or e-mail jknight@fertilityUK.org
Is there any truth to the theories about timing intercourse, sexual positions, vitamins, etc. for trying for to influence the sex of the baby? We have two girls and would like to try for a boy.
"It seems that there really is no hard scientific evidence on timing,
diet, or positions for intercourse.
‘For practical purposes the timing of intercourse in relation to ovulation
has no influence on the sex of the baby according to the data from the
latest study (Wilcox, Weinberg and Baird, 1995).
I attach a copy of an article on sex pre-selection, published in our newsletter, ‘Fertility File’. in December 1995
Note : This article is now included in our on-line newsletter.
Sex/Gender Selection by Barbara Gross
FERTILE DAYS - after ovulation
Could you please tell me how long after ovulation I am fertile for? I have heard a day. Thank-you for any help.
Although you are correct in that following ovulation the egg only lasts for a maximum of 24 hours, it is not possible to tell precisely when ovulation occurs.
The indicators of fertility define the fertile phase taking into consideration sperm survival in fertile mucus and then the lifespan of the egg (allowing for the possibility of a twin ovulation).
As the temperature goes up approximately 24 hours following ovulation and then stays on the elevated level until the next period, it is possible to use this as a reliable indicator.
(A minimum of three high temperatures are required to determine that the fertile phase is past).
It is most important to have proper instruction to use this method effectively, to learn to take accurate readings and to understand the disturbances which can affect your recordings.
The method is explained very fully in the book and video Fertility details of which are on our homepage.
Ive been investigating your web site and it is among the very best Ive seen regarding fertility awareness.
Ive been charting for six cycles and my husband and I have just started to try to conceive.
I have short cycles (shortest 19 days - longest - 24) in the past we have had intercourse in days 6 - 10 but rather randomly.
I am concerned if perhaps these short cycles may be indicative of a luteal phase defect.
What would I have to do to determine this?
Any advice you have would be most helpful.
I am pleased that you have found our web-site of interest.
It is possible as you suggest that your short cycles indicate a luteal phase defect.
A minimum of nine days of a sustained high temperature is normally required to allow time for the completion of the implantation process.
To optimise timing of intercourse to conceive - look out for any signs of fertile mucus secretion - increased wetness or clear, slippery stretchy secretion.
With very short cycles this may occur very soon after your period (or even towards the end of your period).
You will find our book Fertility has more information on this subject.
REDUCED FERTILITY AFTER CHILDBIRTH
Does fertility decrease after the birth of a baby?
Yes - fertility will be decreased after the birth of a baby
for varying amounts of time dependant largely on whether and for
how long a woman breast-feeds her baby.
Research among the Eskimos and the rural Indians of North America where no other forms of contraception were used, and where there was no taboo on sexual intercourse during lactation revealed that the time taken for 50 per cent of the women to conceive again was 6 months in those artificially feeding, but an average of 18-24 months among the breast-feeders.
In 1981 Professor Howie and others compared the return of fertility among bottle feeders and breast-feeders. The mothers who were bottle feeding had all resumed ovulation and menstruation by fifteen weeks, averaging a return of fertility between 9 and 13 weeks postpartum.
Howie found that ovulation did not occur among breast-feeding mothers who gave at least five feeds, totalling 65 minutes a day. Ref. Howie
Lactational amenorrhoa method (LAM) uses the natural phase of infertility
following childbirth and is 98% effective in avoiding pregnancy.
Factors which may precipitate the return of fertility -
If a woman chooses to bottle feed her baby then her fertility is likely to return around six weeks after the birth, but ovulation may occur as early as the fourth week.
Caution - In 50 per cent of women ovulation occurs before the first menstrual period. (i.e there is no warning bleed)
If the mother breast-feeds her baby for a short time - one month or less, she will be infertile for the four weeks following the birth.
Ovulation may occur as early as the fifth week or may be delayed to the second or third month. Menstruation commonly occurs at the seventh or eighth week.
Women who wish to use a natural method of family planning post-natally require the support of a qualified NFP teacher.
IRREGULAR CYCLES - the Menopause
I have been married now for 15 years and successfully used natural family planning to plan our two children. (We taught ourselves using the temperature and a calculation)
I now feel I may be reaching the menopause.
I am 41 years old, and my mother went through ‘the change’ early in life.
From being as regular as clockwork, I am now no longer regular and am currently four weeks late. Although we have always relied on the safe time following my shift in temperature, this would now mean a very long time of abstinence which we would find difficult.
A friend told me of a device which indicates the ‘safe’ and ‘unsafe’ periods - would this help in my case?
Congratulations on your successful use of NFP for the last 15 years.
It is possible that your irregular cycles indicate the start of the
pre-menopause, but you would be advised to have a health check from
Other factors, including stress, can result in irregular cycles.
Although you will be able to continue using the safe time following ovulation (confirmed after your third high temperature), this will be unnecessarily restrictive.
Your calendar calculation can no longer be relied on when cycles become irregular.
It would be useful to learn to recognise signs of approaching fertility - the changes in the cervical mucus and possibly changes directly at the cervix.
I am including details of your local teacher who will be able to offer support at this time of change.
The device you refer to sounds like the ‘Personal Contraceptive System’ due to be launched in Autumn 1996 in the UK. We are currently awaiting the results of efficiency trials.
Unfortunately the device is not designed for women at times of hormonal change, so is unlikely to help in your case.
OVULATION PREDICTION KIT
I read in the paper some months ago that an ovulation prediction kit had been developed, which, by means of a urine dipstick test, could detect when ovulation was about to occur and thereby indicate fertile and infertile days.
As the article stated that it would be readily available sometime during this year, I was hoping you may be able to advise me as to the current situation.
