Man and woman make baby
Getting pregnant: How to make a baby
Sure, you may know the basics about how babies are made – a sperm and egg meet, and nine months later, a beautiful baby is born. But there's actually a lot more to it than that. From the development of an egg to sperm production, ovulation, fertilization, and implantation, there are many steps. Here are some biological facts about making a baby.
How do women's eggs develop?
For women, a potential pregnancy begins in the ovaries, those two almond-shaped glands attached to either side of the uterus. (See illustration below.)
Ovaries come fully stocked: Newborn baby girls are born with about 2 million eggs that have developed in utero – that's more than a lifetime's supply. The eggs begin dying off almost immediately, and no more are ever produced.
At the time of her first period, a young woman has approximately a couple hundred thousand eggs. An accelerated decline begins at age 37 or 38, with about a thousand eggs left at menopause (usually between age 45 and 55).
During the middle of the menstrual cycle, most likely between days 6 and 14 for women with a 28-day cycle, follicle-stimulating hormone, produced by the pituitary gland, causes follicles in one of a woman's ovaries to begin to mature. At about day 14, an increase in luteinizing hormone, also made by the pituitary, causes the ovary to release its egg. The egg then travels through the fallopian tube to the uterus.
This release, called ovulation, starts the conception clock ticking. The egg lives only about 24 hours after ovulation, so it has to be fertilized soon for conception to happen. Your "fertile window" is the five days leading up to ovulation, as well as the day of ovulation and the day after. That's about seven days total.
So how do you make a baby, exactly? If your egg meets up with a healthy sperm on its way to the uterus, the two can join and begin the process of creating a new life.
If not, the egg ends its journey at the uterus, where it either dissolves or is absorbed by the body.
When pregnancy doesn't occur, the ovary eventually stops making estrogen and progesterone (hormones that help maintain a pregnancy), and the thickened lining of the uterus is shed during your period.
How is sperm produced?
A man's body is almost constantly at work producing millions of microscopic sperm, whose sole purpose is to penetrate an egg. While women are born with all of the eggs they'll ever need, men aren't born with ready-made sperm. They have to be produced on a regular basis, beginning at the onset of puberty when a man begins to produce millions of sperm cells each day.
The average sperm lives only a few weeks in a man's body, and up to 500 million are released with each ejaculation. That means new sperm are always in production, ready for making a baby.
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Sperm begin developing in the testicles, the two glands in the scrotal sac beneath the penis. (See illustration above.) The testicles hang outside a man's body because they're quite sensitive to temperature.
To produce healthy sperm, testicles have to stay about 1 to 2 degrees Celsius cooler than normal body temperature – that's around 95 degrees Fahrenheit. The sperm are stored in a part of the testicle called the epididymis before mixing with semen just prior to ejaculation.
Despite the millions of sperm produced and released with each ejaculation, only one can fertilize an egg – this is the case even for identical twins. (When two separate eggs are fertilized by two separate sperm in the same pregnancy, a mother has fraternal twins.)
The sex of the resulting embryo depends on which type of sperm burrows into the egg first. Sperm with a Y chromosome make a boy baby, and sperm with an X chromosome make a girl. Plenty of myths about how to choose a baby's sex have been circulating for centuries. Some are backed by a bit of scientific evidence, but a child's gender is pretty much randomly determined.
Will having an orgasm help you get pregnant?
Besides being pleasurable, that sensation known as an orgasm also has an important biological function.
In men, having an orgasm propels sperm-rich semen into the vagina and up against the cervix, helping them reach the fallopian tubes minutes later. This gives sperm a head start on their way to the egg, which could help you get pregnant fast.
Some researchers theorize a woman's orgasm could help with conception – that the wavelike contractions associated with the female orgasm pull sperm farther into the cervix. But there's no real evidence that having an orgasm will help you get pregnant.
Still, having an orgasm couldn't hurt – and just might help – your chances of getting pregnant.
Does lying on your back after sex help you get pregnant?
Many couples also wonder whether a particular sexual position is best to make a baby. You may have heard that certain positions are ideal because they allow for deeper penetration, but there is no evidence that sex position has any effect on pregnancy rates.
