The Importance of Preconception Tests
Preconception Tests are a crucial aspect of reducing risks associated with infertility, subfertility, recurrent miscarriage and other pregnancy complications. Sadly, many couples from all around the world face these difficult physical, emotional and often traumatic challenges. In fact, according to Boivin et al. (2007) a 9% prevalence of infertility (for at least 12 months) exists in women across the developed and developing world. An earlier study conducted in France yielded similar results – 1 in 7 women experienced infertility and 39% of cases involved fertility complications in both partners, the data also suggested that men were solely responsible for infertility in 1 in 5 cases (Thonneau et al., 1991). For this reason it is important to look to preconception tests as a precaution to prepare both men and women’s bodies for healthy conception. Though this article will focus on some important aspects of female preconception and natal health, we will also be looking into how male preconception tests can be utilised later in this series.
It is difficult to imagine that a staggering 50% or more of pregnancies spontaneously abort, with most of these occurring in the first three months of pregnancy (see Heller et al., 2003). Many of these are due to genetic or chromosomal defects in the fetus, though infection, maternal nutritional deficiencies, autoimmune responses, endometriosis and uterine adhesions have also been implicated (see Heller et al., 2003, Sanu and Lamont, 2011, Senapati and Barnhart, 2011, Safi et al., 2012). Preconception tests can be used to assess many of these risk factors and may help to increase fertility and decrease the risk of congenital defects, miscarriage, stillbirth and premature birth.
As reported by Michels and Tiu (2007), 10 to 25% of pregnancy loss in the second trimester (13 to 27 weeks) may be attributed to maternal and/or infant infection. Proposed agents of infection include bacteria, spirochetes, protozoa, viruses and fungi. Unfortunately, it is difficult to establish a clear causal relationship between these agents and second trimester pregnancy loss since examination on the infant is conducted post-mortem. Thus, controversy remains within the medical and allied health professions as to what precautions should be taken. This includes what infections should be checked for prior to conception and during the early stages of pregnancy, including bacterial vaginosis, which has been suggested to be tested and treated for in women with a history of preterm birth (see Michels and Tiu, 2007).
Sexually transmitted infections or diseases (STIs/STDs) and Pelvic inflammatory disease have also been proposed as potential risk factors for infertility and miscarriage. According to Price et al. (2012), it estimated that 45% of tubal factor infertility cases are caused by Chlamydia trachomatis. Neisseria gonorrhoeae is also a common cause of tubal factor infertility with both diseases having the potential to occlude the fallopian tube (Mardh, 2004). STIs are also a common risk factor for ectopic pregnancy and pelvic inflammatory disease (PID) and according to Paavonen & Eggert-Kruse (1999) ”Chlamydial PID is the most important preventable cause of infertility and adverse pregnancy outcome” with estimates of the development of PID from Chlamydia applying to 20% of women – 3% of which will experience infertility as a result and another 2% of which will experience an adverse pregnancy outcome.
Though once considered controversial, it is now generally accepted that there are a number of important nutritional requirements for the proper growth and development of the fetus during pregnancy (see Safi et al., 2012). It is also important to recognise that moderate-to-severe nutritional deficiencies not only increase the risk of adverse outcomes for the unborn child, but that the deficiency cannot be resolved overnight through supplementation. For this reason, it may be important that deficiencies are tested for prior to conception.
Nutritional deficiencies that may be particularly necessary to test for include:
Folate – It is well documented and widely accepted that a folate (or vitamin B9) deficiency leads to an increased risk of neural tube defects, with supplementation or adequate consumption of folate reducing this by 50-70%. It can also prevent other congenital defects and abnormalities including cardiovascular malformations, cleft lip and palate, urogenital abnormalities, and limb reductions (Safi et al., 2012).
Iodine – There are a number of risk factors that iodine deficiency can increase, potentially resulting in negative outcomes for both the mother and fetus. As discussed by Zimmerman (2012), deficiency during pregnancy can be problematic for the neurological and cognitive development of the fetus and result in maternal and fetal hypothyrodism. Since the nutritional requirement for iodine during pregnancy increases by greater than 50% it is important to ensure that iodine levels are tested for prior to or during the early stages of pregnancy. Nutritional supplementation of moderate-to-severely iodine deficient women has been affective in reducing adverse outcomes for both the mother and child (Zimmermann, 2012). The risk of hypothyroidism is increased in even the mildly iodine deficient, so it is important that iodine supplementation is also considered in these cases.
Vitamin D – Vitamin D levels in women have been shown to influence female reproductive health and pregnancy outcomes, with low vitamin D levels linked to impaired fertility, endometriosis and polycystic ovarian syndrome (PCOS) (Grundmann and von Versen-Hoynck, 2011). As noted by Grundmann and von Versen-Hoynck (2011), though there is still a need for bigger, clinical randomised-controlled studies, observational data has shown that low vitamin D levels are also associated with higher rates of gestational hypertension (previously known as preeclampsia), preterm birth, bacterial vaginosis and gestational diabetes.
Of course, we have only scratched the surface of some of the risk factors associated with infertility and adverse pregnancy outcomes along with some common preconception tests. In the weeks to come we will be reviewing these and other factors in more detail to promote greater reproductive health awareness.
Want to know more? See our references for links to the peer-reviewed articles cited in this post.
Note: Many of these references are freely available as full text journal articles 🙂
Next Time: Autoimmune Disease and Reproductive Health
Boivin, J., Bunting, L., Collins, J. A., & Nygren, K. G. (2007). International estimates of infertility prevalence and treatment-seeking: potential need and demand for infertility medical care. Hum Reprod, 22(6), 1506-1512.
Price, M. J., Ades, A. E., Welton, N. J., Macleod, J., Turner, K., Simms, I., et al. (2012). How much tubal factor infertility is caused by Chlamydia? Estimates based on serological evidence corrected for sensitivity and specificity. Sex Transm Dis, 39(8), 608-613.
Sanu, O., & Lamont, R. F. (2011). Periodontal disease and bacterial vaginosis as genetic and environmental markers for the risk of spontaneous preterm labor and preterm birth. The Journal of Maternal-Fetal and Neonatal Medicine, 24(12), 1476-1485.
Thonneau, P., Marchand, S., Tallec, A., Ferial, M. L., Ducot, B., Lansac, J., et al. (1991). Incidence and main causes of infertility in a resident population (1,850,000) of three French regions (1988-1989). Hum Reprod, 6(6), 811-816.