Bleeding in early pregnancy can occur for various reasons. Some of the most common causes include:

1. Implantation Bleeding

Implantation bleeding happens when the embryo embeds itself into the uterine lining. This usually happens around 6 to 12 days after fertilization and may cause light spotting. It is typically pink or brown and lasts only a short time.

2. Cervical Sensitivity

During pregnancy, increased blood flow to the cervix can make it more sensitive. Activities such as sexual intercourse or a pelvic exam can sometimes trigger minor bleeding.

3. Hormonal Changes

Hormonal fluctuations in early pregnancy can lead to spotting. Since IVF involves hormonal support, this may contribute to mild bleeding in some women.

4. Subchorionic Hemorrhage

This occurs when blood collects between the uterine lining and the gestational sac. It is a relatively common finding in early pregnancy and, in many cases, resolves on its own.

5. Ectopic Pregnancy

In rare cases, the embryo may implant outside the uterus, leading to an ectopic pregnancy. This condition can cause severe pain, and heavy bleeding, and requires immediate medical attention.

6. Threatened Miscarriage

Bleeding can sometimes indicate a threatened miscarriage. However, many pregnancies continue to develop normally even after experiencing some bleeding.

7. Multiple Pregnancies

Women undergoing IVF have a higher chance of conceiving twins or multiple babies. This can sometimes lead to an increased risk of bleeding due to changes in the uterus and additional pressure on the uterine lining.

8. Placental Issues

Conditions like placenta previa, where the placenta partially or completely covers the cervix, can cause bleeding during pregnancy. Placental abruption, where the placenta detaches from the uterus prematurely, can also lead to bleeding and requires urgent medical attention.