Maternal age and risk for adverse outcomes

Published:August 25, 2018DOI:


      The objective of this study was to characterize the risk for severe maternal morbidity and other pregnancy complications by maternal age during delivery hospitalizations.

      Study Design

      This retrospective cohort analysis used the Perspective database to characterize the risk for adverse maternal outcomes from 2006 to 2015 based on maternal age. Women were divided into 7 categories based on maternal age: 15–17, 18–24, 25–29, 30–34, 35–39, 40–44, and 45–54 years of age. The primary outcome of this study was severe maternal morbidity as defined by the Centers for Disease Control and Prevention. Secondary outcomes included (1) overall comorbid risk; (2) risk for pregnancy complications such as postpartum hemorrhage, gestational diabetes, preeclampsia, and cesarean delivery; and (3) risk for individual severe morbidity diagnoses such as stroke, embolism, eclampsia, and hysterectomy. Adjusted models were fitted to assess factors associated with severe morbidity with adjusted risk ratios (aRRs) and 95% confidence intervals (CI) as measures of effect. Population weights were applied to create national estimates.


      Of 36,944,292 deliveries included, 2.5% occurred among women aged 15–17 years (n = 921,236), 29.1% to women aged 18–24 years (n = 10,732,715), 28.6% to women aged 25–29 years (n = 10,564,850), 24.9% to women aged 30–34 years (n = 9,213,227), 12.1% to women aged 35–39 years (n = 4,479,236), 2.6% to women aged 40–44 years (n = 974,289), and 0.2% to women aged 45–54 years (n = 58,739). In unadjusted analyses, severe morbidity was more than 3 times higher (risk ratio [RR], 3.33, 95% confidence interval [CI], 3.03–3.66) for women 45-54 years compared with women 25–29 years. Women aged 40–44, 35–39, and 15–17 years were also at increased risk (RR, 1.83, 95% CI, 1.77–1.89; RR, 1.36, 95% CI, 1.33–1.39; RR, 1.39, 95% CI, 1.34–1.45, respectively). In the adjusted model, the 45–54 year old group was associated with the highest relative risk (aRR, 3.46, 95% CI, 3.15–3.80) followed by the 40–44 year old group (aRR 1.90, 95% CI, 1.84–1.97), the 35–39 year old group (aRR, 1.43, 95% CI, 1.40–1.47), and the 15–17 year old group (aRR, 1.20, 95% CI, 1.15–1.24). Cesarean delivery, preeclampsia, postpartum hemorrhage, and gestational diabetes were most common among women aged 45–54 years, as were thrombosis and hysterectomy.


      While differential risk was noted across maternal age categories, women aged 45 years old and older were at highest risk for a broad range of adverse outcomes during delivery hospitalizations.

      Key words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to American Journal of Obstetrics & Gynecology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Martin J.A.
        • Hamilton B.E.
        • Osterman M.J.K.
        Births in the United States, 2016.
        NCHS Data Brief. 2017; : 1-8
        • Hamilton B.E.
        • Martin J.A.
        • Osterman M.J.K.
        • et al.
        Births: provisional data for 2016. Vital statistics rapid release, no 2.
        National Center for Health Statistics, Hyattsville (MD)2017 (Available at) (Accessed January 20, 2018)
        • Hodes-Wertz B.
        • Druckenmiller S.
        • Smith M.
        • Noyes N.
        What do reproductive-age women who undergo oocyte cryopreservation think about the process as a means to preserve fertility?.
        Fertil Steril. 2013; 100: 1343-1349
        • Sauer M.V.
        Reproduction at an advanced maternal age and maternal health.
        Fertil Steril. 2015; 103: 1136-1143
        • Sauer M.V.
        • Paulson R.J.
        • Lobo R.A.
        Reversing the natural decline in human fertility. An extended clinical trial of oocyte donation to women of advanced reproductive age.
        JAMA. 1992; 268: 1275-1279
        • Sauer M.V.
        • Paulson R.J.
        • Lobo R.A.
        Pregnancy after age 50: application of oocyte donation to women after natural menopause.
        Lancet. 1993; 341: 321-323
        • Usta I.M.
        • Nassar A.H.
        Advanced maternal age. Part I: obstetric complications.
        Am J Perinatol. 2008; 25: 521-534
        • Jackson S.
        • Hong C.
        • Wang E.T.
        • Alexander C.
        • Gregory K.D.
        • Pisarska M.D.
        Pregnancy outcomes in very advanced maternal age pregnancies: the impact of assisted reproductive technology.
        Fertil Steril. 2015; 103: 76-80
        • Ben-David A.
        • Glasser S.
        • Schiff E.
        • Zahav A.S.
        • Boyko V.
        • Lerner-Geva L.
        Pregnancy and birth outcomes among primiparae at very advanced maternal age: at what price?.
        Matern Child Health J. 2016; 20: 833-842
        • Khalil A.
        • Syngelaki A.
        • Maiz N.
        • Zinevich Y.
        • Nicolaides K.H.
        Maternal age and adverse pregnancy outcome: a cohort study.
        Ultrasound Obstet Gynecol. 2013; 42: 634-643
        • Stulberg J.
        • Delaney C.
        • Neuhauser D.
        • Aron D.
        • Fu P.
        • Koroukian S.
        Adherence to surgical care improvement project measures and the asssociation with postoperative infections.
        JAMA. 2010; 303: 2479-2485
        • Cozowicz C.
        • Poeran J.
        • Olson A.
        • Mazumdar M.
        • Morwald E.E.
        • Memtsoudis S.G.
        Trends in perioperative practice and resource utilization in patients with obstructive sleep apnea undergoing joint arthroplasty.
        Anesth Analg. 2017; 125: 66-77
        • Poeran J.
        • Opperer M.
        • Rasul R.
        • et al.
        Change in off-label use of bone morphogenetic protein in spine surgery and associations with adverse outcome.
        Global Spine J. 2016; 6: 650-659
        • Cozowicz C.
        • Poeran J.
        • Zubizarreta N.
        • Mazumdar M.
        • Memtsoudis S.G.
        Trends in the use of regional anesthesia: neuraxial and peripheral nerve blocks.
        Reg Anesth Pain Med. 2016; 41: 43-49
        • Kuklina E.
        • Whiteman M.
        • Hillis S.
        • Jameieson D.
        • Meikle S.
        • Posner S.
        An enhanced method for identifying obstetric deliveries: implications for estimating maternal morbidity.
        Matern Child Health J. 2008; 12: 469-477
      1. Centers for Disease Control and Prevention. Severe maternal morbidity in the United States. Available at: Accessed Jan. 20, 2018.