So, do whatever you like. The most important thing about sex is that you're both having a good time and you're doing it frequently enough to have live sperm in the woman's reproductive tract during ovulation.
That means you should aim to have sex every 1 to 2 days during the middle of your cycle.
At this point, you can't do much except cross your fingers and hope. You may have also heard that it helps if the woman stays on her back afterward with a pillow elevating her bottom so gravity can help the sperm get to the waiting egg, but there's no evidence this helps achieve pregnancy either.
What happens to the sperm and egg after you have sex?
After sex, a great deal of activity is taking place inside your body. Those millions of sperm have begun their quest to find the egg to make a baby, and it's not an easy journey.
The first obstacle is the acid level in your vagina, which can be deadly to sperm. Then there's your cervical mucus, which can be impenetrable, except on the days when you're most fertile. Then it miraculously thins enough for a few of the strongest sperm to get through.
But that's not all – the sperm that survive still have a long road ahead. They need to travel from the cervix through the uterus to the fallopian tubes.
If there isn't an egg in one of the fallopian tubes after ejaculation, the sperm can live in the woman's reproductive tract for up to five days. Only a few dozen sperm ever make it to the egg. The rest get trapped, head up the wrong fallopian tube, or die along the way.
It's important to know that regular cannabis use by your partner can contribute to lower sperm count as well as the ability of the sperm to travel.
For the lucky few who get near the egg, the race isn't over. They still have to penetrate the egg's outer shell and get inside before the others.
And as soon as the hardiest one of the bunch makes it through, the egg changes instantaneously so that no other sperm can get in. It's like a protective shield that clamps down over the egg at the exact moment that first sperm is safely inside.
Now the real miracle begins. The genetic material in the sperm combines with the genetic material in the egg to create a new cell that starts dividing rapidly. At the end of this period, the embryo becomes a mass of very organized cells called a blastocyst.
You're not actually pregnant until the blastocyst travels the rest of the way down the fallopian tube and attaches itself to the wall of your uterus. This is known as implantation and usually happens five to six days after fertilization.
That final leg of the trip can take another three days or so, but it may be a few more weeks until you miss a period and suspect that you're going to have a baby. If you miss your period or notice another sign of pregnancy, you can use a home pregnancy test to find out for sure if you have a little one on the way.
The Slow March Toward the First Same-Sex Couple to Have a Baby
Cara Gormally’s pregnancy was shadowed by grief. As a queer woman wanting to have a baby, the biology professor had figured finding a sperm donor would be the only obstacle she and her partner faced. But thanks to Gormally’s organizational skills and love of making lists, the couple landed on a donor with relative ease.
Then, Gormally struggled to conceive.
Each month brought fresh disappointment and loss.
“So much of the process depended on random, heart-breaking chance,” she says. The emotional and financial roller coaster was exhausting.
But it wasn’t the hardest part. The couple had accepted that, as much as they wanted a baby, their child wouldn’t be biologically related to Gormally’s spouse.
“I grieved that our child wouldn’t be genetically related to both of us,” Gormally says. “I longed for the biologically impossible.”
But now, a new set of technologies have the potential to change what’s possible — allowing same-sex partners to have kids who share their genetic material, just like straight couples.
Inconceivable
In mammals, pretty much every cell in the body carries two sets of genetic material. One set comes from mom and the other from dad. Eggs and sperm are the only exceptions; they have just one set. Then, when a sperm fertilizes an egg, those two sets combine, restoring the usual number to two sets per cell.
Gormally and other same-sex partners are currently barred from their dreams by a phenomenon called genomic imprinting. It uses a distinct tag from each parent to mark the DNA that mammals pass on to their offspring. The process ensures that, for a small percentage of genes, we only express the copy of genetic material provided by our mother or our father. When this imprinting process goes awry, kids can end up with inactive gene regions that cause miscarriages, developmental defects and cancer.
(Credit: Jay Smith/Discover)
During this genomic imprinting, mom’s distinct collection of tags typically turns off certain genes, so that just dad’s copy is expressed. And dad imparts his own marks that leave only the maternal copy on. (Most imprints silence gene expression, but some activate it.) That’s a problem for same-sex couples who want to have a baby. If both sets of an offspring’s genes come from maternal DNA, for example, then both copies of imprinted genes will be off.
