Ovaries

Today, I tackle a body part upon which I consider myself to be somewhat of an expert. Had my left ovary behaved years ago, I would not be typing this today–and I would still have both ovaries. Speaking with other women, it becomes obvious very quickly that we tend to know very little about our ovaries.  Hopefully, I will shed some light on this for you today!

Where are the ovaries?  It’s safe to say we know they’re in our pelvis, but where exactly?  A good estimate is to make a triangle with with your index fingers and thumbs and place that over your pelvis with the index fingers pointing downward.  In the upper corners is about where your ovaries are.  (They tend to be a bit lower and more centralized than most assume they are.)  The ovaries are held in place by a network of ligaments which also attach to the uterus and Fallopian tubes.  The ovaries are not connected directly to the Fallopian tubes.  Many diagrams shows the fimbriae (the leafy looking parts on the far left and right below) of the Fallopian tubes as been directly adjacent to the ovaries, which leads many to believe that the ovaries are directly attached to them.  They are not.  (Read more about the relationship between the ovaries and the Fallopian tubes in the section about Fallopian tubes.)


The ovaries are, ironically, shaped like eggs but are smaller than the chicken eggs that one typically purchases at the grocery.  The ovaries are about the size of a walnut, are slightly pearl colored, and have bumpy, soft surfaces.  The ovaries are responsible for producing a variety of sex hormones.  At birth, the ovaries of a healthy baby girl contain between one and two million eggs.  By the time puberty begins, most of these have wasted away leaving about 300,000 eggs–plenty for the reproductive lifespan.  Thus, a woman has a finite number of eggs, but men have a different mechanism that continually makes sperm.  This is why women have “childbearing” years, but men can father children throughout their adult lives.

The eggs have a complicated lifespan before they are even released for potential fertilization.  The term “egg” is generic and refers to a single cell’s journey through maturation.  Before maturation, the egg is referred to as an oocyte.  Once it finishes maturing (see diagram below), it becomes an ovum and three polar bodies.  The polar bodies are actually inside of the ovum and serve to “fuel” the egg once it is fertilized continuing cell division and replication before it implants in the uterine lining (where it forms a network of blood vessels that forms the placenta and umbilical cord).

Each month, the ovaries usually release one mature egg (not one from each).  The ovaries are covered in cells called follicles and within each follicle is a single egg.  Once an egg is matured, the process of ovulation can begin.  During this time, the follicle that houses the mature egg expands and eventually ruptures forcing the egg outward.  This rupturing is completely normal–it would be abnormal for ovarian follicles to never rupture, and in fact some women can actually feel a quick pain when the rupture occurs.  The diagram below is an illustration of the ovulation process, beginning in the upper-left hand corner and going clockwise.


Following a woman’s “childbearing” years, the ovaries continue to play an important role.  For years, many doctors prescribed a surgery called a hysterectomy to remove the ovaries (as well as the uterus and Fallopian tubes) once a woman was finished having children.  This was performed to prevent cancer from developing.  However, we now know that ovarian cancer can actually develop anyway after the ovaries have been removed.  This is because the ovaries share tissue with the internal cavity that remains following a hysterectomy.  Leaving the ovaries intact provides a number of hormonal benefits throughout menopause that are difficult to replace.  Thus, the benefits of leaving the ovaries intact often outweigh the drawbacks.  (This is something that should be discussed with a physician, because each individual has a different medical history that will affect any such decision.)

There is a lot more that could be said about ovaries, but let’s save that for another day.  Hopefully this gives you a better understanding of how the ovaries work!

The Uterus

Pound for pound, the uterus is the strongest muscle in the human body. The uterus weighs about 40 ounces (2.5 pounds; 1.1 kg) and is about the size of a pear when not pregnant. Yet, in the process of giving birth, the uterus can exert over 100 pounds of force (440 newtons). The uterus is responsible for protecting and nursing a growing fetus during a pregnancy, and also for pushing that fetus out when it’s time to give birth. Let’s further explore this great muscular feat of nature–the human uterus.

The word uterus comes from Latin meaning “womb” or “stomach.”  It is an organ particular to mammals.  The human uterus consists of two parts:  the main body, generally just called the uterus, and the narrow “neck” called the cervix (Latin for “neck”).  In humans, the uterus is labeled as simplex because it is generally a single (simple) compartment, but sometimes the uterus does not end up like this.  When a female fetus is developing in the womb, it starts out initially as an organ shaped like a V–as though the cervix has two horn-shaped compartments.  As the fetus develops, the horns will generally fused into one, “simplex” uterus.  About 6.7% of the time, though, this does not happen resulting in a malformed uterus.

