Q I am 30 years old, married and have been trying to conceive for four years. I'm currently undergoing IO treatment with fertility tablets. My gynaecologist has noticed that my lining is thin at just 4mm.
I have been advised that my lining has to be a minimum of 6mm or above before a successful pregnancy can occur. Is there any other method or medication that can help improve the thickness of my lining? Will I be able to conceive in the future?
A I presume 'IO' means 'induction of ovulation' and lining refers to the lining of the wall of the uterus (endometrial lining).
In inducing ovulation, a fertility drug such as clomiphene is given to stimulate the ovary to produce an egg. If the egg is fertilised, it begins to divide, grow and travel down the fallopian tube into the womb (uterus). Finally, it attaches itself to the endometrial lining.
The endometrial lining undergoes cyclical changes under the influence of the ovarian hormones, oestrogen and progesterone. Soon after menstruation, it becomes thick due to the effect of oestrogen. Once ovulation occurs, progesterone gradually changes it into a spongy layer in preparation for the fertilised egg to implant. Thus, if the endometrial lining is insufficiently prepared, implantation will fail and pregnancy will not ensue.
The endometrial lining is measured by vaginal ultrasound. It is a biological indicator of how ready the uterus is to receive the fertilised egg. Medical studies have yet to define what the optimal thickness of the lining is for a successful pregnancy. In general, 8-13mm is good, less than six is potentially a problem, and greater than 14 could also reduce chances for pregnancy. Pregnancies, however, do occur when the thickness is less than 6mm, but not as often.
Besides endometrial thickness, fertility specialists also look at the endometrial pattern. A triple-layer or trilaminar pattern for the endometrium would be optimal for implantation. Nonetheless, pregnancies could still occur when there is a non-trilaminar pattern.
Methods that might help to improve endometrial thickness include:
>>Adding oral oestrogen after taking fertility pills
>>Using different ways of stimulating the ovary to increase the blood level of oestrogen.
>>Taking low-dose aspirin or Viagra or undergoing acupuncture, which may improve blood flow to the lining. However, data on these modes of treatment is limited.
DR PETER CHEW, CONSULTANT OBSTETRICIAN AND GYNAECOLOGIST, GLENEAGLES HOSPITAL
