[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:08.12,0:00:11.23,Default,,0000,0000,0000,,Muscles and joints shift and jostle.
Dialogue: 0,0:00:11.23,0:00:16.66,Default,,0000,0000,0000,,The heart’s pounding rhythm speeds up. \NBlood roars through arteries and veins.
Dialogue: 0,0:00:16.66,0:00:21.03,Default,,0000,0000,0000,,Over the course of a pregnancy, \Nevery organ in the body changes.
Dialogue: 0,0:00:21.03,0:00:23.51,Default,,0000,0000,0000,,Ignited by a range of hormones,
Dialogue: 0,0:00:23.51,0:00:26.94,Default,,0000,0000,0000,,these changes begin \Nas soon as pregnancy begins.
Dialogue: 0,0:00:30.38,0:00:36.24,Default,,0000,0000,0000,,Just days after fertilization, the embryo \Nimplants in the lining of the uterus.
Dialogue: 0,0:00:36.24,0:00:39.61,Default,,0000,0000,0000,,Because its DNA doesn’t exactly match \Nthe mother’s,
Dialogue: 0,0:00:39.61,0:00:43.51,Default,,0000,0000,0000,,the immune system should theoretically \Nrecognize it as an invader,
Dialogue: 0,0:00:43.51,0:00:48.42,Default,,0000,0000,0000,,attack, and destroy it, like it would \Nbacteria or other harmful microbes.
Dialogue: 0,0:00:48.42,0:00:51.58,Default,,0000,0000,0000,,That’s the challenge: \Nthe mother’s immune system
Dialogue: 0,0:00:51.58,0:00:57.08,Default,,0000,0000,0000,,needs to protect both her and the fetus, \Nbut can’t act as it usually does.
Dialogue: 0,0:00:57.08,0:01:01.05,Default,,0000,0000,0000,,What happens is not as simple \Nas decreasing the immune response.
Dialogue: 0,0:01:01.05,0:01:06.14,Default,,0000,0000,0000,,Instead, it’s a complex interaction \Nwe’re just beginning to understand,
Dialogue: 0,0:01:06.14,0:01:08.98,Default,,0000,0000,0000,,involving many different types \Nof immune cells—
Dialogue: 0,0:01:08.98,0:01:13.52,Default,,0000,0000,0000,,some of which seem to protect the fetus \Nfrom attack by other immune cells.
Dialogue: 0,0:01:15.98,0:01:20.54,Default,,0000,0000,0000,,The body also creates an antibacterial \Nplug made of mucus on the cervix,
Dialogue: 0,0:01:20.54,0:01:24.51,Default,,0000,0000,0000,,which keeps germs away \Nand stays sealed until labor.
Dialogue: 0,0:01:24.51,0:01:26.10,Default,,0000,0000,0000,,As a pregnancy progresses,
Dialogue: 0,0:01:26.10,0:01:30.08,Default,,0000,0000,0000,,the uterus expands upward and outward \Nwith the growing fetus.
Dialogue: 0,0:01:30.08,0:01:33.81,Default,,0000,0000,0000,,To make room, hormones \Ncalled progesterone and relaxin
Dialogue: 0,0:01:33.81,0:01:36.35,Default,,0000,0000,0000,,signal muscles to loosen.
Dialogue: 0,0:01:36.35,0:01:41.21,Default,,0000,0000,0000,,The muscles that propel food and waste \Nthrough the digestive tract also loosen,
Dialogue: 0,0:01:41.21,0:01:42.64,Default,,0000,0000,0000,,which makes them sluggish,
Dialogue: 0,0:01:42.64,0:01:46.78,Default,,0000,0000,0000,,causing constipation as passage \Nthrough the tract slows down.
Dialogue: 0,0:01:46.78,0:01:48.83,Default,,0000,0000,0000,,Loosened muscles \Nat the top of the stomach
Dialogue: 0,0:01:48.83,0:01:52.15,Default,,0000,0000,0000,,might allow acid to escape \Ninto the esophagus and throat,
Dialogue: 0,0:01:52.15,0:01:54.35,Default,,0000,0000,0000,,causing heartburn and reflux.
