A MoMo pregnancy, often referred to as a Mono Mono pregnancy, is a rare type of twin pregnancy where identical or semi-identical twins share the same amniotic sac and the same placenta within their mother's uterus. The term "MoMo" is short for Monoamniotic-Monochorionic.
Understanding Monoamniotic-Monochorionic (MoMo)
This designation highlights two key characteristics of the pregnancy:
- Monoamniotic: This means "single amniotic sac." Unlike most twin pregnancies where each baby has its own protective fluid-filled sac, MoMo twins develop within one shared sac.
- Monochorionic: This means "single chorion," which implies they share a single placenta. While they share the placenta, each twin typically has its own separate umbilical cord.
This specific configuration arises when a single fertilized egg splits later than usual (typically between 8 to 13 days after fertilization), resulting in twins who are genetically identical or very similar and share the most intimate parts of their intrauterine environment.
Key Characteristics of a MoMo Pregnancy
To summarize, a MoMo pregnancy is defined by the following unique features:
| Feature | Description |
|---|---|
| Twin Type | Identical or semi-identical twins. |
| Amniotic Sac | Share a single amniotic sac. |
| Placenta | Share a single placenta (monochorionic). |
| Umbilical Cords | Each twin has a separate umbilical cord. |
| Occurrence | A less common type of twin pregnancy. |
In essence, a MoMo pregnancy describes a scenario where two babies share the most fundamental resources and space within the womb, growing together in the same protective fluid and nourished by a single shared placenta.
