Spina bifida
Anencephaly
Blood tests and ultrasounds
Extensive research has now proven beyond a doubt that women, who have adequate intakes of the folate for around 1 to 2 months before they conceive a baby, and for the first 6 to 12 weeks of their pregnancy, have a greatly reduced chance of having a baby with abnormalities known as 'neural tube defects' (or NTD's). The likelihood of having a baby with a neural tube defect is reduced by up to 70% when adequate folic acid is taken.
Neural tube defects occur when there are problems with the development of the baby's brain, skull and spinal cord, mostly during the first 6 weeks of the pregnancy. This phase of the pregnancy is calculated as 6 weeks after the woman's last menstrual period, or 4 weeks after the baby was actually conceived. (You can read more about calculating the baby's age from conception
here.) However, this is also the time that most women are unaware they are pregnant.
It is during the early weeks of the pregnancy that the growing baby develops the beginnings of their spinal cord and brain. A row of specialised cells form along the baby's back. These cells first turn into a long groove, and then create a hollow tube (called the 'neural tube'). The neural tube closes over at sometime between 21 and 28 days (or 3 to 4 weeks) after conception (or 5 to 6 weeks after the woman's last menstrual period).
Inside the neural tube, the baby's brain and spinal column grow and develop. However, if the neural tube does not completely close, the baby develops what is called a 'neural tube defect', or an opening in the neural tube. For some reason, which is not fully understood, low levels of folic acid in the woman's body can encourage this defect to occur. However, adequate levels of folic acid can in many cases prevent it from happening. Adequate folic acid taken around this time also appears to decrease the incidence of some other abnormalities, such as cleft lip and/or palate.