. Clearly, an unknown, but probably significant, number of haemorrhages were prevented by this treatment.

Given that 9.2% of grand multiparous women still had a postpartum haemorrhage, any prospective randomised controlled trial that allowed some of these women not to have active management of the third stage would be unethical. Numerous other studies have shown an association between grand multiparity and postpartum haemorrhage. 2-4 These include the study of Babinszki and colleagues, which limited study subjects to upper-class, private patients and thereby eliminated many confounding variables.4

Humphrey’s study does not report the severity of the postpartum haemorrhages that did occur; even a small number of life-threatening haemorrhages could justify continuing very active preventive measures in grand multiparous women. The incidences of anaemia and previous postpartum haemorrhage, not recorded in the study, would also be of interest; both are independent reasons to actively manage the third stage in women of any parity, and there are good reasons to believe that both may be more common in grand multiparous women.

Humphrey also states that grand multiparous women did not have higher perinatal mortality rates or poorer maternal outcomes than women of lower parity. However, whenever possible throughout the period of the study, grand multiparous women were identified on booking into antenatal care and treated by senior obstetricians. Many had conditions such as diabetes, hypertension, anaemia and heart disease managed carefully to ensure as good a pregnancy outcome as possible. This focused obstetric care could well have counteracted any natural tendency of grand multiparous women towards poorer outcomes, and thus it is not possible to draw any conclusions about perinatal results from the data provided.

What is clear from these data is that grand multiparous women in far north Queensland are often economically and socially disadvantaged compared with women of lower parity. This is a common finding in almost all studies of grand multiparity. 2,3,5 We should remember that these women are taking home a new baby to conditions that may already be quite compromised. They deserve the best obstetric care we can offer them, and we should be very cautious when reviewing protocols that we do not increase risks to these women or their babies.