How to Take an Obstetric History

How to Take an Obstetric History


In this tutorial, let us see how to take an obstetric history. The interior ethos of obstetric CAT is aiming for a healthy mother and a healthy baby at the end of the pregnancy journey. So this begins right at the start with a good history-taking. The basic principles of obstetric history-taking remains the same like with any other history. We need to have an adequate information about the presenting complaint. We need to know the past obstetric and gynecological history, the past medical history, and the surgical history. We need to know what medications they are on. We need to know their allergies, their social history, and their family history. Let’s move on to dating of pregnancy. Because this is unique in obstetrics that when a pregnant person presents to you, the first thing you want to know is how far pregnant this particular person is. So this can be done in two ways. One from the period of amenorrhea. That is using the first day of her last menstrual period, or by using an ultrasound scan. When using her period of amenorrhea, you can calculate the expected date of delivery by either adding nine months and seven days, which is the natal history, or you could use the pregnancy calculator wheel. If you align the last period arrow with the date that she gives you, the expected date of delivery arrow will point to her expected date of delivery. Nowadays, it’s even easier. We have a computer software that gives you the due date. The big problem that we would face by using just the last menstrual period to calculate the pregnancy dating would be the reliability, because if a patient’s cycles are irregular, the dates may not be reliable. But if the person has used subfertility treatments like fertility inducing medications or assisted reproductive techniques, the dating is more reliable. If a person has come off combined with a contraceptive pill and got pregnant in the first cycle, those dates may not be reliable. So now we date all pregnancies using an ultrasound scan. It’s most accurate when done in first trimester, and we measure the CRL, which is the crown-rump length, up to 12 weeks. If the person persons in second trimester, the head circumference is measured, which gives us the expected due date, but you need to aware that there’s a plus or minus one week error. If a person presents even late, as in third trimester, which is more than 28 weeks, we use the female length to calculate the expected due date, and this has a margin of error of up to two to three weeks. So when a person presents late in her pregnancy, the dating by LMP helps you when the EDD based on the LMP calculation and the ultrasound scan correlate with each other. Now let’s move on to the past obstetric history and the obstetric code. There are a few terminologies that are peculiar to obstetrics. One is gravida. It means the number of pregnancies irrespective of gestation and site. Please do not mention the term gravida when the person is not pregnant. For example, a person presenting with a gynecological problem, and if she has had two children in the past, you would just say that she is para 2. But a person who is currently pregnant and has had two children in the past, you would mention as gravida 3 para 2, which leads us to the next terminology, which is parity or para, which is the number of babies born alive or dead after the period of viability– generally, more than 500 grams or more than 24 weeks. Miscarriage means loss of pregnancy before the period of viability. Termination is ending pregnancy. So when a pregnancy has ended before 24 weeks, either as a miscarriage or termination, you should always ask for the gestational age at which it happened, if there are any complications like bleeding, infection, and if they have to go for evacuation of retained products after the termination of a miscarriage. And also remember, ectopic pregnancy adds to the gravida. Now let’s look at the history that you have to elicit for every pregnancy that has gone past 24 weeks. You need to ask for any antenatal complications like pregnancy-induced hypertension, pre-eclampsia, or gestational diabetes, if she had any antenatal admissions in a previous pregnancy and the reasons for the same, and if there are any other antenatal concerns. The intrapattern problems I’ll discuss in the next slide. You also need to ask the post-natal complications like manual removal of placenta, if there was any post-partum hemorrhage, or any puerperal infection or sepsis. And also, do not forget the mental health of the women, especially post-natal depression and puerperal psychosis. There is about two in three chance of recurrence in future pregnancies. So for every birth after 24 weeks, we need to know the gestational age of delivery, and if the person had labor, whether it was a spontaneous or induced labor, and the mode of delivery, whether it was a normal vaginal delivery, instrumental delivery, or cesarean section. If it was cesarean section, we need to know whether it was a planned cesarean section or an emergency cesarean section, the reason for that, and whether there were any intra-operative or post-operative complications. And specifically, we need to ask if there are any special instructions for next birth. Now let’s look at the baby details. So for our babies, we need to know the gestational age at which the baby was born, the birth weight of the baby, is the baby currently alive or dead, if dead, at what age, the baby died and what was the cause of death, and if alive, what was the condition of the baby at birth and present. Also, we need to know if there are any congenital anomalies, and if there are, if the anomalies were detected in either antenatally or post-natally. And also if there were any neonatal complications– for example, neonatal jaundice, which needed admission to the unit. We may not always see the pregnant woman at the start of the pregnancy. For example, if you saw a patient for the first time when she was 32 weeks pregnant, you may want to ask for the history about the present pregnancy. We need to know when she booked, at what gestational age, what is her BMI. Did she have a booking ultrasound scan? If so, at what gestation, and what are the relevant findings? And whether she had the first trimester screening tests like full blood count, blood grouping, and antibody testing, tests for syphilis, HIV, hepatitis B, and the total cell status of the husband. And did she have to undergo any invasive testing like chorionic villus sampling or amniocentesis? Did she have a screening scan at 18 to 20 weeks, and if so, whether any concerns raised from the screening scan? And did she have any glucose tolerance test at 26 to 28 weeks? And did she have any further scans in the pregnancy after the screening scan, and if so, what were the results? Let’s move on to the presenting complaint. When approaching up a presenting complaint in obstetrics, it is just like evaluating a symptomotology in any other discipline, so we need to know the details of the problem, the origin, the duration, the progress, and what is the diagnosis, were there any tests performed, and was she treated for it previously? And for any person, who is pregnant who presents to you, always ask for abdominal pain, any vaginal bleeding, or leaking of any fluid vaginally, and if they are in the later part of pregnancy, ask if they feel the fetal movements. And of course, at the end of this, we should always find out what is the plan. After eliciting a detailed history about the presenting complaint, the present pregnancy, the past obstetric history, we need to move on to the other history like her past history. We need to know the past medical and surgical history with particular emphasis on hypertension and diabetes and if any previous uterine surgery or tubal surgeries. Also, ask for any medications she’s currently on and if she has any drug allergies, and also the social history of smoking, alcohol, or substance misuse, and the family history. In particular, ask for diabetes, hypertension, or pre-eclampsia in your family members. So in this presentation, we saw the history that we need to elicit from a pregnant patient. Thank you for listening.

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