Update on Meconium Aspiration

I’m now working in the OB/GYN service so I had the opportunity to find out more about the Meconium Aspiration case from my first week here. As it turns out, there was a lot that the pediatricians didn’t know.

As I said in my earlier post, this was the patient’s first pregnancy and she was a little over a week post term. The OB had performed a biophysical profile (a detailed ultrasound) the week before (week 40) to evaluate the baby, the placenta, and the amniotic fluid level. At that point, the baby was measured at 8lbs 8oz with a good heart rate. The amniotic fluid level was 15 (this is considered normal). Everything seemed to be ok, so the OB scheduled the mother for repeat non-stress tests (NSTs – monitoring contractions and fetal heart rate) every 3 days to make sure that the fetus was ok while she waited for the onset of labor. The patient missed her appointment on Tuesday – what would have been her second NST. Instead, she presented to the L&D with strong contractions.

When she got to the hospital, she was strapped to the fetal monitor which showed lots of decelerations indicating that the fetus was in distress. They administered oxygen, IV fluids, and put the mom in the lateral position to increase blood flow. At this point, the fetal heart rate returned to normal. The mother was still have regular contractions and was dilating normally. The OB planned to rupture the amniotic sac when the mom was dilated to 4-5cm (this is sometimes done to augment labor). When she performed the amniotomy, she noticed that there was scanty amniotic fluid despite a bulging amniotic sac and a normal amniotic fluid level one week before. She also noticed that the amniotic fluid was stained green. She knew immediately that the baby had passed meconium in-utero. She immediately scheduled the mom for an emergency C-section, but the baby had already aspirated the meconium. He was 9lbs 15oz at birth (quite a growth spurt!).

So, based on the patient’s presentation and the information obtained, the OB did everything appropriately. One could still ask why a C-section was not performed earlier (at initial presentation and signs of fetal distress) but the fetal heart rate returned to baseline with normal accelerations after the administration of oxygen and fluids. Would an American OB have gone straight to the OR? Maybe, but we often say that American OBs are too quick to rush patients back for C-sections rather than letting them labor down. Which is the right way? Unfortunately, there isn’t one – it’s a call based on clinical judgment and either one would be criticized for different reasons. Sadly, the cost in this case was high.