        • Combs C.A.
        • Robertson P.A.
        • Laros Jr., R.K.
        Risk factors for third-degree and fourth-degree perineal lacerations in forceps and vacuum deliveries.
        Am J Obstet Gynecol. 1990; 163: 100-104
        • Bateman B.T.
        • Mhyre J.M.
        • Hernandez-Diaz S.
        • et al.
        Development of a comorbidity index for use in obstetric patients.
        Obstet Gynecol. 2013; 122: 957-965
        • Metcalfe A.
        • Lix L.M.
        • Johnson J.A.
        • et al.
        Validation of an obstetric comorbidity index in an external population.
        BJOG. 2015; 122: 1748-1755
        • Carolan M.
        Maternal age >/=45 years and maternal and perinatal outcomes: a review of the evidence.
        Midwifery. 2013; 29: 479-489
        • Fitzpatrick K.E.
        • Tuffnell D.
        • Kurinczuk J.J.
        • Knight M.
        Pregnancy at very advanced maternal age: a UK population-based cohort study.
        BJOG. 2017; 124: 1097-1106
        • Yogev Y.
        • Melamed N.
        • Bardin R.
        • Tenenbaum-Gavish K.
        • Ben-Shitrit G.
        • Ben-Haroush A.
        Pregnancy outcome at extremely advanced maternal age.
        Am J Obstet Gynecol. 2010; 203: 558.e1-558.e7
        • Dulitzki M.
        • Soriano D.
        • Schiff E.
        • Chetrit A.
        • Mashiach S.
        • Seidman D.S.
        Effect of very advanced maternal age on pregnancy outcome and rate of cesarean delivery.
        Obstet Gynecol. 1998; 92: 935-939

      Linked Article

      • Reply
        American Journal of Obstetrics & GynecologyVol. 220Issue 2
        • Preview
          We agree with the thoughtful comment from Drs Snowden and Klebanoff.1 The discharge hospitalization data that were used are cross sectional and unlinked to previous or subsequent health data.2 Given that we are not able to determine whether exposures occurred before individual outcomes, it is appropriate to characterize it as cross sectional.
        • Full-Text
        • PDF
      • Re: Maternal age and risk for adverse outcomes
        American Journal of Obstetrics & GynecologyVol. 220Issue 2
        • Preview
          We believe that the study design of the paper “Maternal age and risk for adverse outcomes”1 was mischaracterized as a retrospective cohort. As we have noted previously,2,3 in a cohort study, participants are identified as exposed or unexposed to the factor of interest, regardless of outcome, and are then followed over time to determine who experiences the outcome of interest.4 In particular, in a retrospective cohort, exposure occurs in the past and is ascertained from preexisting records, and follow-up time also occurs in the past.
        • Full-Text
        • PDF