The alarming rate of infertility among couples calls for serious efforts and attention from any woman who is serious about getting pregnant. Most women, and sometimes their partners, would want to learn when ovulation and implantation occurs, what is the best time for intercourse to achieve pregnancy and probably what are the usual miscarriage or pregnancy loss rates. Most often, the figures and data women are given are based upon averages, theoretical numbers or sometimes just plain guesses. This is because, ovulation, conception and implantation of fertilized ovum are a difficult topic to scientifically investigate, due to several human factors.
Timing the ovulation period is a very important step towards getting pregnant. With the latest scientific improvements, several methods and tests are available for determining, with a high degree of certainty, when your ovulation occurs. Pelvic ultrasound, looking at the ovaries, is the known standard in ovulation prediction researches, but obviously, in a practical situation of a woman trying to conceive, ultrasound is not feasible. A very important test which measures urinary LH has been shown to have a 100% correlation with ultrasound as far predicting timing. In a study, cervical mucous change only had a correlation of 48%, salivary ferning has 37% correlation and Basal Body Temperature charts correlated 30% with ultrasound ovulation prediction. You would, therefore, agree that those ovulation prediction tests are actually worth the headache.
For home use, ovulation detection kits that measure urinary LH surge just before ovulation, detection of LH occurs at above 30mIU/ml. This shows that even women with Polycystic Ovarian Syndrome (PCOS), with slightly higher resting LH values will still have accurate ovulation detection. The urinary LH surge occurs between 24-36 hours before ovulation. It is very important and useful for women seriously seeking conception because it gives you a window of warning. The test will show positive for a day or two and on rare occasions, three days, if you are lucky enough to catch the increase right at the beginning, when it is always a large release of hormone.
With timing and predicting ovulation out of the way, the next important thing is when is the best time for intercourse, in order to get pregnant?
A research report conducted in 1995 demonstrated that pregnancy only occurs if intercourse occurs within 6 days prior to and including ovulation day. Intercourse after the day of ovulation is not likely to result in pregnancy. The probability of conception ranged from 10% when intercourse occurred five days before ovulation to 33% when it occurred on the day of ovulation itself. This information suggests, therefore, that the best timing of intercourse for a woman seeking pregnancy, with a 28 day cycle would be days 10, 12, 14 and in cases of late ovulation, day 16. But if your cycle is longer or shorter than 28 days, the best timing for intercourse would be days -4, -2, 0, +2 with respect to the expected ovulation day.
After a keen ovulation timing and rounds of rigorous workout on the bed, you would definitely want to know if you've been successful. Most home use pregnancy tests that check urine beta HCG hormone are sensitive to a 20-25mIU/ml of HCG. The general applicable rule is to test for pregnancy when you are a day late for your menses or around 15 days after ovulation. The test would normally be positive anywhere from about 2-3 days before a missed menses to 4-5 days after.
The usefulness of testing for pregnancy really does depend upon how regular your menses are, or in effect, how regularly your ovulation occurs. It won't make sense testing on day 15 after ovulation, or 28 days after the onset of the last menses, if you have a cycle that's longer than 28 days or varies several days each month.
Getting pregnant is one thing, carrying the pregnancy to term, without losing it, is another important thing.
The time of implantation into the uterine lining plays an important role in pregnancy loss. It was generally believed that a pregnancy implants itself in the uterine lining on the 7th day after ovulation. But recent studies have shown that this is rarely the case. The study accurately determined the day of implantation by a very sensitive pregnancy test, HCG measurement compared to ovulation. The HCH hormone starts being produced when the fertilized ovum implants into the uterine lining. Findings from normal women trying to conceive showed that the first appearance of HCG, hence implantation, occurred 6-12 days after ovulation. 84% of the pregnancies evaluated implanted 8-10 days after ovulation and early pregnancy loss was shown to increase with later implantation. The study showed early pregnancy loss and day of implantation as thus:
- 13% of pregnancy loss implanted on day 9 - 26% on day 10 - 52% on day 11 - 86% on day 12 or more.
The overall total pregnancy loss up to 6 weeks was put at 25%. That may seem very high to most people, but it is important to remember that many of these pregnancy losses occur at the time that the women involved wasn't even aware of the presence of the pregnancy. The normal pregnancy loss rate that most women know about is only about 15-18% of clinically recognized pregnancies making more than 40% of pregnancy loss unrecognized.
Michael Russell
Your Independent guide to Infertility