So, the embryo can’t make any of the genes’ products.
“We don’t get the full set of [gene] products that we need to undergo proper development unless we have both a maternal and paternal contribution to a fertilized egg,” says Marisa Bartolomei, a geneticist at the University of Pennsylvania in Philadelphia, who discovered one of the first imprinted genes in mice.
Scientists discovered genomic imprinting in mammals about 30 years ago. During experiments in the mid-1980s, researchers removed either the maternal or paternal genetic contributions from newly fertilized mouse eggs. Then, they transferred in a second set of genes from another mouse to create embryos with either two sets of female genetic material or two sets of male genetic material. A surrogate mouse was able to gestate the embryos, but none survived. The finding showed normal development requires genetic material from both a father and the mother. More than that, the outcomes revealed that maternal and paternal genetic material differ from each other in meaningful ways.
Later experiments revealed mice developed differently depending on whether they happened to receive both copies of certain regions of DNA from one parent (rather than one copy from each parent).
Mice with hairpin-shaped tails were telling examples. When researchers deleted the gene region responsible for a hairpin tail from a mother’s genome, mice embryos grew large and died partway through gestation. In contrast, deleting the same region from the paternal genome had no effect on the rodents’ growth or development.
In the three decades since, researchers have found more imprinted genes (they suspect there are between 100 and 200 such genes) and the molecular tags that silence them. Scientists have also taken strides connecting imprinting defects to developmental disorders in humans. But all along, researchers have known that imprinting prevents same-sex parents from having children.
Editing Out Impossibility
In October 2018, researchers overcame this impossibility in mice.
By deleting imprinted regions, Wei Li and a team at the Chinese Academy of Sciences in Beijing produced healthy mice from two moms. The researchers also created mouse pups from two dads for the first time. However, the offspring died just a few days after birth.
Despite the loss, Li is optimistic. “This research shows us what is possible,” he says.
To overcome the imprinting barrier, Li and his fellow researchers turned to CRISPR, a gene-editing technique that’s made altering genomes easier than ever. They used the tool to delete gene regions from embryonic stem cells from mice mothers. The researchers then injected these modified stem cells into the egg of a female mouse and then used a third surrogate female mouse to carry the fetus to term.
The team had already seen some success two years earlier when they created mouse pups with two genetic mothers by deleting two imprinted regions. Although these bimaternal mice also grew to adulthood and produced pups of their own, they developed growth defects.
On average, the bimaternal mice were 20 percent lighter than their hetero-parental counterparts. In their latest study, Li and his team also deleted a third region from the mothers’ genes, which restored the animals’ growth to normal.
But the scientists had to clear a few more hurdles to generate mice with two genetic fathers. They found, through a process of trial and error, that they needed to remove twice as many imprinted regions in the bipaternal mice as the bimaternal mice. In total, the team deleted seven imprinted regions to successfully create mice from two dads.
Still, the numbers were not in their favor. Only two and a half percent of embryos made it to term and less than half of one percent lived for two days. None made it to adulthood.
“The produced bipaternal mice are not viable, which implies more obstacles are needed to cross to support their postnatal survival, if possible,” Li says. “The lower birth rate, on the other hand, implies the existence of an unknown barrier hindering the development of bipaternal embryos.
”
In contrast, the bimaternal mice fared much better. These mice grew to adulthood and were healthy enough to have pups of their own by mating with typical male mice. They also behaved the same as the control mice. As far as the researchers could tell, the bimaternal mice appear as healthy and normal as any other laboratory mice.
“It does not mean that they are normal in every aspect,” Li cautions. “One cannot investigate all the aspects under restricted experimental conditions with a limited number of animals.”
Despite the researchers’ success, Li says the technique is not ready for use in humans. “It is never too much to emphasize the risks and the importance of safety before any human experiment,” he says, particularly in regard to the bipaternal offspring, which currently “are severely abnormal and cannot survive to adulthood.”
The bimaternal offspring hold more promise. The team is now working to translate their findings to monkeys. And that work could bring the impossible one step closer to feasible for humans.
