Advance Age Pregnancy in a Tertiary Care Centre: A Descriptive Cross-sectional Study

ABSTRACT Introduction: Women who conceive at advance age are at risk of pregnancy complications and adverse foetal outcome. This study aims to find out the prevalence of pregnancy at advance age in a teaching hospital. Methods: A descriptive cross-sectional study was conducted between October 2019 to August 2020 at department of obstetrics and gynaecology of a tertiary care centre of Nepal, after obtaining ethical clearance from Institutional Review Committee (dated 03/09/2019 with ref no. 266) and informed consent from patient. Convenience sampling was done. All the patient who were ≥35 years and >28 weeks of gestation without any chronic illness were selected. Data and descriptive analysis were done using Statistical Package for the Social Sciences version 16. Point estimate at 95% Confidence Interval was calculated along with frequency and percentage for binary data. Results: Women aged 35 years and above constituted 104 (5.73%) of the total deliveries of study period. Most were multigravida 72 (69.23%) and 23 (22.12%) had preterm delivery. Rate of caesarean section were higher in advance maternal age 69 (66.35%). Maternal complications such as Hypertensive disorder of pregnancy 9 (8.65%), and mal-presentation 15 (14.42%) were higher among them. Perinatal outcome in form of low birth weight 9 (8.65%) and perinatal death 5 (4.80%) were increased in those women. Conclusions: From this study, it can be concluded that prevalence of advanced age at pregnancy was lower than study done in developed country but it was similar to study in India and is increasing in Nepal.


INTRODUCTION
Advanced maternal age is defined as 35 or more years at the time of delivery. 1 A study done in 29 countries revealed average prevalence of advanced maternal age was 12.3% and 2.8% in Nepal. 2 With increasing maternal age pregnancy may be complicated by hypertensive disorder of pregnancy, gestational diabetes mellitus (GDM), and antepartum haemorrhage. There is higher incidence of caesarean section, and postpartum haemorrhage and is a risk factor for stillbirth. Neonates are affected due to prematurity, low birth weight, Intra Uterine Growth Restriction, and foetal distress, which increase rates of Neonatal Intensive Care Unit admission. These increased risks appeared to be independent of maternal co-morbidities. 3,4 Although pregnancy with advanced age has also been increasing in developing countries like ours, limited study has been conducted to identify adverse outcome of pregnancy at advance age.
Hence, we aimed to find out the prevalence of advance maternal age at pregnancy in a tertiary hospital. Adding a 10% non-response rate, the sample size was 1174. But we collected data from 1813 patients.

METHODS
All patients were analysed for maternal outcome such as, pregnancy induced hypertension, gestational diabetes mellitus, placenta Previa, Premature Rupture of Membranes (PROM), malpresentation, oligohydramnios and postpartum haemorrhage. Perinatal outcome analysed as, preterm birth, Intrauterine Growth Retardation (IUGR), birth weight, perinatal deaths, and congenital anomalies. Information related to patient's general characteristics (age at the time of delivery, gravida, and gestational age), complication during pregnancy, mode of delivery and perinatal outcome was recorded in a predesigned pro forma and the data was tabulated in excel sheet.
The recorded data were analysed statistically using Statistical Package for Social sciences (SPSS) version 16.

RESULTS
Out of 1813 deliveries conducted during the study period, out of them 104 were above the age of 35 years at the time of admission. The overall prevalence of advanced maternal age at pregnancy was 104 (5.73%).
It was observed that multigravida 72 (69.23%) were more common in advanced maternal age. It appears that, majority had their first child before 35 years old and had delayed the second and subsequent pregnancy. In our study, rate of caesarean section 69 (66.35%) was higher in women 35 years and older as compared to vaginal delivery 32 (30.77%) ( Table 1).  Nine babies were low birth weight 9 (8.65%). There were 5 (4.80%) perinatal deaths in women of age 35 and above. Only 1 (0.96%) patient had congenital anomaly in the form of cleft lip and palate (Table 3).  8 In this study common malpresentation observed was breech. Pre-labour rupture of membranes and antepartum haemorrhage were also more common in advance maternal age (6.73% and 3.84% respectively). 8 These result were comparable with the study done by Ritu et al. where pre-labour rupture of membrane was 7.80% and antepartum haemorrhage was more than our study (6.50%). 9 Preterm birth (22.12%) was found to be the common complication of advance maternal age higher to study done by Pawde et al. were 17% were preterm. 9 Maternal complication such as PPROM, preeclampsia, antepartum haemorrhage were the major causes of preterm birth in our study. We also found that 4.80% of advance age mother had post-partum haemorrhage. Mehari, et al. and Radon-Pokracka, et al. showed similar result were 5.2% and 4.3% respectively had post-partum hemorrhage. 10,11 Lower contraction potential and decreased oxytocin receptor of uterus in elderly women might be the result of PPH. 12 We also observed that 8.65% of babies were of low birth weight. Our results are similar to study done by Radon-Pokracka, et al. where low birth weight in advance maternal age was 10.7%. 11 Low birth weight may be due to age-related changes in the uterine vasculature, poorer placental perfusion. In our study five women of 35 years and more had perinatal death (4.80%) where two had intrauterine foetal death, one had still birth and two were neonatal death. Similarly, Lean SC, et al. also reported increased rate of perinatal death (4.70%). 13 Antenatal complications, such as preeclampsia, antepartum haemorrhage and preterm birth can be the reason for perinatal death in our study.
Congenital anomalies (0.96%) was observed in our study in women of 35 years and more. This is similar to study done by Pawde et al (0.95%). 9 The main limitation of our study was single centre population and lack of data on race/ethnicity, socioeconomic status and BMI which also contribute to adverse pregnancy outcome. Our study also failed to collect information about reason for delayed pregnancy. This failure to examine the population of different centre and reason for delayed pregnancy may be addressed in future studies.

CONCLUSIONS
Prevalence of advance maternal age is increasing with increasing time. This study has shown that pregnancies over 35 years of age are high-risk pregnancies and have higher incidence of hypertensive disorder of pregnancies, premature rupture of membrane and malpresentation. Caesarean delivery was increased in those mothers. Along these advanced maternal age pregnancy was also found to be a major risk factor for preterm delivery, low birth-weight and perinatal death. So, they should be advised for frequent antenatal visits and increased maternal and foetal surveillance should be done to ensure a better maternal and perinatal outcome Conflict of Interest: None.