Increasingly, many women are delaying childbirth until well into their thirties. Women who are trying to conceive beyond the peak reproductive years of their twenties, however, are often very concerned about their conception chances. While it is true that fertility rates decline with age across virtually all human populations (Wood 1989; 102; O’Connor et al 1998; 127) and the time to conception is generally longer for women who are past their mid-twenties, (Dunson et al 2002) the chances of conceiving within a year or two are fairly good for women in their late thirties, especially when intercourse is timed well in the fertile period.
The cumulative conception rate for women aged 35-39 is 60% after one year of trying and 85% at two years (Taylor 2003). While this may not sound so promising when you want to have a baby right now, these figures may be higher for women who are able to identify their fertile time and focus intercourse within the fertile window. Time to conception is considerably reduced when intercourse is focused within the most fertile window of the menstrual cycle (Hilgers et al 1992).
Women may delay childbearing for a variety of reasons. In a recent survey of women aged over 35 years seeking assisted reproductive technology, Hammarberg and Clarke (2005) found that 18% of the women in their survey cited “being unaware of the impact of age on fertility” as a reason for their delay in childbearing. Other reasons cited included the desire to complete one’s education, the lack of an appropriate mate, career ambitions, financial concerns, and not wanting a child earlier (Hammarberg and Clarke 2005).
Whatever the reason for delaying childbearing, the pressures of trying to conceive quickly are often greater for women beyond their peak reproductive years. It is generally recommended to begin investigations after one year of trying without conceiving or six cycles of trying with “fertility focused” intercourse (Gnoth et al 2005). Women who are beyond their mid-thirties, however, may want to consult their physicians earlier if they suspect any potential fertility issues or if they are concerned that conception is not happening as quickly as they hoped.
Dunson, D. B., B. Colombo, et al. (2002). "Changes with age in the level and duration of fertility in the menstrual cycle." Hum Reprod 17(5): 1399-403.
Gnoth, C., E. Godehardt, et al. (2005). "Definition and prevalence of subfertility and infertility." Hum Reprod 20(5): 1144-1147.
Hammarberg, K. and V. E. Clarke (2005). "Reasons for delaying childbearing--a survey of women aged over 35 years seeking assisted reproductive technology." Aust Fam Physician 34(3): 187-8, 206.
Hilgers, T. W., K. D. Daly, et al. (1992). "Cumulative pregnancy rates in patients with apparently normal fertility and fertility-focused intercourse." J Reprod Med 37(10): 864-6.
O'Connor, K. A., D. J. Holman, et al. (1998). "Declining fecundity and ovarian ageing in natural fertility populations." Maturitas 30(2): 127-36.
Taylor, A. (2003). "ABC of subfertility: extent of the problem." Bmj 327(7412): 434-6.
Wood, J. W. (1989). "Fecundity and natural fertility in humans." Oxf Rev Reprod Biol 11: 61-109.