Annals of African Medicine Annals of African Medicine Society ISSN: 1596-3519 Vol. 10, Num. 3, 2011, pp. 204-208

Annals of African Medicine, Vol. 10, No. 3, July-September, 2011, pp. 204-208

Original Article

Pregnancy outcome in elderly primigravidae

JD Ojule, VC Ibe, PO Fiebai

Department of Obstetrics and Gynecology, University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria
Correspondence Address:J D Ojule, Department of Obstetrics and Gynecology, University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria, ojeydee@yahoo.com

Code Number: am11042

PMID: 21912003
DOI: 10.4103/1596-3519.84699

Abstract

Keywords: Elderly primigravidae, perinatal, maternal outcome, younger primigravidae

Introduction

With increasing cases of infertility, educational and career pursuits among women resulting in delay in child-bearing, more women are starting their obstetric career at the age 35 years and above. ^[1] Advanced maternal age and parity constitute two major factors in the outcome of pregnancy and labor, both in developed and developing countries. ^[2] The elderly primigravida is generally believed to have decreased fertility and increased risk for adverse pregnancy outcomes. ^[3] Reduced fertility with increasing maternal age is evidenced by decline in ovarian oocyte reserve and quality with increasing number of ovulatory cycles. ^[4] Poor oocyte quality is associated with an increased risk for aneuploidy, chromosomal abnormalities, and spontaneous abortions in this group of women who are routinely screened for these problems in some countries. ^[5]

With advanced maternal age, pregnant women are also more prone to medical conditions that can adversely influence their health and that of their fetuses. Women aged 35 years and above have been reported to have twice the rates of antepartum hospitalization than their younger counterparts. ^[6] Advanced maternal age is a risk indicator of several pregnancy and labor complications including spontaneous miscarriage, ectopic pregnancy, chromosomal abnormalities, twins, degenerating fibroids, hypertensive disorders, gestational diabetes, prolonged labor, cephalopelvic disproportion necessitating operative delivery, low birth weight, antepartum and intrapartum fetal loss and neonatal mortality. ^[7] Although these pregnancy complications have been observed over time, information regarding maternal and perinatal outcomes has been inconsistent. While some studies have found adverse outcomes among the elderly primigravidae ^[8],[9] others found no significant difference. ^[10],[11]

This study examines the maternal and perinatal outcome among elderly primigravidae, and compares them with those of younger primigravidae at the University of Port-Harcourt Teaching Hospital (UPTH).

Materials and Methods

This was a two-year retrospective case controlled study involving primigravid women aged 35 years and above (elderly primigravidae) who delivered at the UPTH between 1 ^st January 2005 to 31 ^st December 2006, and the younger primigravidae aged below 35 years, as the control group. Ethical approval was given by the UPTH Ethics Committee.

The study and control subjects were identified from the hospital antenatal and delivery registers and their case notes retrieved. Information on their sociodemographic characteristics, antenatal history, maternal and labor complications, babies′ sex, weight, Apgar scores, and perinatal complications were extracted. The data was coded, entered into a personal computer and analyzed using SPSS version 11.0 software. The results are presented as rates and proportions in tables. The Chi-square test was used for comparison of the two groups. Statistical significance was set at P values of ≤0.05 at 95% confidence levels.

The following definitions were used in this study: elderly primigravidae are those having their first delivery at age ≥35 years, ^[3],[12] younger primigravidae are those having first delivery at age ≤34 years, ^[12] preterm babies are those born at ≤36 weeks of gestation, ^[13] term babies refers to those born between 37 and 42 weeks gestation, ^[13] post-term; those born >42 weeks of gestation. ^[13] Birth asphyxia ^[14] refers to babies whose 5 min Apgar score was <7, babies who weighed <2.5 kg at birth are low birth weight, ^[13] those who weighed between 2.5 and 3.9 kg are normal birth weight, ^[13] while those who weighed ≥4.0 kg are macrosomic babies. ^[13]

Results

There were a total of 5147 parturients during the period under review and 74 of these were elderly primigravidae, while 1515 were young primigravid mothers. The prevalence of elderly primigravidae was 1.44%, accounting for 4.7% of all the primigravid mothers. Table 1 shows the sociodemographic characteristics of the elderly and younger primigravidae. The mean age of elderly primigravidae was 36.91 ± 1.87 years, while the mean age of other primigravidae was 26.78 ± 3.46 years.

All (100%) of the elderly primigravidae were married while, 1493 (98.5%) of other primigravidae were married. Sixty seven (90.5%) of the elderly primigravidae were Christians while 1490 (98.3%) of other primigravidae were Christians.

All (74) of the elderly primigravidae had formal education, of these 32 (43.2%) had secondary education while 42 (56.8%) had tertiary education. Only 18.5% (281) of the younger primigravidae had tertiary education while 87(5.7%) were uneducated.

