You can maximise your chances of conception by becoming aware of factors that affect your fertility.

Below you will find information on some important changes you can make to improve your chances of conception. Research suggests that the factors listed below may have an effect on conception and the outcome of fertility treatment. The factors can influence both male and female fertility.

More information:

Improving your chances of conception

  • Male partner's role

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    Male partners are recommended:

    • to achieve and maintain a healthy weight
    • be a non-smoker
    • limit alcohol intake
    • avoid hot baths and spas
    • wear loose underwear
    • avoid working with a laptop on the thighs 
    • Current research also indicates that sperm health is improved by frequent ejaculation (every 48-72 hours). Long periods without ejaculation (abstinence) may have a negative effect on sperm DNA and result in poor embryo quality after fertilisation.
    • There is some limited evidence that it may be helpful to take a supplement of antioxidants e.g. Menevit.
    • The male partner is advised to abstain from ejaculation or sexual intercourse for two to three days prior to treatment. 

    Some partners often feel there is not much they can do to help during the cycle.  Feedback from couples that have been through IVF suggest that practical and emotional support is incredibly valuable during this time.

  • Body weight

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    The most effective lifestyle change you can make to improve your chances of conception and having a healthy baby is maintaining a healthy body weight. A BMI of 20 to 25 is ideal. Calculate your BMI from our BMI table here.

    Body weight in women

    Women who are overweight or underweight are less likely to conceive following most forms of infertility treatment, particularly IVF. This is why the Ministry of Health has made it so that only women with a body mass index (BMI) of 32 or less can be eligible for publically funded fertility treatment. Losing weight can improve conception for some women, improving menstrual regularity and reducing their need for fertility treatments.

    Body weight in men

    There is also increasing evidence that male obesity is associated with reduced sperm concentration and motility. Male partners are advised to achieve and maintain a healthy BMI.

    Body weight during pregnancy

    Being overweight during pregnancy also increases your chances of having a baby with an abnormality or issues with growth (too big or too small), of developing diabetes or pre-eclampsia, of developing a blood clot, of having difficulties with monitoring pregnancy and labour, and of requiring delivery by caesarean section.

  • Age

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    A large factor in determining a couple's chance of conceiving - naturally or through fertility treatment - is the age of the female partner.

    Older women are more likely to develop  pre-eclampsia, diabetes in pregnancy, and obstetric complications. They are also more likely to have other health problems that will make specialist care necessary during pregnancy.

    Success rates for all fertility treatments decline with age and reduce quickly after 40. Public funding for fertility treatment is only available to women under 40.

    Despite this, many older women do conceive with treatment and we see many women over 40 as part of our private service. Talking to us will give you a realistic view of whether treatment is likely to be effective. In some cases it is more appropriate to have in vitro fertilisation (IVF) and use eggs from another younger woman (egg donor).

  • Smoking

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    Smoking in women

    Evidence suggests that embryo implantation can be affected by smoking.

    Smokers are not eligible for public funding; a woman needs to have stopped for three months before becoming eligible and remain non-smoking throughout the course of treatment. It is strongly recommended that private patients who smoke  consider giving this up.

    Smoking in men

    There is evidence to suggest that smoking reduces sperm quality and numbers.

    Smoking during pregnancy

    Smoking in pregnancy can increase the risk of ectopic pregnancy, miscarriage, haemorrhage, fetal anomalies, low birth weight babies, pre-eclampsia and premature labour. After pregnancy it increases the risk of childhood respiratory conditions and sudden unexpected death in infancy (SUDI).

    If you stop smoking you can improve your chances of conception and having a healthy child. Nicotine patches are not recommended because they may mimic the biological effects of smoking.

    We can refer you to a smoking cessation programme if you require support.

  • Alcohol

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    Alcohol is discouraged for both men and women. 

    There is evidence to suggest that alcohol reduces sperm quality and numbers. Embryo implantation can also be affected.

    There is little evidence that occasional or moderate drinking of alcohol reduces either male or female fertility, but higher levels of alcohol intake can have negative effects.

    We encourage women not to drink alcohol if they are trying to become pregnant. Any alcohol intake is harmful in pregnancy, and is linked to miscarriage, stillbirth and Fetal Alcohol Syndrome.

