How in vitro fertilization (IVF) works - Nassim Assefi and Brian A. Levine

Kako napraviti bebu (u laboratoriji) - Nasim Asefi i Brajan A. Levin

Prevodilac: Marina Ivanovic Lektor: Mile Živković

In 1978, Louise Brown became

Luiz Braun je 1978. postala

the world's first baby to be born by in vitro fertilization, or IVF.

prva beba na svetu rođena nakon in vitro oplodnje iliti IVF.

Her birth revolutionized the field of reproductive medicine.

Njeno rođenje je napravilo revoluciju u polju reproduktivne medicine.

Given that approximately one in eight heterosexual couples

Uzimajući u obzir da jedan u osam heteroseksualnih parova

has difficulty conceiving,

ima poteškoće sa začećem

and that homosexual couples and single parents

i da homoseksualnim parovima i samohranim roditeljima

often need clinical help to make a baby,

često treba klinička pomoć da bi napravili bebu,

the demand for IVF has been growing.

potražnja za IVF-om raste. IVF je toliko uobičajen

IVF is so common, that more than 5 million babies have been born through this technology.

da je više od 5 miliona beba začeto na ovaj način.

IVF works by mimicking the brilliant design of sexual reproduction.

IVF radi po principu imitiranja sjajnog dizajna seksualne reprodukcije.

In order to understand IVF,

Da bismo razumeli IVF,

we first need to take a look at the natural process of baby making.

prvo moramo da pogledamo prirodan proces pravljenja beba.

Believe it or not, it all starts in the brain.

Verovali ili ne, sve počinje u mozgu.

Roughly fifteen days before fertilization can happen,

Oko 15 dana pre nego oplodnja može da počne,

the anterior pituitary gland secretes follicle stimulating hormone, FSH,

prednji stimulirajući folikul hormona hipofize, FSH,

which ripens a handful of follicles of the ovary

proizvodi nekolicinu folikula jajnika,

that then release estrogen.

koji zatim otpuštaju estrogen.

Each follicle contains one egg,

Svaki folikul sadrži jedno jaje,

and on average, only one follicle becomes fully mature.

i prosečno, samo jedan folikul dostigne punu starost.

As it grows and continues to release estrogen,

Dok raste i nastavlja da otpušta estrogen,

this hormone not only helps coordinate growth and preparation of the uterus,

ovaj hormon ne pomaže samo u koordinaciji rasta i pripremljenosti materice,

it also communicates to the brain how well the follicle is developing.

već i u komunikaciji sa mozgom o tome koliko dobro se folikul razvija.

When the estrogen level is high enough,

Kada je nivo estrogena dovoljno visok,

the anterior pituitary releases a surge of luteinizing hormone, LH,

prednja hipofiza otpušta talas lutenizirajućeg hormona, LH,

which triggers ovulation

koji pokreće ovulaciju

and causes the follicle to rupture and release the egg.

i uzrokuje pucanje folikula i otpuštanje jaja.

Once the egg leaves the ovary,

Nakon što jaje napusti jajnik,

it is directed into the Fallopian tube by the finger-like fimbriae.

odlazi u jajovod kroz fimbrije u obliku prsta.

If the egg is not fertilized by sperm within 24 hours,

Ako jaje nije oplođeno spermom u naredna 24 časa,

the unfertilized egg will die,

neoplođeno jaje umire

and the entire system will reset itself,

i ceo sistem se resetuje,

preparing to create a new egg and uterine lining the following month.

spremajući se da stvori novo jaje i postavu materice narednog meseca.

The egg is the largest cell in the body

Jaje je najveća ćelija u telu

and is protected by a thick, extracellular shell of sugar

i zaštićeno je debelom vanćelijskom opnom od šećera

and protein called the zona pellucida.

i proteina zvanog zona pellucida.

The zona thwarts the entry and fusion of more than one sperm,

Zona onemogućava ulazak i spajanje više od jedne sperme,

the smallest cell in the body.

najmanje ćelije u telu.

It takes a man two to three months to make sperm,

Muškarcu je potrebno dva do tri meseca da stvori spermu,

and the process constantly renews.

i proces se konstantno obnavlja.

Each ejaculation during sexual intercourse releases more than 100 million sperm.

Svaka ejakulacija tokom sekualnog odnosa otpušta više od 100 miliona spermatozoida.

But only 100 or so will ultimately make it to the proximity of the egg,

Ali samo stotinak će na kraju prići dovoljno blizu jajetu,

and only one will successfully penetrate through the armor of the zona pellucida.

a samo jedno će uspešno penetrirati štit od zone pellucida.

Upon successful fertilization,

Nakon uspešne oplodnje,

the zygote immediately begins developing into an embryo,

zigot se odmah razvija u embrion,

and takes about three days to reach the uterus.

i treba mu tri dana da dođe do materice.

There, it requires another three or so days

Tu mu je potrebno još manje ili više tri dana

to implant firmly into the endometrium, the inner lining of the uterus.

da čvrsto uđe u endometrijum, unutrašnju postavu materice.

Once implanted, the cells that are to become the placenta

Jednom kada je unutra, ćelije koje kasnije postaju placenta

secrete a hormone that signals to the ovulated follicle

luče hormon koji daje signal oplođenom folikulu

that there is a pregnancy in the uterus.

da se u materici odvija trudnoća.

This helps rescue that follicle, now called the corpus luteum,

Ovo omogućava zaštitu tog folikula, sada zvanog corpus luteum,

from degenerating as it normally would do in that stage of the menstrual cycle.

od degeneracije kao što bi se normalno desilo za vreme menstrualnog ciklusa.

