Pre-Conception & Antenatal Care

Why is pre-conception counselling recommended?

If you are planning to have a baby, pre-conception counselling encompasses a health assessment and education to optimise your future pregnancy outcome. Generally, both parents' histories will be assessed, and any pre-existing medical conditions and medications will be optimised. A genetic screening test for silent genes such as cystic fibrosis, spinal muscular atrophy and fragile X will also be recommended. The existence of these genes may put offspring at risk of having these conditions, even if neither parent is affected.

This pre-screening will help prevent stressful, serious and perhaps devastating outcomes for the parents in the future. Certain supplements, such as folic acid, which helps reduce the risk of neural tube defects, may also be recommended. Some of these supplement doses are dependent on an assessment by a health professional.

What is genetic carrier screening, and should we do it?

Genetic carrier screening is a recommended test for all mothers-to-be in the pre-conception period. This screening test will evaluate whether you are a carrier of some of the serious silent genes, such as cystic fibrosis. The test can be taken using either a blood or a saliva sample, and the saliva test can be done at home. If two of the same silent genes are inherited from the parents of the future offspring, then they are at risk of developing the full spectrum of this silent condition.

If, after screening for the gene, it is determined that you and/or your partner are carriers of a silent gene, we can help you with management options to ensure that you have a healthy baby and pregnancy in the future. Currently, labs in Australia offer a wide variety of genes to screen for. From late 2023, Medicare provides a rebate for a basic carrier screening test for Cystic Fibrosis, Spinal Muscular Atrophy and Fragile X. For more information, please visit the Mackenzie’s Mission website and read the RANZCOG pamphlet on carrier screening.

What are the highlights of first-trimester antenatal care?

First-trimester antenatal care begins by confirming the pregnancy, usually by a urine and/or blood test. Following confirmation, your general practitioner (GP) will arrange booking antenatal investigations, which are general routine tests that are recommended in all pregnancies. A dating scan is also recommended, particularly if your periods are irregular. You will also discuss screening your baby for the likelihood of certain chromosomal abnormalities, such as Trisomy 21 (Down syndrome), 13 and 18. This can be done by a combination of a blood test performed at about 10 weeks and an ultrasound to check the thickness of the baby’s neck (Nuchal Translucency) at about 12–13 weeks or a blood test alone. You will also have plenty of support from your healthcare provider concerning strategies to help with nausea and vomiting (hyperemesis gravidarum), which, in most instances, should start to improve by the end of this trimester.

What are the highlights of second-trimester antenatal care?

As you complete your first trimester, you will feel much better as your hyperemesis gravidarum starts to disappear. You will have a detailed anatomy ultrasound to ensure that the major structures of the baby, such as the heart, brain, spine, etc., are forming without major or serious abnormalities. Your health care provider will arrange blood tests that screen for certain conditions such as gestational diabetes and iron deficiency. Almost all pregnant women will start to feel the baby move towards the middle of this trimester and consider this trimester the best one before the accelerated foetal growth that occurs in the third trimester!

What are the highlights of third-trimester antenatal care?

The third trimester is characterised by an accelerated growth of your baby. This will be more appreciated as you get closer to your due date. You will be having regular visits with your doctor and midwife. This will become more frequent as you get closer to 37 weeks. Your healthcare provider will request third-trimester blood tests, including haemoglobin and iron stores checks at about 34 weeks. A Group B streptococcus (GBS) screening will also be recommended at about 35-36 weeks.

By screening for GBS, we can reduce the risk of severe infection by 80% in babies that are born to mothers with GBS using the simple measure of commencing antibiotics in labour or when the amniotic sac ruptures before birth. If your pregnancy is uncomplicated, it is possible to await the onset of labour if you pass your due date. In general, if you have not gone into labour at 41 weeks, most clinicians will recommend inducing labour. This has been shown to reduce the risk of maternal and fetal complications associated with being postdate as you approach 42 weeks.

Can I have a vaginal birth after a Caesarean section?

Many women consider an attempt to give birth vaginally after a previous Caesarean section, known as VBAC. It is important for your healthcare provider to support your wishes and provide a safe environment when you are birthing after a previous Caesarean section so you can achieve your goal whether you want to attempt a VBAC or plan to have a repeat Caesarean. During antenatal visits, your healthcare provider will review your history and explore your wishes.

Attempting a VBAC carries a success rate of up to 70%. This rate could vary depending on the circumstances of your previous delivery and current pregnancy course. Although there is a small baseline risk of scar rupture, allowing for an adequate time interval between pregnancies will ensure that this risk remains as low as possible. Discussing your wishes and concerns with your healthcare provider will ensure you have adequate information and understanding to make an informed decision.

I am pregnant with twins! Can I have a vaginal birth?

Twins are exciting! Generally, the answer is yes, as long as the twins are healthy, do not share the amniotic sac, and the first twin (presenting twin) is in a head-down position. Your birth wishes will be discussed during antenatal care, as not all women are comfortable attempting a vaginal birth with twins. You will have plenty of time to chat with your midwife and doctors about your birth wishes and plan, provided there is no other contraindication to vaginal birth, such as placenta praevia.