Table 1.

Table of included studies related to obstetric risk associated with pregnancy in old age.

Title	Authors	Sample	Research Design	Objective	Results
Pregnancy outcome in primiparae of advanced maternal age	Delbaere, I. et al., 2007 [7]	n = 2970 women aged ≥35 n = 23,921 primiparous women aged 25–29 years old	Population-based retrospective cohort study	To investigate the impact of maternal age on singleton pregnancy outcomes	Older maternal age correlated with very preterm birth, low birth weight, and perinatal death. This results independently in confounding and intermediate factors
The effect of advanced maternal age on perinatal outcomes in nulliparous singleton pregnancies	Kahveci, B. et al., 2018 [12]	n = 471 women <35 years n = 399 women 35–39 years n = 87 women ≥40 years	Retrospective analyses	Investigate the impact of AMA on perinatal and neonatal outcomes of nulliparous singleton pregnancies	Pregnancy at AMA is significantly associated with gestational diabetes and hypertension, preeclampsia increased cesarean section rates, SGA and spontaneous late preterm delivery
Increased maternal age, and the risk of fetal death	Fretts, R.C. et al., 1995 [8]	n = 94,346	Retrospective cohort study	Evaluate risk factors for fetal death among all deliveries	Women 35 years of age or older have a significantly higher rate of fetal death than their younger counterparts
Advanced maternal age and adverse pregnancy outcomes: evidence from a large contemporary cohort	Kenny, L.C. et al., 2013 [13]	n = 215,344 births; n = 122,307 mothers aged 20–29, 62,371 mothers aged 30–34, 33,966 mothers aged 35–39 7066 mothers aged ≥40	Population-based cohort study	Investigate the association between AMA (≥35) and adverse pregnancy outcomes	AMA is associated with a range of adverse pregnancy outcomes
Advanced maternal age and pregnancy outcomes: a multicountry assessment	Laopaiboon, M. et al., 2014 [14]	n = 308,149 singleton pregnant women	Secondary analysis of the facility-based, cross-sectional data of the WHO Multicountry Survey on Maternal and Newborn Health	Assess the association between advanced maternal age and adverse pregnancy outcomes	AMA significantly increased the risk of maternal adverse outcomes, including maternal near miss, maternal death, severe maternal outcomes, risk of stillbirths, and perinatal mortalities
Maternal risk factors for post-term pregnancy and cesarean delivery following labor induction	Roos, N. et al., 2010 [15]	n = 1,176,131 singletons births from gestational week 37 and onwards	Population-based cohort study	Investigate risk of post-term pregnancy (delivery at > or =42 weeks) and cesarean delivery following labor induction	Post-term pregnancy increased with increasing maternal age and was higher among primiparous women. The risk of a cesarean section following labor induction post-term, increased with maternal age and BMI: it was more than double among women ≥35
Pregnancy at or beyond the age of 40 years is associated with an increased risk of fetal death and other adverse outcomes	Hoffman, M.C. et al., 2007 [10]	n = 126,402 singleton deliveries divided into age groups of younger than 35 years, 35–39 years, and 40 years old or older	Retrospective study of all singleton pregnancies	Determine the frequency of fetal death in women aged ≥40 years	Pregnancy at advanced maternal age is associated with an increased rate of fetal death and other adverse pregnancy outcomes
Pregnancy outcomes at extremely advanced maternal age	Yogev, Y. et al., 2010 [17]	n = 177 women aged ≥45 years. Subgroup analysis compared women aged 45–49 years with women aged ≥50 years	Comparative analysis	Evaluate pregnancy outcomes in women at extremely advanced maternal age (>45 years)	Pregnancy at extreme advanced maternal age is associated with increased maternal and fetal risk
Advanced maternal age and adverse perinatal outcomes in an Asian population	Hsieh, T et al., 2010 [11]	n = 39,763 women, divided into age groups: Age 20–34 (n = 33,881), Age 35–39 (n = 5161), Age ≥ 40 (n = 721)	Retrospective cohort study	Investigate the association between AMA and adverse perinatal outcomes in an Asian population.	Advanced maternal age is associated with pregnancy complications and adverse perinatal outcomes.