The most common type of malformation is the bicornuate (or “two-horned”) uterus.   Other malformations include unicornuate (“one-horned”) uterus, double uterus (two whole, functioning uteruses), and absent uterus (where the uterus fails to develop at all).  Each of these malformations has its own set of issues, and a medical professional can help counsel a person with a malformed uterus.

The uterus consists of three main “layers,” much like the different layers of skin.  The innermost layer on the inside of the uterus is called the endometrium.  It is a temporary layer that builds up and jettisons away over the course of a menstrual cycle.  The middle layer is called the myometrium.  This is the main, muscular layer of the uterus and consists of smooth muscle mass.  The outermost layer is referred to as the perimetrium.  It is a thin membrane that secretes serous fluid.

Uterus IllustrationIn the reproductive cycle, the uterus receives the egg after it has been fertilized while traveling down the Fallopian tube (labeled here as the uterine tube).  Once the fertilized egg is in the uterus, it will usually implant in the endometrial lining of the uterus (that is normally shed when a woman has her period).  From this implantation, the uterus and the embryo form a network of blood vessels that exist only during the pregnancy.  This is called the placenta and is what the umbilical cord is attached to.

The uterus, besides being key to the reproductive cycle, is also important in the sexual response cycle.  It directs blood flow toward the pelvis and outer genitalia during sex. This directed flow of blood happens during arousal and allows for sex to be pleasurable to the woman.  The uterus is also involved in a somewhat rare type of orgasm called, of course, the uterine orgasm.

The uterus is, arguably, the most central organ to not only reproduction but also sexual response.  Take good care of your uterus and go to the gynecologist for your regular check-up!  Have questions or comments?  Let’s hear ’em.

Rare Ectopic Pregnancy, again

In the last blog entry I detailed the story of Zahra Aboutalib, a Moroccan woman with a rare complication of an ectopic pregnancy, a lithopedion.  The second incredibly rare complication of an ectopic pregnancy that I will cover happened to an English woman named Jane Ingram.  Jane was a 32 year old woman living in Suffolk, England, when she discovered in early 1999 that she was pregnant for the third time.  She and her husband Mark had a total of four children from previous marriages; this was their first child together.

Shortly into the pregnancy, a routine scan showed that she was carrying twins.  Continued abdominal pain led to further scans that showed eighteen weeks into pregnancy that Jane was indeed carrying triplets, the third baby had not implanted in the uterus as the other two had and had ruptured Jane’s fallopian tube.  This baby, the only boy of the pregnancy, had miraculously survived the rupture and continued to grow attaching his placenta to the outside of Jane’s uterus.  Jane had not been taking fertility drugs, a frequent cause of sets of multiple babies.

Immediately, the rarity of Jane’s case caught the attention of top doctors in the United Kingdom and leading obstetrician Davor Jurkovic at King’s College Hospital in London became the lead attending physician.  Jurkovic placed the odds of all three children and the mother surviving this situation were one in 60 million–if they did all survive it would be the first time in medical history.

Jane was closely monitored and at twenty-nine weeks, eleven weeks prematurely, it was decided that the cesarean section should go ahead.  A team of twenty-six medical professional assembled at King’s College Hospital on September 3, 1999 to assist in the two-hour long procedure.  The twin girls, Olivia (2lbs 10oz) and Mary (2lbs 4oz) were delivered first and the procedure went routinely.  The next challenge was to safely access the boy, who was in an awkward position.  Doctors decided to shift Jane’s intestines in order to reach him and successfully delivered Ronan (2lbs 4oz).

Amazingly, the triplets were born with no more complications than would be expected of any other triplets born at twenty-nine weeks.  Each was kept in the intensive care unit and placed on ventilators.  They only remained on the ventilators for about a week, Ronan being the first to grow strong enough to not need its assistance.  The worry remained that the pieces of Ronan’s placenta that could not be removed would cause complications for Jane.  No such complications arose and Jane was discharged from the hospital after about a week.

Today, the triplets are in fine health and not long ago celebrated their ninth birthdays.  The parents say that each has his or her own very distinct personality.  Doctors and newspapers have called Ronan a miracle baby.  Mark Ingram described himself shortly after the birth of the triplets as “the luckiest man on earth.”  With such amazing odds against them, many point to Jane’s optimistic though realistic attitude as the key to their survival.  So what do you think about Jane and her triplets?  Such a rare complication is not likely to be see again during our lifetimes.  Comments, questions, or otherwise?  You know what to do!