Eight (10.8%) of the elderly primigravidae had preterm deliveries as compared to 77 (5.1%) of the young primigravidae who delivered before 37 weeks of gestation. The difference was statistically significant χ² = 4.49; P = 0.03. There was however no significant difference in the post-term delivery rate for the elderly primigravidae compared to the control group [(4.1% (3) vs 4.7% (72); χ² = 0.03, P = 0.9] as illustrated in [Table - 2].

[Table - 3] shows the mode of delivery. Up to 58.1% (43) of the elderly primigravidae had caesarean delivery as compared to 486 (32.1%) of the younger primigravidae (χ = 23.75, P = 0.001). The main indications for the caesarean deliveries were severe pre-eclampsia with unfavorable cervix, breech presentation, cephalopelvic disproportion, and placenta previa. However, the instrumental vaginal delivery rates of 4.4% (4) and 2.9% (47), respectively, for the elderly and young primigravidae was not significantly different (χ² = 4. 57, P = 0.06).

Eight (10.8%) of the babies delivered to the elderly primigravidae were low birth weight babies while 160 (10.6) of the babies of the younger primigravidae were low birth weight (χ = 0.15, P = 0.7). However, a significantly larger proportion 12 (16.2%) of the elderly primigravidae had macrosomic babies compared to the younger primigravidae 101 (6.6%); χ = 9.9, P = 0.002. The birth weight distribution is shown in [Table - 4].

Seven (9.5%) of the babies delivered to the elderly primigravidae had birth asphyxia while 148 (9.8%) of the babies of the young primigravidae had birth asphyxia. This was not statistically significant as P = 0.9. Similarly, I7 (1.1%) of the young primigravid mothers had stillbirths while there was none among the elderly primigravidae (χ² = 0.84, P = 0.3). The perinatal mortality rate of the babies of the younger primigravidae was 11.34/1000 live births. There was no congenital malformation in both groups. The perinatal outcome is shown in [Table - 5].

Discussion

The results of this study indicate that elderly primigravidae are at increased risk of caesarean delivery compared to their younger primigravid counterpart, in keeping with findings of other investigators. ^{[8],[9],[11],[12]} The increased caesarean section rate in elderly primigravidae found in this study resulted from various pregnancy and labor complications, including placenta previa, cephalopelvic disproportion, breech presentations, and pre-eclampsia among others, similar to earlier findings. ^{[9],[10],[12]}

There was also increased risk of instrumental vaginal delivery among the elderly primigravidae (4.4% vs 2.9%) compared to the younger primigravidae although this was not statistically significant ( P = 0.6). The indications were mainly for maternal exhaustion and fetal distress in second stage of labor. The increased instrumental vaginal delivery rate in elderly primigravidae had previously been documented by other workers. ^[13]

Similarly, the preterm delivery rate (10.8% vs 5.1%, P = 0.03) and fetal macrosomia (16.2% vs 6.6%, P = 0.002) were significantly higher in elderly primigravidae compared to the other primigravidae. The increased risk of preterm delivery in elderly primigravidae have been reported by other authors. ^{[9],[11],[12]} This may be as a result of increased pregnancy complications including placenta previa and hypertensive disorders warranting delivery before term in this group.

There were no significant differences in other outcome measures: post-term delivery, low birth weight, birth asphyxia, and stillborn and perinatal mortality rates between the two groups. This is also in keeping with the results elsewhere. ^{[9],[15],[16]}

The limitations of this study include its retrospective nature and the relatively small number of cases. Also, being a hospital-based study; we were only able to assess the outcomes of viable pregnancies. Early pregnancy losses could not be examined, but have also been associated with advanced maternal age. ^{[16],[17],[18]} Deliveries in our hospital constitute only a proportion of all deliveries and are therefore not representative of the entire situation in Port Harcourt.

The social status of the subjects was difficult to assess because of the retrospective nature of the study. The occupation of both women and their husbands do not necessarily correlate with their income and socioeconomic status in our experience in Port Harcourt. Artisans and unskilled workers with some oil workers have higher incomes and living standards than some professionals. Other sociodemographic variables including education, marital status and religion were similar between elderly primigravidae and their younger primigravid controls and therefore did not significantly influence the outcome measures.

Conclusion

This study shows that the elderly primigravidae are at increased risk of pre-term, macrosomic and caesarean deliveries compared to their younger primigravid counterparts.

Since there is presently no consensus on the negative impacts of advanced maternal age on the pregnancy outcome and whereas most of the studies have been retrospective and hospital based, a population-based study preferably a prospective one that will have a wider scope is advocated. Until this is done the inconsistencies that trail the results in this and other researches in these subjects will take a long time to settle.

References

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