What to expect during an advanced maternal age pregnancy
Pregnancy at any age is a remarkable journey, but when it occurs after the age of 40, it is classified as an ‘advanced maternal age’ (AMA) pregnancy. While the term may sound clinical, it simply reflects a pregnancy that requires more specialised care due to the natural changes that come with age.
AMA pregnancies occur more often now, mainly due to social factors and medical advancements. Many families start their journeys later on in their adult life because of increased higher education and work opportunities, people getting married later, medical advancements in birth control and the rise of assisted reproductive technology.
It’s important to understand that although some AMA pregnancies can be considered high risk, these risks are small if specialised and individualised care is given. Here's what to expect during an advanced maternal age pregnancy and how to navigate this exciting chapter.
Understanding Advanced Maternal Age
As women age, their reproductive system undergoes various changes that impact fertility. These changes are part of the natural ageing process and affect both the quantity and quality of eggs, hormonal balance, and overall reproductive health.
It is considered an AMA pregnancy when a woman is aged 40 years or over at the time of conception and the physiological demands of the pregnancy can increase the risks if the right treatment isn’t received. Here are some of the physiological changes that happen and why they affect fertility:
1. Decline in egg quantity
Finite egg supply: Women are born with a fixed number of eggs, approximately 1-2 million. By the time of puberty, this number decreases to around 300,000-400,000. Over time, the number of eggs continues to decline due to ovulation and natural degeneration.
Reduced egg count: By the late 20s and early 30s, egg reserves start to diminish significantly. The decline becomes more rapid after the age of 35, and by the time a woman reaches menopause (around age 50-52), her egg supply is nearly depleted.
2. Decline in egg quality
Age and chromosomal abnormalities: The quality of eggs also decreases with age, particularly after 35. As women get older, eggs are more likely to have chromosomal abnormalities, increasing the risk of conditions such as Down Syndrome and miscarriage.
DNA integrity: Older eggs are more prone to DNA damage, which can reduce their ability to be fertilised or result in developmental issues during pregnancy.
3. Hormonal changes
Decreased oestrogen and progesterone levels: As women age, the ovaries produce less oestrogen and progesterone, the hormones essential for regulating the menstrual cycle and maintaining pregnancy. These hormonal fluctuations contribute to irregular cycles and reduced ovulatory function.
Perimenopause and menopause: Perimenopause, the transition period before menopause, can begin as early as the late 30s or early 40s. During this time, hormone levels fluctuate significantly, leading to irregular periods, hot flashes, mood swings, and a decline in fertility. Menopause, defined as 12 consecutive months without menstruation, marks the end of a woman’s reproductive years.
4. Reduced ovulatory function
Irregular ovulation: With age, ovulation becomes less predictable and less frequent. Women in their late 30s and 40s may experience anovulatory cycles (cycles where no egg is released), which decreases the chances of conception.
Weaker ovarian response: As ovarian function declines, the body’s response to fertility hormones weakens. This means even if ovulation occurs, the quality of the released egg may be suboptimal for fertilisation.
5. Increased risk of reproductive health conditions
Fibroids: Uterine fibroids (non-cancerous growths in the uterus) are more common as women age. Fibroids can interfere with implantation, cause miscarriages, and contribute to fertility challenges.
Endometriosis: This condition, where tissue similar to the uterine lining grows outside the uterus, becomes more prevalent in older women and can affect fertility by causing inflammation and scarring around the reproductive organs.
Polycystic Ovary Syndrome (PCOS): Although often diagnosed in younger women, the effects of PCOS may persist into later years and affect ovulation, making it harder to conceive naturally.
6. Cervical and uterine changes
Cervical mucus: Cervical mucus, which helps sperm travel to the egg, becomes less abundant and of poorer quality as women age. This can make it more difficult for sperm to reach and fertilise an egg.
Uterine lining: The uterine lining may become thinner with age, potentially reducing the chances of successful implantation of a fertilised egg. Additionally, conditions like uterine polyps or scarring may increase with age, further complicating implantation.