Dialogue: 0,0:01:54.35,0:01:56.61,Default,,0000,0000,0000,,These changes can worsen morning sickness,
Dialogue: 0,0:01:56.61,0:02:03.12,Default,,0000,0000,0000,,which is caused in part by hormone HCG— \Nand can also happen at other times of day.
Dialogue: 0,0:02:03.12,0:02:06.09,Default,,0000,0000,0000,,As the uterus grows, \Nit pushes on the diaphragm,
Dialogue: 0,0:02:06.09,0:02:10.49,Default,,0000,0000,0000,,the muscle that expands and contracts \Nthe chest with each breath.
Dialogue: 0,0:02:10.49,0:02:12.92,Default,,0000,0000,0000,,This limits the diaphragm’s range.
Dialogue: 0,0:02:12.92,0:02:17.59,Default,,0000,0000,0000,,To compensate, the hormone progesterone \Nacts as a respiratory stimulant,
Dialogue: 0,0:02:17.59,0:02:21.32,Default,,0000,0000,0000,,making the pregnant woman breathe \Nfaster so both she and the baby
Dialogue: 0,0:02:21.32,0:02:25.12,Default,,0000,0000,0000,,can both get enough oxygen \Nwith less lung capacity.
Dialogue: 0,0:02:25.12,0:02:29.22,Default,,0000,0000,0000,,This all may leave the pregnant woman \Nfeeling short of breath.
Dialogue: 0,0:02:29.22,0:02:32.70,Default,,0000,0000,0000,,Meanwhile, the kidneys \Nmake more erythropoietin,
Dialogue: 0,0:02:32.70,0:02:35.81,Default,,0000,0000,0000,,a hormone that increases \Nred blood cell production.
Dialogue: 0,0:02:38.90,0:02:43.69,Default,,0000,0000,0000,,The kidneys also keep extra water and salt\Nrather than filtering it out into urine
Dialogue: 0,0:02:43.69,0:02:46.42,Default,,0000,0000,0000,,to build up the volume of the blood.
Dialogue: 0,0:02:46.42,0:02:50.89,Default,,0000,0000,0000,,A pregnant woman’s blood volume \Nincreases by 50% or more.
Dialogue: 0,0:02:50.89,0:02:52.40,Default,,0000,0000,0000,,But it’s also a bit diluted,
Dialogue: 0,0:02:52.40,0:02:56.38,Default,,0000,0000,0000,,because it only has 25% \Nmore red blood cells.
Dialogue: 0,0:02:56.38,0:03:00.21,Default,,0000,0000,0000,,Usually, the body makes blood cells \Nusing iron from our food.
Dialogue: 0,0:03:00.21,0:03:04.15,Default,,0000,0000,0000,,But during pregnancy, the fetus \Nis also building its own blood supply
Dialogue: 0,0:03:04.15,0:03:06.01,Default,,0000,0000,0000,,from nutrients in the mother’s food—
Dialogue: 0,0:03:06.01,0:03:09.28,Default,,0000,0000,0000,,leaving less iron and other nutrients \Nfor the mother.
Dialogue: 0,0:03:09.28,0:03:12.30,Default,,0000,0000,0000,,The heart has to work extra hard \Nto pump all this blood
Dialogue: 0,0:03:12.30,0:03:14.44,Default,,0000,0000,0000,,through the body and placenta.
Dialogue: 0,0:03:14.44,0:03:16.83,Default,,0000,0000,0000,,A pregnant woman’s heart rate increases,
Dialogue: 0,0:03:16.83,0:03:21.33,Default,,0000,0000,0000,,but we don’t fully understand how blood \Npressure changes in a healthy pregnancy—
Dialogue: 0,0:03:21.33,0:03:23.40,Default,,0000,0000,0000,,an important area of research,
Dialogue: 0,0:03:23.40,0:03:25.90,Default,,0000,0000,0000,,because some of the most serious \Ncomplications
Dialogue: 0,0:03:25.90,0:03:29.27,Default,,0000,0000,0000,,are related to the heart \Nand blood pressure.
Dialogue: 0,0:03:29.27,0:03:31.92,Default,,0000,0000,0000,,The expanding uterus may press on veins—
Dialogue: 0,0:03:31.92,0:03:35.19,Default,,0000,0000,0000,,causing fluid buildup \Nin the legs and feet.
