Superfetation and the the weird story of getting pregnant while already pregnant.

Many weird tales have surrounded pregnancy and every aspect of this phenomenon, how one comes to produce a smaller being of its kind would marvel anyone. Getting pregnant and putting to bed not only ushers in a new life cycle but it is also as important as life itself and this supports the claim that life started from one pair of beings.

It all starts with an adventurous journey of a speedy and determined spermatozoa as he swims all through to meet the love of his life–the ovum. Fertilization is unarguably a very vital stage in the process of reproduction, this is the union of the spermatozoa and the ovum to form a zygote at the ampulla of the Fallopian tube.

In the course of mating/intercourse, the male ejaculates, releasing a white sticky fluid which contains billions of sperm cells in to the genital tract of the female counterpart. The sperms cells possess a head, a neck and a tail. The head contains acrosome which releases a trypsin-like protease – acrosin which facilitates the penetration of the sperm cells through the covering of the ovum– the Zona pellucida. The neck of the sperm contains mitochondria which produces energy for propelling the sperm cells through the metabolism of fucose. The flagella constitutes the tail of the sperm, via it’s whipping action, it moves the sperm towards the ovum.

On reaching the ovum, *fertilin*, a protein on the surface of the sperm cell’s head mediates the fusion of the sperm to the membrane of the ovum. Of the billions of sperms that were released, only one makes it to this stage. The fusion of the sperm and the ovum triggers the influx of calcium, this influx of calcium ion prevents the penetration of other spermatozoa through a reduction of the membrane potential of the ovum which prevents polyspermy/double fertilization. To form monozygotic (identical) twins, the fertilized egg splits and develops separately into two babies, in non-identical twins, two eggs are fertilized by two spermatozoa, hence conceiving twins is very different from double fertilization which rarely occurs.

The initiation of growth signals and the onset of pregnancy is accompanied by several hormonal changes which makes the woman unable to get pregnant while she is pregnant, this is due to a dramatic increase in oestrogen and progesterone levels. The increase in oestrogen helps to improve the formation of blood vessels and the transfer of nutrients to support the baby in development. Progesterone increase causes an increase in the size of internal structures such as ureters and in the uterus to accommodate the size of the baby. Changes in other body parts such as the breasts, cervix, and even the ligaments accompanies pregnancy, the general goal is to support the baby’s development, prepare the mother for delivery and maternity and also to prevent getting pregnant with another baby while already pregnant.

But not always!, the last goal is defeated in some cases and a pregnant woman can get pregnant while already with a baby in her wombs. 31 years old Julia Grovenburg from Arkansas conceived twice, not to twins this time around, the babies were conceived two weeks apart. She first became pregnant with a girl and the Two weeks later with a boy, they had due dates on Dec 24 and Jan. 10 respectively. Elsewhere, Jessica Allen, a surrogate mother from California in December 2016 had given birth to two kids– unarguably assumed to be twins, unfortunately, later discoveries as regards the characteristics of the two kids revealed noticeable variations in terms of appearance of the two babies, this led to a DNA test which revealed that these two kids were not actually twins, in fact, they were half brothers, one belonging to the Chinese couples for whom Jessica was a surrogate and the other a biological son of Jessica and her husband Jasper.

This is like two out of ten reported cases as presently, only ten cases of this phenomenon has been reported, this has been termed ‘Superfetation’. Superfetation is more pronounced in mammals such as minks and badgers and also in fishes and hares, it is a very rare phenomenon in humans.

Superfetation is not believed to occur naturally in humans; it is the simultaneous occurrence of more than one stage of developing offspring in the same animal, it occurs only when there are two uteri or a formation of an embryo from a different estrous cycle while another embryo or fetus is already developing in the uterus. Most reported cases are associated with women undergoing fertility treatments such as in vitro fertilization(IVF).

In humans, Superfetation is believed to occur when ovulation continues in a pregnant woman, the released ovum is fertilized by a sperm, however the success of this process also depends largely on the ability of the fertilized ovum to implant itself in the uterine lining.

Depending on the time interval of these fertilization and implantations, the babies are expected to be delivered healthy as in the case of Jessica and Julia. A British woman in 2007 conceived of a boy and a girl three weeks apart, fortunately these babies were delivered without any complications. Even though the babies in Superfetation are conceived at different time, they are delivered at the same time and hence considered ‘twins’, this entails that many cases of Superfetation have gone unreported in the guise of ‘twins’.

Any symptoms?

Superfetation is a very rare situation, hence no much occurrence for symptom study are available. However, some cases of **Growth discordance** (two fetus of different sizes and growth rate) of twins in ultrasound tests are due to Superfetation, but this doesn’t always come to mind as there are many other more popular reasons such as placental insufficiency and uneven distribution of blood between the twins which are believed to be the cause of this disproportionate growth.

What now?

Superfetation is yet to come to light as serious medical complication, this is not only because of the rarity of this condition but also because the babies are delivered healthy at most times, hence there’s always less to worry about… though there could be; if the interval of the two conception exceeds a month, the later conceived baby is expected to be delivered prematurely, this would put the baby at more risk of having medical problems such as low birth weight, difficulties with feeding and breathing and respiratory distress syndrome.

Most pronounced cause is continued sexual intercourse during pregnancy and fertility treatments, thus it is advisable that the couples decreases their rate of sexual intercourse with their spouse while she is pregnant. Prior to fertility treatments, the woman should be tested to ensure that she is not already pregnant before undergoing such program.

This post first appeared on steemit, all accounts belongs to me

References

1.How Can a Pregnant Woman Get Pregnant Again?~Times

2.Yes, You Can Get Pregnant While Already Pregnant. We Asked a Doctor to Explain~Health.com

3.Superfetation~wikipedia

4.What Bodily Changes Can You Expect During Pregnancy?~Healthline

5.Superfetation~Healthline