7. Increased risk of pregnancy complications
Higher risk of miscarriage: The likelihood of miscarriage increases with age due to a combination of reduced egg quality, hormonal changes, and underlying health conditions.
Pregnancy conditions: Older women are more prone to pregnancy complications such as gestational diabetes, preeclampsia, and hypertension. These conditions can further complicate both conception and the health of the pregnancy.
8. Overall health and lifestyle
Impact of health: Aging often comes with the development of health conditions such as obesity, diabetes, or thyroid issues, all of which can impact fertility. Additionally, lifestyle factors like smoking, alcohol consumption, and stress can further contribute to fertility decline.
Body’s ability to sustain pregnancy: As the body ages, its ability to maintain a healthy pregnancy becomes more challenging due to a combination of physical changes, hormonal shifts, and the increased likelihood of chronic conditions.
Medical Risks and Management Strategies
AMA is associated with increased risks of complications. Some of the most significant risks include gestational diabetes, hypertension, and placental problems. Here’s a detailed look at these risks and how they can be managed through specialised care.
1. Gestational Diabetes
Risk: Gestational diabetes is more common in women of advanced maternal age due to insulin resistance, which tends to increase with age. Insulin resistance can lead to higher blood sugar levels during pregnancy, affecting both the mother and the baby.
Consequences: Poorly controlled gestational diabetes can lead to larger babies (macrosomia), which increases the risk of birth injuries, caesarean delivery, and neonatal complications like low blood sugar or breathing problems. It also increases the mother's risk of developing type 2 diabetes later in life.
Management:
Screening: All pregnant women are typically screened for gestational diabetes between 24-28 weeks, but for women of AMA, earlier screening can sometimes be recommended.
Diet and exercise: Managing blood sugar levels through a healthy diet and regular exercise is crucial. Working with a dietitian can help develop a tailored meal plan.
Monitoring: Frequent monitoring of blood glucose levels after a diagnosis of gestational diabetes helps ensure they remain within a healthy range. Some women may need to check their levels multiple times a day.
Medications: If dietary changes aren’t sufficient, insulin or other medications may be prescribed to help control blood sugar levels.
2. Hypertension (high blood pressure)
Risk: Hypertension, both chronic and pregnancy-induced (gestational hypertension), is more common in older pregnant women. Preeclampsia, a condition characterised by high blood pressure and signs of organ dysfunction (often involving the kidneys), is also more prevalent with AMA.
Consequences: Untreated high blood pressure can lead to serious complications like preeclampsia, placental abruption, preterm delivery, or even stillbirth. For the mother, it increases the risk of long-term cardiovascular diseases.
Management:
Regular monitoring: Blood pressure is closely monitored throughout the pregnancy, particularly after 20 weeks. Frequent prenatal visits help catch any early signs of hypertension or preeclampsia.
Lifestyle modifications: Maintaining a healthy weight, eating a balanced diet low in sodium, and engaging in regular physical activity can help manage blood pressure.
Medication: Safe antihypertensive medications may be prescribed to control blood pressure. Some medications are preferred over others during pregnancy to minimise risks to the baby.
Early delivery: If preeclampsia develops and is severe, early delivery may be recommended to protect both the mother and the baby.
3. Placental problems
Risk: Women of advanced maternal age are at increased risk for placental issues, including placenta previa (where the placenta covers the cervix) and placental abruption (where the placenta detaches from the uterine wall before delivery). These conditions can be more likely in AMA pregnancies due to changing uterine structures or previous surgeries.
Consequences:
Placenta previa: Can cause severe bleeding during pregnancy or delivery, leading to complications for both the mother and baby. It often requires caesarean delivery.
Placental abruption: This is a medical emergency that can result in severe bleeding, preterm birth, and can be life-threatening for both mother and baby.
