Objective
The purpose of this study was to evaluate pregnancy outcome in women at extremely advanced maternal age (≥45 years).
Study Design
We compared the condition of women aged ≥45 years (n = 177) in a 10:1 ratio (20-29, 30-39, and 40-44 years.). Subgroup analysis compared the condition of women aged 45-49 years with those women aged ≥50 years.
Results
The rates of gestational diabetes mellitus and hypertensive complications were higher for the study group, compared with the whole group (17.0% vs 5.6% and 19.7% vs 4.5%, respectively; P < .001), as was the rate of preterm delivery at <37 and <34 weeks of gestation (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.2–3.6 and OR, 3.5; 95% CI, 1.4–9.0, respectively). The rates of cesarean delivery (OR, 31.8; 95% CI, 18.0–56.1), placenta previa, postpartum hemorrhage, and adverse neonatal outcome were significantly higher among the study group. The risk for gestational diabetes mellitus, preeclampsia toxemia, preterm delivery, and neonatal intensive care unit admission was increased for women aged ≥50 years.
Conclusion
Pregnancy at extreme advanced maternal age is associated with increased maternal and fetal risk.
Advance maternal age is considered to maternal age of >35 years at the estimated date of delivery. In the last decades, a trend of shifting family planning and childbearing towards advanced maternal age became more widespread. Moreover, more women defer pregnancy to the fifth decade of their life and even further by taking advantage of the artificial reproductive technologies. As a result, the live birth rate for women of advanced maternal age has increased steadily over the past years.
The impact of advanced maternal age and delayed childbearing on perinatal outcome is equivocal. Some researchers have suggested compromised pregnancy outcome ; other researchers have reported comparable outcome for this subgroup. Nevertheless, most studies have evaluated pregnancy outcome in women aged ≥35 years, and insufficient data exist concerning pregnancy outcome in women who conceive in the fifth and sixth decades of life. Thus, we aimed to determine whether these older mothers (>45 years old) constitute a specific and unique risk group that is distinct, in terms of magnitude of risks, from their younger counterparts.
Methods
The study sample consisted of women who were at least 45 years old at the time of delivery and who gave birth in our hospital between 2000 and 2008. For the purpose of comparison groups, data were compared with 3 control groups, which were matched by maternal age, in a 10:1 ratio (20-29, 30-39, and 40-44 years.). These groups were comprised of the next 10 deliveries for each of the 3 age subgroups after a delivery of a woman at ≥45 years old in the same time period. In addition, we further divided the study group to 2 subgroups that compared women who were 45-50 years old with those ≥50 years old at the time of delivery. Data for the study and control groups were obtained from the delivery room logbook and from a comprehensive perinatal database that is maintained in our institution. Eligibility for the study was limited to pregnancies that have reached at least 24 weeks of gestation. The local institutional review board approved the study.
All pregnant women were screened for gestational diabetes mellitus (GDM) with a 50-g oral glucose challenge test between 24 and 28 weeks of gestation. Women with abnormal glucose challenge test (>140 mg/dL − ) underwent a 3-hour oral glucose tolerance test with a 100-g oral glucose load. The diagnosis of GDM was made when ≥2 values exceeded the criteria of Carpenter and Coustan. Hypertension that was present at <20 weeks of gestation that did not progress to preeclampsia toxemia was classified as chronic hypertension. After 20 weeks of gestation, hypertensive disorders in pregnancy were categorized according to the International Society for the Study of Hypertension in Pregnancy guidelines. Spontaneous preterm labor was defined as occurring >24 and <37 weeks of gestation in which the delivery was the result of spontaneous onset of delivery, premature rupture of membranes, or suspected cervical incompetence (painless dilation). Indicated preterm birth was defined as involving an infant born at <37 weeks of gestation in which labor was induced or primary cesarean section delivery was performed because of fetal and/or maternal indications. Maternal obesity was defined as prepregnancy body mass index ≥ 30 kg/m 2 . Gestational age at delivery was based on last menstrual period and, whenever available, confirmation by first-trimester ultrasound scans. For patients who underwent in vitro fertilization, gestational age was calculated from the date of the embryo transfer.
Low birthweight was defined as <2500 g; very low birthweight was defined as birthweight <1500 g; small for gestational age was defined as birthweight below the 10th percentile for gestational age with the use of local, population-based liveborn infant birthweight curves. Metabolic complications were defined by the presence of ≥1 of the following events: neonatal hypoglycemia (<40 mg/dL), erythrocytemia (hematocrit, >60%), hyperbilirubinemia (>12 mg/dL), or hypocalcemia (<8 mg/dL).
