Women and the Reproductive Lifecycle

Women and the Reproductive Lifecycle

The reproductive lifecycle ushers in a variety of changes for women. The biological progression from childhood into puberty and on through to menopause is dependent upon an intricate balance of a number of physiological processes resulting in modulations of the reproductive hormones.

Throughout the reproductive lifecycle, there are a number of conditions that occur in women that may impact their health and quality of life. In addition, while the reproductive hormones are essential in the natural biological progression of both women and men, in women the sex hormones have also been linked to the development of many diseases and conditions, such as allergies, autoimmune disorders, thyroid disease, breast cancer, osteoporosis, and cardiovascular disease.

Precocious puberty (early puberty) has been seen to occur 10 times more often in girls than boys.1

Approximately 40% of infertility-clinic patients are diagnosed with anovulation—a condition in which the ovary does not release an egg each month as part of a woman’s normal cycle.2

Eight hundred women a day die from preventable causes related to pregnancy and childbirth.3

After menopause, women are more likely to suffer from poor bladder and brain function, poor skin elasticity and muscle power and tone, deterioration in vision, and some weight gain.4


Puberty is the process of physical changes by which a child’s body becomes an adult body capable of reproduction.5 For females, puberty is marked by the onset of menstruation, an important milestone in their reproductive lives.

What Is the Menstrual Cycle?
Menstruation is when the body sheds the lining of the uterus (womb). Having regular menstrual cycles is a sign that reproductive parts of the body are working normally.6

Two of the most significant differences between puberty in girls and boys are the age which puberty begins and the major sex steroids involved. Girls attain reproductive maturity about 4 years after the first physical changes of puberty appear. In contrast, boys accelerate more slowly but continue to grow for about 6 years after the first visible pubertal changes.7 Any increase in height beyond the post-pubertal age is uncommon for both boys and girls.
In North America, the first sign of puberty for young girls—breasts budding—normally occurs between ages 8 and 13, with an average age of 10 years.8

  •  The average duration of puberty is 4 years but can range from 1.5 to 8 years.8
  • The first menstrual period for U.S. girls today occurs on average between ages 12 and 13, compared with age 14 for girls in 1900. Regular ovulation is established by about 20 menstrual cycles after the first period.8
  • A normal menstrual cycle lasts about 28 days but can vary from 21 to 45 days in adolescents.8
  • In developing countries, abnormal uterine bleeding appears to affect about 5–15% of women of reproductive age.9
  • Abnormal uterine bleeding is a leading indication for hysterectomy, the most common non-obstetric operation in women in both the United States and the United Kingdom.9

Amenorrhea—lack of a menstrual period. This term is used to describe the absence of a period in:6

  • Young women who haven’t started menstruating by age 15
  • Women and girls who haven’t had a period for 90 days, even if they haven’t been menstruating for long
  • Causes include:

          • Pregnancy

          • Breastfeeding

          • Extreme weight loss

          • Eating disorders

          • Stress

Dysmenorrhea—painful periods, including severe cramps. Menstrual cramps in teens are caused by too much of a chemical called prostaglandin.6


Infertility affects approximately 10% of the population. Since infertility strikes diverse groups—affecting people from all socioeconomic levels and cutting across racial, ethnic, and religious lines—chances are great that a friend, relative, or neighbor is attempting to cope with the medical and emotional aspects of infertility.10
What Is Infertility?
Infertility in women is a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular, unprotected sexual intercourse.11
The Economic Burden of Infertility
The American Society of Reproductive Medicine (ASRM) lists the average price of an in vitro fertilization cycle in the U.S. to be $12,400 (medications not included).12

Both women and men can have problems that cause infertility. About one-third of infertility cases are caused by the male.13

Risk factors that may impact a woman’s ability to have a baby include:13

  • Age
  • Smoking
  • Excessive alcohol use
  • Stress
  • Poor diet
  • Athletic training
  • Being overweight or underweight
  • Sexually transmitted infections (STIs)
  • Health problems that cause hormonal changes, such as polycystic ovarian syndrome and primary ovarian insufficiency

Most cases of infertility in women are caused by problems with ovulation. Signs that a woman is not ovulating normally include irregular or absent menstrual periods.13
Ovulation problems are often caused by polycystic ovarian syndrome (PCOS). PCOS is a hormone-imbalance problem that can interfere with normal ovulation. PCOS is the most common cause of female infertility.13
Primary ovarian insufficiency (POI) is another cause of ovulation problems. POI occurs when a woman’s ovaries stop working normally before she is 40 years of age. POI is not the same as menopause.13
Less-common causes of infertility in women include:13

  • Blocked fallopian tubes due to pelvic inflammatory disease, endometriosis, or surgery for an ectopic pregnancy
  • Physical problems with the uterus
  • Uterine fibroids, which are noncancerous clumps of tissue and muscle on the walls of the uterus