Re-creating Potential
Li’s research is encouraging but it’s a long way from helping Gormally and her spouse. However, it’s also not the only shot for same-sex couples. Another new technology called in vitro gametogenesis, or IVG, may be an alternative potential path for same-sex couples to have their own kids.
Scientists use the technique to make eggs and sperm from other cells in the body. To do so, biologists first reprogram adult skin cells to become stem cells. Then, they stimulate the skin-derived stem cells to develop into eggs or sperm.
Researchers from Japan have now perfected the technique in mice. And in groundbreaking work, Katsuhiko Hayashi and Mitinori Saitou and their team generated functional eggs from mice tail cells.
The researchers then fertilized the eggs with sperm from male mice and implanted the embryos into surrogate mothers. The offspring grew up healthy and fertile. In principle, this approach could allow a woman’s skin cells to be engineered into sperm and used to fertilize her partner’s egg.
IVG could transform same-sex couples’ ability to have their own children. “If it had been possible at the time, we definitely would’ve have tried to do it,” says Gormally, who is now a proud parent to a toddler thanks to her and her spouses’ sperm donor. “[It’s] a total game-changer.”
This story is part of "The Future of Fertility," a new series on Discover exploring the frontiers of reproduction. Read more:
Can Humans Have Babies in Space?
George Church Wants to Make Genetic Matchmaking a Reality
Human Gene Editing is Controversial. Shoukhrat Mitalipov Isn't Deterred
Preparing a man for conception - clinic "Family Doctor".
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Preparation for conception is necessary for both a woman and a man. This is because the child receives 50% of the genetic material from each parent.
So, for the birth of a healthy child, his parents must be healthy.
Many factors can affect the male reproductive system. First of all, bad habits should be mentioned, which include smoking and alcohol abuse, as well as constant stress and chronic lack of sleep. It is also the presence of sexually transmitted infections, exacerbation of chronic prostatitis, hormonal disorders, taking certain medications and steroids, a sedentary lifestyle, obesity, overheating of the groin and perineum, etc.
When planning a conception, a man needs to exclude the impact of all of the above factors in three months and cure diseases and infections, because. the full cycle of sperm renewal takes three months.
What can you do to improve the quality of your sperm = the genetic material of your unborn child?
1. Remember that sperm do not like overheating. Therefore, it is advisable to cancel visits to baths and saunas, to keep the seat heating in the car turned on for too long.
2. Reduce weight if you are obese. For men, a waist circumference in centimeters (at the level of the navel) over 94 cm = obese. In adipose tissue, testosterone is converted to estrogens, many inflammatory factors are produced, and this can also lead to type 2 diabetes, etc. Which, as you understand, are not the best companions for easily injured sperm!
3. Exclude sugary carbonated drinks, dyes, trans fats, confectionery from the diet.
4. Do not abuse alcohol. Alcohol, in addition to a direct toxic effect on spermatozoa, reduces the body's ability to absorb zinc, which is necessary for normal spermatogenesis.
5. Stop smoking. According to numerous studies, up to 50% of couples suffering from idiopathic infertility, after stopping smoking, find a long-awaited baby.
6. Try to be less nervous and sleep more.
7. Do not take medicines without a doctor's prescription (many drugs can significantly impair sperm quality). From here follows the rule: treat your chronic diseases before the moment of pregnancy planning.
In order to understand how fertile you are, you need to come to a consultation with a urologist-andrologist. It is advisable to have at least a spermogram with you. The rest of the list of examinations will be consulted by a doctor of the aforementioned specialty. It is better for a married couple to undergo an examination in parallel so that the treatment does not work out late, because. after the age of 35, a woman loses the ability to bear children faster than a man, and many couples miss the moment just because the man does not want to visit medical institutions.
To make an appointment with a specialist, call the single contact center in Moscow +7 (495) 775 75 66, fill out the online appointment form or contact the receptionist of the Family Doctor clinic.
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How a man prepares for conception and wife's pregnancy | 59.
ru Before conception, a man should check his health
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We have already talked about the responsibility and preparation for pregnancy on the part of the expectant mother, but now we decided to deal with the health of future fathers. We talked with urologist Danil Yudin about how bad habits, overweight, diseases and other factors affect the possibility of conception and fetal development.
Danil Yudin advises giving up bad habits while preparing for conception
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— It is believed that women should not smoke and drink at least three months before conception. What about men?