Rare Ectopic Pregnancy

Last night The Learning Channel replayed a program that I originally saw about a year ago entitled “Extraordinary Pregnancies.” It told the story of two women and their ‘extraordinary pregnancies’: Zahra in Morocco and Jane in England. The program is the repackaging of two other British programs that aired several years ago. Both women experienced rare complications from ectopic pregnancies. Each case is fascinating, to me at least, so let’s explore their cases a little more in depth–Zahra here, Jane in the next entry.

Zahra Aboutalib, a woman from just outside Casablanca, became pregnant at twenty-six years old and early in her pregnancy experienced excruciating abdominal pain. The pain eventually went away and in 1955 she went into labor. After laboring for more than two days, her family decided to take her to the closest hospital. In the hospital she saw other women undergo cesarean section and die because of the poor conditions in the hospital. Doctors told her she must have a c-section, too, and she decided she did not want to die too. She left the hospital still in pain and went home. Eventually the pain ceased and she remained pregnant. In Moroccan culture, there is a belief that babies can “sleep” inside of their mothers for indefinite periods of time. Assuming she had a sleeping baby, Zahra continued her life and adopted three children remaining pregnant for 46 years until terrible pain returned in her early 70s. Her children finally insisted she see a doctor. Doctors examined her and believed she had an ovarian tumor. After several rounds of testing and imaging, the doctors realized she was still carrying the child she conceived nearly five decades before.

When Zahra had become pregnant years before she had had an ectopic pregnancy in the fallopian tube. An ectopic pregnancy is any implantation of a fertilized egg outside of the uterus. As the fetus grew the fallopian tube expanded and finally burst, cause the pain early in her pregnancy. This occurrence can be quite dangerous for the mother and very often results in the death of the fetus. Amazingly, Zahra’s fetus continued to grow and attached itself through its placenta to Zahra’s internal organs. Because her fetus was outside of the uterus she could not vaginally deliver the child when she went into labor. C-section would have been the only way to extricate the child, though because of the dangerous circumstances she and her child may have perished. When the pain of labor subsided it was because her child has died inside of her. Her body could not absorb the child and, recognizing it as a foreign object, began to calcify the child resulting in what is called a lithopedion (stone child).

When the doctors decided to operate they faced a difficult challenge. The calcification of the baby Zahra bore had attached itself to many of her internal organs and her peritoneum (the lining of the abdominal cavity). The surgery was dangerous, but after hours of delicate maneuvering the surgeons were able to remove the whole, calcified child from Zahra’s stomach. The medical team dissected the lithopedion to study just how the calcification process works in cases like this. Zahra’s is one of the oldest lithopedions ever recorded. Zahra recovered fully from the procedure and returned to normal life.

Lithopedions are rare and are an extremely interesting occurrence. As the world moves towards a more Western model of medicine it is less likely that lithopedions will develop as most ectopic pregnancies can be surgically treated with less of a risk of to the mother and child. However, when other complications arise, that may change as we will see with the case of Jane in the next entry. Stay tuned! Comments, question? I’d love to hear from you.

Introduction to the Cervix

The word cervix has only recently come to refer almost exclusively to the portion of the uterus that narrows between the vagina and the body of the uterus (corpus uteri). Cervix is from the Latin for “neck” and uterus is from the Latin for “womb.” Thus, the cervix is the neck of the womb–strange imagery, non? Anyway, what exactly is it that the cervix does? Does it do anything special if it is only an extension of the uterus? Of course it does something special!

The cervix, during an average menstrual cycle, goes through several important changes. Generally the cervix is stiff (like the texture of your nose) and positioned high with a small opening. However, during ovulation, the cervix becomes softer and lower with a wider opening. This quality of the cervix during ovulation promotes the movement of the sperm in their upward journey toward the released ovum (egg). Also, during orgasm the cervix convulses. Some research has linked this movement of the cervix as an evolutionary means of improving the chances of conception, though other scientists have argued that there is no correlation between cervical orgasm and increased rates of conception. So, just because you don’t orgasm during sex doesn’t mean you won’t get pregnant or are any less likely to get pregnant. The cervix also produces the mucus or normal vaginal discharge that varies over a woman’s menstrual cycle.