Pregnancy—the nine months or so for which a woman carries a developing embryo and fetus in her womb—is for most women a time of great happiness and fulfillment. However, during pregnancy, both the woman and her developing child face various health risks. For this reason, it is important that all pregnancies be monitored by skilled care providers.14
What Is Pregnancy?
Pregnancy is the fertilization and development of one or more offspring, known as an embryo or fetus, in a woman's uterus. It is the common name for gestation in humans.
The Global Burden of Pregnancy

  • According to the WHO, 287,000 women died due to pregnancy or childbirth-related complications in 2010.15
  • In developing countries, nearly half of all mothers and newborns do not receive skilled care during and immediately after birth.16
  • Up to two-thirds of newborn deaths can be prevented if known, effective health measures are provided at birth and during the first week of life.16
  • In the United States, maternal stays with pregnancy- and delivery-related complications account for approximately 5% of total hospital costs.17

The factors that place a pregnancy at risk can be divided into four categories:
Existing health conditions

  • High blood pressure
  • Polycystic ovary syndrome
  • Diabetes
  • Kidney disease
  • Autoimmune disease
  • Thyroid disease
  • Infertility
  • Obesity


  • Teen pregnancy
  • First-time pregnancy after age 35

Lifestyle factors

  • Alcohol use
  • Cigarette smoking

Conditions of pregnancy

  • Multiple gestation
  • Gestational diabetes
  • Preeclampsia and eclampsia

In addition to a missed period, the earliest signs and symptoms of pregnancy might include:

  • Tender, swollen breasts
  • Nausea, with or without vomiting
  • Increased urination
  • Fatigue
  • Food aversions or cravings
  • Slight vaginal bleeding
  • Cramping
  • Mood swings
  • Dizziness
  • Constipation


Menopause is the permanent end of menstruation. It's a turning point, not a disease, but it can have a big impact on a woman's well-being. Although women can experience physical upheaval from hot flashes, night sweats, and other menopausal symptoms, it can also be the start of a new and rewarding phase of a woman's life—and a golden opportunity to guard against major health risks such as heart disease and osteoporosis.20
What Is Menopause?
Menopause is a natural, biological state in a woman’s life. It occurs when a woman stops having her monthly menstrual cycle, and it marks the end of her reproductive years. Menopause occurs when a woman is in her late 40s to early 50s; however, women who have their ovaries surgically removed undergo “sudden” menopause.21
The Economic Burden of Menopause
Women with diagnosed menopausal symptoms (DMS) have significantly higher medical, pharmacy, and sick-leave costs, according to a study published in April 2013.22

For both women and men, the changes in reproductive-hormone levels have an impact on health later in life. These changes, however, appear to have a greater impact on the health of women in comparison to their male counterparts.21

Common menopausal symptoms include:21

  • Hot flashes
  • Night sweats
  • Difficulty sleeping
  • Vaginal changes
  • Changes in sex drive
  • Mood changes
  • Urinary changes/stress incontinence
  • Skin changes

A major effect of menopause is a significant decrease in estrogen. It is unknown why some women pass through menopause with mild or no symptoms, while others struggle with more-bothersome symptoms.21

  • Approximately 55% of women going through menopause don’t do anything at all to treat symptoms.21
  • Approximately 75% of women experience hot flashes and night sweats at some point during perimenopause.21
  • About two-thirds of North American postmenopausal women experience hot flashes, and an estimated 10–20% of postmenopausal women have severe hot flashes. Most flashes last between 30 seconds and 5 minutes.21
  • Approximately 25% of women who experience hot flashes and night sweats have them for more than 5 years.21

Women lose an average of 25% of their bone mass from the time of menopause to age 60, due in large part to the loss of estrogen.21

  • Estrogen loss can also increase the risk of certain diseases, such as osteoporosis, which leads to hip, wrist, and spine fractures.21
  • Approximately 50% of women older than 50 will suffer an osteoporosis-related bone fracture, and one-third of white women ages 65 and older will have a fracture of the spine in their lifetime.21

Coronary artery disease
After menopause, a woman’s risk for coronary artery disease increases.21 A decline in the natural hormone estrogen may be a factor in heart-disease increase among post-menopausal women. Estrogen is believed to have a positive effect on the inner layer of the artery wall, helping to keep blood vessels flexible.23


Laboratory diagnostic testing plays an integral role in caring for women throughout the continuum of their reproductive lives. As an integrated diagnostics company, Siemens' comprehensive solutions, which include multiple imaging modalities, support reproductive care for a lifetime, including accurate diagnosis and monitoring. In addition, our solutions in healthcare IT support the exchange of data for making informed decisions.



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