The grand multipara--still an obstetrical challenge?

To study whether grand multiparity (parity of 6 or more) still carries risk, we studied two birth cohorts in northern Finland: the first comprised 12,231 births to 12,068 mothers in 1966 and the second comprised 9478 births to 9362 mothers in 1985/86. The percentage of grand multipara decreased from 7.7 to 4.0. The grand multipara made fewer antenatal visits than the others. The proportion of grand multipara referred to maternity outpatient clinics of hospitals was smaller, but the mean number of visits was higher than of lower parity women. The mean number of admissions to hospital was similar in both groups but grand multipara stayed longer in hospital, smoked less (4.3% vs. 22.7%) and had a higher incidence of essential hypertension than women of lower parity. The grand multipara had fewer caesarean sections (7.5% vs. 14.1%) and vacuum extractions (0.5% vs. 5.1%) but more inductions of labour (33.1% vs. 23.5%) than mothers of lower parity. The number of low birth weight (LBW) infants (less than 2500 grams), stillbirths and neonatal deaths (before 28 days) was significantly lower in 1985/86 than in 1966 in women of lower parity but there was no such change in grand multipara. However, the percentage of LBW infants was smaller among grand multipara than among women of lower parity in both cohorts (2.7% vs. 4.1%, NS). The stillbirth plus neonatal death rate in grand multipara was higher than in women of lower parity (1.9% vs. 0.9%, P less than 0.05) partly because of a higher incidence of major congenital anomalies.