The cervix also plays a key role in detecting gynecological cancers. As discussed yesterday, the cervix is the object of Pap smears testing for cancerous and pre-cancerous cells. In this procedure–if you are unfamiliar, in which case you need to get a Pap smear A.S.A.P.–a clinician collects epithelial cells from the cervix and sends them to a lab where they are studied for abnormalities. The greatest cause of cervical cancer, the most common form of gynecological cancer, is the human papilloma virus (HPV). HPV has also been proven to cause neck cancer (remember the Latin lesson?). Thankfully, researchers at my own university helped discover a vaccine that prevents most types of HPV and thus prevents most incidences of cervical cancer. So when you are getting that Pap smear make sure to ask about getting an HPV vaccine.

The cervix also plays an integral part in the maintaining of a pregnancy. During pregnancy, the cervix develops a mucus plug that secures the fetus, placenta, and the amniotic fluid from bacteria and other “intruders.” Close to delivery the cervix begins to thin (or can be thinned by pharmaceuticals such as Cervidil, a formulation of dinoprostone) in preparation for birth. The uterus contracts during labor to widen the opening of the cervix up to ten centimeters in order to allow the passage of the baby through the cervix down into the birth canal.

Some women have weaker than average cervices and require a procedure called a cerclage during pregnancy in order to bolster the cervix’s support of the growing fetus. A new method has recently been developed to make a cerclage more effective by entering through the abdomen rather than the vagina. A cerclage, essentially, sutures the cervix in order to make it firmer for the duration of the pregnancy. The cerclage should be undone before the onset of labor in order to keep the cervix from rupturing. Elective cerclage is extremely effective (around 90% success) though emergency cerclage is less effective (usually because the cervix has dilated too much) at about 50% success.

Well, that is a brief outline of the functions of the cervix. The cervix is quite an interesting and indispensable part of our bodies. Do you have more to add or have a burning question? Leave it in the comments, thanks!

Lactation: Mother’s Milk

So, since we talked about conventional cow milk a couple of days ago as well as soy and organic milks, I thought we should spare a thought for human-produced milk.  I have no firsthand experience with human lactation, so please feel free to jump in with your two cents!  Many new mothers will tell you, though, that they did not realize how difficult breastfeeding would be.  Babies, unfortunately, don’t just attach themselves naturally to a woman’s breast and easily begin to suckle.  It is a skill that must be cultivated.  (No wonder wet nurses came to be.)

During a woman’s pregnancy a woman’s breasts become enlarged, to varying degrees, due to a chemical released by the placenta called human placental lactogen (HPL).  The first stages of lactation begin during the latter part of a woman’s pregnancy.  During this period a woman’s breast begin to produce “first milk” called colostrum that can be yellow in color.  Progesterone during this time is too high to allow true milk production.

When the placenta is delivered following birth, the woman’s body experiences a sudden drop in progesterone, HPL, and estrogen.  This shift causes the breast tissue to begin to produce real milk.  Milk will usually be produced within a day or two of birth, though it is not uncommon for it to take longer.  Colostrum production will slowly cease over a two week period as mature breast milk as steadily produced.  Colostrum is an important part of breastfeeding, though, because it contains larger amounts of antibodies and white blood cells helping to protect the child from germs and food allergies.

After the breasts become more accustomed to producing milk they begin to function on what I call a “made-to-order” system.  A woman’s breasts produce milk as the milk is removed from the breasts (through direct latching, breast pumps, or otherwise.)  Breasts will continue making milk so long as it is being removed.  The only other reasons that would inhibit continued milk production are maternal endocrine disorders, maternal malnutrition, breast hypoplasia, and in some cases lack of sexual activity, as sexual activity increases milk production.

When actually breastfeeding, the mother may experience milk ejection reflex though it is not unusual to not have this experience.  Essentially, the muscles in the breast push out the milk which may result in pain or a tingling sensation.  Another cause of pain due to lactation is contraction of the uterus.  The same hormone that causes the muscles in the breast to contract and express milk also cause the uterus to contract helping it return to its original size.  These contractions may range from mild and menstrual-like to severe and labor-like.  I shudder to think what they would feel like following a c-section.

That, in a nutshell, is the basic biology of lactation, though it does not begin to touch on the enormous issue of breastfeeding (perhaps in later entries).  But here are a few interesting facts about lactation you might not have known:

*Men can lactate, it’s true!  They have mammary glands just like women, and it can result due to a hormone imbalance.

*A woman can lactate without ever having given birth.  It is a phenomenon known as galactorrhea and happens either due to a specific hormone imbalance, continued stimulation to the nipples, and in rare cases is caused by prescription drugs.

*New born babies often lactate, colloquially called “witch’s milk,” as a result of the mother’s hormones just before birth.  It generally only lasts a few hours.

Questions?  Comments?  Don’t be shy.