Infertility and adverse outcomes of pregnancy

What are the major causes of subfertility?

Subfertility is defined as a failure to conceive after one year of unprotected regular sexual intercourse.  One in six couples have an unwanted delay in conception, with many factors being described as possible causes (1).
The relationship between subfertiltiy and coeliac disease has been well described and may be the only presenting feature of coeliac disease (2).

What is the relationship between untreated coeliac disease and subfertilily?

Studies have shown that the prevalence of unrecognised coeliac disease (as a cause of subfertility) in women presenting to subfertility clinics is in the range of 2.7-3%, a significantly higher prevalence than that found in the general population (1.06%) (3,4).  Molteni et al found that menarche was significantly delayed among untreated patients with coeliac disease (5). Sher and Mayberry confirmed this and also reported significantly earlier age of menopause (6). Undiagnosed coeliac disease is also associated with a poorer outcome for the foetus (7). A cohort Danish study found that babies of patients with untreated coeliac disease had significantly lower birth weights than controls. This was not observed in newborns of treated patients, therefore suggesting treatment with a gluten-free diet is of importance in reducing the incidence of foetal growth restriction (8).  The prevalence of low birth weight before and after a gluten-free diet prescribed to coeliac mothers fell from 29% to 0% (7). 
An increased incidence of miscarriage among patients with untreated coeliac disease has also been reported (5,6).  Following a gluten free diet, the miscarriage rate among patients with untreated coeliac disease was similar to that of controls.  Conversely Kolho et al found no difference in the incidence of coeliac disease among patients with recurrent miscarriage screened for coeliac disease and among healthy controls (9).

Is there a difference between pregnancy-related events in coeliac versus non-coeliac populations?

In a cohort study the proportion of births by caesarean section was almost 30% higher for women with coeliac disease than for the women in the comparison group (10). The study also showed miscarriages were slightly more common in women with coeliac disease (RR 1.31) and pregnancy experiences such as preeclampsia, postpartum haemorrhage, and still births to be similar between the two groups.  Also none of the women with coeliac disease had babies with neural tube defects, despite the concerns about folate deficiency in coeliac disease.  These results indicate that the risks of adverse pregnancy-related outcomes for women with coeliac disease are not as high as previously reported (3,6).

Dietary implications in pregnancy for coeliacs

There are no specific guidelines for pregnant women with coeliac disease.  Standard nutritional advice during pregnancy is appropriate for women with coeliac disease and general guidelines are suitable, in particular advice to take folic acid supplements should be followed.
It is important that people with coeliac disease are followed up regularly, particularly at times of stress, i.e. pregnancy.  Patients may experience deterioration in their symptoms and require additional support at this time. 
Depending on individual assessment and diet, supplementation with calcium, iron, and vitamin B12 may be required.

References

1 Taylor A (2003) Extent of the problem. BMJ 327: 434-436.

2 Sanders DS et al. A primary care cross-sectional study of undiagnosed adult coeliac disease.  Eur J Gastroenterology and Hepatology 2003;4:407-413.

3 Meloni GF et al. The prevalence of coeliac disease in infertility. Hum Reprod 1999;14:2759-2761

4 Collins P et al. Infertility and coeliac disease.  Gut 1996;39:382-384.

5 Molteni N et al. Obstetric and gynaecological problems with untreated sprue.  Journal of Clinical Gastroenterology 1990;12:37-39.

6 Sher KS and Mayberry JF. Female fertility, obstetric and gynaecological history in coeliac disease.  Digestion 1994;55:243-246.

7 Ciacci C et al. Coeliac disease and pregnancy outcome.  American Journal of Gastroenterology 1996;91:718-722.

8 Norgard S et al. Birth outcomes of women with celiac disease; A nationwide historical cohort study.  American Journal of Gastroenterology 1996;94:2435-2440.

9 Kolho KL et al. Screening for celiac disease in women with a history of recurrent miscarriage or infertility.  British Journal of Obstetrics and Gynaecology 1999;106:171-173.

10 Tata LJ et al. Fertility and pregnancy-related events in women with celiac disease: A population-based cohort study.  Gastroenterology 2005;128:849-855.

11 Office for National Statistics. Population trends: spring 2003. No 111. Published with permission of the Controller of Her Majesty's Stationery Office.  Office for National Statistics, London, England, 2003.