Folic acid usage and associated factors in the prevention of neural tube defects among pregnant women in Ethiopia: cross-sectional study

Neural tube defects (NTDs) are congenital anomalies that result from failure of the neural tube to close between day 21 to 28 post conception [1–4]. NTDs are contributing to miscarriage, infant mortality, severe congenital abnormalities and serious disabilities and are the second most common congenital anomaly [3, 5]. NTDs account for 10% of all neonatal mortality, 10% of the burden of all congenital conditions and these defects are responsible annually for 41,000 deaths and 2.3 million disability-adjusted life years [3, 6]. NTDs are affecting 0.5–2 per 1000 pregnancies and occurring in about 2–3% live births worldwide [1, 7, 8]. Because of the lower living standard and low antenatal diagnosis and termination of pregnancy [9]; the incidence of NTDs in developing countries have been reported to be up to fourfold higher than in developed ones [10]. The lifelong medical and socioeconomic consequences of NTDs in affected children are equally known to be worse in low-resource settings [3]. A study conducted in Ethiopia reported that hydrocephalus (35.5%) and neural tube defects (27.5%) were the major leading causes of admission to hospitals for surgical procedures among children [11].

Neural tube defects have a heterogeneous and multifactorial etiology, including genetic and environmental factors as well as predisposing maternal factors [3, 8, 12]. Among known environmental factors folic acid deficiency is the most common one [12–14].

The basic characteristic of embryonic and fetal development is widespread cell division; and folic acid has a major role in DNA and RNA synthesis, for cellular development and division, the metabolism of amino acids and the regulation of homocysteine in the blood [15–18]. Folic acid deficiency is a serious problem that affects women worldwide [4]. In Ethiopia, one in every three women had a deficiency of folic acid, suggesting that these women are at a higher risk of giving birth to a baby with NTDs [19].

Folic acid intake is limited by cooking losses and poor bioavailability estimated to be from 50% to 82% [2, 19–22]. In addition, during pregnancy, maternal serum and erythrocyte concentrations of folic acid decline for several reasons: increased demand, dilution secondary to increased intravascular volume, increased folate catabolism and clearance, decreased absorption and inadequate intake [1, 6].

Many studies have documented that daily intake of 400 micrograms folic acid at least one month before pregnancy and the entire first trimester of pregnancy could reduce the risk of NTDs by up to 80% [4, 21, 23–25]. Because the neural tube closes by the fourth week after conception, it is important that folic acid be consumed on a regular basis before pregnancy [17, 26, 27].

Previous studies internationally shows different level of folic acid usage for prevention of NTDs [1, 21, 23, 25, 28–33] and discovered age [1, 21, 25, 28–30, 34], parity levels [21, 25, 29, 30], smoking status [25], history of spontaneous abortions [25], planning of pregnancy [21, 23, 28], number of ANC visits [29, 30, 35], timing of ante-natal registration [30], educational status [1, 21, 25, 30, 35], marital status [21, 25, 35], monthly income [21, 25] and number of pregnancy [28] as factors associated with preconception folic acid usage.

Although folic acid usage for prevention of NTDs were well studied internationally, there are no published reports that indicate the usage of folic acid at the recommended time among pregnant women in Ethiopia. The aim of this study was to assess folic acid usage and associated factors for the prevention of NTDs among pregnant women in Ethiopia.

About 46.3% the women were primigravidae while 49.2% had 2–4 pregnancies and 4.6% had 5 or more pregnancies. The number of pregnancies ranges from 1 to 10 (2 ± 1.3). The mean gestational age at the time of interview was 29.2 weeks with the minimum 13 week and maximum 40. About 11.3% of the women consulted a healthcare provider when they plan to become pregnant. Among those who consulted healthcare providers 93.6% could mention what was done by a healthcare provider when they consult them. Advice was reported by 4.5%, general check up by 72.7% and general checkup plus folic acid supplement by 18.2%.

Of al1 9.7% of women comes for the first visit while 63.3% comes for the 2nd to 4th visit and 17.0% comes for 5th and more visits at the time of interview. The month of first ANC visit ranges from one month to nine months (mean = 3.8, median = 4, mode = 4). 42.2% of the women made their first ANC visit in the first trimester, 53.5% in the second trimester and 4.3% in the third trimester of pregnancy. 19.4% had a history of unsuccessful pregnancy in a lifetime and 1.7% of the women had a history of a baby with other birth defects.

Folic acid usage for NTD prevention was significantly associated with advanced age (p value =0.02 and OR = 9.4 with 95% CI 1.14–76.8), early antenatal registration (p value =0.03 and OR = 0.974 with 95% CI 0.96–0.99), number of ANC visit (p value = 0.04), consultation during preconception period (p value = 0.000 and OR = 0.063 with 95% CI 0.15 to 0.275), previous history of unsuccessful pregnancies (p value = 0.04 and OR = 4.3 with 95% CI 1.1 to 17) and level of folic acid awareness (p value = 0.00).

There was no significant correlation between folic acid usage and the women’s educational status, occupation, monthly household income, number of pregnancy and partner’s educational status.

