Medicalized birth practices are common in almost every hospital in the USA. 

In fact many of the birthing practices are considered almost routine. They include procedures such as intravenous fluids, breaking a laboring woman's waters; restricting her ability to move during labor, and inducing or helping speed up labor with medications, which tend to result in slow and/or painful labor, increasing the women's need for an assisted birth (giving birth with the assistance of a device, for example forceps or vacuum extractor) and/or analgesia, especially epidural.

Pain Medication: 

Pain medication given to the mother during birth appears in the umbilical cord blood within a few seconds to a few minutes. (Loftus, Hills, & Cohen, 1995) Babies tend to be sleepy after birth and may not show any hunger cues. The use of medication during birth can not only delay the newborn's "breast-seeking" and breastfeeding behaviors. It can also make latching difficult and cause baby to have an uncoordinated suck/swallow response for hours or even days. (Ransjo-Arvidson et al.,2001) 

Medications used during labor can also have an impact on the mothers milk supply. A 2014 study reports, "Mothers who received labor pain medications were more likely to report delayed onset of lactation (DOL), regardless of delivery method." The highest rates of DOL occurred in women who had an emergency cesarean section with an epidural plus another medication. (Lind, Perrine, Li.,2014)

Epidural: 

The research about epidurals and breastfeeding is mixed. However, the use of epidurals has been shown to cause other needs for interventions such as, intravenous fluids, augmentation (speeds up labour with synthetic oxytocin), as well as an assisted birth using assistance of a device due to the loss of feeling/mobility which can continue well into the pushing stage. A 2003 study reports, "Labor epidural anesthesia had a negative impact on breastfeeding in the first 24 hours of life even though it did not inhibit the percentage of breastfeeding attempts in the first hour." So, in other words the baby has an opportunity to breastfeed, but was unable to latch/suck. (Baumgarder, Muehl, Fischer, & Pribbenow, 2003)

Intravenous Fluids:

A 2014 study showed that majority of US mothers reported getting continuous intravenous fluids during labor. (Declercq et al. 2014) Fluid overload can cause  painful swelling in the mother, constricting the milk ducts, which not only reduces milk flow from the breast, but makes it harder for the baby to latch and transfer milk. (Wambach & Riordan, 2016). Fluid overload can also cause the newborn to have excess fluid at birth making the birth weight artificially inflated. Current guidelines state that if a newborn weight loss is greater than 7% from birth at 3 to 5 days of age is a sign of ineffective breastfeeding which could mean that supplementation of formula is necessary. A 2003 study reports, that breastfed babies regain birth weight at an average of 8.3 days, with 97.5% having regained their birth weight by 21 days. (Macdonald, Ross, Grant, et al., 2003) Breastfed infants should be monitored closely, but majority do not require supplementation. 

Formula Supplementation: 

Babies of mothers who have had epidural anesthesia are significantly more likely to receive a bottle supplement while at the hospital. A 2009 study reported that newborns who were exposed to an epidural during labor were almost 4 times less likely to suckle the breast within the first 4 hours of life, and half as likely to be exclusively breastfed at discharge. (Wiklund et al.,2009) Early supplementation with infant formula is associated with decreased exclusive breastfeeding rates in the first 6 months and an overall shorter duration of breastfeeding.

Baby Interventions:

But medications aren't the only thing affecting breastfeeding, newborn interventions straight after birth can also affect breastfeeding. 

A normal baby that is born and placed directly on the mother can crawl (yes crawl) to the breast and initiate breastfeeding within the first hour after birth. When baby is separated from mom, the transitioning to suckling may be disrupted.