The aim of this observational study is to whether fibroids increase the risk of miscarriage in women in our early pregnancy population.

We will be collecting lots of data detailing other factors, which may have an impact on overall health and on the risk of miscarriage (this includes age, weight, use of vitamins or progesterone supplements, postcode which is linked to national deprivation scoring status and employment status).

By collecting all this data, we hope to remove the effect of other factors and purely assess the effect that the fibroids have on the outcome in early pregnancy.

We will also be looking closely at whether the location, number or size of the fibroids can affect the pregnancy too and following up women at 24 weeks via phone. We will also look at other secondary outcomes such whether women with fibroids experience symptoms of pain or bleeding in the first or second trimester more so than their control counterparts. We will also look at the value of uterine volume as a surrogate marker of fibroid mapping.

Once all the data has been analysed, we will be able to assess whether fibroids lead to an increased risk of miscarriage. We hope that this information will be useful in counselling women affected by fibroids in the pregnancy.

Inclusion Criteria:

• All women presenting at less than 10 weeks gestation either by last menstrual period or by transvaginal scan findings with an early intrauterine or ongoing pregnancy on scan

Exclusion Criteria:

• Women declining participation and follow up
• Women wishing to pursue termination of pregnancy
• Women who refuse transvaginal scan
• Multiple pregnancy
• Ectopic pregnancy
• Pregnancy of unknown location
• Embryonic demise
• Under 16
• Unable to understand - interpreting services will be used such as language line if required.

Women attending the early pregnancy unit in our London hospital will be the target population.

Data is available for reasonable requests including study protocol and anonymised data.