Pre-pregnancy care or trying to conceive

Aims of a pre-pregnancy check-up

1. Investigate for potential problems that may reduce fertility

2. Optimise control of pre-existing medical conditions (if any)

3. Optimise health in general

4. Institute lifestyle changes

5. Up to date in vaccination schedule

6. Screen for common and/or serious conditions that could impact one’s future pregnancies

Investigate for potential problems that may reduce fertility

See a doctor for further investigation if:

• You have irregular/heavy periods

• Painful sexual intercourse

• Trouble conceiving even after trying for 1 year with regular frequent sexual intercourse of 3-4 times a week. If you have been trying to conceive for 1-2 years without success, you may wish to see a doctor for further investigation. The gynaecologist could assist by prescribing medications (e.g. clomiphene or letrozole) to increase ovulation e.g. in patients who do not ovulate regularly, or prescribe other more advanced fertility treatments such as SOIUI (superovulation in utero insemination) and IVF (in vitro fertilization).

Optimise control of pre-existing medical conditions

Certain chronic medical conditions may lead to increased risks of complications in pregnancy, though the risks may be minimised with better control of the medical conditions. Poor control of conditions such as high blood pressure, diabetes mellitus, and high or low levels of thyroid hormones may increase the risk of miscarriage, premature delivery, small birth weight, pre-eclampsia and stillbirth.

Optimise health in general

1. Aim for or maintain BMI of 20-25 (20-23 For Asians) - for those with high BMI, even if one is not able to lose enough weight to reach the ideal BMI, a weight loss of 3-5 kg may be enough to see some benefits.

• This is associated with lower risk of miscarriage, premature labour, growth restricted fetus, and stillbirth.

• Regular exercise and a healthy diet may achieve this.

• A diet technique of intermittent fasting (limiting food intake to 8 hours per day e.g. 12-8p.m.) may be used to restrict calories. Side effects may include hunger pangs and irritability in the first month for this diet change.

2. Exercise at least 150 minutes every week - it has been found that exercise before and during pregnancy may reduce the risk of Caesarean birth, preterm birth, high birthweight infants in women of healthy weight and also women who are overweight or obese.

3. Stop / reduce smoking, alcohol and caffeine intake. Caffeine is present in coffee, tea, some soft drinks and chocolate. Caffeine and alcohol consumption may reduce fertility - the more you drink, the more the adverse effect. Both active and passive smoking reduce male and female fertility and are harmful for the growing baby

4. Reduce delay in trying to conceive - this is because risks do increase with increasing maternal and paternal ages.

Risks with advanced maternal age

Older mothers have reduced fertility, increased miscarriage risks and increased risk of chromosomal abnormalities like Down syndrome.  More recently, older mothers have also been shown to increase the risk of autism spectrum disorders among the offsprings.

Risks with advanced paternal age

More recently, risks have now been attributed to older fathers (especially those older than 40-45). These include increased risks of miscarriage, rare birth defects, autism, schizophrenia, and even childhood acute lymphoblastic leukemia.   

Institute lifestyle changes

1. Folic acid - take 400-800 microgram (or 0.4-0.8 mg) 1-3 months before trying for a baby - this reduces risks of severe birth defects like spina bifida (exposed spinal cord) and anencephaly (absence of parts of skull and brain)

2. Regular sexual intercourse - 3 - 4 times a week.

3. As sperms last for about 72 hours and the egg that is released lasts for about 24 hours, intercourse 3-4 times a week regardless of timing of ovulation is the optimal method. This method has a better success rate than sexual intercourse 3-4 times a week during the week of ovulation.
   

Up to date with vaccination schedule

An infection of rubella and chicken pox can be dangerous for the fetus. These potentially cause birth defects, premature birth, stillbirth, or miscarriage. If there is no documented immunity, it is advised to get a vaccination at least 1 month before pregnancy if not earlier. Vaccinations before trying to conceive include:

• Rubella vaccination (if there is no detectable Rubella IgG level in the blood) - this involves 1 jab

• Chickenpox vaccination (if there is no past history of chickenpox and / or the VZV IgG is negative i.e. you do not have any chickenpox antibodies in your blood) - this involves 2 jabs 4-6 weeks apart 

Your other vaccination needs may be assessed by filling up this questionnaire designed by Center for Disease Control and Prevention (CDC), US.

Screen for common and/or serious conditions that could impact one’s future pregnancies

Blood tests that are normally done to screen include:

• Full blood count (to screen for thalassaemia, a common genetic disorder among Chinese, Malay and Indians in Singapore)

• Syphilis, HIV, Hepatitis B, Rubella IgG

• Less routine tests include thyroid function tests and IgG antibodies towards toxoplasma, cytomegalovirus (CMV) and chickenpox (VZV).

Carrier screening for genetic risks

Increasingly, international guidelines have recommended that couples be screened for carrier states of either the 3 basic common genetic syndromes (i.e. spinal muscular atrophy, Fragile X syndrome and cystic fibrosis) or expanded panels that screen for about 300-500+ genetic syndromes. In a recent study done in Australia, up to 2% of couples were found on expanded panels to be at increased risks of having a child with a genetic condition that is being screened for (see this link for more information: https://www.nejm.org/doi/full/10.1056/NEJMoa2314768)

If couples are both carriers of any autosomal recessive condition, there is a 25% chance of having offsprings that are affected with major disorders. If the woman is a carrier of a X-linked recessive disorder, there is a 50% chance of having male offsprings that are affected with major disorders.

Carriers are individuals who carry genes related to genetic disorders. Though they do not suffer from any symptoms it is possible for their children to inherit major disorders if both parents are carriers (e.g. autosomal recessive conditions) or if the mother carries a gene on her X chromosome (e.g. X-linked recessive conditions).

This can be helpful for individuals to understand if their child is at risk for certain genetic diseases especially if:

1. One has a family history of genetic disease

2. One is at higher risk for one based on ethnicity

In Singapore, the commonest genetic disorder is Thalassaemia, a blood disorder. This can be screened for by doing Full Blood Count and Haemoglobin Electrophoresis test. Another common disorder is Spinal Muscular Atrophy, which is not easy to screen from simple blood tests though. This can be screened through carrier screening.

The American College of Obstetricians and Gynecologists recommends offering at least basic screening tests regardless of ethnicity. Other countries, including Singapore, do not have such recommendations.

Our clinic offers an option for extended carrier screening for up to 500+ genetic mutations for those couples who want it. It is important to note that expanded carrier screening checks for the common mutations that cause many but not all genetic conditions. If the test shows that both parents are screened positive, invasive tests like chorionic villus sampling or amniocentesis may be performed during pregnancy to check if the fetus is affected with a severe disease. Alternatively, couples may opt for in vitro fertilization (IVF) with pre-implantation genetic testing of the embryos to sieve out the genetically affected embryos.

If the test shows that one or both parents are screened negative, it drastically reduces the risk that the screened negative parent(s) are actually positive for the condition - this is because not all mutations for the genetic condition are known or tested for in the carrier screening, only the common ones.