obesity and dilation

[delphmoon]

Hi girls.
A co worker said today that large woman are known to have problems dilating during labor.
Can someone explain to be why this is?
TIA

Sent from my GT-S5830 using Tapatalk 2

[e_p]

sounds like crap to me but who knows?

[*LittleMissSummer*]

I would think its crap too unless someone else can come in and shed some light.

[Maruschke]

Seems there is some merit to it.

http://journals.lww.com/greenjournal...ty_and.10.aspx

Maternal Prepregnancy Overweight and Obesity and the Pattern of Labor Progression in Term Nulliparous Women
Vahratian, Anjel PhD, MPH*â€*; Zhang, Jun PhD, MDâ€*; Troendle, James F. PhDâ€*; Savitz, David A. PhD‡¶; Siega-Riz, Anna Maria PhD*§¶

Abstract
OBJECTIVE: To examine the effect of maternal overweight and obesity on labor progression.

METHODS: We analyzed data from 612 nulliparous women with a term pregnancy that participated in the Pregnancy, Infection, and Nutrition Study from 1995 to 2002. The median duration of labor by each centimeter of cervical dilation was computed for normal-weight (body mass index [BMI] 19.8–26.0 kg/m2), overweight (BMI 26.1–29.0 kg/m2), and obese (BMI > 29.0 kg/m2) women and used as a measurement of labor progression.

RESULTS: After adjusting for maternal height, labor induction, membrane rupture, oxytocin use, epidural analgesia, net maternal weight gain, and fetal size, the median duration of labor from 4 to 10 cm was significantly longer for both overweight and obese women, compared with normal-weight women (7.5, 7.9, and 6.2 hours, respectively). For overweight women, the prolongation was concentrated around 4–6 cm, whereas for obese women, their labor was significantly slower before 7 cm.

CONCLUSION: Labor progression in overweight and obese women was significantly slower than that of normal-weight women before 6 cm of cervical dilation. Given that nearly one half of women of childbearing age are either overweight or obese, it is critical to consider differences in labor progression by maternal prepregnancy BMI before additional interventions are performed.

[*LittleMissSummer*]

Wow, fair enough then!

[Maruschke]

Applies to induction as well?

Obstetrics & Gynecology:
March 2004 - Volume 103 - Issue 3 - pp 452-456
Original Research
The Association of Maternal Weight With Cesarean Risk, Labor Duration, and Cervical Dilation Rate During Labor Induction
Nuthalapaty, Francis S. MD; Rouse, Dwight J. MD, MSPH; Owen, John MD

Abstract
OBJECTIVE: To assess the relationship among maternal weight and cesarean delivery, cervical dilation rate, and labor duration.

METHODS: We used a secondary analysis of 509 term women who were previously enrolled in a prospective observational study of a labor induction protocol in which standardized criteria were used for labor management. A variety of analyses were performed, both unadjusted and adjusted. P < .05 was considered significant.

RESULTS: The mean ± standard deviation weight of women who underwent a cesarean (97 ± 29 kg) was significantly higher than that of women who were delivered vaginally (87 ± 22 kg, P < .001). In a logistic regression model of nulliparas who comprised 71% of the study population, after adjustment for the confounding effects of infant birth weight, maternal age, initial cervical dilation, and diabetes, for each 10-kg increase in maternal weight, the odds ratio for cesarean delivery was significantly increased (odds ratio 1.17; 95% confidence interval 1.04, 1.28). In a linear regression model also limited to nulliparas and after adjusting for the same confounders, the rate of cervical dilation was inversely associated with maternal weight: for each 10-kg increment, the rate of dilation was decreased by 0.04 cm/h (P = .05). Similarly, labor duration was positively associated with maternal weight: for each 10-kg increment, an increase in the oxytocin to delivery interval of 0.3 hours was observed in nulliparas (P = .02). Neither lower rates of oxytocin administration to heavier women nor diminished uterine responsiveness (as reflected in measured Montevideo units) accounted for the slower labor progress.

CONCLUSION: In nulliparous women undergoing labor induction, maternal weight was associated with a higher cesarean risk and longer labor and was inversely proportional to the cervical dilation rate.

LEVEL OF EVIDENCE: II-2

[delphmoon]

no. Im thinking there is truth in it. I am thinking perhaps it relates to hormones taking longer to work because of larger distribution of fat which slows absorption/distribution....but....Im not sure if this is the case.

Sent from my GT-S5830 using Tapatalk 2

[delphmoon]

snap!

thanks M. Just what I was looking for
I wonder why though?

Sent from my GT-S5830 using Tapatalk 2

[Tegam]

Also I wonder if large women are less active???

