refacontact.blogg.se - Pregnancy due date calculator ivf

In any case, ultrasound does not give a very accurate prediction of the actual birth date. A recent study 3 of women who conceived by IVF and therefore knew when their egg was fertilised, found that the routine ultrasound dating scan consistently put their estimated birth date earlier than it should have been by an average of 3 days. This suggests that in general ultrasound dating is more accurate in predicting the birth date than counting from the last monthly period 1,2 but it is still only an estimate and may not always be accurate. There is quite a lot of evidence to suggest that when an ultrasound scan in the first trimester is used for the estimate instead of calculating from the last monthly period, the number of apparently “post-term” births (those which occur 15 days or more after the estimated date) is reduced. In that case, if the EDD is later than it should be that could mean that the birth is delayed unnecessarily.

Sometimes there are medical reasons such a pre-eclampsia which mean it may be better for a baby to be born as soon as they reach “term” (37 weeks of pregnancy). Induction of labour is routinely offered at 42 weeks of pregnancy (or in some circumstances even earlier) but if the EDD is too early, the baby might be born before s/he is fully prepared for life outside the womb. There is a tendency for midwives and doctors to talk as though the EDD written in your maternity notes is something definite, rather than an estimate which may or may not be accurate. The EDD will be used to decide things like whether your baby seems to be growing too fast or slow, or when you will be offered induction to prevent a long pregnancy, so it’s important to understand how firm a prediction it is. Why does the accuracy of the 'due date' matter?

estimating your baby's size from various measurements made during an ultrasound scan.Ĭharting temperature, monitoring mucus, using ovulation test kits and knowing times when you could have conceived, or having conceived by IVF may mean you have your own information about when you became pregnant.

counting 280 days from the first day of your last monthly period.

There are two methods doctors and midwives use to estimate a EDD: For more information you might like to have a look at the "AIMS Guide to Induction of Labour" which is available from the shop. For some women this will be the right decision, but it is important to know that this is your decision to make. Many women with longer pregnancies find that everyone is asking whether they have had their baby yet, and that health care workers start to suggest inducing labour. It may be more helpful to be prepared for you baby arrive some time after 37 weeks, and to focus on 42 weeks as the time by which you have a good chance of having given birth.

Only about 5% of babies will arrive on their due date and focusing on this single date can make the end of pregnancy quite stressful. It is common to be given a single 'estimated due date' (EDD) which corresponds the point at which it is estimated that your pregnancy will have lasted 40 weeks. Please note that this page is awaiting updateĪbout 90% of pregnancies will naturally last between 37 and 42 weeks, and this period is referred to as "term pregnancy".