Management:
Ultrasound monitoring: Routine ultrasounds are used to monitor placental position and function.. In cases of placenta previa, additional ultrasounds may be performed to track changes as the pregnancy progresses.
Planned caesarean delivery: If placenta previa persists, a caesarean section is usually scheduled before labour begins to prevent complications from bleeding during a vaginal delivery.
4. Preterm labour and birth
Risk: Advanced maternal age is associated with an increased risk of preterm labour (labour that occurs before 37 weeks of gestation).
Consequences: Preterm birth can result in complications for the baby, including respiratory issues, underdeveloped organs, and a greater risk of long-term developmental and health problems.
Management:
Cervical length monitoring: Regular ultrasounds may be used to monitor cervical length, as a shortened cervix can be a predictor of preterm labour.
Progesterone therapy: For women at high risk of preterm labour, progesterone therapy can be prescribed to help maintain pregnancy to full term.
Bed rest and hospitalisation: In some cases, bed rest or even hospitalisation may be recommended to prevent early labour. In severe cases, medications may be administered to delay labour.
5. Foetal chromosomal abnormalities
Risk: The likelihood of chromosomal abnormalities, such as Down Syndrome, increases significantly as women age. This is due to the decreased quality of eggs, which are more prone to errors during cell division.
Consequences: Chromosomal abnormalities can result in miscarriage, stillbirth, or congenital disabilities that affect the baby’s development and health.
Management:
Prenatal screening: Early screening tests, such as non-invasive prenatal testing (NIPT), measure foetal DNA in the mother’s blood to detect chromosomal abnormalities. Other screening options include the first trimester combined test (blood test and ultrasound) and second trimester quad screening.
Diagnostic testing: For more definitive results, diagnostic tests like chorionic villus sampling (CVS) or amniocentesis can detect chromosomal abnormalities with high accuracy. These tests carry a small risk of miscarriage and are typically offered based on risk factors.
6. Increased risk of caesarean delivery
Risk: AMA pregnancies are more likely to result in caesarean sections (C-sections) due to increased rates of complications such as labour dystocia (failure to progress), foetal distress, placental issues, and maternal health concerns.
Management:
Planning and preparation: If a caesarean is anticipated, women can work with their healthcare providers to plan the safest delivery. This may include discussions about timing, anaesthesia options, and postoperative recovery.
Support for Vaginal Birth After Cesarean (VBAC): In some cases, women may still be candidates for vaginal birth after a previous caesarean. A detailed evaluation will determine the safest approach.
Working with Obstetricians who are experienced in AMA pregnancies and knowledgeable about the potential risks involved helps ensure that potential complications are detected early and managed effectively. Tailored antenatal care, regular screening, and individualised treatment plans can significantly reduce the risks for both the mother and the baby, leading to healthier outcomes.
Success Rates and Positive Outcomes
Thanks to our profession and technologies, AMA pregnancies are now more successful than ever.
Statistics of AMA pregnancy risk factors (refer to table) can be manageable with correct personalised care. While there is an increased risk of complications, the majority of women in this age group deliver healthy babies with proper antenatal care and monitoring.
We also offer pre-conceptual care, a consultation that happens before pregnancies that can identify and treat conditions so that the chances of a healthy pregnancy are higher.
Wellington Obstetrics look after plenty of women aged 35-45 years who’ve had successful pregnancies under our specialised care. We have a holistic approach that helps you feel confident that we’ve addressed all risks and the management around those risks.
Preconception and Prenatal Care Recommendations
For women of AMA, recommended medical tests and health screenings are essential to ensure the health of both the mother and the baby. These screenings help identify potential risks early and allow for timely interventions. Here’s an outline of the recommended medical tests and health screenings for AMA patients:
1. Preconception counselling
Purpose: To evaluate overall health and address any issues before conception, improving the chances of a healthy pregnancy.
Components:
Medical history review: Discussion of previous pregnancies, any existing health conditions, family history of genetic disorders, and lifestyle factors.
Physical examination: Assessment of general health and identification of any pre-existing conditions that could affect pregnancy.
