Lifestyle factors play a pivotal role in fertility. They affect overall health and well being including fertility and are modifiable.
• Age at which a couple decides to start a family Fertility in general declines with increasing age in both males and females. In men semen parameters decline as early as 35 years with decrease in semen volume, morphology, motility and significant DNA damage.In women as age increases, number of eggs decline,menstrual cycles are shorter and irregular.
When age is less than 30 years,chance of conception approaches 71% and when more than 36 years only 41%. Also with age time to conceive is longer, ability to maintain pregnancy decreases and increase in chromosomal abnormalities and aneuploidy cause increase rates of spontaneous abortion and implantation loss.
• Diet and exercise: In men increased consumption of both protein and fat adversely affects fertility. In women increase in intake in animal fat specially trans fat and carbohydrates over vegetable proteins is detrimental to ovarian function causing ovulatory dysfunction. Besides diet, lack of optimal exercise and sedentary lifestyle increases infertility.
• Weight: Measured as BMI.
Below 18.5 - Underweight
18.5 - 24.9 - Normal
Above 25 - Overweight
Above 30 - Obese
In men increase in BMI more than 30 even by 3 units is associated with infertility by causing decrease in sperm concentration, motility and DNA damage.Obesity also causes erectile dysfunction further compounding the problem. Women with BMI more than 30 take longer to conceive with increased rate of early and recurrent miscarriage, decrease in implantation and decrease in ongoing pregnancy rates
Even being underweight negatively affects fertility in both men and women. In women with eating disorder eg anorexia nervosa cause ovulatory dysfunction ,menstrual irregularity and increase in preterm births. Psychological effects:
• Stress (physical, psychological, social) adversely affects fertility by causing decrease in sperm motility ,morphology and spermatogenesis. While in women even physical stress plays a role with women working more than 32 hours per week take longer time to conceive. Also psychological stress caused decreased fertilisation of oocytes and increase in still births due to increase in stress hormones.
• Recreational and prescription drugs:
Cigarette smoking causes decrease in sperm motility, morphology, semen volume and fertilising capacity and also DNA damage.
In women smoking causes decreased ovarian function and reserve. Also there is menstrual dysfunction and infertility.Impaired oocyte pick up and transport increased ectopic, longer time to conceive and compromised uterine environment. Besides tis, drugs like marijuana, cocaine and to a lesser extent opiates cause infertility by affecting spermatogenesis, semen parameters and in women impaired ovarian response, endocrine disruption and even still birth.
Prescription drugs like ampicillin, gentamycin, antiandrogens ,anabolic steroids, antipscychotics affect reproductive function adversely in both males and females. Alcohol will cause testicular atrophy in males decrease in all semen parameters and decreased chance of conception, increased rate of spontaneous abortion, fetal malformation, fetal death and ovarian dysfunction.
Caffeine: negative effects on female fertility specially if consumed more than 500 mg/day causing increased abortion, fetal death and still birth.
• Environmental and Occupational exposure:
Air pollution-sulfer dioxide, carbon monoxide etc cause decrease in sperm.motility, morphology and DNA damage while in women increased miscarriage, preterm birth, abortion and fetal death.
Heavy metals like lead and Boron (paint, batteries,metal products) mercury (batteries,thermometers, tainted seafood) can negatively affect semen quality.
exposure to pesticides, those with greater exposure to organic solvents ,welders have greater incidence of infertility due to altered semen parameters. Also hobbies like gardening, painting, jewellery making and glass workers are exposed to excessive lead leading to poor fertility.
• Radiation: Exposure to Xrays and Gamma rays cause damage to germ cells and leydig cells and even cause permanent sterility. Modern day cell phone use causes decrease in all semen parameters, sperm vitality by ROS specially if carried around hip or belt region.