The decision to pursue pregnancy at age 40 comes with a natural and important question about the likelihood of success. While it is certainly possible to conceive and have a healthy baby after this age, the journey is statistically more complex and often takes longer than it would for a younger woman. The main factor driving this complexity is the biological aging of the ovaries, which affects both the number and the genetic quality of the available eggs. Understanding these biological realities and the available medical support options allows for informed family planning and a proactive approach to conception.
The Biological Reality of Ovarian Aging
The decline in fertility after age 40 is primarily due to changes in the eggs (oocytes). Women are born with a finite number of eggs, the ovarian reserve, which naturally diminishes with age, reducing the number of follicles available each cycle.
The more significant factor is the decrease in egg quality, which accelerates significantly after the mid-30s. This diminished quality is characterized by a higher incidence of aneuploidy, meaning the eggs contain an incorrect number of chromosomes. By age 40, the percentage of eggs with chromosomal abnormalities can exceed 50%.
These chromosomal errors occur during the meiotic division process, which is prone to errors in older eggs. The increased rate of aneuploidy is the leading biological cause for higher rates of failed implantation, miscarriage, and chromosomal conditions like Down syndrome.
Conception Statistics and Timelines
Ovarian aging translates directly into a reduced probability of achieving natural conception each month. While a healthy, fertile 30-year-old woman has about a 20% chance of getting pregnant per cycle, this drops to less than 5% by age 40.
For women under 35, medical evaluation is typically recommended after one year of trying to conceive. For a woman age 40, the timeline is significantly shortened due to the accelerated decline in egg quality. Physicians recommend seeking a full fertility evaluation after just six months of actively trying. This earlier assessment allows for quicker intervention and the exploration of assisted reproductive options.
Health Considerations for Mother and Baby
Once conception is achieved, pregnancy at age 40 is associated with increased health risks for both mother and baby. For the mother, there is a higher likelihood of developing hypertensive disorders, such as preeclampsia and gestational hypertension. The risk of gestational diabetes is also at least twice as high compared to younger women.
Mothers also face higher rates of delivery complications, including placenta previa, preterm birth, and a greater need for cesarean delivery. For the baby, the primary concern is the increased rate of pregnancy loss, with the risk of miscarriage climbing to around 34% for women aged 40 to 44. The risk of stillbirth is also elevated.
The higher incidence of aneuploidy directly correlates to a greater risk of the baby having a chromosomal abnormality. The risk of a chromosomal condition is over seven times higher for women aged 40 and older compared to those aged 20 to 34. Therefore, comprehensive prenatal screening and diagnostic testing are common parts of prenatal care for older mothers.
Options for Conception Support
Women trying to conceive at age 40 should take proactive steps to assess their reproductive goals. An early fertility assessment is recommended, including testing hormone levels like Anti-Müllerian Hormone (AMH) and Follicle-Stimulating Hormone (FSH) to gauge the ovarian reserve. AMH reflects remaining egg quantity, while elevated FSH can indicate a diminished ovarian response.
Assisted Reproductive Technologies (ART) are frequently utilized, with In Vitro Fertilization (IVF) being the most effective treatment. While IVF success rates using one’s own eggs decline significantly after 40, it allows for Preimplantation Genetic Testing for Aneuploidy (PGT-A). PGT-A selects the healthiest embryos for transfer, improving the chance of a successful pregnancy.
For women with severely diminished egg quality, IVF with donor eggs offers a substantially higher success rate, as the quality of the egg is no longer tied to the recipient’s age.
Lifestyle adjustments are also important for optimizing the environment for conception. Maintaining a nutritious diet rich in antioxidants, managing stress, and stopping the use of alcohol and tobacco can help support reproductive health.