It may be that you are not familiar with the meaning of the words molar pregnancy or ectopic pregnancy. They are medical terms that thankfully, are not very commonly used as they refer to different types of pregnancy that can occur.
In assisted reproduction treatments, gestation begins once the egg has been fertilized (in artificial insemination) or when the embryo is transferred and followed by implantation in IVF or egg donation. During embryo implantation, the blastocyst goes through different phases (hatching, apposition, and adhesion) until it is in full contact with the uterus where it can continue its development as a fetus. This is the moment when the body starts to experience the changes that signal a pregnancy has occurred.
Following an embryo transfer, the main are abdominal discomfort, a sensation of bloating, increased urge to urinate, breast swelling and/or tenderness, abdominal cramps, and increased vaginal discharge, amongst others. However, in some cases, embryo implantation may evolve abnormally, resulting in a non-viable pregnancy of one type or another.
INTRAUTERINE PREGNANCY (NORMAL PREGNANCY)
A normal pregnancy develops favorably when the embryo correctly implants into the lining of the uterus. In an assisted reproduction treatment, this occurs after the embryo transfer, when the blastocyst adheres to the internal uterine wall without any type of problem, and continues its development until it reaches approximately 40 weeks (9 months). This type of pregnancy is divided into three trimesters with distinct changes for both the mother and the developing fetus. Those changes that occur at the end of the pregnancy prepare the woman for the upcoming childbirth.
This type of pregnancy can happen when two or more eggs are fertilized by two or more sperm (fraternal twins, or higher), or when the zygote splits at an early developmental stage leading to identical twins. Some factors that contribute to multiple pregnancies are hereditary (family history) or genetic (women who have a gene giving them a predisposition to multiple ovulation), amongst others.
ECTOPIC PREGNANCY (EXTRAUTERINE)
An ectopic pregnancy occurs when the embryo implants and begins to grow outside the uterus. There are different locations in the female reproductive tract where this can happen, mainly in the Fallopian tubes and less commonly in the abdominal cavity or in the cervix. Unfortunately, an ectopic pregnancy cannot continue to develop, and usually, the patient presents with pain and discomfort after the sixth week, or even before. These pregnancies present a gynecological emergency as they can result in a serious hemorrhage. The most frequent symptoms are intense pain in the lower abdomen (usually on one side), vaginal bleeding, weakness, and nausea.
Although this is the least common, it is one of the most dangerous. A molar pregnancy is also known as a “hydatidiform mole” and it happens when the egg is incorrectly fertilized and the placenta develops abnormally, resulting in the formation of various cysts. There are two types of molar pregnancy; complete molar pregnancy – where there is an abnormal placenta and no embryonic development, or partial molar pregnancy – where there is both normal and abnormal placental tissue. In both cases, urgent treatment is recommended to resolve the situation.
This article is for informational purposes only. All these types of pregnancies should be diagnosed and treated by the specialist who is following your process. If you do not feel well from the beginning of your pregnancy or notice any unusual symptoms, please contact your doctor.