Comparisons between the groups and subgroups were performed with analysis of variance with Turkey’s multiple comparisons or Student t test for continuous data and with χ 2 or Fisher’s exact test for categoric data. A probability value of < .05 was considered significant. For the purpose of comparison, women who were 20-29 years old were referred as an odds ratio of 1.0. The odds ratio and 95% confidence interval were calculated where appropriate.
Results
During the study period, 79,650 women gave birth in our hospital; 177 of these women (0.2%) were ≥45 years old at the time of delivery.
The demographic and obstetric characteristics for the study and the control groups are given in Table 1 . Gravidity and parity and the rates of chronic hypertension and pregestational diabetes mellitus increased all through maternal age categories. The rates of GDM and preeclampsia toxemia in the study group were significantly higher in comparison with the overall rate in the control groups (17% vs 5.6% and 10.7% vs 1.8%, respectively; P < .01 for both). There were no maternal deaths within the study and the control groups.
| Variable | Overall (n = 5487) | Group 1: 20-29 y (n = 1770) | Group 2: 30-39 y (n = 1770) | Group 3: 40-44 y (n = 1770) | Group 4: ≥45 y (n = 177) | P value |
|---|---|---|---|---|---|---|
| Maternal age, y a | 34.2 ± 7.0 | 26.1 ± 2.5 | 33.7 ± 2.6 | 41.5 ± 1.2 | 47.4 ± 2.6 | < .001 (4≠3≠2≠1) |
| Gravidity a | 3.6 ± 2.7 | 2.0 ± 1.3 | 3.4 ± 1.9 | 5.1 ± 3.2 | 4.3 ± 3.4 | < .001 (3≠4≠2≠1) |
| Parity a | 1.3 ± 1.1 | 0.4 ± 0.8 | 1.0 ± 0.9 | 2.4 ± 1.6 | 2.2 ± 2.0 | < .001 (3,4≠2≠1) |
| Nulliparity, n (%) | 2895 (52.8) | 1287 (72.7) | 954 (53.9) | 585 (33.1) | 69 (39) | < .001 |
| Maternal obesity, n (%) | 1139 (21) | 336 (19) | 354 (20) | 407 (23) | 42 (24) | .07 |
| Multifetal gestations, n (%) | 169 (3.1) | 41 (2.3) | 64 (3.6) | 52 (2.9) | 12 (6.8) | .004 |
| Oocyte donation, n (%) | NA | NA | NA | NA | 141 (79) | |
| Previous cesarean delivery, n (%) | 752 (13.8) | 91 (5.1) | 246 (13.9) | 375 (21.2) | 40 (22.6) | < .001 |
| Chronic hypertension, n (%) | 76 (1.4) | 2 (0.1) | 14 (0.8) | 48 (2.7) | 12 (6.8) | < .001 |
| Pregestational diabetes mellitus, n (%) | 66 (1.2) | 14 (0.8) | 19 (1.1) | 25 (1.4) | 8 (4.5) | < .001 |
| Gestational diabetes mellitus, n (%) | 309 (5.6) | 25 (1.4) | 74 (4.2) | 180 (10.2) | 30 (17.0) | < .001 |
| Gestational hypertension, n (%) | 149 (2.7) | 36 (2.0) | 41 (2.3) | 56 (3.2) | 16 (9.0) | < .001 |
| Preeclampsia toxemia, n (%) | 99 (1.8) | 12 (0.7) | 26 (1.5) | 42 (2.4) | 19 (10.7) | < .001 |
| Oligohydramnios, n (%) | 145 (2.6) | 43 (2.4) | 39 (2.2) | 55 (3.1) | 8 (4.5) | .04 |
Delivery outcome is given in Table 2 . The rate of preterm delivery (≤37, <34, and <32 weeks of pregnancy) was higher for the study group in comparison with the control groups. Overall, the cesarean section delivery rate was increased significantly in the study group in comparison with the control groups (78.5% vs 28.9%; P < .001). The indications for cesarean delivery are specified in Table 2 . Of interest is that the rate of breech presentation was significantly higher in the study group ( Table 2 ). Additionally, the rate of postpartum hemorrhage, the need for blood products transfusion, febrile complications, and prolonged hospitalization were increased in the study group ( Table 2 ).
