You have probably not used the word ‘Superfetation’ in a conversation this week, or perhaps you have never even heard of that word before. Don't worry, superfetation is not something you hear about every day, and although it has to do with pregnancy, many OB-GYNs have never dealt with cases of Superfetation in their entire careers.
Superfetation describes a situation where a woman gets pregnant while she is already expecting a baby. In a more scientific explanation, Superfetation is when two fetuses grow inside the womb at the same time, although at different stages of growth. It may be hard to imagine how that can be possible, but it is not as unbelievable as it sounds.
Biologically, Is Superfetation Supposed To Happen?
With only 10 cases reported in the entire medical history, Superfetation is very rare with human beings but quite common with animals.
When a woman becomes pregnant, her system releases hormones that help to keep the fertilized egg implanted and growing, as well as stop her from ovulating. Consequently, the menstrual cycle stops also because the system stops releasing the hormones that cause ovulation. In that regard, ovulating while pregnant does not make biological sense. That is because, the biological processes that happen during pregnancy, do not allow the release of hormones that will make fertilization to continue taking place.
How Does It Happen?
Medical practitioners cannot rule out the possibility of ovulation occurring during pregnancy, even though the reason as to why it happens continues to be a medical mystery.
Superfetation happens when an expectant mother’s ovary releases another egg within the first few weeks of the initial pregnancy, and the egg becomes fertilized resulting in another pregnancy. Some medical researchers hold to the possibility that another egg gets released if the first embryo’s implantation delayed.
Moreover, cases of Superfetation prove that ovulation can still take place during the gestation period. For instance, in 2016, Jessica Allen became pregnant with her own baby, while carrying a Chinese couple’s surrogate child. Jessica, already a mother of two at the time, was not aware that such a thing could happen. The mother of two who continued to ovulate normally even during her pregnancy thought the Chinese couple was having twins when a second baby appeared in the ultrasound six weeks later.
Another case in 2016 was of Kate Hill, an Australian woman who conceived her two daughters 10 days apart. She got pregnant on two different days and the girls were born on the same day, despite having different due dates.
Before Kate’s and Jessica’s case, in 2009, Julia Grovenburg, a woman from Arkansas became pregnant twice within two weeks, after years of trying to conceive. Her case puzzled the doctors who took her scans when the ultrasound showed two separate babies in two separate sacs. Moreover, one of the babies was bigger and more developed than the other.
Is It Like Having Twins?
Twin pregnancies occur in three different ways. First, if more than one egg gets released during ovulation, and a sperm fertilizes each, the result is fraternal twins. The second type that results in identical twins happens when a single fertilized egg splits. The third type occurs when identical twins are born physically connected to one another, resulting in Siamese twin pregnancies.
Superfetation, therefore, is not like having twins, because, in Superfetation, a woman conceives two separate times, from two separate ovulations. The babies can belong to the same father, or to two different fathers. That is different from the way twin pregnancies take place.
However, it is possible that cases of Superfetation have been mistaken for twin pregnancies, especially in cases where babies are born during the same gestation period.
Do The Babies Come Out At The Same Time?
According to healthline.com, babies born from Superfetation often come out during the same birth, or on the same day. That is regardless of the difference in time of conception, or how much time they have had to grow.
Because it may be impossible to deliver one baby at a time, doctors can resort to induced labor or delivery through C-section. However, in a rare case, like Julia Grovenburg’s, the babies were born two weeks apart. Nevertheless, there is no need to panic, because doctors will advise accordingly, in cases of double pregnancies. The good news is that all the children born from double pregnancies have survived; therefore, the success rate for delivering such babies is high.
Are There Signs And Symptoms Of Superfetation?
If your menstrual cycle does not stop during pregnancy, that could ring a bell. In such a case, you may want to consult an OB-GYN regarding the matter.
Apart from that early indication, there are no specific signs and symptoms associated with double pregnancies. That is unless your doctor notices two fetuses developing at different rates in the womb. Although there can be different explanations that may not point to a double pregnancy, as is the case when blood is unequally distributed between the fetuses, it could still be a sign of Superfetation.
When Can It Happen?
Getting pregnant while pregnant can happen if a woman menstruates several times within one cycle, and the second egg becomes inseminated, or when she has a double uterus.
It is advisable to see your OB-GYN if you have given birth to twins who were at different maturity levels at birth, and you suspect that you might have had a double pregnancy. Your doctor will be able to conduct some tests that will tell whether that is the case or not.
Moreover, you can stay calm because the medical world has evolved, and has advanced enough to safeguard the health of your babies, as well as your own.
Are There Any Risks Associated With It?
When the difference in the length of time it takes for each fetus to develop is huge, there is the risk that the younger baby may be born prematurely.
As a result, the baby will be exposed to health risks that result from premature births.
Sources: health.com, em-consulte.com, womenshealthmag.com, journals.plos.org, independent.co.uk, babymed.com, moms.com.