Dialogue: 0,0:03:35.19,0:03:38.85,Default,,0000,0000,0000,,If it presses on a large vein \Ncalled the inferior vena cava,
Dialogue: 0,0:03:38.85,0:03:41.95,Default,,0000,0000,0000,,it might interfere with blood \Nreturning to the heart,
Dialogue: 0,0:03:41.95,0:03:46.61,Default,,0000,0000,0000,,causing a dizzying drop in blood pressure \Nafter standing for too long.
Dialogue: 0,0:03:46.61,0:03:51.22,Default,,0000,0000,0000,,Some of these changes start \Nto reverse even before birth.
Dialogue: 0,0:03:51.22,0:03:54.67,Default,,0000,0000,0000,,Shortly before delivery, \Nthe fetus drops down,
Dialogue: 0,0:03:54.67,0:03:56.94,Default,,0000,0000,0000,,decreasing the pressure on the diaphragm
Dialogue: 0,0:03:56.94,0:04:00.91,Default,,0000,0000,0000,,and allowing the pregnant woman \Nto take deeper breaths.
Dialogue: 0,0:04:00.91,0:04:02.49,Default,,0000,0000,0000,,During labor and birth,
Dialogue: 0,0:04:02.49,0:04:05.72,Default,,0000,0000,0000,,much of the extra fluid in the body \Nis lost when the water breaks.
Dialogue: 0,0:04:08.61,0:04:13.23,Default,,0000,0000,0000,,The uterus shrinks back down \Nin the weeks after birth.
Dialogue: 0,0:04:13.23,0:04:16.54,Default,,0000,0000,0000,,Like the rest of the body, \Npregnancy affects the brain—
Dialogue: 0,0:04:16.54,0:04:20.25,Default,,0000,0000,0000,,but its effects here are some \Nof the least understood.
Dialogue: 0,0:04:20.25,0:04:23.10,Default,,0000,0000,0000,,Recent studies show differences \Nin brain scans
Dialogue: 0,0:04:23.10,0:04:25.61,Default,,0000,0000,0000,,after pregnancy and early parenting,
Dialogue: 0,0:04:25.61,0:04:28.71,Default,,0000,0000,0000,,and suggest that these changes \Nare adaptive.
Dialogue: 0,0:04:28.71,0:04:31.74,Default,,0000,0000,0000,,That means they could help \Nwith parenting skills,
Dialogue: 0,0:04:31.74,0:04:37.50,Default,,0000,0000,0000,,such as an increased ability to read \Nfacial cues since babies can’t talk.
Dialogue: 0,0:04:37.50,0:04:41.08,Default,,0000,0000,0000,,The lack of information about pregnancy’s \Neffects on the brain
Dialogue: 0,0:04:41.08,0:04:47.17,Default,,0000,0000,0000,,highlights a general truth: historically, \Nalmost all the research around pregnancy
Dialogue: 0,0:04:47.17,0:04:51.04,Default,,0000,0000,0000,,has focused on the fetus, \Nrather than pregnant women.
Dialogue: 0,0:04:51.04,0:04:53.78,Default,,0000,0000,0000,,Experiences of pregnancy vary widely,
Dialogue: 0,0:04:53.78,0:04:56.24,Default,,0000,0000,0000,,both within the range \Nof healthy pregnancies
Dialogue: 0,0:04:56.24,0:05:01.71,Default,,0000,0000,0000,,and due to complicating health conditions—\Nnew research will help us understand why,
Dialogue: 0,0:05:01.71,0:05:05.27,Default,,0000,0000,0000,,and develop effective treatments \Nwhere necessary.
Dialogue: 0,0:05:05.27,0:05:08.54,Default,,0000,0000,0000,,In the meantime, \Nevery pregnancy is different,
Dialogue: 0,0:05:08.54,0:05:12.27,Default,,0000,0000,0000,,and it’s important to consult a doctor \Nwith any specific questions.
Dialogue: 0,0:05:13.19,0:05:16.78,Default,,0000,0000,0000,,Today, we’re turning an exciting corner,
Dialogue: 0,0:05:16.78,0:05:21.72,Default,,0000,0000,0000,,as more research is devoted \Nto the astounding biology of pregnancy.