Low Estrogen Levels and High Basal Body Temperature

When you are actively trying to get pregnant, an internal state that combines low estrogen levels, with a high basal body temperature is the Holy Grail, the magic formula that can mean the difference between having your next period as usual, or embarking on a nine month pregnancy.

The mid-point of your menstrual cycle, Days 14 – 15, are the most exciting time of all if you are trying to conceive (or conversely, if you wish to avoid getting pregnant, then this is definitely time for ‘Uh uh!! Not now, dear!’) This is the high peak of your monthly reproductive cycle, and things are heating up – quite literally. Hopefully if conception is on your mind, then you’ll be feeling distinctly hot, hot, hot!

Physiologically, your basal body temperature – you can check this temperature first thing in the morning, before any exertion – will now rise, as ovulation has just occurred. This happens when the egg, stimulated by a rise in LH or Luteinizing hormone due to high levels of oestrogen, comes out of its ovarian follicle – the place in the ovary where the egg is nurtured - and starts its journey down the fallopian tubes.

Once embedded in the uterus, it awaits the miracle of conception. The egg will only survive for around twelve to twenty four hours. Though sperm, having entered the cervix, can stay around for several days – and incidentally the X bearing chromosomes, which create girls, are stronger and tend to last longer - it is the life of the egg (or in the case of multiple births, eggs) that determines how long a woman will remain fertile during her reproductive cycle.

Determining high fertility levels is the tricky part, whether you wish to get pregnant, or conversely, if you want to avoid getting pregnant! Either way, this is a life changing (or life forming) decision, so every trick in your arsenal is worth employing. Measuring your bodily temperature is the first port of call.

Basal body temperature is the resting level of your body heat, in other words, your temperature before any exertion, so its optimum testing time is as soon as you wake in the morning – ie, before you have generated enough energy for it to rise. Usually this is around 97.2 – 97.7 F, but when you ovulate, and are therefore at your most fertile, it will rise by typically between a half to one and a half degrees.

It will remain higher until your period, at which point your body will enter its ‘cool’ phase. Your basal body temperature drops, and your estrogen levels rise again, thus triggering LH the following month. At this point, when ovulation begins all over again, estrogen levels quickly drop as your body heat rises.

Some women experience discomfort, usually lower back pain when they ovulate. If you want to get pregnant, this could be sweet pain indeed, as it may be the green light you are waiting for. To be on the safe side – and particularly if you want to avoid pregnancy, then become familiar with the fluctuations and rhythms of your cycle.

This circle of life is driven by your hormones, and particularly estrogen, which hits its lowest ebb just when you are most likely to conceive. The ‘cool’ and the ‘hot’ stages of your cycle are determined by estrogen – when building up to its highest levels before ovulation, your body temperature is in its cool stage. At its highest point, estrogen triggers ovulation, then rapidly decreases, as your body heat increases. This is when you are most likely to conceive a child.