  • Recreational drugs

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    Marijuana

    The use of marijuana and other recreational drugs should also be avoided if you are planning to become pregnant. Marijuana has a negative effect on both sperm and egg quality.

    Marijuana use in pregnancy and breastfeeding can result in childhood neurodevelopmental delay, attention deficit disorders and depression.

    Methamphetamines

    There is limited evidence regarding the effect of methamphetamines on fertility. Use in pregnancy results in increased pre-term birth (less than 37 weeks pregnancy), haemorrhage, babies with low birth weight, and children with developmental delay (especially attention, memory, motor skills and learning).

  • Caffeine

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    We suggest that women experiencing fertility problems limit their intake of caffeine to 100-130mg daily. An approximate average for one cup of coffee is 100mg of caffeine.

    Tea, chocolate and energy drinks also contain caffeine. Decaffeinated coffee should also be restricted, as the chemicals used in the process are also potentially harmful.

    Substances containing tannin such as tea and red wine should also be limited.

  • Stress

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    The stress associated with treatment needs to be acknowledged by both you and your partner. Be aware that people cope with pressure differently.

    To help with the stress of fertility treatment:

    • Consider learning relaxation techniques or enrolling in a programme of yoga or meditation.
    • Think carefully about when you want to have treatment. You could, for example, choose a time when you can easily take a few days off work before and after the cycle.
    • Don't worry if you can't take time off - the evidence that stress affects pregnancy rates is limited and most studies suggest that stress in itself has no effect on the chances of treatment being successful.

    The counsellors are available before, during and after your treatment if you wish to talk to someone for extra support.

  • Diabetes or pre-diabetes

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    Poorly controlled diabetes has a negative effect on fertility for men and women. It can affect erectile dysfunction, menstrual regularity and ovulation. Many women may also have associated PCOS.

    High sugar levels at the time of conception can increase the risk of miscarriage, birth defects (especially heart), and issues with your baby's growth (too big or too small), early delivery and high blood pressure. It is important to try to control your sugar levels before you become pregnant. See your GP prior to conception.

    Good sugar control may improve your fertility as well as your pregnancy outcomes.

    Women with pre-diabetes are at higher risk of developing diabetes in pregnancy and should consider making some lifestyle changes prior to conception.

    What should I do if I am planning pregnancy with diabetes, pre-diabetes or PCOS?

    • Healthy lifestyle and exercise. If you are overweight (your BMI is greater than 25) then weight loss can improve your sugar control.
    • Eat plenty of fresh vegetables and exercise for 30 minutes each day - this should be at a moderate intensity at minimum (where you can just hold a conversation).
    • Portion control is important to maintain a healthy weight and blood sugar level.
    • Limit your complex refined sugars (all those things that are white - white sugar, white bread, white rice, potatoes etc). Take care with salt in your food. Eat lean meats where possible.
    • If you have diabetes, know what your blood sugars are and how your diet and activities affects your levels.
    • Seek assistance from your GP.
    • Metformin can be of benefit for many women, improving fertility outcomes.
  • Medication and other medical problems

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    Some medications can affect the reproductive system of men and women. These include medication for epilepsy, hay fever, gout, gastric and blood pressure disorders, steroids, and antibiotics.  Please talk to your doctor if you have concerns about the medication you are taking. This includes vitamins and herbal supplements.

    Some medical conditions can reduce your chances of conceiving. If you have any medical problems, these need to be assessed and your general health optimised before you become pregnant.

  • Travel and zika virus

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    Travel is usually safe pre-pregnancy, but it is important to consider the possible effects of infections contracted while overseas such as Zika or malaria. Other infections can be contracted from the environment, food or water ingested, such as toxoplasmosis, listeriosis or cytomegalovirus.

    Malaria

    Malaria is an infection caused by a parasite and spread via mosquitos. It causes significant infections in mothers and can lead to miscarriage and prematurity (birth before 37 weeks pregnancy). The Centres for Disease Control and Prevention recommend women planning pregnancy or in early pregnancy avoid countries with a malaria transmission risk. Talk to your doctor if you are taking anti-malarial drugs to ensure these are safe for conception.

    Zika Virus

    What is it?

    Zika virus disease is caused by a virus transmitted primarily by Aedes mosquitoes. There is growing information available about the risk of sexual transmission of Zika virus.