- In men, preparation for pregnancy also lasts three months - this is the period of renewal and full maturation of spermatozoa, their transformation into the final cell, which is ready for fertilization.
You need a complete cessation of smoking and alcohol.
— How does sperm change when smoking and drinking alcohol?
— If we are talking about systematic daily smoking and alcohol consumption in general, then this is oxidative stress (damage to the cell as a result of oxidation. — Note ed. ) for the body. First of all, brain cells suffer, as well as spermatozoa, in which mobility decreases. It directly depends on bad habits.
Alcohol reduces sperm motility
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— Tell us, what is the effect of systematic drinking by a man on an unborn child? How much and how often can you drink so that it does not affect anything?
— The consumption of alcohol itself affects the decrease in sperm motility. In certain cases, it leads to their morphological (external structure. - Note ed. ) change.
If the use continues for years, then spermatozoa can accumulate altered DNA in themselves, and this can cause congenital malformations, but it is quite difficult to predict this at the initial stage. It is advisable to minimize alcohol consumption for at least three months. This is definitely worth doing when a couple for a year or more cannot conceive a child with the lifestyle that they have. The main thing is to have self-control - a glass of dry wine will not hurt.
— What is the risk of smoking?
- Here again it is worth remembering about oxidative stress. When smoking, free radicals accumulate, which adversely affect all processes in the body - from reproductive function to neurology, cardiology and others. Spermatozoa are very sensitive to this, they go through many more stages in their development than other cells, and the risk of deviations is much greater.
- Should nutrition be special in preparation for pregnancy? How long before conception should it be corrected?
- Everything is simple - a balanced diet.
There just needs to be more protein, the right carbs, and vitamins. It is not necessary to constantly eat seafood, as some believe, fast food and similar things can be excluded. We're not talking about three months. We count from the moment when the couple came to the conclusion that it was time to have a baby, because pregnancy may not occur immediately.
The doctor emphasizes that even with the exclusion of fast food and other junk food, variety and balance are important. That is, you should not constantly eat, for example, only pasta and meatballs. Nutrition does not affect the development of the fetus, but the process of fertilization - it can simply delay it.
Nutrition must be balanced. Eating buckwheat with chicken all week is not an option. In any form? Why?
- I will not say that shrimp, seafood have an extremely beneficial effect. But one cannot but agree that some varieties of fish are richer in trace elements. At the same time, there is no panacea in the form of products.
- Weight is thought to affect sperm. How?
- That's right. By itself, adipose tissue produces estrogens. Their excess is harmful not only to men, but also to women. This entails a violation of the production of other hormones that are involved in the maturation of eggs in women. And in the male body, an excess of female hormones affects the lack of male sex hormones, which affect the production of sperm. Here we are talking about the quantity and quality of spermatozoa.
— Is overweight of the future father dangerous for the fetus?
— No. In a man, overweight matters only at the stage of conception. The tendency to be overweight can be passed on to the child at the genetic level, but it is unlikely to affect his intrauterine development.
The urologist also recommends women to monitor their weight at the stage of preparation for pregnancy. Excess body weight affects the cardiovascular system, and the load on it affects the condition of the fetus.
Hypertension may occur, that is, peripheral vasospasm (not associated with the heart or brain. - Note ed. ), including placental vessels, fetal hypoxia will occur (oxygen starvation. - Note ed. ). This condition threatens the lives of the fetus and the expectant mother.
— Why is underweight dangerous?
- If we are talking about physical exhaustion, then there will be changes in the form of low sperm motility and their reduced number. Possible violations of morphological forms. And when a man is exhausted, what kind of pregnancy planning can we talk about? You need to get your health in order first.
— When is it worth addressing the issue of excess weight, if the man was not previously puzzled by it?
- There is no need to panic and limit yourself in some way - everything should go in parallel. There are a million men with overweight bodies and they have no problems at all with conception. And if they are, then they need to be addressed.
Adjust the weight and you'll be fine.
— What diseases can affect the reproductive organs?
