LETTER TO THE EDITOR
Pregnancy, birth, gynecologic operations and multiple sclerosis EGONSTENAGER, ELSEBETH NYLEVSTENAGER AND KNUDJENSEN
From the Clinical Neuro-Psychiatric Research Unit, Odense University Hospital, Odense, Denmark
Arm 0 h . w Gynecd S c m d 1992; 71: 88-89
Sir, Papers on multiple sclerosis (MS) have been published for more than 150 years. Many of them have dealt with the correlation between pregnancy and MS. In the past 40 years papers have specifically dealt with the question of whether pregnancy and childbirth cause deterioration in the course of MS. However, there are other aspects of the correlation of pregnancy with MS that we wish to draw attention to in our communication. Since Bang’s description in 1861 (1) many case reports have described the onset of MS during pregnancy, subsequent to childbirth, gynecological operations or natural abortion. Furthermore, exacerbation of the disease has been seen during pregnancy and following childbirth. In the first four decades of this century, several studies have demonstrated that 10-20% of women with MS had onset after pregnancy or childbirth and the finding led to the conclusion that pregnancy o r childbirth could trigger MS. A study by Tillman in 1950 (2) challenged that theory as he found that 31 ”/” of the women with MS had onset after pregnancy or childbirth. The possibility that pregnancy or childbirth could affect the course of MS was then put forward. This theory became the premise for studies in the succeeding 40 years. Reviews of the studies (3, 4) have concluded that the disease can stabilize in pregnancy. but that in the 6 months succeeding childbirth there is an increased risk of deterioration. Subsequent to Tillman’s study it was, however, found possible in ii few studies to estimate the percentage of women with onset after pregnancy or childbirth, and there are studies confirming the earlier findings and which show that about 10-20% of the women with
MS had onset of the disease during pregnancy or subsequent to childbirth. However, this should be considered in relation to the preponderance of women found in all MS populations. For all age groups the sex ratio is: female : male = 3 : 2. However, the incidence for men increases with increasing age at onset. An obvious question seems to be whether the excess of women in MS populations is due to a higher risk of the disease in connection with pregnancy and childbirth. The excess would seem compatible with the equivalence of the sex ratio in MS populations with onset in the older age groups (> 35-40 years), while the skewed sex ratio is seen in the younger age groups (20-35 years) when most women give birth. From studies on the cerebrospinal fluid and MRI. we know that patients with MS have defects in the blood-brain barrier, but we d o not know if these defects are inherited o r acquired. It would be interesting to find out whether the defects could be generated in connection with pregnancy or childbirth. More studies are required before the question can be answered. Such studies could take the form of MRI examinations on large populations. It would, however, be a complicated task in view of the h i ited resources available. O n the other hand, it could be practicable to examine pregnant women, suspected of having MS, by MRI and study changes in the blood-brain barrier during pregnancy and after childbirth. Such studies could probably clarify some of the following points: Does pregnancy ‘safeguard’ against exacerbation of MS? Does childbirth ‘activate’ MS? Does cesarean section ‘safeguard’ agqjnst exacerbation of MS? Clarification on these and
Pregnuncy, birth, gynecologic operations other aspects would require close cooperation between many centers. This brings us back to the purpose of this letter, namely to stimulate further discussion on the subject and create interest in establishing the intercenter co-operation needed.
References I . Bang 0 . Den almindelige lamhed. Bib1 laeger 1861; 53: 3-24. (in Danish). 2. Tillrnann JB. The effect of pregnancy on multiple scle-
rosk and its management. Res Pub1 Ass Rcs Nerv Mcnt Dis 1950; 2X: 548-82. 3. Birk K , Smeltzer SC, Rudick R. Pregnancy and multiple sclerosis. Sem Neurol 1988; 8: 205-13. 4. Stenager E N , Stenager E, Jcnsen K. Graviditet og dissernineret sklerosc. Ugeskr L q e r 1989; 151: 17446. (in Danish). Address for correspondence.
Egon Stcnager Neuromedicinsk afdeling Odense University Hospital, DK-5000 Odense C. Denmark
Actu Obstet Gyiiecol
. ~ ~ . u i i71 d