Thursday, August 15, 2013

When All Else Fails, Blame The Obstetrician

Now that the vaccine-autism link has been debunked again, Jenny McCarthy notwithstanding, everything but the kitchen sink is being put forth as potential causes of this affliction. The latest out of Duke finds a connection between autism and induction of labor.

... Overall, the likelihood of autism increased by 23% in association with induced or augmented labor as compared with children whose mothers had unassisted labor, Simon G. Gregory, PhD, of Duke University, and colleagues reported inJAMA Pediatrics.

Induction only, augmentation only, or the combination all were associated with significantly increased odds of autism. The magnitude of increased risk was similar to that associated with fetal distress, meconium, prematurity, and maternal diabetes, they said.
Curiously, this linkage seemed to hold predominantly for boys. The connection for females was more tenuous.
While this is certainly interesting, remember that association hardly proves cause and effect. Emily Willingham in Forbes gives this article a thorough review and notes some quite strange findings. For one thing, moms' having a college education increase the odds of her child attending special education. Yes, you read that right. Also, maternal smoking apparently decreases the risk of later autism diagnosis. So should we infer that women should drop out of school and commence smoking? Hardly.
While the dust settles around this study, remember that there have been numerous studies linking various genetic factors and autism, the latest trumpeted by the New York Times. Here's a thought - perhaps whatever genetic or epigenetic factor which may lead to autism spectrum may also predispose to a situation which subsequently require induction of labor. 
Remember that as Mark Twain ( often attributed to Benjamin Disraeli) said, there are "lies, damned lies, and statistics." I learned in high school that statistics are like bikinis - what they reveal is suggestive but what they conceal is vital. 

Friday, August 9, 2013

When Is The Baby Due? It's Complicated

While intellectually, most expectant mom's understand that the due date is only accurate within an up to two week window, folks still want to know a specific estimated time of arrival. Now from comes news of this research, concluding that mom's may do better with a range of dates.

... A cohort of pregnant mothers who were followed from conception to birth showed that, despite a median gestational period of 268 days, length of pregnancy varied by 37 days even after excluding mothers who gave birth preterm, according to Anne Marie Jukic, PhD, of the Epidemiology Branch of the National Institute of Environmental Health Sciences in Durham N.C., and colleagues.
Factors affecting length of pregnancy included length of time to conception, rate of progesterone rise, the mother's age, birth weight, and length of pregnancy in previous births, they wrote online inHuman Reproduction.
The authors noted that despite an estimated pregnancy period of 280 days from the mother's last menstrual period routinely assigned to mothers, only 4% of pregnancies fall on that date, while 70% occur within 10 days of that estimate "even when the date is estimated by ultrasound."
Here's what I've learned from my patients - nobody seems to worry if the baby arrives a week early. But one or two days late is quite a different story. There's also evidence to suggest that the medical equivalent of eviction proceedings aka induction of labor at 41 weeks results in fewer Cesareans and better perinatal outcomes than just waiting. Of course you won't know when 41 weeks is reached unless you know a due date.
Finally, as I tell my patients, due dates are like train schedules. Just because the train is expected doesn't mean that's when it pulls into the station.

Tuesday, August 6, 2013

Hysterectomy? What About the Ovaries?

Hysterectomy is one of the most common surgeries performed in the US. Many women have a hysterectomy prior to menopause, bringing up an important issue - what about the ovaries? The answer to this question is not always an easy one.

It was not that long ago that most medical authorities urged that if a woman were over 40 years old, ovaries should be removed at the time of hysterectomy. The reasons were twofold - that ovarian cancer was too difficult to diagnose so removal would prevent a dread disease and also, that the risk of subsequent surgery for benign disease was significant. Moreover, hormone therapy would ameliorate some of the side effects of removal.

Today, the pendulum has shifted. For premenopausal women, the ovaries produce hormones which have incredible benefits - protection against heart disease and bone loss being two. Oophorectomy may also affect mental health and sexuality. Moreover, ovarian removal causes acute onset of menopausal symptoms. While estrogen administration is surely helpful, it turns out that a patient compliance is often an issue with many women simply ceasing to take the medication long term - human nature.

What about cancer? Again, the risk of subsequent ovarian cancer for most women is about 1.4 %. This drops even further with a history of pregnancies and use of oral contraceptives.

The risk of subsequent surgery is also lower, especially with the improved resolution of transvaginal ultrasound, allowing many asymptomatic benign entities to be followed.

What about the older woman? Even here, the evidence for ovarian removal is not clear cut and ovarian conservation should be an option.

There is one asterisk - the woman with a strong family history of breast and/or ovarian cancer. Here, the woman may carry a BRCA mutation and genetic counseling is advised. Those who carry such a mutation are the exceptions for whom risk reductive removal of the tubes and ovaries would be strongly advised.

OBG Management  has a useful algorithm:

I'm quite certain that with further advances in diagnosis and therapy, management will be tweaked further. Stay tuned.