“Baby is getting tired” during birth

[theprincessthepea]

What is actually happening when the midwife says “baby is getting tired” - I know it can be a mix of things like baby is distressed or the heart rate is slowing down - but why does it happen? If anyone experienced it what happened?

It’s basically what you just said. Ds was starting to show distress when I was pushing with him. His heart rate was dropping and the midwife was concerned to the point where she said she might have to use forceps. Luckily, I pushed harder and he came out.

Yep, had this. I had been pushing for 90 mins by this point as he was back to back (undiagnosed until the very end). His heartrate was dropping with contractions. Red button, episiotomy, forceps and out. He was very quiet for a while, but OK. My other 2 were fast and furious and a very different experience for me and the babies.

It means the babies heart is taking longer and longer to recover to normal which is a sign that the baby is not coping with the physical demands of labour and if continues, will lead to a degree of hypoxia.

very basically, every time the uterus contracts or the cord gets squashed it interrupts the supply of oxygen to the baby. Most of the time they are able to cope with that because it doesn't last long and there's time to recover in between, but if things aren't going completely to plan then it gets really tiring. An (imperfect) adult analogy might be something like comparing walk-running a 5k park-run, vs doing an ultramarathon with no snacks and no option to just stop when you get tired. The baby's physiology is set up to protect the oxygen supply to the heart at all costs (takes priority over the brain even) and because oxygen gets to the heart muscle when it's relaxed, the protective mechanism in the body is to slow the heart rate down so there's more time to offload oxygen to that muscle. If the heart isn't getting enough oxygen then it can take longer and longer to recover/not recover at all and start happening at unusual points in the contraction. The baby will also start making more lactic acid which makes the blood more acidic and makes things harder for the heart. If you add on other more or less subtle things like infection, a naff placenta, problems with the maternal circulation or oxygen supply, the cord being wrapped around the baby, etc then that can contribute to more physiological stress for the baby. Fetal physiology is different to that of an adult or even a neonate, so it is set up to deal with the stress of labour so long as things are going relatively smoothly, but they have limited options for compensation so once those are becoming exhausted it can get pretty hairy pretty quickly. The MWs and obstetricians can see on the CTG/hear if they're listening intermittently how a slowing down of the heart rate relates to a the timing of a contraction, how quickly it recovers (if it recovers), how often it's happening, whether it relates to something that's happened to the mother etc and tell whether it's a normal response to a normal contraction, or if it's a sign that the baby is running out of oxygen and energy. How they'd aim to deal with a baby that's getting 'tired' will depend on what stage of labour they're at, what might be causing it, whether there's something to do with the maternal physiology that can be improved to make things better for the baby, etc.

Pretty much what Greybeardy said.

You could see on the CTG, baby's heart rate was taking longer and longer to return to baseline, and was pretty static otherwise. As I wasn't progressing (only got to 5cm in 11 hours on the drip), I knew the writing was on the wall, and it was only going to get worse, so I had a C-section. Turns out baby was back to back, and had tipped his head back. He was very stuck, and was never coming vaginally.

I have learned a lot from this thread! Like several PPs my baby was back to back. I ended up with an EMCS and the obstetrician said afterwards that we’d made the right decision.

This happened with DS1. The Dr came in had a look and said she'd come back with a ventouse. While she was out of the room the midwife told me to push like my life depended on it. I did and DS was born without intervention.

Thanks - especially for the in-depth biological explanations. I was told “baby is tired” and that I really needed to step up with the pushing but I wondered what it actually meant and what baby was really going through so these responses have been super insightful.