top of page

13 May 2023

Preconception Care

Article by Dr Greg Phillipson

Increasing the Chance of Pregnancy

Fertility tracking using a menstrual calendar or a smartphone app, cervical mucus monitoring, ovulation detection kits, and basal body temperature tracking can help identify the fertile time of a menstrual cycle.

Studies suggest frequent intercourse (every 1–2 days) during the fertile time of the cycle increases the chance of pregnancy, although 2–3 times per week is often advised and has nearly the same pregnancy rate.

Women's pregnancy and live birth chances significantly decrease after age 35, and the risk of miscarriage increases.


Preconception Advice

Preconception care involves optimising health before trying to conceive to increase the chances of a healthy pregnancy and baby. The following are evidence-based preconception advice that can help optimise health before pregnancy:


  • Discuss your preconception health and any pre-existing medical conditions or concerns with a healthcare provider. Blood tests and a check for sexually transmitted infections (STIs) can minimise the risk of infertility and pregnancy complications.

  • Folic acid, iodine and vitamin D supplements:

a. Women should take a daily folic acid supplement of at least 400 micrograms before conception and during the first three months of pregnancy. This can reduce the risk of a child with neural tube defects such as spina bifida. Also, 150mcg of Iodine daily is advised, as deficiency can alter the development of the nervous system. Folic acid and Iodine are available over the counter and combined with several commercial multivitamin preparations.

b. Women with a previous history of a baby with a neural tube defect (or with a family history), those taking medication for epilepsy, women with diabetes, previous weight loss (bariatric) surgery such as gastric bypass or banding, or if overweight with BMI more than 30 are advised to take a higher dose (5mg) of folic acid. Discussion with a health professional is advised in these situations.

c. Some people have low levels of vitamin D. If you have darker skin and spend most of your time inside, you are at a higher risk of vitamin D deficiency. Those living in the South Island may also be at risk.

  • Maintain a healthy weight:

a. Being overweight or underweight can affect fertility and increase the risk of pregnancy complications. Achieving a healthy weight through a healthy diet and regular exercise can optimise fertility and pregnancy outcomes.

  • Medical disorders:

a. Conditions such as diabetes, hypertension, and thyroid disorders can increase the risk of pregnancy complications. Polycystic ovary syndrome (PCOS) may interfere with ovulation. It is important to manage these conditions with the guidance of a healthcare provider before trying to conceive.

  • Avoid harmful substances:

a. Smoking, alcohol consumption, and recreational drug use can all affect fertility and increase the risk of pregnancy complications. It is important to avoid these substances before and during pregnancy.

b. Recent reviews have suggested maternal caffeine intake is associated with possible negative pregnancy outcomes. The evidence supports women planning pregnancy and pregnant women being advised to minimise caffeine intake.

c. Exposure to certain environmental toxins, such as pesticides and chemicals, can affect fertility.

  • Vaccination recommendations:

a. Many women will already have immunity from previous vaccination, and for some conditions, immunity can be confirmed by a blood test.

b. Some vaccines are best not given during pregnancy. Measles, mumps and rubella (MMR) vaccine and Varicella (Chicken Pox) vaccine are recommended at least a month prior to pregnancy. These infections can have serious negative effects during pregnancy if they occur, and vaccination can prevent infection.

c. During pregnancy, Influenza and COVID-19 vaccines can be given at any time if required. From 16 weeks of pregnancy, the whooping cough vaccine can be given and is strongly recommended.



References can be provided upon request.

Dr Greg Phillipson (MB, ChB, FRANZCOG, CREI) is an Obstetrician, Gynaecologist and Subspecialist in reproductive medicine and surgery.

This article is for informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment before undertaking a new healthcare regimen.

bottom of page