    People with Zika virus disease can have symptoms including mild fever, skin rash, conjunctivitis, muscle and joint pain, malaise or headache. These symptoms normally last for two to seven days. Cases of Zika virus have been reported in Africa, southern Asia, the Pacific Islands, throughout the tropical and sub-tropical areas of the western hemisphere, and as far north as the USA, Mexico and Puerto Rico.

    How does it affect mother and baby?

    There are concerns that pregnant women who become infected with Zika virus can transmit the disease to their unborn babies, with potentially serious consequences. Zika virus infection is known to be a cause of microcephaly (incomplete brain development) and other serious brain anomalies in developing fetuses.

    Recommendations

    The New Zealand Ministry of Health recommends that women who are pregnant or plan to become pregnant in the near term should defer travel to areas with Zika virus present. If travel is essential, we recommend delaying pregnancy when travelling to these affected countries.

    The Ministry of Health website regularly updates as more information on Zika becomes available, and we recommend checking their site when considering overseas travel.

    If travel to Zika-infected areas is essential, we recommend protecting yourself from mosquito bites, and if planning pregnancy that you delay this until two months (for women) or six months (for men) after returning from an affected country.

    There is growing information available about the risk of sexual transmission of Zika virus. We do not know exactly how long the virus remains in semen, but initial research has found Zika virus present in semen at least two months after infection develops. Until more information becomes available, men should use condoms or abstain from sexual activity (oral, vaginal or anal) for at least six months after leaving a Zika-affected area.

  • Pre-treatment screening

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    All women having fertility treatment will have bloods tests to confirm whether they are immune to rubella and negative for hepatitis, syphilis and HIV. Rubella infection in pregnancy increases the chance of miscarriage, severe birth defects, childhood deafness, cataracts and intellectual disabilities. Women who are not immune to rubella need to be vaccinated and delay conception for 28 days.

    Male partners also have their hepatitis and HIV status checked.

    This is a regulatory requirement to ensure the safety of couples and any children born from treatment.

  • Folic acid and iodine supplementation

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    Folic acid

    Increasing your intake of folic acid leading up to and during pregnancy will reduce the chances of having a baby affected by neural tube defects. The neural tube is a structure from which the brain and spinal cord form. Defects in the development of the neural tube can leaf to spina bifida or other defects.

    Research over the last 20 years has suggested a relationship between maternal diet and the occurrence of neural tube defects in babies.  Neural tube defects (spina bifida, anencephaly and encephalocele) result from defective closing of the neural tube in early pregnancy.  The neural tube is the embryological structure from which the brain and spinal cord develops.  It closes around the 27th day post-fertilisation.  Recent studies on the effect of vitamin supplements in women planning a pregnancy have found that folic acid can considerably reduce, though not entirely eliminate, the chance of neural tube defects.

    What is it?

    Folic acid is a water-soluble vitamin found in many fruits (particularly oranges, berries and bananas), leafy green vegetables, cereals and legumes. It can also be taken in tablet form.

    When should I take it?

    You should be taking folic acid two months before the possibility of becoming pregnant i.e. one month prior to treatment, through to 12 weeks after becoming pregnant. If there is a possibility of pregnancy occurring naturally, you should begin taking folic acid.

    The recommended dose of folic acid is 800 micrograms (0.8 milligrams) per day.

    Iodine supplements

    Iodine supplements are recommended from when you know you are pregnant onwards. Iodine is essential for healthy brain development and fetal growth. Many New Zealanders have a diet mildly deficient in iodine. The recommended dose is 150 micrograms (0.150 milligrams) per day. Iodine supplements should be continued right through your pregnancy.

    Both folic acid and iodine supplements are available over the counter at any chemist. We can also provide you with a prescription. For more information, you can download the Ministry of Health's leaflet on folic acid and iodine in pregnancy.

  • Complementary therapies

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    Many people wanting to become pregnant try complementary therapies such as Chinese herbs, aromatherapy, naturopathy, and acupuncture. Most alternative treatments have not been tested scientifically for their effects on hormones, sperm, eggs or embryos, or the uterus. Some studies have shown that particular herbs inhibit sperm and egg function. Please tell us if you are using complementary therapies. Recently the use of acupuncture during IVF was shown not to improve fertility outcomes.