Trying to Conceive

Through the generationsThrough each generation, genes are shuffled and re-shuffled. Half of a baby's genes come from its father and half from its mother. The baby's parents in turn inherited half each of their genes from each of their own parents...

Each woman is born with her full quota of follicles that contain immature eggs, some of which will mature and be released in her lifetime. Every month, follicle-stimulating hormone (FSH), released from the pituitary gland, encourages a number of ...

Your baby todayThe ball of cells, known as the blastocyst, that will form the embryo has now completely embedded within the lining of the uterus and the lining has regenerated over it.Unfortunately, in the complex process of conception, only abou...

Some couples find that conception takes longer than anticipated. If you haven't become pregnant after two years of trying, your doctor may suggest fertility testing to identify if your fertility or that of your partner is suboptimal. If this is t...

  Today in the US, one in every 31 births is a twin birth. Twins are conceived in two ways that result in either identical or nonidentical twins. Identical twins occur when one fertilized egg splits into two separate cells. This type of twin ...

Genes are located on rodlike structures called chromosomes that are found in the nucleus of every cell in the body. Each gene occupies a specific position on a chromosome. Because genes provide instructions for making proteins, and proteins deter...

What's happening insideThe sperm cell can be seen here inside the fallopian tube. Since sperm can stay active and alive inside you for up to 72 hours, it's possible to get pregnant even if you don't ovulate for two to three days from now. ...

Toward the end of this week, one of the eggs in your ovaries is likely to have reached full maturity. Ovulation occurs as the egg, under the influence of hormones, bursts out of its follicle. If it meets a sperm, you may become pregnant. Now is t...

It's business as usual for your body this week. You're having a period, so you know you're not pregnant. But if you conceive during this menstrual cycle, the first day of your period will count as the first day of pregnancy. It's a good idea to r...

Your baby todayExternal appearances are deceptive: although your baby seems very well developed, it's still early in the pregnancy-the state of the cervix and progesterone produced by the placenta both play a part in ensuring that labor does not ...

Your baby todayThe size of your uterus may have reduced slightly as your baby's head becomes more deeply engaged within your pelvis, allowing her body to move down. This can take some of the pressure away from your ribs, which is a welcome relief...

What's happening insideWhen the two nuclei have pooled their genetic material to create a cell containing its full complement of 46 chromosomes-23 each from the mother and father-the cell can start dividing, shown here at the first division creat...

What's happening insideThis is an embryo at the 16-cell stage, when it has changed from a zygote into a morula. It is in the process of dividing into a hollow ball of cells-the blastocyst-which will eventually implant in the lining of the uterus....

What's happening insideHere the egg is shown surrounded by sperm. Although only one sperm will fertilize the egg, several hundred are thought to be necessary to break down its defensive layers and enable fertilization to take place. ...

Your baby todayThe embryo is implanted and is 10 days old. The entry point at which the embryo buried into the lining of the uterus is now covered by a clot, and this prevents blood loss and protects the embryo. ...

What's happening insideHere is a diagram of a human egg cell 24 hours after fertilization. Around the egg is a thick layer (yellow) that has now become impenetrable. The circles inside, or pro-nuclei, contain genetic material from the mother and ...

What's happening insideAs ovulation approaches, more cervical mucus is produced. Here it has crystallized to form a "fern leaf" pattern. Around the time of ovulation the mucus becomes clear, slippery, and stretchy, which makes it easier for sperm...

What's happening insideIn this color 3-D scan of the human brain, the green central structure is the hypothalamus. This controls emotions and body temperature, and releases chemicals that regulate the release of hormones from the pituitary gland ...