Becoming pregnant at age 37 is possible, but this age represents a significant shift in a woman’s reproductive journey. Fertility does not suddenly cease, but the biological changes that began in the early 30s accelerate during this late-thirties window. Understanding the realities of fertility decline, the increased risks involved, and the timeline for seeking support allows women to make informed choices. Focusing on optimizing health and knowing when to ask for specialized help is key to conception and a healthy pregnancy.
Fertility Decline and Ovarian Reserve at Age 37
The primary factor affecting conception at age 37 is a decline in both the quantity and quality of a woman’s eggs. The finite supply of eggs, known as the ovarian reserve, diminishes steadily over time. While the decline is gradual through the early 30s, it becomes noticeably steeper after age 35, with age 37 often cited as a point of more rapid acceleration.
At age 37, a woman may have approximately 25,000 eggs remaining. More concerning than the sheer number is the deterioration in egg quality, as a higher percentage of the remaining eggs carry chromosomal abnormalities, a condition called aneuploidy. For women at 37, about 42% of eggs may be aneuploid, which significantly increases the chance of an embryo failing to implant or resulting in miscarriage. This biological reality means that while a woman in her early 20s has about a 25% chance of conceiving in any given cycle, a woman aged 37 to 39 has a lower chance, with an estimated 67% likelihood of achieving a live birth within one year of trying.
Lifestyle Factors to Optimize Conception Odds
Maximizing the chance of natural conception involves adopting several proactive lifestyle strategies. The first step is accurately identifying and timing intercourse with the fertile window. This window is the six-day period leading up to and including ovulation, with the highest probability of conception occurring in the two days immediately before the egg is released.
Other factors that optimize conception odds include:
- Maintaining a healthy Body Mass Index (BMI), as being significantly over or underweight can disrupt regular ovulation.
- Engaging in moderate physical activity, while avoiding excessive exercise that may negatively affect reproductive hormones.
- Eliminating habits like smoking and limiting alcohol intake, which can accelerate the decline in egg quality.
- Managing chronic stress through techniques like mindfulness or therapy, as high stress levels can negatively impact fertility.
Understanding Advanced Maternal Age Risks
A woman who is 35 or older at the time of delivery is medically classified as having Advanced Maternal Age (AMA), which entails increased monitoring due to a higher risk of complications. Risks to the fetus are primarily linked to the age-related decline in egg quality, leading to higher rates of chromosomal conditions. For instance, the risk of having a baby with Down syndrome rises noticeably with maternal age.
The risk of miscarriage also increases sharply, rising to about 20% for women aged 35 to 39, compared to around 10% for women in their 20s. Maternal health risks are also elevated, including a higher incidence of gestational diabetes and preeclampsia (high blood pressure during pregnancy). Older mothers also face an increased risk of preterm birth, low birth weight, and the need for a Cesarean delivery. These elevated risks necessitate specialized prenatal care, often involving enhanced screening and monitoring, such as non-invasive prenatal testing (NIPT) or specialized ultrasounds.
The Timeline for Seeking Fertility Assistance
For women who are 35 or older, the clinical guidance for seeking fertility assistance is significantly accelerated compared to younger women. While couples under 35 are advised to try to conceive naturally for twelve months, women aged 35 to 40 should consult a specialist after just six months of regular, unprotected intercourse. This condensed timeline recognizes the accelerated pace of age-related fertility decline.
Seeking assistance involves a comprehensive evaluation for both partners. For the woman, initial diagnostic testing typically includes blood work to assess ovarian reserve markers like Anti-Müllerian Hormone (AMH) and Follicle-Stimulating Hormone (FSH). The male partner usually provides a semen analysis to check sperm count, motility, and shape. Early intervention and diagnosis allow specialists to recommend the most appropriate path forward, whether that involves lifestyle modifications or assisted reproductive technologies.