Genetic counselling: Evaluation of the risk for inherited conditions or chromosomal abnormalities, particularly if there is a family history of genetic disorders.
Lifestyle modifications: Advice on optimising health through diet, exercise, and quitting harmful habits (e.g., smoking, excessive alcohol).
2. Preconception tests
Fertility assessment: Evaluation of ovarian reserve through tests such as:
Anti-Müllerian Hormone (AMH) Levels: Measures the quantity of remaining eggs.
Antral Follicle Count (AFC): Ultrasound assessment of the number of small follicles in the ovaries.
Day 3 FSH and estradiol levels: Hormone tests to evaluate ovarian function.
3. Early pregnancy testing and screenings
Confirmatory tests:
Pregnancy Test: To confirm pregnancy, usually through a urine test or blood test.
Initial prenatal visit:
Comprehensive history and physical examination: Detailed evaluation to assess health risks and establish a baseline for monitoring.
Blood tests: These include complete blood count (CBC), blood type, and Rh factor, as well as screening for infections such as hepatitis B, syphilis, and HIV.
4. Genetic screening and diagnostic tests
First-trimester screening:
Nuchal Translucency (NT) scan: Ultrasound to measure the thickness of the nuchal fold, which can indicate the risk of Down syndrome and other chromosomal abnormalities.
First-trimester blood tests: Measures levels of pregnancy-associated plasma protein-A (PAPP-A) and human chorionic gonadotropin (hCG).
Second-trimester screening:
Quad screen: Blood test that measures four substances to assess the risk of Down syndrome, trisomy 18, and neural tube defects.
Non-Invasive Prenatal Testing (NIPT):
NIPT: An advanced blood test that analyses foetal DNA in the mother's blood to assess the risk of chromosomal abnormalities like Down syndrome, trisomy 18, and trisomy 13. It is highly accurate and can be performed as early as 10 weeks of pregnancy.
Diagnostic testing:
Chorionic Villus Sampling (CVS): Performed between 10-13 weeks of pregnancy to collect and analyse placental tissue for genetic conditions.
Amniocentesis: Performed between 15-20 weeks of pregnancy to collect and analyse amniotic fluid for genetic abnormalities.
5. Regular prenatal monitoring
Routine check-ups:
Monthly visits: Regular visits to monitor maternal and foetal health, including measuring blood pressure, weight, and foetal heart rate.
Ultrasound scans:
First trimester: Confirm gestational age and number of embryos and assess for early signs of potential issues.
Second trimester: Detailed anatomy scan (18-22 weeks) to assess foetal development and check for structural abnormalities.
Third trimester: Growth scans, if needed, to monitor foetal growth and amniotic fluid levels.
Blood pressure monitoring:
Regular checks: To monitor for signs of gestational hypertension or preeclampsia, which are more common in AMA pregnancies.
Foetal monitoring:
Non-Stress Test (NST): Assesses foetal heart rate and response to movement, especially if concerns about foetal well-being exist.
Biophysical Profile (BPP): Combines ultrasound and NST to evaluate foetal health and amniotic fluid levels.
6. Management of complications
Gestational diabetes:
Glucose tolerance test: Typically performed between 24-28 weeks to screen for gestational diabetes.
Preeclampsia:
Regular monitoring: Close monitoring of blood pressure and urine for signs of proteinuria (protein in urine).
Pregnancies at an advanced maternal age (AMA) can indeed be successful and healthy with the right medical care and support. While age-related factors can pose challenges, advances in reproductive medicine and prenatal care offer promising solutions that enhance the likelihood of a positive pregnancy and healthy birth.
With individualised treatment plans created by highly trained obstetricians, women of advanced maternal age can benefit from tailored care that addresses their specific health needs and concerns. This includes preconception counselling, targeted fertility treatments, and proactive management of any pregnancy complications.
We're here to support you through every step of this incredible journey. Find out more about our obstetricians and how we can help you.