The Ovulation Prediction kit to which you refer is the
‘PERSONA - The Personal Contraceptive System’
Further details of this device are available from:
Unipath on 0800 387 326
My local family planning clinic recommended that I write to you for some detailed information on the ‘Billings Method’.
I am planning on using this method as my main form of birth control.
Could you send me any info’ you may have and any suggestions regarding accurate thermometers specifically for this purpose.
I enclose information on natural family planning methods.
Our organisation teaches the sympto-thermal method which includes a double check of at least two indicators - usually temperature and cervical mucus.
The Billings method to which you referred uses cervical mucus as a single indicator of fertility.
Research studies indicate that sympto-thermal method is generally more effective than mucus only methods.
You will find details of specially designed accurate thermometers and recording techniques in the book ‘Fertility’
Your local teacher will be able to supply relevant charts and assist you in recording and interpreting your charts.
I am a married woman with two small boys (two and a half and ten weeks).
Having found my second son difficult to conceive and not being totally opposed to having another child (although we do not currently plan to have any more),
I feel that NFP might well be the perfect option for us.
I was recommended to you by my GP, who said you could send me further information and details of my local teacher.
We would advise you to see your local NFP teacher.
NFP might well be the perfect option in your current circumstances.
The dilemma over planning (or not planning another child) is highlighted in ‘Pandora’s Clock’
You may be interested to note that NFP users who consider themselves to be ‘limiting’ their families will be more effective users than the family ‘spacers’.
Couples planning another child later frequently take more risks, and therefore have a higher pregnancy rate while using the method.
Breast-feeding suppresses fertility. Many women who breast-feed longer term experience difficulty conceiving their next child, which may explain your delay in conceiving your second son.
Every woman is an individual and every breast-feeding experience will be different.
The contraceptive effect of breast-feeding is described on the breast-feeding page.
The Rhythm or Calendar Method
My wife and I (both now in our mid-seventies) followed what was then the rhythm method as advised by a priest, but it was not a success despite great care on our part and resulted in eight children.
One of our friends had a similar experience.
We were fascinated by the article in the ‘Daily Telegraph’ about the newer natural methods of family planning which seem to be based on years of much-needed research.
I hope that future generations will benefit from this knowledge.
We have just bought a copy of ‘Fertility’ for one of our grand-daughters who is to be married soon.
The Rhythm or Calendar method was discovered in 1929 by Dr Knaus in Austria who observed that ovulation occurred at a fixed time of around 14 days before the next menstrual period.
In 1930 Dr Ogino in Japan, made a similar observation independently.
This knowledge formed the basis of the rhythm method in which calculations were made to predict the fertile and infertile phases of the cycle.
This method is still being practised in some countries, but due to its reliance on regular cycles and the long period of abstinence required, it is less effective than more modern methods and it is not widely used.
In the sympto-thermal method, we still use part of the calculation when considering the onset of the fertile phase, in correlation with day to day observations of fertility indicators.
Hormone Replacement Therapy (HRT)
- Effects on NFP
For several years now I have been using natural methods of birth control, but recently I have been advised to start taking HRT because of low bone density.
I am 47 years old and before starting HRT my cycles were regular showing signs of ovulation (bi-phasic charts).
Now that I am taking HRT the hormones are masking my natural bodily signs.
When I take oestrogen only, the mucus appears wetter, more fertile-type.
When taking oestrogen and progesterone, the mucus changes to a drier type and my temperature goes up accordingly. It seems that I am unlikely to know my own cycle or if an ovulation is occurring.
Would it be possible to use the second two weeks (while taking the oestrogen / progesterone) for safe intercourse as the mucus appears to be changed to the infertile variety.
I assume I could ovulate during this time without knowing.
I have been very satisfied using NFP previously and am not keen to change to other contraceptives.
I have investigated alternatives to HRT including herbal treatments, but HRT currently seems to offer the best known protection against further bone loss.
There is very little documented about women using natural methods while
taking HRT, but it is an area of increasing interest.
You described very accurately the effects of the hormones oestrogen and progesterone on cervical mucus.
The effects of the hormones in the HRT will be similar to those of your body’s natural hormonal fluctuations (and therefore could be misleading).
It may be possible to observe your natural shift in temperature (and reversion to less fertile mucus characteristics) before you start taking your progesterone supplement.
By observing a series of cycles you may be able to accurately define the post-ovulatory infertile phases.
If you would like further support with these charts they can be posted or faxed to us at ‘Fertility’, where our Medical Director will be able to offer an opinion.
If you know of any research in this area please E-mail Jane Knight
I am new to this area and am writing in the hope that you can recommend someone locally to help me.
I am 32 years old, and my husband and I have been trying to conceive for nearly a year now (it seems like forever).
I have bought various ovulation prediction kits and collected fertility information generally.
I recently bought a copy of ‘Fertility’ by Dr Elizabeth Clubb and Jane Knight and this has helped me a great deal in terms of knowing my own body and the fertility signs.
I am however concerned as my temperature is staying on one level indicating that I may not be ovulating.
I am unsure what to do, or who to see next and what can be done if I am not ovulating.
I am pleased that you have found the book ‘Fertility’ helpful.
Your local teacher ..... will be able to check with you that you are making accurate recordings and that readings are not affected by disturbances which could give misleading results.
In order to get a more accurate picture of your fertility, it is preferable to do a series of charts (2 or 3 may be sufficient).
A single temperature chart without a shift in temperature is not necessarily a cause for concern, but if you have two or more accurately recorded cycles which do not show a temperature shift you should consult your doctor.
Your NFP teacher will be able to check that you are optimising your chances of pregnancy by timing intercourse to coincide with your most fertile symptoms, and will be able to offer further support alongside your general practitioner, should you require further fertility investigations.
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