Either because they are pressure into more monitoring because they are over weight (sort of chicken or the egg debate)

Or if larger women are just less active full stop.....

[~ Zarava Flutterby ~]

I am obese and had no issues, quite the opposite in fact.
Also in regards to being less active I walked around, moved around etc etc.
I do think it's obviously different for each person but to me labor IS different for each person (no matter their weight or size)


Sent from my iPhone, more than likely while I should be doing something else!

[delphmoon]

I was induced twice.With both labors I had spontaneous contractions but didn't dilate until I was induced. FWIW I was also active during the labor.

i was hoping a mid or doula could shed some light on what they know. I am hoping with my next birth (whenever that may be) I can avoid the non dilation issue.

ETA the study M provided above does state that overweight/obese women dilated slower but no reason given other than oxytocin not being an issue..hmmm. Thanks for the info M provided:-)
Sent from my GT-S5830 using Tapatalk 2

[The[cookie]Doctor]

LOL as a 40kg overweight nullip with 6.5 active stage followed by primip precipitate labour < 3hrs from first cx - I dread to think about a non overweight one then.

[Trillian]

yeah fatty-mcfat-fats with their fat vaginas cant possibly give birth quickly. what horse ****.

[Maruschke]

yeah fatty-mcfat-fats with their fat vaginas cant possibly give birth quickly. what horse ****.

It's not saying that. General trends can never predict the lengths of individual labours. All there is, is an association. Seems on average obese women labour for longer, but there are other papers out there showing stage 2 is similar length, and that obese women pushing put the same out of pressure out as other women. It's just stage 1 that differs.

[LuluHB]

All I can say is if my being obese slowed down my labour then thank goodness I wasn't a skinny girl!! I certainly was the exception to prove the rule with my second and third births.

[e_p]

yeah fatty-mcfat-fats with their fat vaginas cant possibly give birth quickly. what horse ****.

don't forget their fat stupid cervixes that don't dilate the right way! :/ Even if there is a trend (I'd want to see a big sample size of physiological births (very unlikely to happen)), it still stinks of blaming and pathologising women's bodies :/

[AngelPants]

Interesting, do you think maybe it has to do with muscle tone or strength? contractions are less effective at shortening muscle fibres to dilate cervix?

sent from my watzamajig so may not make sense....

[Maruschke]

Interesting, do you think maybe it has to do with muscle tone or strength? contractions are less effective at shortening muscle fibres to dilate cervix?

sent from my watzamajig so may not make sense....

You guys might like to read this paper

http://edoc.hu-berlin.de/oa/degruyter/jpm.2009.110.pdf


Other clinical evidence is in harmony with the potential for obesity to compromise the intensity or efficiency of uterine contractility. Onset of labor may be delayed by obesity, and dysfunctional labor may be abetted. Obese women have been observed to have longer-term gestations, and more post-dates pregnancies than thinner women w4, 22x. Also, in a prior analysis of labor duration, Vahratian et al. studied rates of dilatation in a data base of 612 nulliparas and found active phase labor (defined as 4–10 cm dilatation) was significantly longer in overweight and obese women, after adjusting for birth weight w24x. Zhang et al. w27x showed in a clinical study that obese women had a higher risk of cesarean, related primarily to abnormal progress in the first stage of labor.

Until recently, there has been no biologic basis to explain why simply being obese would affect labor, but accumulating evidence supports the association of
obesity with impaired uterine contractility. In one study, myometrial tissue obtained at cesarean from obese women was shown in vitro to contract with less force (as indicated by lower calcium fluxes) than those from normal weight subjects w27x.

The basis for this contractile inhibition may reside in some of the biochemical changes induced by obesity. For example, leptin, a protein with diverse metabolic and
regulatory functions, is produced in increased amounts in obese individuals. Moynihan et al. demonstrated that leptin strongly inhibited myometrial contractility in vitro w12x. Cholesterol, also increased in obesity, has similar inhibitory effects on myometrial activity and calcium signaling w21, 28x. We conclude that obesity may interfere with the progress of labor, resulting in dysfunctional patterns of dilatation. The mechanism for such an effect may be mediated through diminished uterine contractility in the active phase of labor, a consequence of increased levels of leptin, cholesterol, or other metabolic features of the obese state. Obesity should be added to the list of possible causes of abnormal labor progression.


The effect of obesity doesn't seem to reach to second stage (where similar pressure is exerted by all women regardless of obesity status): http://journals.lww.com/greenjournal...tage_of.3.aspx


And if you want to see how they have "tried" to isolate the effect of obesity from other complications in pregnancy / labour, see here:
http://www.ncbi.nlm.nih.gov/pubmed/16108107


That's scientist mcfatty, over and out for the evening .