Intake of folic acid at least one month before pregnancy and the entire first trimester is highly recommended to decrease birth defects, particularly NTDs [10, 17, 36]. But, the prevalence of folic acid usage at the recommended time in Adama, Ethiopia was found to be 1.92%. Ethiopia is one of the developing countries where the incidence of NTDs is highly prevalent and where 1/3 of women were affected by folate deficiency [10, 19].

In the present study, pregnancy was planned by 71% of the interviewed women, which was consistent with the planning of pregnancy in Croatia [21]. It was higher than usual reports of 50% of pregnancies, being unplanned [7, 16, 34].

Of those women who planned pregnancy 69% used contraceptive and 30.4% inform the healthcare provider before ceasing the contraceptive. As compared to survey in Europe, where 18% of the women were consulted healthcare provider prior to stopping contraceptive, the finding in this study was higher [24]. About 11.3% of the women consulted healthcare providers, particularly about their pregnancy when they plan to become pregnant. Despite all these convenient conditions to give a folic acid supplement only 2.7% of the planning women were prescribed for folic acid during the protective period against NTD, which was very low as compared with 21% usage in Croatia that had similar levels of planned pregnancy [21].

Even though the number of women who consulted healthcare providers prior to stopping contraceptive in the present study was higher than surveyed women in Europe, usage in Ethiopian women was extremely low as compared to usage by 28% plan to become pregnant and 55% pregnant women in Europe [24].

In this study, 1.92% of the women were diabetic, 0.7% women had previous history of NTD pregnancies, both of which are high risk factors for occurrence and recurrence of NTD [3]. However, none of them were user of folic acid at the recommended time. This finding was in contrast to the study done in Nigeria, where 40% of women with a previous history of NTD pregnancy were the user at protective period [1].This difference may be because of the difference in health policy, i.e. there is preconception care in Nigeria but not in Ethiopia [37].

The occurrence of NTDs among spontaneously aborted fetuses is 10-fold higher than the rate of NTDs at birth [17]. In this study, 15.1% of the study subject had at least one spontaneous abortion in their lifetime. So those women are at high risk for having a baby affected by NTDs.

Women whose age were above 25 were 9.4 fold user of folic acid at protective period than women age 25 and below which was consistent with other studies in USA [27, 34], Croatia [21], Lebanon [25], and Tanzania [29]. This finding was in contrast to the other study in Lebanese where young women were more user [28].

Early timing of antenatal registration and number of ANC visits also positively associated with folic acid usage for NTD prevention as other studies done in Tanzania, India, Honduras [29, 30, 35].The study findings were consistent with other studies who have reported that the level of folic acid awareness predicts folic acid usage at protective period.

In this study, women who consulted healthcare providers when they plan to become pregnant were 6.3 times more likely to take folic acid at protective period than who did not consult. Similar to studies in Lebanon and Nigeria previous history of unsuccessful pregnancies was positively associated with intake of folic acid at protective period against NTDs [1, 25].

Data reported during the last 7 years from USA, Australia, Lebanon, Iran, United Arab Emirate and Nigeria shows folic acid usage at protective period against an NTDs range from 2.5% to 76% [1, 5, 10, 15, 25, 31, 36, 38]. The prevalence of folic acid users in this study is even lower than the least range. However, it is higher than a study done among Honduran women in 2007 which was 0.2% [10].

In Ethiopia, there are health facilities distributed in every city and villages in which healthcare providers deliver different medical and health need of the society including the ANC. However, folic acid usage is very low.

The poor intake of folic acid among Ethiopian women could be a result of low recommendation from policy makers, less prescription, and recommendations by healthcare providers and lack of awareness about folic acid supplements, its importance and the recommended time among women. The other one may be failures of healthcare providers to prescribe folic acid at protective time and lack of preconception care.

The study is a hospital based study on women who seek routine ANC. The result may only reflect usage among women who might have high health service seeking behavior. Another limitation of the study was it is conducted in one region, relatively a big city. So the finding of this study may not be generalized to other regions of the country, especially rural areas and small towns. Despite those limitations, the present study provides some insight into the practice of women for usage of folic acid for prevention of neural tube defects.

Even though preconception folic acid intake is simple measures to prevent many severe birth defects, particularly NTDs; in Ethiopia it is unnoticed by policy makers, less prescribed at the protective period by healthcare providers, underused by pregnant women and/or women planning pregnancy.

The folic acid intake rate for NTD prevention in the present study indicates special intervention plans should be developed by health policy makers. This intervention could be screening childbearing-age women for folic acid use and providing information on the benefits of folic acid supplementation, as well as training healthcare providers on NTD and other birth defect prevention mechanisms, providing education for the whole community even early in high school level using media and other methods.

The other most important intervention that could be done by policy makers and other stakeholders is starting preconception care for women who plan to become pregnant. This action might improve folic acid usage for preventing NTDs and other birth defect and also early ANC registration.

Folic acid rate of intake in this study also indicates urgent action is required from healthcare providers to improve usage at protective period against NTDs and other congenital anomalies. So further effort is required and it is necessary to have health education on NTDs and folic acid usage during premarital health examination, when providing family planning services and during other contact with the community.