Do primiparas aged 40 years or older carry an increased obstetric risk?

It is unclear whether older primiparas are at increased risk for complications of pregnancy other than an increased cesarean section rate. The aim of this study was to compare the rate of complications of pregnancy and delivery of primiparas aged 40 years or older with those of primiparas aged 20 to 30 years.

We reviewed the maternal and neonatal hospital records of 59 consecutive primiparas aged 40 years or older who delivered at our institution between 1986 and 1995. A total of 118 primiparas aged 20 to 30 years who preceded and followed the cases served as controls.

The mean duration of gestation was significantly shorter in primiparas > or = 40 years of age. Induction of labor was more common and the cesarean delivery rate was higher (47 vs 12%) in older primiparas. The mean birth weight was significantly lower in the offspring of the cases. The perinatal mortality rate was 5% in the primiparas over 40 years and 0% in the control group; fetal malformations were found in 5% (vs 1%) of the children of older primiparas.

In our series, older primiparas were at increased risk for prematurity, preeclampsia, and perinatal mortality. The high rate of cesarean section in older primiparas is due mainly to a higher incidence of obstetric complications. These data suggest that the prenatal care of older primiparas in the third trimester should concentrate on the early detection of premature contractions and signs of preeclampsia.