Quick questions and answers:
Obstetrics:
1. When can a successful pregnancy be confirmed?
2. When should the non-invasive prenatal test (NIPT) be performed?
3. Is it still necessary to have an OSCAR test if the NIPT shows normal results?
4. When is the best timing for scheduling an elective caesarean section?
5. When should pregnant women have a fetal morphology ultrasound scan?
6. Is it dangerous to the fetus if the umbilical cord has wrapped around the neck (nuchal cord)?
7. Are leg cramps during pregnancy due to calcium deficiency?
8. Is it safe to exercise during pregnancy?
9. Are varicose veins normal during pregnancy?
10. How can serious varicose veins be managed in pregnancy?
11. Is uterine fibroid(s) harmful to the fetus?
12. Are there vaccination to be recommended during pregnancy?
13. What are the precautions on acne treatment during pregnancy?
For a successful pregnancy, an embryo with heart pulsation can be observed by a transvaginal ultrasound scan at 4 weeks after conception (6 weeks after last menstrual period).
For a singleton pregnancy, NIPT should be arranged after 10 weeks of gestation. For twin pregnancy, the NIPT should be arranged after 12 weeks of gestation.
No. The NIPT has higher detection but much lower false positive rates for Downs, Edwards and Pataus syndromes. However, an ultrasound for the nuchal translucency of the fetus is still recommended even if the NIPT results are normal.
In general, an elective caesarean section should be scheduled at ~39 weeks of gestation for singleton pregnancy. For twin pregnancy, elective caesarian section is suggested to be scheduled between 37-38 weeks of gestation. For more details, please read “Best timing of elective caesarean section”.
For a routine fetal morphology scan, it should be between 20-22weeks. However, if there is any personal or family history of fetal structural or chromosomal abnormality, or any suspicion of fetal abnormality on an earlier ultrasound scan, the fetal morphology scan can be scheduled much earlier.
No, nuchal cord is common and is usually transient. It does not increase the risk of intrauterine fetal demise. Vaginal delivery is not contraindicated but continuous fetal heart monitoring during labour is advised. Please refer to “Nuchal cord (cord round neck)” for more information.
No, muscle fatigue is more likely to be the underlying cause. There is no research evidence that calcium supplements can prevent leg cramps. For more details, please read “Leg cramps in pregnancy”.
8. Is it safe to exercise during pregnancy?
Yes, regular exercise (2-3 times per week) is suggested. Stroll (walking exercise) and swimming are two good forms of exercise in pregnancy. Please refer to “Guidelines for exercises in pregnancy”.
Yes, varicose veins are relatively common especially in the late pregnancy. These swollen veins typically are seen at the lower limbs and vulva. Factors leading to varicose veins include the increase in blood volume, pressure of the pregnant uterus on the pelvic veins and hormonal effects on the venous system. For women who have already got varicose veins before pregnancy, the condition tends to get more severe during pregnancy. Apart from their physical appearance, varicose veins should not cause any serious health issues.
Wearing a maternity support hose might prevent the varicose veins from getting more severe. After the postpartum period, they tend to resolve to the pre-pregnant state.
Most of the fibroids are located within the uterine wall or at the external wall. These fibroids do not, in general, cause problem to the fetus and they do not compete with the fetus for nutrition. Fibroids usually grow in size during pregnancy and occasionally acute severe pain at the fibroid can occur due to red degeneration. The treatment is by strong analgesia. Fibroids located at the lower uterus or cervix may cause mal-presentation of the fetus at term or obstruct the labour. Those fibroids growing into the endometrial cavity may increase the chance of miscarriage. They should be removed prior to an attempt of pregnancy.
Two- the flu vaccination and the whooping cough vaccination. Studies have shown that pregnant women have a higher chance of developing severe complications following flu. In case the mother has developed severe respiratory illness, the baby will have a higher chance of premature birth or intrauterine demise. Flu vaccination has been shown to protect the mother from severe complications from flu and is safe for pregnancy. After birth, the whooping cough vaccination is only given at 2 months of age. There is a window period when the baby can get infected. Vaccination with the pregnant women from 16-32 weeks of gestation allows the transfer of the antibodies to the baby via the placenta before he or she is born. There is no single whooping cough vaccination and hence a combined vaccine consisting of diphtheria, tetanus and whooping cough vaccines is used. It has been shown to be safe in pregnancy.
Effective acne treatment regimen containing the followings should NOT be used during pregnancy: Isotretinoin (birth defect), tetracycline (discolouration of teeth of fetus), hormonal therapy (birth defect), topical retinoids (controversial on birth defect but better to avoid). Treatment with the following ingredients are considered to be safe in pregnancy: erythromycin, clindamycin, topical benzoyl peroxide, topical salicylic acid, Glycolic acid and Azelaic acid.
Sunscreens are topical agents used to protect the skin from the sun’s ultraviolet irradiation. These products have very limited skin or systemic absorption. They are considered to be safe in pregnancy.
15. Can I dye (colour) my hair during pregnancy?
The safety of colouring the hair during pregnancy is not well established. Theoretically, the chemicals involved can be absorbed by the scalp and get passed to the unborn fetus. However, it is believed that the amount absorbed should be very low. The National Health Service in the UK opinionated that colouring the hair is probably safe after 12 weeks of pregnancy. In a case-controlled study from Brazil published in 2013, maternal exposure to hair dyes and straightening cosmetics in the first 12 weeks of pregnancy is associated with acute lymphocytic leukaemia in children under the age of 2. And the exposure during breastfeeding is associated with acute myeloid leukaemia. Although the case-controlled study has its limitation, women considering to dye their hair are advised to weigh balance their need and the potential risks.