- Cardiovascular or disease of the respiratory, endocrine system can affect men's health. The most common chronic problem is diabetes mellitus. This is the scourge of modern society, which is progressing and getting younger. The second place is hypertension, they are connected with each other. Also diseases of the thyroid gland, because its hormones are also involved in the process of spermatogenesis. Well, sexually transmitted diseases are those problems that lead not only to impaired fertility, but also to fetal pathologies, if they are not cured in time. Gonorrhea, of course, occurs, but not so often, it is not worth focusing on it. Even if the pregnancy proceeds normally, then at a certain stage infection of the amniotic fluid may occur. Chlamydia can interfere with both male and female fertility. But if you keep them under control, and the titer of infections is not high, then there are chances that the child will not become infected.
For a man, these diseases are fraught with bacterial damage to the organs of the reproductive system. Suppose there is inflammation of the appendages, testicles. By itself, the diseased organ cannot produce cells normally, an infection occurs in the prostate gland, urethra in the form of urethritis, chronic prostatitis.
— Is it possible to conceive during an exacerbation of chronic diseases? Why?
— If a couple is planning a pregnancy and an exacerbation of gastric ulcer occurs, which involves treatment, including antibacterial drugs, then this matter should be postponed for this period of time. While a person is taking drugs that affect fertility, then a month and a half should be protected.
— What will happen to the fetus if conception occurs during an exacerbation of a chronic disease in a man?
— If the pregnancy is spontaneous, and at that moment the man or woman was taking some drugs, do not panic, just contact a specialist.
Here the man has already done everything, then the girl should go to the gynecologist, pass certain tests. Very few drugs can cause any teratogenic effect on the fetus.
- And if you have recently had coronavirus, how does this affect?
- There are no observations of how this disease affects fertility in men who have had it.
— How does sport affect the male reproductive system in general?
- Positive. But you need to understand what kind of sport it is, if it is a sport of great achievements - a person is preparing for the Olympic Games and he has such loads that he barely reaches the bed, then there can also be changes in the spermogram. For example, decreased mobility due to overwork.
— Which sport has the most beneficial effect? Why?
- Positive effect of aerobic exercise, outdoor activities - skiing, running, football, but without injury. The main thing is that the body has time to recover - you do not need to train twice a day.
Outdoor running is what doctors recommend
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— Is there any point in physical activity a few months before conception, if a man has not been involved in sports all his life?
— There is a sense, because the muscular system begins to work, which provokes the endocrine system to work better, male sex hormones begin to work more competently, and this favorably affects the quality of sperm.
- A woman should take iodine and folic acid before pregnancy. What should men take? What will it affect?
— Before starting any treatment, you need to be examined. Before conception, a man goes to an andrologist, whose examination includes a study of the level of hormones that are involved in spermatogenesis, the cardiovascular system, a blood test and STDs (sexually transmitted diseases). If there are violations, then treatment is prescribed.
As for supplements and vitamins, there is such a thing as preventive preparation, if you drink vitamins, they will not hurt in any way, in conjunction with observing the regime of work and rest, proper nutrition will only get better. You can take some course at least from one to three months.
– How early can I start the course?
- There is no strict time frame, but you need to reconsider your preferences from the moment when the couple comes to the decision that it is time to have a baby. If we are talking about the notorious three months when sperm is renewed, then we must understand that this does not happen at the moment, but gradually.
- Is there a better age to conceive? What period is this?
- It is believed that after the age of 35, male sex hormones begin to decline. But there are men who have everything in order at 40 and at 50. But there are those who are stressed at work or have a long history of smoking.
All this accumulates over the years and can affect the quality of sperm. If, for example, a person from the age of 13 drank, smoked, did not take care of his health, then you should not expect miracles from an andrologist. Well, with age, chronic diseases still accumulate, DNA can change, and the changed DNA can be passed on to offspring.
- It is believed that in men over 50 years of age, testosterone production decreases, this can create difficulties for successful fertilization. Is it so?
- For some it happens earlier, for others later, it's impossible to predict - it's inherent in nature. We can only hold back what is laid down due to the right way of life. There are a number of hereditary diseases that already at an early age reduce the level of the hormone, for example, congenital hypogonadism (lack of testosterone. - Note ed. ). This is a mistake in embryonic development, the set of chromosomes changes.
- List the tests that a man must pass before conception.
