Uterine positions and physical barriers to pregnancy.
The uterus is a hollow space which normally allows for a healthy embryo to grow, but not everyone’s uterus is the same. So what are the abnormalities which can make it more difficult to conceive? There are a few which can require surgery or are present at birth and may or may not impact the ability to conceive:
Segmental hypoplasia - undeveloped uterus
Unicornuate uterus - only half of the uterus develops, usually with one fallopian tube
Uterine didelphys - the uterus develops as two sections with two cervices, two for one!
Bicornuate uterus - the uterus develops as two sections with one cervix
Septate uterus - a septum divides in the inner portion of the uterus but it’s still one uterus
Other drug exposure changes.
There are also other physical barriers to pregnancy which affect the uterus:
Polyps - a little growth, kind of like an internal skin tag, which can cause abnormal bleeding
Leiomyoma or fibroids - a benign tumour which can cause abnormal bleeding or miscarriage
Endometrial hyperplasia - excess growth of endometrial tissue inside the uterus
Adenomyosis - endometrial tissue grows into the uterine myometrium and usually causes heavy, painful periods
Endometriosis - endometrial tissue which grows outside of the uterus and causes pain and difficulty falling pregnant
Some of these may need surgery to resolve and some can be managed with treatment and medication (Ameer, Fagan, Sosa-Stanley & Peterson, 2020). The treatment will vary depending on the condition and other presenting symptoms, but it is useful to understand how the positioning and condition affects conception rates or ability.
Additionally to this, the uterus can also be in one of three different positions; anteverted, midposition or retroverted. Midposition means the uterus stands up vertically. Anteverted just means the uterus is tilted forwards and is the most common presentation. A retroverted uterus is more rare, where the uterus is tilted backwards and can cause an issue if you have endometriosis (Ameer, Fagan, Sosa-Stanley & Peterson, 2020). It may not always stay in that position, after pregnancy it may appear differently. Usually the position will not affect ability to conceive, but a retroverted uterus may come with symptoms (which can be because of an associated condition) (Feminist Midwife, 2013).