The corpus luteum is responsible for producing the progesterone

Corpus luteum je zadužen za prozvodnju progesterona

required to maintain the pregnancy until six to seven weeks of gestation,

neophodnog za održavanje trudnoće do šeste ili sedme nedelje gestacije,

when the placenta develops and takes over,

kada se formira placenta i preuzima posao,

until the baby is born approximately 40 weeks later.

dok beba nije rođena, posle otprilike 40 nedelja.

Now, how do you make a baby in a lab?

Dakle, kako napraviti bebu u laboratoriji?

In patients undergoing IVF,

Sa pacijenta koji podlegnu IVF-u,

FSH is administered at levels that are higher than naturally occuring

otkucaji srca bebe se beleže na nivou koji su viši od uobičajenih

to cause a controlled overstimulation of the ovaries

da bi se prouzrokovala kontrolisana prekomerna stimulacija jajnika

so that they ultimately produce multiple eggs.

da bi oni na kraju stvorili više jaja.

The eggs are then retrieved just before ovulation would occur,

Jaja se zatim vraćaju pre ovulacije,

while the woman is under anesthesia,

dok je žena pod anestezijom,

through an aspirating needle that is guided by ultrasound.

kroz iglu, praćeno ultrazvukom.

Most sperm samples are produced by masturbation.

Najveći deo sperme proizveden je masturbacijom.

In the laboratory, the identified eggs are stripped of surrounding cells

U laboratoriji, identifikovana jaja se oslobađaju okolnih ćelija

and prepared for fertilization in a petri dish.

i spremaju za oplodnju u posudi.

Fertilization can occur by one of two techniques.

Oplodnja se može odvijati upotrebom jedne od dvaju tehnika.

In the first, the eggs are incubated with thousands of sperm

U prvoj, jaja su inkubovana sa hiljadama spermatozoida

and fertilization occurs naturally over a few hours.

i oplodnja se odvija prirodno tokom nekoliko sati.

The second technique maximizes certainty of fertilization

Druga tehnika uvećava sigurnost oplodnje

by using a needle to place a single sperm inside the egg.

upotrebom igle da bi se ubacio jedan spermatozoid u jaje.

This is particularly useful when there is a problem with the quality of the sperm.

Ovo je posebno uspešno kada postoje problemi sa kvalitetom sperme.

After fertilization, embryos can be further screened for genetic suitability,

Nakon oplodnje, embrioni mogu dalje biti posmatrani za genetsku podrobnost,

frozen for later attempted pregnancies,

zamrznuti za naknadne pokušaje oplodnje,

or delivered into the woman's uterus via catheter.

ili ubačeni u ženinu matericu putem katetera.

Common convention is to transfer the embryo three days after fertilization,

Uobičajena procedura je da se prebace embrioni tri dana nakon oplodnje,

when the embryo has eight cells,

kada embrion ima osam ćelija,

or on day five, when the embryo is called a blastocyst,

ili petog dana, kada je embrion poznat kao blastocit,

and has hundreds of cells.

i ima stotine ćelija.

If the woman's eggs are of poor quality due to age or toxic exposures,

Ako su ženina jaja lošeg kvaliteta usled starosti ili izlaganju toksinima,

or have been removed due to cancer,

ili su bila uklonjena zbog kancera,

donor eggs may be used.

donorska jaja mogu biti upotrebljena.

In the case that the intended mother has a problematic uterus, or lacks one,

U slučaju da namenjena majka ima problema s matericom, ili je nema,

another woman, called the gestational carrier or surrogate,

druga žena, tj. gestacioni nosilac ili surogat,

can use her uterus to carry the pregnancy.

može upotrebiti svoju matericu da iznese trudnoću.

To increase the odds of success,

Da bi se povećale šanse za uspeh,

which are as high as 40% for a woman younger than 35,

koje idu i do 40% za žene mlađe od 35 godina,

doctors sometimes transfer multiple embryos at once,

doktori nekada ubacuju više embriona odjednom,

which is why IVF results in twins and triplets

zbog čega su IVF rezultati sa dvojkama i trojkama

more often than natural pregnancies.

mnogo češći nego tokom prirodnih trudnoća.

However, most clinics seek to minimize the chances of multiple pregnancies,

Ipak, većina klinika gleda da minimalizuje šanse višestrukih trudnoća,

as they are riskier for mothers and babies.

budući da su one rizičnije za majke i bebe.

Millions of babies, like Louise Brown, have been born from IVF

Milioni beba, kao Luiz Braun, rođene su koristeći IVF

and have had normal, healthy lives.

i imali su normalan i zdrav život.

The long-term health consequences of ovarian stimulation

Dugoročne zdravstvene posledice stimulacije jajnika

with IVF medicines are less clear,

sa IVF medicinom su manje jasne,

though so far, IVF seems safe for women.

iako do sada, IVF se čini bezbednim za žene.

Because of better genetic testing,

Usled boljeg genetskog testiranja,

delayed childbearing,

kasno donošenje beba na svet,

increased accessibility and diminishing cost,

povećane pristupačnosti i smanjenih troškova,

it's not inconceivable that artificial baby making via IVF and related techniques

nije nezamislivo da veštačko pravljenje beba putem IVF-a i sličnih tehnika

could outpace natural reproduction in years to come.

može nadmašiti prirodnu reprodukciju u godinama koje dolaze.