Dr Tan Chee Hoe, Obstetrics and Gynaecology (O&G), Pantai Hospital Cheras (PHC)
There are times in your menstrual cycle when you are at your most fertile, and this is the time of the month when you are most likely to get pregnant.
Each menstrual cycle begins on the first day of your menstruation and continues until the subsequent first day of your next menstruation. A normal menstrual cycle falls typically between 21 – 35 days. The menstruation (menstrual flow) usually lasts within 2-7 days on average. If your menstrual cycle is at regular intervals with a few days in variation, you are likely to ovulate during most of your menstrual cycle.
Ovulation is usually followed by the cessation of menstruation and the egg maturing process. You can use 3-4 of your menstrual cycle average length to calculate your Fertile Period (window), especially if you are keen to conceive. You are most fertile at the time of ovulation (when a mature egg is released from your ovary), which usually occurs about 14 days before your next menstruation begins. If the attempt for pregnancy failed, the subsequent menstrual cycle would follow, and your menstruation will begin. If you have successfully conceived, then your menstrual cycle will not resume until the fetus is delivered and you have completed nursing your newborn.
Let us illustrate the estimation of your Fertile Period with an example here. If your menstrual cycle is averaged at 28-30 days, you will most likely ovulate at day 14-16 of your menstrual cycle by subtracting 14 days from the 28-30 days cycle. If your menstrual cycle is averaged at 32-34 days, then your fertile window will be at day 18-20 of your menstrual cycle.
You may need to add or subtract (plus & minus) 1-2 days from your fertile window to buffer cycle length variation. If menstruation happens, it likely indicates a failure to conceive from the previous menstrual cycle. You may continue to try again for another six months if you are above 35. If you are below 35, you may try for another 12 months.
Every step in the human reproduction process must happen correctly for natural conception to take place. The steps include:
- One of the two ovaries releases a mature egg.
- The egg is picked up by the fallopian tube.
- Sperms swim up the cervix, through the uterus and into the fallopian tube to reach the egg for fertilisation.
- The fertilised egg travels down the fallopian tube to the uterus.
- The fertilised egg implants and grows in the uterus.
A menstrual cycle that is too long (35 days or more), too short (less than 21 days), irregular or absent can mean that you are “not ovulating” (Anovulation). Ovulation Disorder is a term for infrequent ovulation or not at all during the fertile period, which accounts for 1 in 4 cases of infertility. Ovulation Disorder can be caused by problems with regulating the reproductive hormones by the brain, ovaries and other causes.
Polycystic ovarian syndrome (PCOS) is the most common cause of female infertility due to hormonal imbalance in the ovaries, leading to anovulation. In addition, PCOS is associated with insulin resistance, obesity, and increased male hormone secretion leading to abnormal hair growth on the face or body and acne.
Premature ovarian failure (primary ovarian insufficiency): This disorder is usually caused by an autoimmune response or premature loss of eggs from your ovaries (Due to genetics, surgery, infection, diseases or even chemotherapy) before 40.
The ovaries no longer produce eggs.
The brain and pituitary gland are responsible for stimulating ovulation each month —by secreting Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH). However, excess physical or emotional stress, extreme bodyweight, recent substantial weight gain or loss can disrupt hormone production leading to anovulation.
High prolactin. The excess production of prolactin (hyperprolactinemia) from the brain inhibits the body’s reproductive function, leading to infertility. This shut down can be caused by thyroid disease, stress, medications, and sometimes a growth inside your brain.
If you are below 35 years old, you should get help from a fertility expert if you have been unable to conceive for 12 months or more. On the other hand, if you are more than 35 years old, you should get help from a fertility expert if you cannot conceive after six months of trying.
Below are some tips for women who are keen to conceive:
Maintain ideal weight. Overweight and underweight women are at an increased risk of ovulation disorders. If you need to lose weight, exercise moderately and take care of your calorie’s intake. Intense exercise is associated with decreased ovulation.
Stop smoking. Tobacco has multiple adverse effects on fertility, not to mention its impact on your general health and well-being of the pregnancy and your baby.
Avoid alcohol. Heavy alcohol use may lead to decreased fertility and can affect the health of your baby too.
Manage your stress. Excessive stress can turn off the reproductive function and leads to poorer treatment outcomes. Divide and conquer your stress by breaking the obstacles into smaller tasks. Meditate, exercise, encourage yourself and discuss the matters with your friends or family members. If you cannot resolve the stress yourself, it is time to get help from an expert.
Limit caffeine intake. Well, you do not need to give up your cup of coffee or tea. Limiting caffeine intake to less than 200 milligrams a day should not affect your ability to get pregnant, according to recent clinical data.
