What do the blood tests check for pregnancy?
Simple blood (serum) tests are carried out to check for any hormonal imbalance that may be affecting your fertility. If you are just starting out, these tests will be done by your GP, or if you are at a fertility clinic, they will be done there.
The first test is done on days 1 to 3 of your cycle and measures your FSH level. This hormone stimulates the growth and development of ovarian follicles and the level of FSH gives an indication of the quality of your eggs and
Blood tests carried out as a first line of investigation will help establish whether or not you have a healthy hormonal balance.
If the result of any test is not what you expected, seek advice from the professionals.
your ovarian reserve. Women who are approaching the menopause (perimenopausal) or who are menopausal have high FSH levels and do not respond well to IVF. Raised FSH levels cause much concern for many of the women I see.
The levels of other hormones, including oestradiol and LH, will also be measured. Raised levels of luteinizing hormone (LH) may indicate polycystic ovary syndrome (22), and increased levels of prolactin may indicate problems with ovulation. Some clinics now also use a newer test, called the anti-mullerian hormone (AMH) test (12), which appears to be a more accurate marker of ovarian reserve.
A second blood test is done on day 21 (of a 28-day cycle, or on the appropriate day if the cycle is shorter or longer). It measures the level of progesterone and shows whether or not ovulation has taken place. The test needs to be done about a week after ovulation, and therefore about a week before your next period is due. However, it is not easy to work out the exact date, so ideally you should time the test for about a week after your peak day of fertility (the last day of the clearer, wetter, slippery secretions – 40).
Hopefully, your period will start about seven days after the test. Don’t panic, though, if the test comes back saying you have not ovulated: it may be due to the fact that the test was not done on the right day after all, or that you simply did not ovulate during that cycle (women do not necessarily ovulate on every cycle). Only if the test repeatedly comes back with a low progesterone level would this alert you to a problem.
Further tests might be done if you have a history of recurrent miscarriage. Increasingly, experts have come to realize that some women have blood-clotting disorders that may be the cause of miscarriage. In some cases, drugs such as aspirin, heparin, or steroids may be used to improve the chances of maintaining a pregnancy. This is a highly controversial area but specialist fertility clinics and miscarriage clinics can now help many women.